Term
| reptilian characteristics of archaeopterix |
|
Definition
-teeth
-gastrilla (belly ribs)
-flat/small sternum (no keel)
-long, bony tail
-3 claws on each wing
-no horny bill
-skull |
|
|
Term
| bird characteristics of archaeopterix |
|
Definition
-light skeleton (pneumatic, hollow)
-feathers
-reduced phalanges (fusion)
-wishbone (furcula)
-flight |
|
|
Term
|
Definition
| classifying organisms based on shared derived characteristics that can be traced to most recent common ancestor |
|
|
Term
| Based upon cladistics, from which dinosaur group did birds evolve? |
|
Definition
|
|
Term
| Why do you think birds survived, while most non-avian dinosaurs went extinct. |
|
Definition
| musta been due to more manageable metabolism due to smaller size |
|
|
Term
|
Definition
| trait that has disappeared phenotypically, but is still present in the genotype |
|
|
Term
|
Definition
| part of an organism that has become reduced or functionless over the course of evolution |
|
|
Term
|
Definition
-wings of ostriches, emus, and other flightless birds
-goose bumps |
|
|
Term
|
Definition
-some babies being born with vestigial tail
-vitamin C pathway in humans |
|
|
Term
| What is significant about the Talpid-2 mutation |
|
Definition
| if it's expressed, it can cayuse a chicken to develop teeth that resemble those of a crocodile |
|
|
Term
| What would be the best route to create a dinosaur? |
|
Definition
| reengineering the genome such that atavisms are reversed and the traits are expressed |
|
|
Term
| Explain what could be targeted in avian embryonic development to create a dinosaur. |
|
Definition
-preventing fusion of the hand
-preventing resorption of the tail |
|
|
Term
| the potential purpose of early feathers in dinosaurs |
|
Definition
-brooding
-anti-predation
-social signaling
-insulation
-camo
BASIC |
|
|
Term
| Provide a possible scenario for the development of feathers leading to the evolution of pennaceous feathers and flight. |
|
Definition
1 and 2: simple feathers likely used for thermoregulation or display
3: body feathers likely provided ancestors of birds more aerodynamic shape useful for leaping between branches in arboreal lifestyle
4 and 5: simple pennaceous feathers on forelimbs possibly provided parachuting ability
6: larger pennaceous feathers that were symmetrical may have permitted gliding
7: asymmetrical pennaceous feathers may have made the gliding more efficient
8: powered flight
[image] |
|
|
Term
| Why would it make evolutionary sense to lose the ability to fly in certain situations? (evolution of flightless birds in New Zealand). |
|
Definition
| no predators, negating the need to fly |
|
|
Term
| What avian order do Chickens belong to? |
|
Definition
|
|
Term
| What is the largest avian order? |
|
Definition
|
|
Term
| the relationship between metabolic rate (heart rate) and size in birds |
|
Definition
-the heart in a bird is about 40% bigger by body weight than in mammals
-chicken heart is 200-400 bpm |
|
|
Term
| What characteristics of bones in birds allows them to be both strong and light weight for flight? |
|
Definition
-light because they are hollow and pneumatic
-strong because of lots of fusion in the hands, hips, and feet |
|
|
Term
| What muscle powers down stroke of wing? |
|
Definition
|
|
Term
| What muscle powers up stroke of wing? |
|
Definition
| pectoralis minor aka supracoracoideus |
|
|
Term
| adaptive characteristics for flight in the digestive system |
|
Definition
-quick and efficient
-centrally located gizzard instead of teeth
-very small large intestine, so they poop ASAP |
|
|
Term
| adaptive characteristics for flight in the renal system |
|
Definition
-large kidneys (twice the size of mammals)
-no urinary bladder
-uric acid (conserves water) |
|
|
Term
| adaptive characteristics for flight in the cardiovascular system |
|
Definition
-heart about 40% bigger than in mammals
-large hearts that beat fast |
|
|
Term
| adaptive characteristics for flight in the respiratory system |
|
Definition
-9 air sacs (2 cervical, 2 anterior thoracic, 2 posterior thoracic, 2 caudal, and 1 interclavicular)
-these air sacs enable unidirectional air flow through lungs, making birds more efficient at absorbing oxygen
-air sacs, no diaphragm, rigid lungs
+w/o diaphragm, birds use obliques to move air around |
|
|
Term
| What advantage does uric acid provide the bird? |
|
Definition
-greatly reduces water loss
-insoluble in water; necessary because that way, it can't harm the embryo |
|
|
Term
|
Definition
-barrier to pathogens
-retains vital fluids and gases
-sensory organ |
|
|
Term
| how avian skin differs from mammalian skin |
|
Definition
-thin
-semi-transparent
-thinner and less keratinized than in mammals, but this less stringent barrier can facilitate evaporate cooling (birds don't have sweat glands) |
|
|
Term
|
Definition
| stratified, keratinized, squamous epithelium, several layers of dead, scaly, keratinized skin |
|
|
Term
| why feathering has become an issue with broiler breeders |
|
Definition
-absence of feathers leads to skin wounds, which is a serious welfare issue
-if they lose their feathers, they won't wanna dfo their job, which is to mate and lay eggs |
|
|
Term
| Uropygial Gland (Preen Gland) |
|
Definition
-bilobed sebaceous gland at the dorsal base of the tail
-this is a holocrine gland |
|
|
Term
|
Definition
| holocrine secretions are produced in the cytoplasm and released by rupture of the plasma membrane, destroying the cell and releasing the product into the lumen. |
|
|
Term
|
Definition
[image]
-holocrine secretions are produced when the mature cell dies and releases content
-apocrine secretions are when the pinched off part of the cell is the secretion |
|
|
Term
| uses of Uropygial Gland (Preen Gland) |
|
Definition
-secretion inhibits fungal growth and bacterial infection
-secretion helps maintain feather health
-secretion can help waterproof feathers
-secretion provides 7-dehydrocholesterol for vitamin D synthesis
-some birds use the secretion to deter predators (fowl smell) or cosmetic (flamingo) |
|
|
Term
| the pathway to produce active vitamin D3 (DRAW THIS!!!!) |
|
Definition
|
|
Term
| What is the rate limiting step in the vitamin D3 pathway? |
|
Definition
| PTH regulates 1-alpha-hydroxylase |
|
|
Term
| What is the trigger to activate the rate limiting step in the vitamin D3 pathway? |
|
Definition
| PTH causes 1-alpha-hydroxylase to be expressed in the kidney and convert 25-OH-cholicalciferol into 1,25-dihydrocholicalciferol |
|
|
Term
| What is the relationship between calbindin and 1,25 (OH)2D3? |
|
Definition
| -1,25 (OH)2D3 promotes synthesis of calbindin (calcium-binding protein, CaBP) and other proteins
-1,25 (OH)2D3 also stimulates Ca and P absorption |
|
|
Term
| depiction of how 1,25 (OH)2D3 promotes synthesis of calbindin (calcium-binding protein, CaBP) and other proteins |
|
Definition
|
|
Term
| How does 1,25 (OH)2D3 increase both renal and intestinal absorption of Ca? |
|
Definition
| by increasing synthesis of Ca binding proteins, mainly calbindin-D28k |
|
|
Term
|
Definition
|
|
Term
|
Definition
-chicken pox (the human form doesn't affect chickens and vice versa)
-sore head
-avian diphtheria
-bird pox |
|
|
Term
| species affected by fowl pox |
|
Definition
-most poultry, such as chickens, turkeys, quail, ducks, pheasants, psittacine, and rattites
-poultry of all ages are susceptible |
|
|
Term
|
Definition
|
|
Term
| clinical signs of the dry form of fowl pox |
|
Definition
-wart-like lesions on unfeathered areas
-unthriftiness
-retarded growth
-transient egg decline in laying hens |
|
|
Term
| clinical signs of the wet form of fowl pox |
|
Definition
canker-like lesions in the mouth, pharynx, larynx, and trachea
-possible respiratory distress by blocking upper passages |
|
|
Term
| how fowl pox is transmitted |
|
Definition
-direct contact between birds
-mosquitoes
-virus-containing scabs
-tend to be more rampant during winter and early spring because of mosquitoes overwintering in poultry houses |
|
|
Term
|
Definition
| none, but vaccination can stop outbreak, since it's slow-spreading |
|
|
Term
|
Definition
-spraying to kill mosquitoes
-if endemic to area, vaccination is recommended |
|
|
Term
|
Definition
|
|
Term
| synonyms for Marek’s disease |
|
Definition
-acute leukosis
-neural leukosis
-range paralysis
-gray eye (when eye affected) |
|
|
Term
| species affected by Marek's disease |
|
Definition
-most commonly chickens 12-25 weeks old
-occasionally pheasants, quail, game fowl, and turkeys |
|
|
Term
| clinical signs of Marek's disease |
|
Definition
-cancerous tumors
-in nerves, they cause lameness and paralysis
-in eyes, they cause irregularly shaped pupils and blindness
-in other tissues, they cause incoordination, unthriftiness, paleness, weak labored breathing, and enlarged feather follicles
-in terminal stages, emaciation with pale, scaly combs and greenish diarrhea |
|
|
Term
| transmission of Maerek's disease |
|
Definition
-by air
-feather dander
-chicken house dust
-feces and saliva
-birds infected for life |
|
|
Term
| treatment for Merek's disease |
|
Definition
|
|
Term
| prevention of Maerek's disease |
|
Definition
vaccination at hatchery
-this prevents tumor formation, but not virus infection |
|
|
Term
| what type of virus is Maerek's disease? |
|
Definition
oncovirus
-this was one of the first oncoviruses to be discovered
-oncogenes were first discovered in chicken oncoviruses |
|
|
Term
| where were oncogenes first discovered? |
|
Definition
|
|
Term
|
Definition
| bumblefoot aka Staphylococcus |
|
|
Term
| synonyms for bumblefoot aka Staphylococcus |
|
Definition
-staph infection
-staph septicemia
-staph arthritis
-bumblefoot |
|
|
Term
| species affected by bumblefoot aka Staphylococcus |
|
Definition
| all fowl, especially turkeys, chickens, game birds, and water fowl |
|
|
Term
| the 3 forms of staphylococcal infection |
|
Definition
-septicemia (acute)
-arthritic (chronic)
-bumblefoot |
|
|
Term
| clinical signs of the septicemia (acute) form of Staphylococcus infection |
|
Definition
-listless
-no appetite
-feverish
-show pain during movement
-possible black rot in eggs, since it's passed down through eggs
-fetid diarrhea
-many have swollen joints (arthritis) |
|
|
Term
| clinical signs of the arthritic (chronic) form of Staphylococcus infection |
|
Definition
-follows the acute form
-lameness
-breast blisters
-painful movement
-reluctant to walk, preferring to sit instead of stand |
|
|
Term
| clinical signs of the bumblefoot form of Staphylococcus infection |
|
Definition
-localized chronic staph infection of foot, thought to be caused by puncture
-bird becomes lame |
|
|
Term
| transmission of bumblefoot aka Staphylococcus |
|
Definition
| -Staphylococcus aureus, which is a soil-borne pathogen
-outbreaks occur when birds drink from stagnant ponds |
|
|
Term
| treatment for bumblefoot aka Staphylococcus |
|
Definition
-Novobiocin (350 g/ton) given in the feed for 5-7 days
-erythromycin and penicillin in water for 3-5 days or in feed (200 g/ton) for 5 days
-other antibiotics and drugs only occasionally effective |
|
|
Term
| prevention of bumblefoot aka Staphylococcus |
|
Definition
-remove objects that cause injury
-isolate affected birds
-balanced nutrition |
|
|
Term
|
Definition
|
|
Term
| clinical signs of omphalitis (mush chick) |
|
Definition
-external navel infection
-large unabsorbed yolk sacs
-peritonitis with fetid odor
-exudates adhering to the navel
-edema of the skin of the ventral body area
-septicemia and dehydration |
|
|
Term
| transmission of omphalitis (mush chick) |
|
Definition
-infection at hatching or shortly thereafter, before navels are healed
-chicks from dirty eggs or eggs with poor quality shells are susceptible
-chicks placed in dirty boxes are also susceptible
-chicks removed before the navel heals due to improper temp and/or humidity are also susceptible
-eggs that explode contaminate other eggs
- |
|
|
Term
| treatment for omphalitis (mush chick) |
|
Definition
|
|
Term
| prevention for omphalitis (mush chick) |
|
Definition
-effective hatchery sanitation
-effective hatchery procedures
-breeder flock surveillance
-proper preincubation handling of eggs |
|
|
Term
| Why has prevention of food pad dermatitis become a major issue in the poultry industry? |
|
Definition
-podotheca (paws) have become the 3rd most valuable part of the chicken ($280-300 million/yr)
-feet used for welfare assessments |
|
|
Term
| What are some potential litter management factors that can lead to an increase in foot pad dermatitis? |
|
Definition
-humidity >70% --> caking
-the resulting friction causes hypoerplasia and hyperkeratosis, causing thicker foot skin |
|
|
Term
| What are some potential diet factors that can lead to an increase in foot pad dermatitis? |
|
Definition
| more watery stool caused by high levels of non-starch polysaccharides (NST) in all-veggie diet, since NST is not as readily digestible |
|
|
Term
| What are some potential drinker system factors that can lead to an increase in foot pad dermatitis? |
|
Definition
| leakiness causes more watery floor |
|
|
Term
|
Definition
| thickening of the outer layer of the skin |
|
|
Term
|
Definition
| enlargement of organ or tissue caused by increased reproduction rate of its cells |
|
|
Term
| What modifications have occurred in the avian neck and head that allows for the rhamphotheca to be an effective organ for prehension? |
|
Definition
-more cervical vertebrae, ranging from low teens to mid twenties, based on length of neck
-bird skull has single occipital condyle, allowing nearly 360 degree rotation of head |
|
|
Term
| ossifications that occurred in the Synsacrum as an adaptation to flight |
|
Definition
-fusion of pelvis and vertebrae
-fused ilium and ischium
-fusion of 3 lumbar, 7 sacral, and 6 caudal vertebrae |
|
|
Term
| ossifications that occurred in the Pygostyle as an adaptation to flight |
|
Definition
| fusion of last few caudal vertebrae |
|
|
Term
| ossifications that occurred in the Thorax as an adaptation to flight |
|
Definition
| fusion of thoracic vertebrae to increase strength and prevent crushing of lungs during downbeat of the wing |
|
|
Term
| ossifications that occurred in the Uncinate processes as an adaptation to flight |
|
Definition
| strengthen rib cage by overlapping witht he rib behind it |
|
|
Term
| ossifications that occurred in the ribs as an adaptation to flight |
|
Definition
| vertebral ribs... sternal ribs |
|
|
Term
|
Definition
thin layer of compact bone that covers the spongy bone of each epiphysis
-functional unit is the osteon
-contains osteocytes, which are former bone cells that have become trapped by the bone matrix |
|
|
Term
|
Definition
-made of lattice of delicate slivers of bone called spicules and trabeculae
-has spongy appearance
-covered with endosteum
-permeated by spaces filled with bone marrow
-typically found at the ends of long bones
-covered by compact bone |
|
|
Term
|
Definition
central cavity of bone shaft where red or yellow bone marrow is stored
-has walls made of spongy bone and lined with endosteum |
|
|
Term
|
Definition
dense irregular connective tissue that covers the outer surface of all bones
-provides blood supply to the body of the marrow
-attachment site for muscles
+becomes continuous with tendon muscles
+contains chondroblasts, osteoblasts, and mesenchymal stem cells |
|
|
Term
|
Definition
thin layer of reticular connective tissue that lines the internal marrow cavity
-covers spongy bone
-lines the canal system in compact bone
+reticular connective tissue
+contains osteoclasts |
|
|
Term
|
Definition
hyaline cartilage that separates the marrow spaces f the epiphysis and diaphysis, where the bone can grow in length
-interstitial growth occurs at epiphyseal plate |
|
|
Term
|
Definition
| the layer of hyaline cartilage that covers the joint surface where one bone meets another |
|
|
Term
|
Definition
extended tubular shaft
-cortical bone with medullary cavity
-red bone marrow
+hematopoiesis |
|
|
Term
|
Definition
| expanded areas at each end |
|
|
Term
|
Definition
narrow zone between diaphysis and epiphysis
-growth plate for bone elongation; this is the growth plate |
|
|
Term
|
Definition
organic part of bone matrix that forms before maturation of bone tissue
-osteoblasts begin the process of forming bone tissue by secreting the osteoid |
|
|
Term
|
Definition
| tiny cavities inside the bone that contain osteocytes and are interconnected by channels called canaliculi |
|
|
Term
| osteon or Haversian system |
|
Definition
functional unit of compact bone
-contains central canal and its lamellae
+its central canal contains arteries and veins
+matrix in concentric rings, called lamellae, around canal |
|
|
Term
|
Definition
| channels that connect the tiny cavities called lacunae and contain cytoplasmic extensions of osteocytes |
|
|
Term
|
Definition
| former osteoblasts that have become trapped in the matrix they deposited |
|
|
Term
|
Definition
produce new bone in process called ossification
-they make and release proteins and other organic compounds into the matrix |
|
|
Term
|
Definition
cells that remove and recycle bone matrix
-they have 50+ nuclei
-they dissolve bone matrix by releasing acids and proteoglycan enzymes
-the minerals go into interstitial fluid |
|
|
Term
| osteogenic/osteoprogenitor cells |
|
Definition
| cells of the osteogenic layer |
|
|
Term
|
Definition
the inner layer of the periosteum
-contains osteoblasts
-important for bone growth and healing of fractures |
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
| flattened horney cell layer- Stratum corneum |
|
|
Term
|
Definition
| transitional cells or prickle cells- Stratum spinosum |
|
|
Term
|
Definition
|
|
Term
|
Definition
| columnar cells- Stratum germinativum |
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
| collagen and elastin fibres |
|
|
Term
|
Definition
|
|
Term
|
Definition
| usually about 3-5 layers thicvk, but thicker in exposed areas such as the rampotheca (beak) and podotheca (feet) |
|
|
Term
|
Definition
| -Stratum corneum
-Stratum spinosum
-Stratum germinativum |
|
|
Term
| Stratum corneum (surface layer) |
|
Definition
-several layers of dead, scaly, keratinized cells
+mammals have the alpha-helix form of keratin while birds and reptiles have the harder to digest beta form
-resists abrasion, penetration, and water loss
-constant shedding of this layer prevents microbes and such from getting a foothold |
|
|
Term
|
Definition
keratinochytes joined together by desmosomes and tight junctions
-make more keratin filaments as they migrate superficially, causing them to flatten |
|
|
Term
|
Definition
| hold adjacent cells together |
|
|
Term
| Stratum basale/germinativum (deepest epidermal layer) |
|
Definition
single layer of stem cells and keratinocytes resting on the basement membrane
-these cells give rise to keratinocytes and migrate superficially
-may contain melanocytes that give off pseudopodia that distribute melanin to migrating keratinocytes |
|
|
Term
|
Definition
| prevent UV damage to underlying cells |
|
|
Term
|
Definition
| area of skin where feathers grow |
|
|
Term
|
Definition
| area of skin without sprouting feathers |
|
|
Term
|
Definition
consists of
-calamus or quill
-vane
-rachis
-barb
-ramus
-barbule
-barbicels/hooklets |
|
|
Term
|
Definition
| seem to consist of just barbs and barbules; this is what down feathers are |
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
| the different microstructural components of feathers |
|
Definition
-calamus or quill
-rachis
-barbs
-barbules
-barbicels/hooklets |
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
hollow shaft connected to skin or bone
-oldest part is the tip
-this part used to have blood running through it |
|
|
Term
|
Definition
|
|
Term
|
Definition
| continuation of calamus but center of vane (barbs projecting out from either side) |
|
|
Term
|
Definition
| extensions of rachis that form vane in pennaceous feathers |
|
|
Term
|
Definition
| part of the barb from which the barbule extends |
|
|
Term
|
Definition
| projections off the ramus of the barb |
|
|
Term
|
Definition
| tiny microscopic projections that interlock with proximal barbs |
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
| Remiges (wing) vs rectrices (tail) |
|
Definition
tail seems more symmetrical and remiges seems more asymmetrical
[image] |
|
|
Term
|
Definition
PTH
-increases blood Ca, 1-alpha-hydroxylase activity, osteoclastic maturation and activity, and Ca absorption in gut
-decreases osteoblast
Calcitonin
-decreases blood Ca, osteoclastic activity, and Ca absorption |
|
|
Term
|
Definition
| -increases blood Ca, 1-alpha-hydroxylase activity, osteoclastic maturation and activity, and Ca absorption in gut |
|
|
Term
|
Definition
| -decreases blood Ca, osteoclastic activity, and Ca absorption |
|
|
Term
| How does the body respond to hypocalcemia (low blood Ca2+) and how is homeostasis reestablished? |
|
Definition
| 1: hypocalcemia triggers release of PTH
2: PTH increases renal expression of 1-alpha-hydroxylase at kidney
3: 1,25-(OH)2 vitamin D3 binds to nuclear VDR (vitamin D receptor) to increase calbindin expression (type 2 steroid receptor)
-sit in particular promoter region
-binding of vitamin D to VDR allows RNA polymerases to bind and transcribe calbindin gene
4: calcibindin temporarily sequesters recently absorbed Ca2+ to allow for optimal absorption from intestinal lumen
5: Ca2+-ATPase pumps on basal lateral side "push" Ca2+ into blood, which increases blood pH |
|
|
Term
| How does the body respond to hypercalcemia (high blood Ca2+) and how is homeostasis reestablished? |
|
Definition
1: increased calbindin expression (ultimobranchial glands)
2: increased 24-hydroxylase (decreased 1-alpha-hydroxylase)
3: decreased osteoclast, increased osteoblast
[image] |
|
|
Term
| How does the relationship between calbindin and 1,25 (OH)2D3 increase both renal and intestinal absorption of Ca? |
|
Definition
| by increasing synthesis of Ca-binding proteins, mainly calbindin-D28k |
|
|
Term
| central canal contains... |
|
Definition
-arteriole
-lymphatic
-nerves
-venule |
|
|
Term
| osteon or Haversian system contains... |
|
Definition
| concentric layers, or lamellae, of compact bone tissue that surround a central canal, the Haversian canal |
|
|
Term
| depiction of the organization of osteons and lamellae in compact bone |
|
Definition
|
|
Term
| Osteoid (organic part of bone matrix) |
|
Definition
organic component of bone matrix made of collagen III and X, glycosminoglycans, proteoglycans, and glycoproteins
-provides framework upon which hydroxyapatite crystals can form
1/3 of bone is collagen, which provides tensile strength (ability to withstand bending and twisting) but poor compressive strength (ability to withstand pressure)
-secreted by osteoblasts |
|
|
Term
| Hydroxyapatite crystals (inorganic part of bone matrix) |
|
Definition
| -hydroxyapatite (Ca10(PO4)6(OH)2) makes up 2/3 of the bone matrix
-provides compressive strength (ability to withstand pressure)
-rigid strength and density |
|
|
Term
| the result of the combination of organic and inorganic components of bone matrix |
|
Definition
a protein-crystal combination that has the flexibiity of collagen and the compressive strength of hydroxyapatite crystals
-this allows bone to be strong, somewhat flexible, and highly resistant to shattering |
|
|
Term
| How would a bone behave in the absence of adequate hydroxyapatite? |
|
Definition
| it would have tensile strength (flexible), but it would lack compressive strength (wouldn't be able to handle pressure) |
|
|
Term
| function of osteoprogenitor (mesenchymal stem) cells |
|
Definition
|
|
Term
| where osteoprogenitor (mesenchymal stem) cells are found |
|
Definition
| in the periosteum outer covering |
|
|
Term
| Explain the difference between compact and spongy bone |
|
Definition
compact bone:
-80% of the osseous tissue
-has osteon as its functional unit
-forms outer shell of most bones
-denser than spongy bone
spongy bone:
-made of lattice of delicate structures called spicules and trabeculae
-spongy appearance
-covered with endosteum
-permeatefd by spaces filled with bone marrow
-typically found at ends of long bones
-covered by compact bone |
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Term
| depiction of the spatial relationship between compact ad spongy bone |
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Definition
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Term
| functions of the skeletal system other than supporting the body and protecting some of the internal organs |
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Definition
| -producing red blood cells (bone marrow)
-regulating blood pH
-regulating blood Ca2+ and PO23-
-medullary bone used for egg shell formation |
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Term
| How does an osteoblast become an osteocyte? |
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Definition
| by becoming completely surrounded by the bone matrix it forms |
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Definition
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Definition
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| What is the difference between the organic and inorganic forms of bone matrix? |
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Definition
-organic made of collagen, which provides tensile strength
-inorganic made of hydroxyapatite, which provides compressive strength |
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Term
| principle component of the osteoid |
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Definition
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Term
| principle component of the inorganic matrix |
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Definition
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Term
| what strength does the organic portion of the bone matrix provide bone? |
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Definition
| tensile strength (withstands twisting) |
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Term
| what strength does the inorganic portion of the bone matrix provide bone? |
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Definition
| compressive strength (withstands pressure) |
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Term
| What is the role of alkaline phosphatase when secreted by osteoblast? |
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Definition
| formation of hydroxyapatite |
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Term
| How do osteoblasts contribute to bone matrix formation? |
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Definition
-making and releasing organic compounds into the matrix
-increasing Ca phosphate levels such that Ca salts are deposited onto the organic matrix to form bone |
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Term
| How are osteoclast regulated? (Role of RANKL and OPG) |
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Definition
RANKL
-1: pre-osteoblasts/osteoblasts release soluble RANKL (RANK ligand)
-2: RANKL binds to RANK receptor on pre-osteoblast
-3: binding of RANKL activates osteoclast
Osteopotegrin (OPG)
-protects the bone
-secreted by osteoblast and competitively blocks RANKL
+impedes osteoclast activity
[image] |
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Term
| role of RANKL in regulating osteoclast |
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Definition
1: pre-osteoblasts/osteoblasts release soluble RANKL (RANK ligand)
2: RANKL binds to RANK receptor on pre-osteoblast
3: binding of RANKL activates osteoclast |
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Term
| role of Osteoprotegrin (OPG) in regulating osteoclast |
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Definition
-protects the bone
-secreted by osteoblast and competitively blocks RANKL
+impedes osteoclast activity |
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Term
| depiction of how RANKL and Osteoprotegrin (OPG) regulate osteoclast |
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Definition
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Term
| Impact of estrogen on bone metabolism |
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Definition
-calcitonin estrogen leads to formation of osteoblasts
-affects OPG in humans
-faster bone growth
-faster cartilage growth and bone formation in epiphyseal plate
-bone formation faster than cartilage growth (eventually all cartilage gets replaced with bone)
-leads to formation of medullary bone in laying hens |
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Term
| Impact of PTH on bone metabolism |
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Definition
| 1: increased osteoclasts
2: more Ca resorption in kidneys
3: promotes final step in vitamin D3 activation
4: inhibits collagen synthesis by osteoblast |
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Term
| Impact of Calcitonin on bone metabolism |
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Definition
-calcitonin estrogen leads to formation of osteoblasts
-affects OPG
-lower blood Ca
-lower osteoclastic activity
-lower Ca absorption
-affects bone composition and growth pattern |
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Term
| Impact of corticosteroids on bone metabolism |
|
Definition
corticosterone:
-stress --> poor bone integrity
glucocorticoids:
-high amounts increase bone loss, impairing growth at epiphyseal plate in children
-induce apoptosis of osteoblasts and increase osteoclasts survival and activity |
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Term
| Impact of blood calcium on bone metabolism |
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Definition
| hypocalcemia
-higher PTH production
+higher 1-alpha-hydroxylase production in kidneys
+lower 24-hydroxylase (inactive vitamin D3
hypercalcemia:
-increased calbindin expression (ultimobranchial glands)
-increased 24-hydroxylase (decreased 1-alpha-hydroxylase)
-decreased osteoclasts and increased osteoblasts |
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Term
| how osteoclasts use CAH to degrade bone |
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Definition
| 1: osteoclasts use this to release H atoms at its ruffled border to acidify and dissolve the bone matrix
2: allows for formation of H+ that can be pumped into the "bay" by H+-ATPase pump (lower pH) |
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Term
| how osteoclasts use TRAP to degrade bone |
|
Definition
-TRAP (tartrate-resistant acid phosphatase) is activated and is thought to assist with dissolution of hydroxyapatite crystals
-this is a marker for osteoclast activity
-this is thought to help break down hydroxyapatite |
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Term
| how osteoclasts use Cathepsin K to degrade bone |
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Definition
| this protease breaks down the osteoid (collagen) |
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Term
| depiction of how PTH affects bone metabolism |
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Definition
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Definition
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Definition
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Definition
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Definition
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Definition
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Term
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Definition
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Term
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Definition
| calcified cartilage spicule |
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Term
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Definition
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Term
| what happens in the resting zone? |
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Definition
| this zone, furthest from the marrow cavity, is made of typical hyaline cartilage with resting chondrocytes and chondroblasts, showing no signs of bone formation |
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Term
| what happens in the proliferative zone? |
|
Definition
| the chondroblasts/chondrocytes quickly divide and push the epiphysis away from the diaphysis, lengthening the bone
-chondroblasts/chondrocytes form in lamellae
-the growth hormone used here is T4/T3
-estrogen/testosterone increase proliferation of chondroblasts/chondrocytes |
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Term
| what happens in the hypertrophic zone? |
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Definition
chondrocytes stop dividing and start to enlarge and signal the surrounding matrix to calcify
-the walls between the lacunae become very thin |
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Term
| what happens in the calcification zone? |
|
Definition
-matrix calcifies
-chondrocytes die, leaving behind trabeculae-shaped calcified cartilage; THIS IS NOT YET BONE!
-chondrocytes secrete collagen and alkaline phosphatase, forming hydroxyapatite crystals at thin walls of lacunae |
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Term
| what happens in the ossification zone? |
|
Definition
-osteoclasts digest calcified cartilage
-osteoblasts replace it with bone in the same shape as the calcified cartilage, resulting in bone trabeculae at metaphysis and bone elongation
-the osteoblasts and osteoclasts come from the metaphyseal blood supply |
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Term
| role of chondroblasts in epiphyseal ossification and its general location among other zones |
|
Definition
-in proliferation zone
-quickly divide and push epiphysis away from diaphysis, lengthening the bone |
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Term
| role of chondrocytes in epiphyseal ossification and its general location among other zones |
|
Definition
-in the hypertrophic zone
+older chondrocytes enlarge and signal surrounding matrix to calcify
-in the calcification zone
+chondrocytes die, leaving behind trabeculae-shaped calcified cartilage; THIS IS NOT YET BONE! |
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Term
| role of osteoclasts in epiphyseal ossification and its general location among other zones |
|
Definition
-in the ossification zone
-digests calcified cartilage |
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Term
| role of osteoblasts in epiphyseal ossification and its general location among other zones |
|
Definition
-in the ossification zone
-replace calcified cartilage with bone tissue in shape of the calcified cartilage, resulting in bone trabeculae |
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Term
| the role of osteopontin (OPN) in bone formation |
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Definition
| this hormone has lots of negative charges that allow Ca to stick to it |
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Term
| Relate Wolff’s law to osteoporosis in chickens |
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Definition
| according to Wolff's law, greater stress on bone causes the bone to become stronger, so osteoporosis in chickens may be partly due to lack of exercise for their bones |
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Term
| How is osteoporosis different in humans and chickens? |
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Definition
-in humans, it's caused by lower levels of estrogen such that bone resorption increases and structural bone formation is suppressed, since estrogen stimulates osteoblasts and inhibits osteoclasts
-in laying hens, higher estrogen levels make osteoporosis possible because higher estrogen makes the osteoblasts switch from forming structural bone to forming medullary bone, which is weaker. Osteoblasts switch back to forming structural bone after the lay cycle. |
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Term
| How is osteoporosis similar in humans and chickens? |
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Definition
| causes less production of structural bone |
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Term
| What are some potential strategies that could be implemented to alleviate osteoporosis in chickens? |
|
Definition
-blocking sclerostin
-exercise |
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|
Term
| why blocking sclerostin can alleviate osteoporosis in laying hens |
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Definition
| sclerostin, which is secreted by osteocytes, inhibits osteoblast activity |
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Term
| why exercise can alleviate osteoporosis in laying hens |
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Definition
| more exercise leads to less sclerostin, leading to more structural bone |
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Term
|
Definition
tibial dyschondroplasia
-characterized by calcification defect and an abnormal mass of unvascularized cartilage in the proximal mass of the tibiotarsus
-abnormal cartilage seems to be the result of proliferation of prehypertrophic cells in relation to lack of metaphyseal vascularization
-formation of cartilage (collagen) plug at the epiphysis of long bones
+leads to secretion of osteoid (failure of ossification) typically at the tibiotarsus (proximal end)
--failure to develop metaphyseal blood supply
--rapid endochondrial growth with lack of calcification
+the lesion is cartilage or collagen on the bone (poor compressive strength |
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Term
| How could TD be controlled in broilers that are susceptible to the condition? |
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Definition
| vitamin D supplementation |
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Term
| On a molecular level, how could you distinguish between TD and rickets? |
|
Definition
test for PTH receptor or mRNA
-TD = normal levels
-rickets = lower PTH receptor due to chronic high PTH
+rickets caused by low vitamin D, causing low blood Ca and high PTH
+increased hormone levels cause downregulation of receptors |
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Term
| What is the cause of the molecular difference between TD and rickets? |
|
Definition
| rickets = lower PTH receptor due to chronic high PTH |
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|
Term
| What is appositional growth? |
|
Definition
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|
Term
| How does appositional bone growth occur? |
|
Definition
1: osteoblasts in periosteum secrete bone matrix and secrete circumfrential lamellae
2: osteoclasts at endosteum actively resorb bone
3: bone matrix deposited within layers parallel to the surface called circumferential lamellae
4: osteoclasts resorb bone matrix along medullary cavity |
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Term
| Name the three-classic calcium-regulating hormones present in birds. |
|
Definition
| -parathyroid hormone (PTH)
-calcitonin
-1,25-dihydroxyvitamin D3 (calcitrol) |
|
|
Term
| What three forms does calcium exist in birds? |
|
Definition
| -extracellular
-intracellular
-hydroxyapatite (Ca10 (PO4)6(OH)2) of the bone |
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|
Term
| Which form of Ca constitutes about 99% of the total body calcium? |
|
Definition
| hydroxyapatite (Ca10 (PO4)6(OH)2) of the bone |
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Term
| the physiologically active form of Ca |
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Definition
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|
Term
| the fraction of calcium that is regulated by interaction with hormonal action |
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Definition
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Term
| Protein-bound calcium is considered physiologically inactive and serves as an extracellular storage pool. What two proteins predominantly bind this calcium? |
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Definition
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Term
| how much of a hen's Ca stores are in the shell of an egg? |
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Definition
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Term
| why might zebra finches use a higher percentage of their Ca in their eggs? |
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Definition
| because smaller birds lay proportionally larger eggs with more shell |
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Term
| What is the main source of the calcium required for eggshell calcification? |
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Definition
| greater intestinal absorption and resorption of Ca from the medullary bone |
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Term
| What parathyroid cell type is responsible for producing PTH? |
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Definition
| chief cells; the parathyroid gland is made entirely of these cells |
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Term
| three mechanisms used by PTH that lead to an increase in blood calcium levels |
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Definition
| 1: faster synthesis of 1,25-(OH)2-D3 by the kidney
2: greater tubular resorption of Ca, leading to less Ca excreted and more PO4 excreted
3: greater bone resorption |
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Term
| do birds have a delayed response to PTH compared to mammals? |
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Definition
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Term
| Why might PTH be more effective in egg-laying hens than in males? |
|
Definition
either because...
-there's more PTH receptors in medullary bone and oviduct OR
-more Ca-binding proteins in the plasma |
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Term
| What calcium regulating hormone is produced by the ultimobranchial glands? |
|
Definition
|
|
Term
| does calcitonin circulate at much higher levels in birds than in mammals? |
|
Definition
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|
Term
| Why is it thought that calcitonin levels are high in egg laying chickens immediately before or after oviposition? |
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Definition
| because Ca is still being rapidly mobilized from the bones and absorbed from the intestines without the shell gland removing the Ca from the blood |
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Term
| the two most important forms of vitamin D |
|
Definition
|
|
Term
| how vitamins D2 and D3 differ |
|
Definition
| -D2 seems to be only 1/10th as efficient as D3, possibly due to D2 having a lower affinity for Ca-binding proteins, which also means the D2 will be excreted more readily
-essentially, D3 is 10 times more efficient and has higher affinity for Ca-binding proteins |
|
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Term
| do birds often ingest nutritionally significant amounts of cholicalciferol during the preening process? |
|
Definition
|
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Term
|
Definition
| -the major circulating form of D3
-serves as a pool for further activation or catabolism |
|
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Term
|
Definition
| the most active form of D3 |
|
|
Term
| where PTH increases hydroxylation when Ca is low |
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Definition
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Term
| where PTH does hydroxylation when Ca levels are normal |
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Definition
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Term
| main target organs for D3 |
|
Definition
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|
Term
| which protein, increased in response to calcitriol, facilitates the absorption of Ca in the duodenum and jejunum? |
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Definition
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|
Term
| where may calbindin-D28k be found other than the duodenum and jejunum? |
|
Definition
| oviduct, which is the distal portion of the uterus |
|
|
Term
| Why would PTH levels fall as calcitriol levels increase? |
|
Definition
| because calcitriol (1,25(OH)2-D3) decreases PTH production in the parathyroid gland |
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Term
| the amount of medullary bone is sufficient to supply Ca for how many egg shells? |
|
Definition
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Term
| Rising estrogen concentrations at the onset of egg production stimulate the osteoblast from forming ______ bone to producing spicules of medullary bone at the ______ surface. |
|
Definition
-lamellar cortical
-endosteal surface |
|
|
Term
| Radiographically, where is medullary bone most prominent? |
|
Definition
| pelvic limb long bones (femur and tibiotarsus) |
|
|
Term
| What is osteomyelosclerosis? |
|
Definition
| formation of medullary bone such that a labile source of Ca becomes available |
|
|
Term
| What is the source of Vitamin D3 in the embryo? |
|
Definition
|
|
Term
| how does calcitriol facilitate the absorption of calcium? |
|
Definition
| by increasing the serum concentration of Ca to reduce the production of PTH |
|
|
Term
| Why is it thought fledglings of altricial species have higher dietary calcium requirements when compared to precocial species? |
|
Definition
| because hatchlings have a less calcified skeleton and grow faster |
|
|
Term
| How much sunlight exposure is needed in chickens to ensure sufficient production of endogenous vitamin D? |
|
Definition
| at least 11-30 minutes of direct exposure to sun light |
|
|
Term
| Why is Vitamin D2 an ineffective nutritional supplement for birds? |
|
Definition
| because compared to D3, it has a lower affinity for vit D binding proteins and is excreted more quickly |
|
|
Term
| Why do you think the dietary calcium requirements for broiler breeders are higher than egg type breeders? |
|
Definition
| because egg-laying birds have much higher levels of albumin, which carries vitamin D3 |
|
|
Term
| the role of albumin in regulating calcium levels |
|
Definition
| excess Ca binds to it such that Ca can be released where it's needed |
|
|
Term
| How and why would a drop in blood pH affect calcium blood calcium readings? |
|
Definition
| increase blood Ca levels because of less binding to albumin |
|
|
Term
| Could you use a human Vitamin D assay kit to measure Vitamin D in avian blood? |
|
Definition
|
|
Term
| What is the range of blood levels of ionized calcium for the domestic chicken? |
|
Definition
|
|
Term
| What is the range of blood levels of ionized 25-OH-D3 for the domestic chicken? |
|
Definition
|
|
Term
| What is the range of blood levels of PTH for the domestic chicken? |
|
Definition
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|
Term
| How might excessive dietary manganese lead to hypocalcemia in birds? |
|
Definition
| by preventing the normal absorption of Ca |
|
|
Term
| Why isn’t hypocalcemia from parathyroid hyperplasia not detected until bone reserves are severely depleted? |
|
Definition
| because blood Ca is maintained at normal levels and fibrous tissue replaces the resorbed bone |
|
|
Term
| What are some common signs of calcium deficiency in adult female birds (hens)? |
|
Definition
-egg binding
-egg abnormalities (soft shell, misshapen, thin shell)
-higher embryo mortality
-"cage paralysis"
-osteomalacia
-pathological fractures |
|
|
Term
| What is often correlated with hypercalcemia in birds? |
|
Definition
-more Ca-binding protein production
-greater secretion of estrogen |
|
|
Term
| What are some clinical signs of hypercalcemia? |
|
Definition
| -hydroxylation of 25-OH-D3, mainly to 24,25-(OH)2D3
-higher excretion of Ca
-more bone formation than resorption
-release of calcitonin, likely to reduce bone resorption
-lower 1,25(OH)2-D3 synthesis
-lower intestinal absorption of Ca
-lower PTH synthesis |
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|
Term
| What percentage of hens experience fractures either during the production period or depopulations? |
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Definition
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|
Term
| The zone of proliferative chondrocytes is nourished by ______ blood capillaries, while the hypertrophic zone receives its blood supply from the ______ blood vessels. |
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Definition
|
|
Term
| Once fully hypertrophied, chondrocytes secrete this enzyme that helps to initiate the formation of hyrodxyapatite crystals. |
|
Definition
|
|
Term
| ______ produce the osteoid and raised concentration of Ca2+ and PO43- ions, while the bone-reabsorbing cells, ______, are also active during the formation of spongy bone in the marrow. |
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Definition
|
|
Term
| By what process to long bones widen? |
|
Definition
| intramembranous ossification |
|
|
Term
| During intramembranous ossification, osteoblast are present in the ______ and lay down concentric layers of lamellar compact bone, while on the ______ surface, osteoclast resorb bone. |
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Definition
|
|
Term
| When do osteoblast change from forming lamellar cortical bone to medullary bone? |
|
Definition
| when the hen becomes sexually mature |
|
|
Term
| What is the purpose of medullary bone? |
|
Definition
| labile Ca source for the formation of egg shells |
|
|
Term
| why structural bone content of the hen declines during lay |
|
Definition
| because the osteoblasts cease to form structural bone, but the osteoclasts continue to resorb structural bone |
|
|
Term
| 2 reasons why medullary bone is weaker than structural bone |
|
Definition
1: it is woven and based on very irregularly arranged collagen fibrils
2: much of it exists in isolated spicules |
|
|
Term
| Can one use radiographic density or ash to measure bone quality in laying hens? Why or Why not? |
|
Definition
| no, because medullary and structural bone have the same radiodensity |
|
|
Term
| How are human postmenopausal osteoporosis and laying hen osteoporosis different? |
|
Definition
-the one in humans is caused by lower estrogen
-the one in hens is caused by estrogen making the osteoblasts switch from forming structural bone to forming medullary bone, which is weaker |
|
|
Term
| the relationship between medullary bone content and shell quality |
|
Definition
| Scarcely any, since egg quality declines during the lay cycle, during which the medullary bone content increases. Therefore, shell quality seems to be a matter of ability to move Ca from the bone to the egg shell, not medullary bone content. |
|
|
Term
| How can exercise potentially increase bone strength? |
|
Definition
may be by either...
-inhibiting egg production OR
-stimulating formation of structural bone |
|
|
Term
| 2 possible reasons why tibia strength increased within 20 days of transfer of hens from cages to an aviary |
|
Definition
-stimulation of structural bone formation
-inhibition of egg production |
|
|
Term
|
Definition
| seems to be a measure of a bone's radiographic density and its breaking strength |
|
|
Term
| how the number for bone index (BI) is obtained |
|
Definition
using this equation:
BI = 0.27 x keel radiographic density + 0.37 x humerus strength + 0.61 x tibia strength - 0.35 x body weight |
|
|
Term
| At what age was there a greater difference in tibial cortical bone width between the two lines of hens selected for resistance (H) or susceptibility (L) to osteoporosis? |
|
Definition
|
|
Term
| Which of the two lines (resistance (H) or susceptibility (L)) had a higher number of osteoclast per unit of medullary bone? |
|
Definition
| the line selected for susceptibility to osteoporosis (L) |
|
|
Term
|
Definition
| bone loss caused by nutritional deficiencies in P, Ca, and cholicalciferol |
|
|
Term
| Why isn't the statement “osteoporosis occurs in hens because they deplete their bones by laying so many eggs” not entirely correct? |
|
Definition
| because the amount of Ca hens consume is greater than the amount used to lay eggs |
|
|
Term
| the relationship between Bone Index (BI) and rate of lay and why this is |
|
Definition
| very weak relationship, likely due to rate of lay being a matter of the lay cycle regulated by hormones |
|
|
Term
| the relationship between Bone Index (BI) and shell quality and why this is |
|
Definition
-hens with higher bone index lay eggs with lower shell quality; inversely related
-this is because resistance to osteoporosis is associated with less bone resorption, leading to less Ca deposited on the egg |
|
|
Term
| Why might dietary calcium from a particulate rather than a powdered form improve egg shell and bone quality? |
|
Definition
| because particulate Ca stays in the digestive system longer, providing Ca such that hens are less reliant on bones for egg shell formation |
|
|
Term
|
Definition
-2 cervical
-1 interclavicular
-2 anterior thoracic
-2 posterior thoracic
-2 abdominal |
|
|
Term
| flow of air in the avian respiratory system |
|
Definition
| 1 way with cross-current exchange |
|
|
Term
| respiratory volume in birds vs. that in mammals |
|
Definition
| 15% for birds and 7% for mammals |
|
|
Term
|
Definition
-no diaphragm; breathing dependent on inspiratory and expiratory muscles that extend the sternum and open the ribs to increase area (or decrease pressure) of thoracic cavity
-this is why you want to be careful when holding a bird |
|
|
Term
| movement of skeleton during breathing |
|
Definition
|
|
Term
| how the sternum and ribs move during inspiration |
|
Definition
-sternum rocks cranially and ventrally with the coracoids and clavicle rotating at the shoulder
-vertebral ribs move cranially to expand the sternal ribs and abdominal cavity laterally |
|
|
Term
| the motion that occurs during inspiration |
|
Definition
| the ribs are drawn forward and the sternum is lowered, allowing the caudal air sacs to receive fresh air |
|
|
Term
| the motion that occurs during inspiration |
|
Definition
| the sternum is drawn caudal and dorsal, the air sacs are compressed, and air from the caudal air sac passes through the lungs while the air in the cranial air sac leaves via the trachea |
|
|
Term
| instead of alveoli, birds use... |
|
Definition
|
|
Term
| depictions of parabronchi |
|
Definition
|
|
Term
| Paleopulmonic Parabronchi |
|
Definition
| these are the main parabronchi and are arranged in parallel formation (neat stacks) |
|
|
Term
|
Definition
| these irregularly arranged parabronchi are located in the caudal region and occupy no more than 25% of the parabronchi |
|
|
Term
| lungs in mammals vs. lungs in birds |
|
Definition
| lungs in mammals are expandable while lungs in birds are rigid |
|
|
Term
|
Definition
| relating to the heart and lungs |
|
|
Term
| for O2 poor blood, the ______ side of the heart pumps to the ______ circulation through ______ |
|
Definition
-right
-pulmonary
-pulmonary arteries |
|
|
Term
| for O2 rich blood, the ______ side of the heart pumps to the ______ circulation through ______ |
|
Definition
-left
-systemic
-the aorta
this is AFTER receiving blood from pulmonary circulation |
|
|
Term
| What function do the Concha (meatus passageways) serve for respiratory system? |
|
Definition
-filtering air (cilliated passageway)
-humidify and warm air
-ensures air comes into contact with respiratory epithelium |
|
|
Term
|
Definition
essentially the nostrils
[image] |
|
|
Term
|
Definition
seems to be the internal nostrils above the epiglottis
[image] |
|
|
Term
|
Definition
|
|
Term
|
Definition
| tube between the glottis and syrinx; this tube is surrounded by cartilage rings |
|
|
Term
|
Definition
where the trachea and bronchial tubes meet; this is basically the bird's voice box
[image] |
|
|
Term
|
Definition
the first bronchial tube that branches out from the trachea
[image] |
|
|
Term
| 1st Inspiration: Air to posterior air sacs. (DRAW THIS!!!!) |
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Definition
| External nares → concha → choanal slit → glottis → trachea → syrinx → primary bronchi → intrapulmonary bronchus → caudal air sacs (abdominal and posterior thorasic) |
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Term
| 1st Expiration: Gas exchange as air enters parabronchi of lungs. (DRAW THIS!!!!) |
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Definition
| Caudal air sacs → neopulmonic parabronchi or dorsobronchi (gaseous exchange) → paleopulmonic bronchi (gaseous exchange) |
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Term
| 2nd Inspiration: Air now enters anterior air sacs. (DRAW THIS!!!!) |
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Definition
| Paleopulmonic bronchi → ventrobronchi → cranial secondary (anterior) bronchi → (anterior) cranial air sacs (cervical, interclavicular, and anterior thorasic) |
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Term
| 2nd Expiration: Air exhaled out the trachea. (DRAW THIS!!!!) |
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Definition
| Cranial air sacs → cranial secondary bronchi (anterior) → primary bronchi → syrinx (sound) → trachea → glottis → conchal slit → concha → external nares |
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Term
| the exchange that occurs in cross-current exchange |
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Definition
| O2 rich air passing from posterior parabronchi exchanges with O2 poor blood flowing in an anterior to posterior manner... "cross-current" |
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Term
| depictions of cross-current exchange |
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Definition
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Term
| what cross-current exchange does for gas concentration |
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Definition
| maintains concentration gradient that allows diffusion of O2 into blood and CO2 out of blood |
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Term
| where cross-current exchange occurs |
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Definition
| air capillaries and blood capillaries exchange gases |
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Term
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Definition
| at the air-water interface for a given temperature, the amount of gas that dissolves in the water is determined by its solubility in water and its partial pressure in air |
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Term
| How would altitude impact Henry’s law |
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Definition
| thinner air means lower partial pressure, thus less dissolved gas in blood |
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Term
| Even though the partial pressure difference is greater for O2 than for CO2, explain why CO2 exchanges at near an equal rate (consider Henry’s law) |
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Definition
| because CO2 is 20 times more soluble |
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Term
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Definition
| protein made of 4 globin subunits, each containing a heme group that binds 1 O2 to the ferrous ion (Fe2+); one hemoglobin molecule can carry up to 4 O2 |
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Term
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Definition
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Term
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Definition
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Term
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Definition
| the group in hemoglobin that binds 1 O2 to the ferrous ion (Fe2+) |
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Term
| the tree different forms of CO2 transport in the blood |
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Definition
-carbonic acid
-carbamino compounds
-dissolved in plasma |
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Term
| the formula for formation of carbonic acid |
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Definition
| CO2 + H2) --> CH2O3 --> H+ + HCO3- |
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Term
| the enzyme responsible for the formation of carbonic acid |
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Definition
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Term
| where is carbonic anhydrase located? |
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Definition
-red blood cells
-osteoclasts |
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Term
| How/Why is Carbon Monoxide (CO) toxic |
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Definition
| because it binds to the hems group 210 times more tightly than O2, making red blood cells more likely to carry it and less likely to release it; this ties up hemoglobin for a long time |
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Term
| treatment for CO toxicity |
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Definition
| hyperbaric oxygen therapy, which is treatment with O2 at more than 1 atm of pressure |
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Term
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Definition
| increased CO2 in active tissue lowers blood pH, promoting release of O2 by way of an H+ released by CAH in red blood cells |
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Term
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Definition
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Term
| 3 factors that adjust oxygen unloading for metabolically active tissues |
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Definition
| -ambient PO2; atmosphere with lower partial pressure of O2 causes release of O2
-temperature; active tissue with higher temperature causes more O2 unloading
-Bohr effect; active tissue with higher CO2 levels causes lower blood pH, which promotes O2 unloading |
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Term
| relationship between hypocapnia and alkalosis |
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Definition
| hypocapnia (decreased blood CO2) --> increased pH --> hypoventilate (bag)
-high pH leads to alkalosis |
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Term
| relationship between hypercapnia and acidosis |
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Definition
| hypercapnia (increased blood CO2) --> lower pH --> hyperventilation --> decreased pH
-lower pH leads to acidosis |
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Term
| some unique adaptations of birds who travel (live) at high altitudes |
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Definition
| -lungs with larger surface area
-cross-current gas exchange
-point mutation in hemoglobin (higher affinity for O2)
-mitochondria closer to capillaries
-higher levels of creatine kinase |
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Term
| chart of some adaptations of birds to high altitudes |
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Definition
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Term
| What is the significance of mitochondria placement and creatine kinase in birds being adapted to high altitude? |
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Definition
| -mitochondria being closer to the capillaries makes it easier for the O2 to diffuse to the mitochondria
-higher levels of creatine kinase enhance the transport of phosphate to where it's needed |
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Term
| What is the mucociliary escalator and why is it significant? |
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Definition
-cilia lining the trachea covered by a layer of mucous
-this helps keep gunk out of the respiratory system |
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Term
| In poultry rearing, what can significantly compromise the mucociliary escalator |
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Definition
-high ammonia levels
-damages cilia such that they're no longer functional |
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Term
| What is the resting membrane potential of neurons? |
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Definition
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Term
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Definition
| when the membrane potential inside the cell increases
-occurs when positive ions enter the cell (usually Na+)
-this is excitatory |
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Term
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Definition
when the membrane potential inside the cell returns to resting potential
-this actually overshoots resting potential and gets down to -85 mV |
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Term
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Definition
| when the membrane potential goes below resting membrane potential |
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Term
| What is threshold for voltage-gated Na channels? |
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Definition
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Term
| At what voltage are voltage-gated Na channels deactivated? |
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Definition
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Term
| At what voltage do K channels open for repolarization? |
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Definition
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Term
| During repolarization, the resting membrane is overshot to this voltage known as hyperpolarization. |
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Definition
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Term
| How is the membrane potential restored after an action potential? |
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Definition
| the Na-K pump restores resting membrane potential |
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Term
| how neurons code for stimulus intensity |
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Definition
-increased frequency of action potentials
-recruitment, which is activating more neurons in a nerve; more neurons get activated (recruited) as the stimulation increases |
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Term
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Definition
| intensity of stimulation increases, activating more neurons and axons in a nerve |
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Term
| Movement of an action potential down an axon relying on cable properties is inefficient, what is present, anatomically, that helps propagate the action potential quickly? |
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Definition
-myelin provides insulation
-Na channels reside at the nodes of Ranvier. Action potential kinda pops between the nodes. |
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Term
| depiction of a neuron and all its components |
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Definition
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Term
| What is saltatory conduction? |
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Definition
| propagation of action potentials along myelinated axons from one node of Ranvier to the next node, increasing the conduction velocity of action potentials |
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Term
| sequence of events that leads to the exocytosis of neurotransmitters into the synapse (WRITE THIS!!!!) |
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Definition
| 1: ACh binds to nicotinic receptor on dendrite of motor neuron
2: nicotinic receptor opens and allows entry of Na+, generating an excitatory postsynaptic potential (EPSP)
-These voltage-gated Na channels open at threshold. These channels are concentrated at the axon.
3: if there's sufficient Na entry, and EPSP opening of voltage-gated Na channels at axon hillock --> action potential
4: action potential generated at axon hillock can travel down the axon via saltatory conduction
5: arrival of action potential at terminal bouton opens voltage-gated Ca channels
-bouton is the end of the axon
6: Ca2+ enters terminal bouton and binds with synaptotagmin to form Ca2+-synaptotagmin complex
7: Ca2+-synaptotagmin complex disrupts SNARE docking proteins and causes neurotransmitter containing vesicles to fuse with synaptic membrane and release neurotransmitter into synapse
-this neurotransmitter is acetylcholine (ACh) |
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