Term
| Amino acid derived hormones overview-2 |
|
Definition
-derivatives of the amino acid tyrosine and amines.
-Produced by thyroid gland and adrenal medulla + CNS |
|
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Term
| functions of the endocrine system-4 |
|
Definition
-maintain homeostasis
-adapt to changes in the external environment
-control processes involving multiple tissues and requiring coordination of complex sequences of events at the whole body level(ion and fluid balance, digestion, metabolism, growth and development, reproduction.)
-regulate processes at the cellular and molecular levels via hormones
- |
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Term
| Steroid derived hormones overview-5 |
|
Definition
Derivatives of cholesterol
-produced from adrenal cortex and the gonads.
-lipophilic(intercellular receptors)
-water insoluble(must be bound by proteins)
-glandular storage is minimal
-can be administered orally |
|
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Term
| Peptide (<20 AA) and Protein (>20 AA) hormones overview-6 |
|
Definition
-Produced by CNS, Parathyroid, and Pituitary
-cannot be administered orally since can be digested
-circulate unbound or free mostly
-relatively polar so have receptors on cell surface
-stored inside the cell
-syntehesized on ribosomes as prehormones or pre-prohormones |
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Term
|
Definition
-Epinephrine-adrenal Medulla
-Norepinephrine-Adrenal Medulla
-dopamine- CNS
-Triiodothyronine(T3)-thyroid
-thyroxine(T4)-thyroid |
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Term
|
Definition
| Testosterone- gonads estradiol-gonads progesterone-gonads cortisol-adrenal cortex aldosterone-adrenal cortex Vitamin D-kidney |
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Term
|
Definition
Oxytocin- Posterior pituitary
Vasopressin- Posterior Pituitary
Gonadotropin releasing hormone-CNS
Thyrotropin releasing hormone-CNS
Somatostatin-CNS |
|
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Term
|
Definition
Insulin and Glucagon-Pancreas
Adrenocorticotropic hormone(ACTH)-Ant Pituitary
Thyroid Stimulating hormone-Ant Pituitary
Follicle stimulating hormone-Ant Pituitary
Luteinizing hormone-Ant Pituitary
Growth Hormone-Ant Pituitary
Prolactin-Ant Pituitary
Parathyroid hormone-Parathyroid
Calcitonin-thyroid
chorionic gonadotropin-placenta |
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Term
|
Definition
Leads to deficiency in Aldosterone and Cortisol causing congenital adrenal hyperplasia.
-leads to ambiguous female genitalia and high DHEA levels |
|
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Term
|
Definition
Exocytosis- AA derivatives, protein and peptides
Diffusion-Steroids and Thyroid hormone |
|
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Term
| Steroid hormone binding Proteins |
|
Definition
1. binding proteins are synthesized and secreted by the liver.
2-binding affinity of a protein with its hormones ligand is greater as a specific binding protein that that of a general (Albumin) and both have a greater affinity than the receptors
3. concentration of bound hormone, free hormone, and binding protein are in equilibrium
4. a decrease in free hormone causes release of bound hormone from its protein
5. bound hormone is not available for metabolism, so therefore the presence of binding protein increases a hormones half life |
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Term
|
Definition
1. Receptors that function as enzymes themselves-tyrosine kinases. (insulin)
2. G-protein coupled receptors(LH, FSH, TSH, Epi, Norepi)
3.Phosholipase C( has calcium binding calmodulin as a second messenger)
4. Steroid receptors(also for thyroid)-have intracellular receptors acting as transcription factors. have 3 important parts (ligand binding, DNA(recognizes HRE), and a variable immunogenic in charge of transcription. |
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Term
|
Definition
| breaks down cAMP to stop the signaling cascade in G-protein coupled receptors. Caffeine inhibits the enzyme which allows epinephrine for example to have longer lasting effects. |
|
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Term
| Hormone Response Elements |
|
Definition
HRE's are 6-12 nucleotides long that are found in the nucleus of cells to recognize DNA and become mRNA for protein synthesis for an altered functional response.
This process is the reason it takes longer for steroids to act than peptide and protein hormones. |
|
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Term
| Regulation of hormone action-3 |
|
Definition
1. Feedback systems or loops
2. Target tissue responsiveness (up or down regulation)
3. hormone interactions(synergism, permissive, antagonistic) |
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Term
|
Definition
Variation throughout the day
Ex. cortisol and testosterone |
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|
Term
|
Definition
Secreted in pulses with no relation to time of day
prevents receptor downregulation
ex. LH |
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|
Term
| Posterior Pituitary hormones |
|
Definition
Made in brain by neurosecretory neurons + 9AA peptide hormones
-Vasopressin
-Oxytocin |
|
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Term
|
Definition
(ADH)
Smooth muscle contraction in blood vessels, Increases Blood pressure.
decreases water excretion by kidneys
-released directly into circulation in response to hypothalamic osmoreceptors and cardiovascular volume receptors |
|
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Term
|
Definition
| Smooth muscle contraction on uterus and mammary glands |
|
|
Term
| Anterior Pituitary hormones |
|
Definition
LH-made by gonadotrophs-target endocrine cells of gonads
FSH-made by gonadotrophs-target endocrine cells of the gonads
GH-made by somatotrophs-target the liver
ACTH-made by corticotrophs-targets adrenal cortex
Prolactin-made by lactotrophs-targets breast
TSH-made by thyrotrophs-targets thyroid gland |
|
|
Term
| Corticotropin-releasing hormone |
|
Definition
| stimulates secretion of ACTH |
|
|
Term
| Thyrotropin releasing hormone |
|
Definition
| Stimulates secretion of TSH by anterior pituitary |
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|
Term
| Growth hormone releasing hormone |
|
Definition
| Stimulates secretion of GH from Ant. Pituitary |
|
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Term
|
Definition
| Inhibits secretion of GH by ant pituitary |
|
|
Term
| Gonadotropin-releasing hormone |
|
Definition
| Stimulates secretion of Lh and FSH by Ant. Pituitary |
|
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Term
|
Definition
| Inhibits secretion pf prolactin from Ant. Pituitary |
|
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Term
|
Definition
Follicle with Tri-iodothyronine(active-T3), Thyroxine T4, thyroglubulin( aids in production of thyroid hormone)
and Parafollicular cells (C cells) that secrete calcitonin |
|
|
Term
| Thyroid hormone biosynthesis |
|
Definition
1. Trapping of iodide, diffusion down conc. gradient
2. in colloid- oxidation of iodide + iodination of tyrosine residues on TG with formation of iodotyrosines (MIT+DIT)
3. In colloid- coupling of iodotyrosines(2 DIT-T4; 1 MIT + 1 DIT= T3), remain attached to TG, stored in lumen of colloid,(2-3 months worth)
4. Endocytosis of TG -Pinocytosis and fusion of colloid droplets with lysosomes
5. Hydrolysis of TG
6. Release of T3 and T4 into cytoplasm and diffusion into extracellular fluid (T4:T3= 20:1 |
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Term
|
Definition
| T3 is the active form T4 and T3 are released together with T4 about 20 fold more half life 3-2 days 4-7 days 2/3 of all T3 is converted from T4 therefore T4 is considered a prohormone |
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|
Term
| Physiological effects of thyroid hormones-8 |
|
Definition
1. Calorigenic effect-increase BMR
2.Sympathomimetic effect-increases beta adrenergic receptors so mimics symp. N.S.
3.Normal maturation of CNS in fetus and infant
4.Normal alertness and reflexes throughout life
5.Normal growth(bone formation and GH synthesis and secretion)
6.fuel metabolism
7. Cardiovascular effects-increased cardiac output, HR
8. Reproductive system function in males and females |
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Term
|
Definition
Primary-Thyroid gland function decreased
Secondary-Pituitary function decreased
Tertiary-CNS function decreased
Iodine deficient |
|
|
Term
| Hypothyroidism Symptoms-7 |
|
Definition
1. Congenital-Cretinism (mental retardation)
2.children-short stature, delayed puberty, decreased intelligence
3.adults-lethargy
4.decreased BMR, HR, BP and GI motility
5. Cold intolerance
6. Decreased libido and fertility
7. myxedema-(puffiness in lips, eyelids, fingers) |
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Term
|
Definition
Primary-Thyroid secreting tumore nodules
Seondary-Pituitary Tumor
Tertiary-hypothalamic or CNS over secretion
-Graves disease- Presence of thyroid stimulating immunoglobulins, antibodies to TSH receptor, that act like TSH |
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|
Term
| Hyperthyroidism symptoms-8 |
|
Definition
1. hyperactivity, impatience, restlessness, irritable
2.palpitations
3.increased GI motility and BMR
4. Heat intolerant-sweaty flushed skin
5. decreased fertility in both sexes
6.increased protein catabolism(muscle weakness)
7.fatigue
8.graves-goiter, lid retraction, exophthalmos |
|
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Term
| Thyroid disorders in Dental Patients-3 |
|
Definition
1. General anesthesia can increase crisis with increased HR and anxiety
2. high iodine can cause pain in gums, swollen salivary glands and increased salivation
3.hypothyroid sufferers can have enlarged tongue and increased sensistivity to pain |
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Term
| Endocrine function regarding growth-6 |
|
Definition
1Growth hormone-major stimulator of postnatal somatic growth
2Insulin like growth factor
3Thyroid hormone as permissive to GH action
4Gonadal estrogen in both sexes.
5insulin
6cortisol |
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Term
|
Definition
| Increasing estrogens (aromatized from androgens), in combination with GH and IGF-1 are the causes |
|
|
Term
| Growth hormone deficiency-2 |
|
Definition
1. Prepubertally- dwarfism
-Decrease GH only
-defect in expression of GH receptors
-defect in IGF response to pubertal increase in GH
2. Adulthood- increased proportion of body fat
-decreased proportion of protein, muscle weakness |
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|
Term
|
Definition
1. Prepubertally-gigantism
2. postpubertally-acromegaly- CT proliferation (in children, accelerated tooth eruption and large jaw causing diastemas)
3.Cause- most often a pituitary tumor
4. Treatment- surgical removal of tumor; somatostatin |
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Term
| Anatomy of the Adrenal Gland-4 |
|
Definition
Cortex
Outer Zona glomerulosa-aldosterone
middle Zona fasciculata-Cortisol and androgens
inner Zona reticularis
Medulla-chromaffin cells secrete the catecholamines |
|
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Term
|
Definition
Secretes 3 classes of steroid hormones
Mineralcorticoids-(aldosterone)-and are essential in maintaining body fluid volume
Glucocorticoids(cortisol)- important in stress response and during fasting
androgens(DHEA and androstenedione) |
|
|
Term
| Fasciculata and Reticularis Zones |
|
Definition
| Pregnenolone is converted to cortisol, the most active glucocorticoid, the main adrenal androgen(DHEA) and the weak androgen Androstenedione |
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Term
|
Definition
catalyzes formation of adrenal androgens and is minimally active by age 8
-appearance of adrenal androgen secretion in children of both sexes is called adrenarche |
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Term
|
Definition
-doesnt possess the enzyme capable of cortisol and androgen synthesis
-produces the mineralcorticoid Aldosterone.
-Regulated by Angiotensin II, not ACTH!! |
|
|
Term
|
Definition
Congenital adrenal hyperplasia
-decreased aldosterone and Cortisol
-Increased androgen levels
-Ambiguous genitalia |
|
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Term
|
Definition
1. Stimulates gluconeogenesis and Lipolysis(increase blood glucose and FA)
2. Decrease glucose uptake in muscle and fat
3.Inhibits protein Synthesis
4. Maintains capillary CT integrity
5. Maintains vasomotor tone by maintaining sensitivity to NE
6.Anti-inflammatory at pharmacological levels
7. permissive to normal growth and cell function
8. inhibits bone formation by stimulating resorption and can lead to osteoporosis at high levels. |
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Term
|
Definition
1. Primary adrenal insufficiency of cortisol secretion(Addisons Disease). Increased ACTH
2. Secondary is an adrenocorticol insufficiency (decreased ACTH) as pituitary function is deficient
3. Symptoms include decreased fasting blood glucose, lipolysis
-hypotension
-hyperpigmentation in some cases of increased ACTH via increase in MSH |
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Term
|
Definition
(Cushings Syndrome)-caused by adrenal tumor, pituitary tumor, or ectopic (increased ACTH in lung cancer) tumor.
Symptoms include increased plasma glucose
-hypertension
-protein catabolism
-osteoporosis
-central obesity-buffalo hump, moon face
poor wound healing
-thin skin, easy bruising |
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|
Term
| Cortisol disorders and the dental patient-3 |
|
Definition
| Hypercortisolism causes increased infection susceptibility, periodontal disease and gums bleed easily |
|
|
Term
| Plasma calcium functions-6 |
|
Definition
1000 fold higher than inside cell
-nerve and muscle excitability
-coagulation of blood
-membrane permeability
-maintenance of tight junctions
-synaptic transmission
-functional integrity of bones and teeth |
|
|
Term
|
Definition
bone contains >99% of body Ca
Stable pool-slow exchange due to bone remodeling.
labile pool-rapid exchange from a readily available pool in the bone.
Remodeling of bone-2 processes, formation and resorption, that are precisely coupled |
|
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Term
|
Definition
By osteoclasts- activation require contact with OB's and which govern these processes by producing cytokines
-osteoclasts and their precursors express calcitonin receptors |
|
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Term
|
Definition
Osteoblasts form a continuous sheet on the surface of newly formed bone.
-express PTH and vitamin D3 receptors
-synthesize matrix proteins for forming bone
synthesize the cytokines that stimulate osteoclast differentation and activity |
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Term
|
Definition
| Quiescent osteoblasts deep within mineralized bone connected by canaliculi that contain calcium. |
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Term
| Sites of Calcium exchange-5 |
|
Definition
1. Extracellular fluid (Plasma + ISF)
2. GI tract- calcium is absorbed in SI, only 1/3 of ingested is absorbed.
3. Major determinant of net Calcium uptake is calcium absorption
4. Kidneys- Filter CA from plasma
5. Bone |
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Term
|
Definition
1. Serum phosphate levels vary widely throughout the day as its not tightly regulated.
2. In contrast to calcium, most of ingested phosphate is absorbed by GI tract
3. Renal phosphate reabsorption is primary site of phosphate homeostasis |
|
|
Term
|
Definition
1. Synthesized and secreted by chief cells of the PTgland
2. increases plasma Ca and decreases plasma Phosphate
3. Released in response to a decrease in plasma Ca
4. Acts on bone to promote osteocytic osteolysis, stimulates osteoclasts and requires permissive action of vitamin D
5. acts on kidney to increase ca reabsorption, and phosphate excretion
6. acts on intestine to increase absorption of calcium, but not directly.-completely mediated by vitamin D |
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Term
|
Definition
-Metabolized to 1,25(OH)2D (Calcitrol)
-functions on bone as permissive to PTH in increasing Ca reabsorption, in absence of PTH, need 30-100X as much vitamin D
-on gut to increase absorption of calcium by increasing synthesis of Ca-binding protein, calbindin
-kidney to increase calcium reabsorption. |
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Term
|
Definition
1. Secreted by the C cells(parafollicular) of the thyroid glands.
2. Decreases plasma Ca by decreasing bone resorption action of osteoclasts.
3.Released in response to an acute increase in plasma Ca
4. Physiologic role in humans is not clear-plasma Ca is well regulated after total thyroidectomy without Ca replacement therapy.
5. important for acute treatment of hyppercalcemia from excessive osteoclastic activity(Paget's disease) |
|
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Term
|
Definition
-essential for pubertal growth spurt in males and females
-High adult levels of E2 attained at the end of puberty causes closure of the epiphyses.
-decrease rate of bone loss by stimulating proliferation of OB's and inhibiting osteoblast cytokine production
-Decreases after menopause causing accelerated bone loss(osteoporosis) |
|
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Term
|
Definition
Primary-hypoparathyroidism(Low PTH and Ca)-autoimmune atrophy of PT glands
Secondary-Pseudohypoparathyroidism-(High PTH, Low Ca) PTH receptor defect, rare hereditary disorder
-Vitamin D deficiency(High PTH, low Ca)-inadequate enzymatic conversion to active form in kidney or liver; increase rate of metabolism of inactive form; insufficient sun/intake/absorption; receptor defect |
|
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Term
|
Definition
1. Osteomalacia(weak bones) in adults, rickets in children
2. Increased neuromuscular activity- hyperactive reflezes, tingling, muscle cramps, seizures, decreased myocardial contractility
3. Tetany-can cause death due to asphyxiation from laryngospasm |
|
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Term
|
Definition
1. Hyperparathyroidism-tumor of PT or ectopic tumor secreting PTH.
2. Vitamin D toxicity |
|
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Term
|
Definition
1. Predisposition to kidney stones
2. Decreased neuromuscular excitability
3. Neuropsychiatric disorders-depression, EEG abnormalities, memory impairment
4. Bone weakness, pain, fractures, abnormalities |
|
|
Term
| Disorders and management of dental patients with Calcium deficiency-2 |
|
Definition
1. Osteoporosis- loose teeth with alveolar bone weakening
2. Osteonecrosis of the jaw-death of alveolar bone from bone cancer or osteoporosis. bone cells in jaw can die during dental procedures-very rare, no treatment |
|
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Term
|
Definition
4kcal/g
-stored as glycogen in liver and muscle
-about 1 days needs |
|
|
Term
|
Definition
-9kcal/g
-stored as triglyceride in adipose tissue
-most abundant(75% of bodys energy stores) and most efficient energy source |
|
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Term
|
Definition
4kcal/g
-stored in muscle
-major source of blood glucose in fasting |
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|
Term
| The absorptive phase of metabolism-5 |
|
Definition
-4hrs
-reactions occure after a meal
-glucose is being absorbed from the GI Tract
-tissues can utilize glucose for energy
-characterized by FUEL STORAGE |
|
|
Term
| The Post-Absorptive Phase of metabolism-4 |
|
Definition
-Fasting - Reactions occur between meals
-liver and kidney begin gluconeogenesis to maintain a constant supply of plasma glucose for the brain.
-all other tissues switch to FA/Ketone metabolism
-characterized by FUEL UTILIZATION |
|
|
Term
|
Definition
synthesized and secreted by beta cells of the pancreatic islet of langerhans
-half life is 4-6mins
-30-70%is inactivated in the liver
-hormone of storage
-biphasic release pattern-1st is stored insulin, 2nd is newly formed
-brings about reactions of the absorptive phase
-receptor is similar to IGF-1, and has tyrosine kinase activity |
|
|
Term
|
Definition
-brings about absorptive phase, increase glucose uptake by cells (exc. CNS kidney medulla, RBC's, ex. muscle, and SI)
-Glut 4(muscle and fat) is translocated from an inactive intracellular pool into plasma membranes
-increased glycolysis, glycogen synthesis, TG synthesis, aa uptake, and protein synthesis
-Decreases glyc. breakdown, gluconeogenesis, TG breakdown, and protein catabolism |
|
|
Term
| Net Result of insulins Actions-2 |
|
Definition
Increased-glycogen, TG storage; protein synthesis
Decreased-Plasma glucose, FFA's and AA's |
|
|
Term
Control of insulin secretion
Stimulatory and Inhibitory |
|
Definition
Stimulatory-Increased-Plasma glucose, amino acids; Gut hormones, and parasympathetic activity
Inhibitory- Increased sympathetic activity; circulating epi or norepi |
|
|
Term
| Hormones opposing Insulin-4 |
|
Definition
1. Glucagon-pancreatic alpha cells(glycogenolysis, gluconeogensis, lipolysis)
2. epinephrine-adrenal medulla(glycogenolysis, gluconeogenesis, lipolysis)
3. Growth Hormone-anterior pituitary(lipolysis, gluconeogensis, decreased glucose uptake in cells)
4. Cortisol-adrenal cortex(lipolysis and gluconeogensis) |
|
|
Term
| Short term control of appetite factors-6 |
|
Definition
1. Condidtioned responses-learned behaviors and social cues
2. stress
3. palatibility of food
4. nutrient availability(blood glucose)
5. neuronal and hormonal gut signals-distension of gi tract, GI satiety peptides
6. increased body temp |
|
|
Term
| Long Term Control of Appetite-3 |
|
Definition
Insulin-signals adiposity and reduces appetite.
Leptin-secreted by adipose tissue, signals adiposity and feeds back on the brain to decrease appetite.
ghrelin-hormone secreted by stomach and GI tract that signals hunger |
|
|
Term
|
Definition
-Sritical site of integration for leptin and ghrelin; their receptors are expressed by two types of arcuate neurons
a. orexigenic (NPY)
b. anorexigenic (POMC) |
|
|
Term
|
Definition
| Increased Leptin-inhibits NPY neurons and stimulates POMC neurons- decreased food intake and increase energy expenditure |
|
|
Term
|
Definition
| Increased ghrelin-stimpulates NPY and inhibits POMC neurons- increased food intake and decrease energy expenditure |
|
|
Term
|
Definition
10%
-insulin dependent
-no insulin synthesis
-beta cells destroyed by autoimmune mechanism
-children and young adults mostly |
|
|
Term
|
Definition
-Insulin Independent
-usually adults
-linked to obesity and overeating.
-may lead to type I like diabetes due to exhaustion of beta cells
-reversible with diet and exercise
-insulin not problem, the receptors are insensitive with the exorbitant amount of insulin in blood |
|
|
Term
|
Definition
-increased plasma glucose
-glucosuria(in urine)
-polyuria (increased urine volume)
-cellular dehydration due to water loss-can lead to decreased blood volume and circulatory failure
-polydipsia- constant thirst
-increased plasma FFA(atherosclerosis)
-increased ketones
-neuropathies due to demyelination |
|
|
Term
| diabetic complications in dental patient-2 |
|
Definition
-more at risk for periodontal disease, gingivitis, poor wound healing
-be aware of change in blood sugar under stressful conditions |
|
|
Term
| Functions of the male reproductive system-6 |
|
Definition
1. Spermatogenesis- produce gametes
2. Steroidogenesis- produce the andrgoens, testosterone and dihydrotestosterone(DHT) for:
a. maintenance of reprod. system
b. secondary sex
c. libido
d.behavior |
|
|
Term
| Differnetation of the Testis-6 |
|
Definition
1. Y chromosome regulates testis development between 6-8 wks of gestation
2. depends on Sex determining Region of Y chromosome (SRY) gene
3. By 8 weeks, fetal Leydig cells in response to hCG produces testosterone
4. Testosterone stimulates maturation of Wulfiaan ducts-epididymis, vas deferens, seminal vesicles, and ejaculatory ducts.
5.Mullerian Inhibiting Hormone from Sertolli cells causes regression of Mullerian Ducts
6. In absence of SRY gene and testosterone, undifferentiated gonads develop into ovaries |
|
|
Term
| Development of External Genitalia-4 |
|
Definition
1. 9-12 wks gestation
2. 5-alpha-reductase in tissues convers T into DHT
3. DHT causes formation of prostate, penis, scrotum from fetal undifferentiated genitalia
4. in absence of DHT, labia, clitoris, and lower 2/3 of Vagina are formed |
|
|
Term
|
Definition
-Adluminal compartment is isolated from the blood and is immunologically privileged.
-blood-testis barrier protects developing sperm
-regulated by FSH and High T in the seminiferous tubules
-begins at puberty and decreases with age
-Spermatogonia, primary and secondary spermatocytes, spermatids, spermatozoa |
|
|
Term
|
Definition
-Nourish germ cells
-form blood testis barrier
-secrete androgen binding protein(binds T therefore increasing levels), MIH, inhibin(decreases FSH), and estradiol(via aromatization of androgens)
-regulated by FSH
-analogous to granulosa cells in ovary |
|
|
Term
|
Definition
1. Analogous to thecal cells
2. androgen biosynthesis(androstenedione and testosterone)
3. regulated by Lh (in fetus by hCG)
4. Pubertal increase initiated by rise in pulsatile GnRH |
|
|
Term
|
Definition
Differentation of male internal and external(DHT) genitalia in fetus
-growth, development, function of male reproductive tract
-secondary sex
-anabolic effects
-pubertal growth spurt and closure of epiphysis
-spermatogenesis
-libido and behavior
neg. feedback on GnRH and LH secretion |
|
|
Term
| Testosterone metabolism-8 |
|
Definition
-In some peripheral tissues, T acts via conversion to 1.DHT by 5-alpha reductase
a. Type 1-skin and scalp
b. Type 2-external genitalia
2. estradiol by aromatase
a. epiphysis of long bones
b. CNS
c. pituitary |
|
|
Term
| Control of Testicular function-2 + 5 |
|
Definition
1. Neg Feedback
a. T, DHT, and E
b. Inhibin
2. Temperature-35C
a. cryptorchidism-7 wks gestation
b. normal leydig and sertoli cells, damaged germinal epi
c. predisposition to cancer if not corrected soon |
|
|
Term
| Hypogonadotropic/ Hypogonadism-4 |
|
Definition
a. panhypopituitaryism-decrease LH and FSH
b. hypoprolactinemia-inhibits GnRH
c.Excess androgens of non testicular origin-(decreased LH)
d. Kallmann's Syndrome-Defect in GnRH neurons |
|
|
Term
| Hypogonadotropic/ Hypogonadism-4 |
|
Definition
a. panhypopituitaryism-decrease LH and FSH
b. hypoprolactinemia-inhibits GnRH
c.Excess androgens of non testicular origin-(decreased LH)
d. Kallmann's Syndrome-Defect in GnRH neurons |
|
|
Term
|
Definition
1. Failure of GnRH neurons to migrate out of olfactory placode in development
2. decreased GnRH secretion
3. delayed puberty and short stature
4. Low plasma LH, FSH, and T
5. Small Testis and low Spermatazoa
6. Often associated with loss of smell(anosmia) |
|
|
Term
| Hypergonadotropic/Hypogonadism-2 |
|
Definition
-Sertolli cell only syndrome
-Androgen insensitivity syndrome |
|
|
Term
| Sertoli cell only syndrome-5 |
|
Definition
Damaged sertoli cells
normal Leydig Cells
-LH and T are normal
Very high FSH since no inhibin
No spermatogenesis |
|
|
Term
| Andorgen insensisitivity Syndrome-8 |
|
Definition
1.Defect in androgen receptors, or their function
2. testicular ferminization syndrome
3. female external genitalia
4. internal genitalia-testis with no ducts
5. high or normal pubertal development
6. no facial, axillary, or pubic hair
7.increased LH, T and E(in breast)
8. Normal FSH |
|
|
Term
|
Definition
Cortex-contains all the germ cells, each enclosed in a follicle, corpora lutea and stroma
-medulla-stromal cells
-hilum-site of entry of blood vessels and nerves
-follicle-the fundamental reproductive unit. consists of a germ cell surrounded by a sphere of endocrine cells |
|
|
Term
|
Definition
Oogenesis-to develop the female gametes
-to secrete the hormones required to maintain the reproductive system and the fetus until it can survive alone
-secrete estrogens, progestins, and androgens |
|
|
Term
|
Definition
Oogenesis-to develop the female gametes
-to secrete the hormones required to maintain the reproductive system and the fetus until it can survive alone
-secrete estrogens, progestins, and androgens |
|
|
Term
|
Definition
1. Begins 5/6th week of fetal life, once germ cells can migrate to genital ridge
2. primordial germ cells undergo mitosis to produce oogonia.
3. Mitosis ends in seventh month, when oocyte numbers are maximal.
4. produces primary oocytes
5. first meiotic division starts in utero, but arrested in prophase until just before a given oocyte ovulates |
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Term
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Definition
1. Resumption is triggered by a preovulatory LH surge
2. first polar body is extruded
3. secondary oocytes are ovulated about a day later
4. arrested until fertilization occurs
5.if fertilization occurs, it triggers completion of the 2nd meiotic division
6. 2nd polar body is extruded |
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Term
| Germ Cell Population with age-7 |
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Definition
-. Oocytes degenerate-atresia
-. occurs at any stage
-max number is 7 million at 20 wks of fetal life
-only 2 million left at birth
-at onset of puberty, only 400k left
-about 400 are ovulated from 15-50 years
-few if any left at menopause |
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Term
| Folliculogenesis-Hormone Independent Stage-4+2 |
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Definition
1. as each primary oocyte is formed, a single layer of cells surrounds it, forming a primary follicle
2. the layer of cells are the granulosa cells that secrete estrogen and inhibin
3. primordial follicles are dormant
4. entry into the growing pool
a. no hormonal support
b. oocyte grows and acquire zona pellucida to form a primary follicle |
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Term
| Folliculogenesis-Hormone Dependent Stage-5 |
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Definition
1. Granulosa cells multiply-follicle grows
2. FSH is required for formation of an outside layer of theca cells
3. LH and FSH post pubertally stimulate antrum formation
4. Graafian Follicle
a. fully mature
b. one per cycle
5. Ovulation
a. caused by Lh and FSh surge
b. results in extrusion of oocyte and cumulus granulosa cells into peritoneal cavity. |
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Term
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Definition
1. Differentiates from the ruptured follicle after ovulation
2. secretes estrogens, inhibin, and progesterone
3. lasts-14 days in a non fertile cycle after which it undergoes regression, or luteolysis
4. LH-dependent
a. formed by LH surge
b. sustained by basal luteal phase LH levels
5. LH receptors gradually decrease
6. if pregnancy occurs, hCG, secreted by the trophoblast, rescues the CL |
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Term
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Definition
1. Biosynthesis begins with cholesterol
2. 1st, or rate limiting step is catalyzed by P450scc
3. Estradiol, the major estrogen secreted by the granulosa cells, aromatized from thecal androgen
4. progesterone-secreted by CL-used as an indicator that ovulation has occured
5. Androstenedione and testosterone
a. secreted by thecal and interstitial cells
b. majority aromatized to estradiol by the granulosa cells
c. growth of pubic and axillary hair and libido |
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Term
| 2 cell, 2-hormone mechanism for steroid biosynthesis-4 |
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Definition
1. LH acts on theca cells to stimulate androstenedione synthesis
2. Androstenedione diffuses to granulosa
3. FSH stimulates aromatase, which causes conversion of androstenedione to estradiol(E2)
4. E2 stimulates E2 and FSH receptors, antrum formation, and LH receptors on granulosa cells of preovulatory follicles |
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Term
| Reproductive functions of Estradiol-5 |
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Definition
1. Causes secondary sex characteristics
2. growth and maintenance of female reproductive tract and accesory tissues
3. increases contractility of oviducts and uterus
4. increases P receptors in brain, uterus, oviduct and FSH, LH, and E receptors in ovary
5. Positive and negative feedback actions on LH and FSH secretion |
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Term
| Non-Reproductive functions of Estradiol-4 |
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Definition
1. stimulates bone growth
2. decreases bone resorption
3. protects against heart disease by decreasing serum cholesterol, increasing HDL and Lowering LDL
4. enhances learning and memory |
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Term
|
Definition
1. Indicator of ovulation
2. increases basal body temperature
3. decreases contractility of oviducts and uterus and uterine response to oxytocin
4. increases secretion of uterine glands
5. neg. feedback action on LH and FSH
6. inhibits positive feedback action of estradiol |
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Term
| Control of steroid hormone secretion-5 |
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Definition
1. Higher centers-NE, epi, DA, opiods, etc modulate GnRH
2. GnRH neurons
a. project from hypothalamus to median eminence
b. stimulates both LH and FSH synthesis and secretion
c. transport of GnRH to ant pituitary via portal capillaries |
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Term
| Feedback Control of LH/FSH Secretion-4 |
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Definition
1. inhibited by neg. feedback action of estradiol and progesterone
2. Preovulatory LH/FSH surges
a. stimulated by pos. feedback action of estradiol-a sustained rise lasting 2 days-on the HPA
b. inhibited by progesterone |
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Term
|
Definition
1. Begins at puberty
2. ends at menopause
3. 28days in length
a. day 1-1st day of menses
b. day 14-ovulation
4. Follicular Phase
a. days 1-14
b. final stages of follicular maturation
c. ends at ovulation
d. most variable phase
e. proliferative phase in uterus |
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Term
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Definition
Days 1-6
-Basal concentrations of LH and FSH decrease due to negative feedback action of estradiol
-basal estradiol levels exert maximal feedback action on LH and FSH
-Progesterone levels are virtually undetectable in absence of CL |
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Term
|
Definition
Days 7-13
-final maturation of a dominant follicle causes exponential increase in estradiol
-increasing estradiol and inhibin levels exert neg. feedback action causing decline in circulating FSH
-LH levels remain low due to neg. feedback action of basal estradiol levels |
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Term
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Definition
Day 14
-Positive feedback action of estradiol induces preovulatory LH and FSH surges
-Lh/FSH surge causes ovulation after 24-36 hours
-estradiol levels decrease
-LH/FSH surge cause luteinization of follicle |
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Term
|
Definition
Days 14-28
1. From ovulation-menses
2. characterized by formation of corpus luteum
3. Increased progesterone is primary indicator of ovulation and luteal function
4. secretory phase in uterus
5. least variable phase
6. absence of fertilization, regression of CL causes fall in E2 and P, leading to menstration and start of new cycle. |
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Term
| Pregnancy-Ovum transport-4 |
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Definition
1 At ovulation, the ovum is released into the abdominal cavity
2. estradiol increases ciliary movement (drawing ovum into oviduct) and increases Sm. musle contractions.
3. Ovum is viable for a day
4. sperm (3 day viability) must traverse vaginal Ph, cervical mucus, and utero-tubal junction |
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Term
| Pregnancy-Zygote transport-4 |
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Definition
1. Site of fertilization is the ampulla, or upper 1/3 of oviduct
2. sperm can arrive at the site of fertilization within 5 minutes
3. takes 3-5 days to transport zygote to uterus
4. zygote floats free in the uterus for 4 days |
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Term
| Pregnancy-Hormonal Events-7 |
|
Definition
1. Implantation occurs about 7-9 days after ovulation
2. Trophoblast secrets hCG. an LH like hormone that rescues the CL
3. hCG stimulates E and P secretion by the CL
4. The placenta takes over E and P for remainder of pregnancy
5. Placenta-hCG + hPL(GH like)
6. Progesterone plasma levels are high throughout pregnancy
7. Estradiol plus progesterone- maintains uterus
a. synergize to help mammary glands in prep for lactation
b. stimulate prolactin production
c. exert neg. feedback on LH and FSH |
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Term
| Pregnancy-Signal for parturition-4 |
|
Definition
1. Complex combination of events, no one signal
2. stretch of uterin smooth muscle causes contraction
3. increased fetal adrenal steroids and prostaglandins
4. Oxytocin-increases stretch of cervix
a. neuroendocrine reflex causes increase in Oxytocin that increases uterine contractions |
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Term
|
Definition
1. Neuroendocrine reflex-Triggered by suckling that increases rate of firing of oxytocin neurons in supraoptic and paraventricular nuclei of Hypo.
2. increased oxytocin release causes contraction of myoepithelial cells in alveoli = milk let down
3. increased prolactin via inhibition of DA adjusts amounts of milk synthesized to intensity of suckling
4. increased prolactin also suppresses gonadotropin secretion |
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