Term
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Definition
Three types of fibers
Most muscles are mix of types
Birds that fly more (red breast meat)
Genetic basis
Proportion can be modified
Impact of use/disuse |
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Term
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Definition
• 1. Slow-oxidative: low ATPase
• 2. Fast-oxidative-glycolytic: high ATPase
• 3. Fast-glycolytic: high ATPase, high glycolytic |
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Term
| Most muscles are mix of types |
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Definition
• Increase in oxidative = red
• Increase in glycolytic = white |
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Term
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Definition
• Change muscle structure and/or function
• Disuse = atrophy (disease too)
• Use = hypertrophy |
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Term
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Definition
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Term
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Definition
• Increasing vascularization
• Incrasing the number of mitochondria
• Decrease in fatigue |
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Term
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Definition
• Increase myofiber diameter
-- Increasing size not amount
-- (increase myofilament number)
• Increase in glycolytic enzymes |
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Term
| Controlling body movement |
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Definition
Motor commands originate in motor cortex
Voluntary movement: similar to reflex
Muscles only stimulated,must work in pairs
Proprioception: sensory system
Spinal reflex: “Involuntary” contraction |
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Term
| Motor commands originate in motor cortex |
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Definition
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Term
| Muscles only stimulated,must work in pairs |
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Definition
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Term
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Definition
sensory system
Info: load and body position
Stretch receptors
Afferent signal to.. |
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Term
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Definition
o Muscle spindle
o Golgi tendon organ |
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Term
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Definition
o Brain
o Local reflex circuits |
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Term
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Definition
“Involuntary” contraction
• Local circuits = Afferents → interneurons → motor neurons
• Example: knee-jerk response
• increase complexity, both sides
• Example: withdrawal response |
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Term
| Example: knee-jerk response |
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Definition
o Stretch patellar ligament
o Stretch receptor input to spinal cord
o Positive input to CNS
o Positive input to extensors
o Negative input to flexor
• (via interneuron) can’t inhibit the muscle itself |
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Term
| Example: withdrawal response |
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Definition
o Pain in foot → spinal cord
o Interneurons in cord
o Result = coordinated moving of body away from painful stimulus |
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Term
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Definition
• I extensor; S flexor
• S contralateral extensors
• I contralateral flexors
• Send input to brain |
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Term
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Definition
Locations
Characteristics
Myofilaments
Contraction
Relaxation |
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Term
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Definition
lines the
• Digestive tract
• Blood vessels
• Urogenital ducts
• Glands |
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Term
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Definition
• Not striated; layered
• Autonomic ( + and - )
• Myofilament arrangement |
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Term
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Definition
• Myosin and actin
• Thick and thin but |
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Term
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Definition
o Thin attach to dense bodies (opposed to z lines)
o Thick lie between thins
o Cells often linked by gap junctions
•-- Synchronize contractions |
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Term
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Definition
| • Increase of [Ca+2] intracellular |
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Term
| Increase of [Ca+2] intracellular |
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Definition
o Autonomic, endocrines, chemical, stretch, pacemaker (metronome)
•-- No troponin in smooth
o Ca+2 activates calmodulin (9-34)
•-- Active calmodulin can activate key enzyme
o Activates myosin light chain kinase
o Phosphorylates myosin
o Cross-bridge formation
o Cross-bridge cycling |
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Term
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Definition
• Decrease in [Ca+2]
• Increase myosin light chain phosphatase
o-- Phosphatase removes phosphate
•---- Any heads with a phosphate, we wanna it to be unphosphorylated and they can’t bind
• No cross bridge |
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Term
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Definition
The other communication system
Pathway
Endocrine/hormone |
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Term
| The other communication system |
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Definition
• Blood-carried signals
• Widespread effects
• Regulated by feedback mechanisms
• Speed? Endocrine << Neural
o Give up speed for widespread effects |
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Term
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Definition
| • Glad (neuron) → release endocrine/hormone →effector |
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Term
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Definition
• Differ in:
TYPE
MECHANISM OF ACTION |
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Term
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Definition
• Amine endocrines
• Peptide endocrines |
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Term
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Definition
Derived from tyrosine (C ring)
Examples
•-- T3 and T4 (Thyroid gland)**
•-- Dopamine (hypothalamus)
•-- Norepinephrine and epinephrine (Adrenal medulla) |
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Term
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Definition
Synthesized as prohormone = inactive form
Packaged into secretory vesicles
•-- Processed into endocrine
•-- Stored
Released on demand
Examples
•-- Insulin
•-- Hypothalamic releasing hormones
•-- Pituitary endocrines |
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Term
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Definition
• Endocrines are ligands
• Spots for disruption (↑ or ↓) |
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Term
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Definition
Hydrophilic: Activate a 2nd messenger system, must bind to a plasma receptor
Hydrophobic: Activate DNA transcription |
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Term
| Spots for disruption (↑ or ↓) |
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Definition
Endocrine synthesis/release
Receptor expression
Alter clearing = catabolism and/or excretion |
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Term
| Regulation of secretion based on… |
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Definition
[Substances] in plasma
Neurotransmitters
Other endocrines |
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Term
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Definition
Ions (i.e. Ca2+)
Nutrients (i.e. glucose) |
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Term
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Definition
ACh stimulates the adrenal medulla
Hypothalamic neurons receive input from other neurons |
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Term
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Definition
| Ex: Pituitary endocrines stimulate other glands |
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Term
| Hypothalamus (surrounds 3rd ventricle) |
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Definition
• Contains neurons that release endocrines
• “Master gland” (many people call the pituitary the master gland, but the hypothalamus is more appropriately named it because it controls the pituitary)
• Two distinct ways to release endocrines to pituitary gland |
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Term
| Pituitary gland (hypophysis) |
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Definition
• Connected by the pituitary stalk, or infundibulum
• Two divisions |
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Term
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Definition
Anterior (adenohypophysis) (FIGURE 11-16)
Posterior (neurohypophysis) (FIGURE 11-13) |
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Term
| Anterior (adenohypophysis) (FIGURE 11-16) |
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Definition
• Via portal vasculature
• Seven endocrines (hypophysiotropic) |
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Term
| Posterior (neurohypophysis) (FIGURE 11-13) |
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Definition
• Via terminals of hypothalamic neurons
• All endocrines released from here are actually made in the hypothalamus; there’s a push to make the neurohypophysis be part of the hypothalamus instead of the pituitary because of this
• Two endocrines |
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Term
| Communication overview: Chain of events |
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Definition
• Stress = neural input
• Hypothalamus (endocrine 1)
• Pituitary gland (endocrine 2)
• Gland (endocrine 3)
• Effector (target organ/cells)
• FIGURE 11-18 has a good table describing this for specific endocrine pathways
• Why all this complexity? |
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Term
| Effector (target organ/cells) |
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Definition
| Regulation occurs; each endocrine exerts negative feedback on the others before it |
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Term
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Definition
Benefits
• Many opportunities to regulate (+ or –)
• Amplification
o-- Fewer endocrine 1 to many endocrine 3 |
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Term
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Definition
Hypothalamus --> hypophysiotropic endocrines
Transmission? To adenohypophysis via portal veins
Posterior pituitary endocrines |
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Term
| Hypothalamus --> hypophysiotropic endocrines |
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Definition
• Stimulate (5)
• Inhibit (2) |
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Term
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Definition
o CRH (cortiocotropin-releasing hormone) --> ACTH (adrenocorticotropic hormone)
o TRH (thyrotropin-releasing hormones) --> TSH (thyroid stimulating hormone)
o GHRH (growth hormone releasing hormone) --> GH (growth hormone)
o GnRH (gonadotropin releasing hormone) --> LH (luteinizing hormone) and FSH (follicle-stimulating hormone)
o PRF (prolactin releasing factor) --> prolactin |
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Term
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Definition
o SS (somatostatin) -->x GH
o DA (dopamine) --> x prolactin |
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Term
| Transmission? To adenohypophysis via portal veins |
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Definition
| • Anterior pituitary hormones |
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Term
| Anterior pituitary hormones |
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Definition
o ACTH --> adrenal cortex --> cortisol secretion
o TSH --> thyroid --> T3 and T4
o GH --> liver, plus others --> IGF-1 (insulin-like growth factor-1)
o FSH and LH --> gonads --> sex hormones
o Prolactin --> mammary gland --> ↑breast tissue, milk
o Beta-lipotropin --> ???
o Beta-endorphin --> ??? |
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Term
| GH --> liver, plus others --> IGF-1 (insulin-like growth factor-1) |
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Definition
| • Impacts on many other organs and tissues --> protein synthesis, carbohydrate and lipid metabolism |
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Term
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Definition
• We don’t know the endocrine that produces this and beta-endorphin
• We also don’t know where they lead and what they do in humans
• For other mammals, this puts fats into circulation |
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Term
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Definition
| • Activated as a painkiller |
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Term
| Posterior pituitary endocrines |
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Definition
• Actually made in hypothalamus and travel to neurohypophysis via neuronal axons (through infundibulum)
• Specific endocrines |
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Term
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Definition
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Term
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Definition
• Involved in lactation and labor and contraction (for females)
• What does it do in males?
We know it’s circulating, but we don’t really know what its doing
However it also acts as a neurotransmitter; it seems to allow us to have social interactions |
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Term
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Definition
• Also called anti-diuretic hormone (ADH)
• Its release alters kidney permeability so that the body conserves water. In high quantities it also raises BP
• Also has been found to act as a neurotransmitter to influence prosocial behavior and bonding
• Transmission: hypothalamus --> influibium? --> posterior pituitary gland 11-13 |
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Term
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Definition
Thyroid gland
Adrenal cortex |
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Term
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Definition
• Located in throat area in two lobes (on either side of the larynx)
• Composed of a structure called a follicle; composed of follicular cells
• Active in fetus
• Thyroid hormones (TH) |
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Term
| Composed of a structure called a follicle; composed of follicular cells |
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Definition
o A follicle is a group of spherical cells that form a cavity
o Their job is to form the boundary of the structure
o Colloid is the fluid inside the structure (extracellular!)
• No free movement
• Tight junctions
o However it’s very controlled, which is why we don’t just call it interstitial fluid |
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Term
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Definition
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Term
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Definition
o T3 (triiodothyronine): Most active form
o T4 (thyroxine): Most abundant in circulation, tends to travel a little better
o These are the most current names for them
o Production
o Nuclear receptors: In most cells
o Metabolic effects
Disorders |
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Term
| T4 (thyroxine): Most abundant in circulation, tends to travel a little better |
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Definition
• # indicates number of iodines
• Most effectors can change this into T3 on site as well
• T4 most easily transported |
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Term
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Definition
• Follicular cells have receptor cells for TSH
• TSH stimulates T3/T4 production in colloid (produced extracellularly—rare!)
• TH then inhibits TSH and TRH |
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Term
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Definition
• Stimulate metabolism (generating heat) eq.2
• Enhance use of metabolic fuels
• Promote effects of sympathetic NS
• Neural development
• Promote effects of Growth hormone |
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Term
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Definition
• Most common endocrine system disease
• Too little or too much
• Hypothyroidism: Iodine deficiency (little T3/4 production)
• Hyperthyroidism: Too much iodine |
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Term
| Hypothyroidism: Iodine deficiency (little T3/4 production) |
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Definition
Not a problem for U.S. because we fortify food with iodine
Can also be an autoimmune disorder
No negative feedback from TH
Symptoms |
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Term
| No negative feedback from TH |
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Definition
• Excess TSH secreted
• Overstimulated follicular cells
• Enlarged gland (called a goiter)
• In other cultures these are present in entire communities |
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Term
|
Definition
• Cold intolerance
• ↑ weight/body fat
• ↑ fatigue |
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Term
| Hyperthyroidism: Too much iodine |
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Definition
Commonly called Grave’s Disease, autoimmune)
Antibodies activate TSH receptor on antibody cell
Symptoms |
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Term
| Antibodies activate TSH receptor on antibody cell |
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Definition
• ↑ TH production
• But negative feedback ineffective
• Enlarged gland (also a goiter) |
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Term
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Definition
• Heat intolerance
• ↓ weight/fat
• ↑ sympathetic NS activation |
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Term
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Definition
• Adrenal gland sits atop the kidney
• Production: CRH --> ACTH --> corticosteroid
• Actions: Mediates stress
Disorders |
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Term
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Definition
o Back when we were evolving, “stress” was not having food
o Metabolic endocrine, main impact on liver
o ↑ vascular smooth muscle response to EPI
o Anti-inflammatory: Inhibits immune response
o Negative feedback on growth and reproduction |
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Term
| Metabolic endocrine, main impact on liver |
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Definition
• ↑ glucose utilization
• Breakdown of fat and protein (and then bone) (!) |
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Term
|
Definition
o No cortisol? Dead within days
o Adrenal insufficiency: Addison’s Syndrome |
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Term
| No cortisol? Dead within days |
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Definition
| • We don’t know exactly why it is that eliminating cortisol results in death, but clearly it is essential for normal functioning |
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Term
|
Definition
Addison’s Syndrome
• Weakness, ↓ glucose, ↓ BP |
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