Test 2 Study Guide Part 4 Flashcards
Weak androgens (cortical):
- Produced from:
- Function:
- Specific name:
- Produced from: zona reticularis - Function: in males unknown in females thought to contribute to sex drive (only source of androgens) - Specific name: androstendione testosterone
Mineralocorticoids:
- Produced from:
- Function:
- Specific name:
- Produced from: zona glomerulosa - Function: regulate mineral concentrations in the blood (Na+ and K+) - Specific name: Aldosterone
Glucocorticoids:
- Produced from:
- Function:
- Specific name:
- Produced from:
zona fasciculata - Function:
Raise blood glucose concentration. Gluconeogenesis of amino acids into glucose.
Break down proteins and stimulates lipolysis - Specific name:
Cortisol or hydrocortisone
What are exogenous glucocorticoids taken for?
Suppress the immune system and inhibit inflammation.
Helps to treat asthma and autoimmune disease
Negative sideaffects: include decreases ECM matrix protein synthesis, osteoporisis (from this), and hyperglycemia
Adrenal Medulla:
- Ratio of hormones:
- Duration of effects in comparison to sympathetic innervation:
- Ratio of hormones:
4 epinephrine to 1 norepinephrine - Duration of effects in comparison to sympathetic innervation:
Lasts 10x as long as sympathetic duration
What meets the metabolic needs of the sympathoadrenal system?
Norepinephrine and epinephrine cause release of glucose form the liver
Who is Hans Selye?
Hans Selye discovered GAS and the stress response
GAS:
- Stands for:
- Phases:
- Stands for:
General adaption syndrome - Phases:
Phase 1: ALARM, body mobilizes resources
Phase 2: RESISTANCE, body copes with stressor
Phase 3: EXHAUSTION, all reserves expended, sickness and death can result
Stressor define:
a deviation from homeostasis
Name positive stressor:
Name negative stressor:
Eustress
Distress
What stimulates the hypothalamus to increase its release of corticotropin releasing hormone (CRH) thereby leading to stress?
What inhibits release of corticotropin releasing hormone?
Limbic system (prefrontal cortex, amygdala, and hippocampus) which regulate responses through the hypothalamus, medulla oblongata, and spinal cord
In rodents what effect did eustress have on illness recovery?
Faster recovery times.
Effects of chronic stress:
atrophy of hippocampus (memory loss)
Promote tumor growth
Insulin resistance
can contribute to metabolic syndrome
Effect of acute stress on memory:
Increases long term potentiation (LTP) promoting memory
Effect of chronic stress on memory:
Decreases long term potentiation (LTP) decreasing memory
Stress hormones potential effect on the amygdala:
Believed that stress can contribute to anxiety and depression by acting on the amygdala and other systems. It is also believed this may help encode a fearful memory.
Metabolic effects of glucocorticoids:
- Effect:
- Condition exasperated by it:
- Metabolic syndrome:
- Effect:
Gluconeogenesis, catabolism of amino acids and fatty acids to build glucose (which is a faster access energy source, the body is preparing) - Condition exasperated by it:
Type 2 diabetes mellitus (because of increased insulin resistance) - Metabolic syndrome:
involves central obesity (apple in the middle of body) and more!
Type 2 diabetes mellitus:
- Cause:
- Cause:
Body becomes ‘resistant’ to insulin. Cells do not use it as well as they should.
What are glucocorticoids antagonistic to?
Glucocorticoids are catabolic steroids.
They are antagonistic to anabolic steroids such as insulin (exasperate insulin resistance) and growth hormone
What are the two functional sections of the thyroid?
broadly: follicles (which contain colloid spaces within them) and parathyroid
glands (secretes calcitonin)
Isthmus:
A narrow strip of land with sea on either side ;)
But also the thin middle section between the two lobes of the thyroid.
Follicle define:
small secretory cavity, gland or sac
What is the interior of a thyroid follicle called?
The colloid space.
Name two functions of the colloid of the thyroid follicles:
Provides a local for the accumulation of iodine.
Has a source of thyroglobulin, which binds to tyrosine as it it is turned into T3 and T4.
Thyroglobulin also holds onto T3 and T4 until it is hydrolyzed from them.
Describe what happens within the thyroid follicles:
Inside the colloid: Thyroglobulin binds tyrosine -> Iodine can be attached -> monoiodotyrosine (MIT) -> Iodine can be attached -> diiodotyrosine (DIT) These can be combined to make MIT + DIT = triiodothyronine (T3) DIT + DIT = tetraiodothyronine (T4)
Basal metabolic rate (BMR):
the minimum amount of energy that your body uses to function (how much cellular energy is being utilized)
What effect does T3 have within the cell?
Stimulates the basal metabolic rate of your body (increases rate of cellular respiration)
In what way is thyroid gland adaptive for the temperature of the environment you are in?
If you are in a colder environment, the thyroid gland can increase secretion of T4 and T3, increasing your basal metabolic rate and providing more energy to warm your body.
What is secreted by the parathyroid glands:
What is its function:
How important is it to human physiology?
What is secreted by the parathyroid glands:
Calcitonin
What is its function:
It removes calcium from the body. Stopping Ca2+ depossition and stopping reuptake of Ca2+
How important is it to human physiology?
Minimal. Calcitonin is easily nullified by other features of the body (kidney’s become resistant to it after a time)
What causes iodine-defiency (endemic) goiter:
Low iodine results in low levels of T4 production. Since thyroxin (T4) normally inhibits production of Thyroid-stimulating hormone, we see over expression of TSH
TSH causes hypertrophy of the thyroid gland, to increase its ability to act, which results in a goiter in the neck.
Hypothyroidism:
- Symptoms (and why):
- Symptoms (and why):
Lethargy (low cellular respiration), weight gain (low basal metabolism), poor ability to adapt to cold stress (low BMR produces less heat)
Sever hyperthyroidism:
Results in myxedema. Mucoproteins (glucosaminoglycans) and fluid accumulate in the viscera causing swelling of hands, feet, face, and tissue around eyes.
It can cause slowing of physical and mental activity, profound lethargy and even a myxedema coma.
What are four possible causes of hypothyroidism:
Gland defect in thymus.
Inadequate release of thyroid stimulating hormone (TSH) by adenohypophysis
Inadequate release of thyroid releasing hormone by hypothalamus
Insufficient iodine in diet
Cretanism:
A condition caused by inadequate iodine in a baby. Results in severe mental retardation. It can also result in dwarfism.
Parathyroid hormone:
- Effect:
- Regulation:
- Import:
- Effect:
Causes release of Ca2+ from the bones, kidney’s to conserve Ca2+, and the small intestine to intake more Ca2+ - Regulation:
Increased blood Ca2+ has an inhibitory (neg. feedback) effect on the parathyroid hormone - Import:
This is the major modulator of Ca2+ levels in the body
What is the effect of deficient parathyroid hormone?
Hypocalcemia (Adequate Ca2+ will not be absorbed in small intestine, released from the bones, and
Why can hypocalcemia cause hypocalcemic tetany?
Low Ca2+ levels decreases the threshold for firing an action potential. Increased action potentials firing causes a lock up of the muscles.
Acinar cells:
- Location:
- Function:
- Location:
Pancreas - Function:
Produce the exocrine, digestive glandular product
Pancreatic beta cells produce:
Pancreatic alpha cells produce:
Pancreatic beta cells produce:
Insulin
Pancreatic alpha cells produce:
Glucagon
Insulin:
- Produced by:
- Function:
- Unique:
- Produced by:
Beta cells of the pancreas - Function:
Insulin increases glucose uptake by liver and muscles (Secondary messenger system initiates binding of GLUT4 carrying vesicles)
Increases activity of glycogen synthase (which is how glucose is stored into glycogen) - Unique:
only known hormone to decrease blood glucose levels.
Glucagon:
- Produced by:
- Function:
- Regulation:
- Produced by:
Pancreatic alpha cells - Function:
Causes glucose to be taken from the glycogen stores of the liver
Lypolysis promoted
Ketogenesis promoted (glucagon is a starvation catabolic hormone) - Regulation:
Activated by low blood glucose (sustains you in the absence of meal)
Pituitary gland:
- Two major connection points to the brain:
- Most active during the day or night?
- Two major connection points to the brain: Suprachiasmatic nucleus Sympathetic nervous system - Most active during the day or night? Night
Retinohypothalamic tract:
Retinohypothalamic tract entrains the circadium rhythm of the brain. The suprachiasmatic nucleus is located in the retinohypothalamic tract.
Melanopsin is used specifically for detection of light levels.
Melatonin:
- Gonodotropic (female):
- Over the lifespan:
- Gonodotropic (female):
may be inhibitory, you may have a delayed onset of puberty with excessive melatonin secretion - Over the lifespan:
Melatonin levels drop off over your lifespan
Seasonal Effective Disorder:
- Alternative name:
- Treatment:
- Alternative name:
Winter Depression - Treatment:
Bright light (stimulate melanopsin which is believed to related to the depression in some way)
Gonads:
- Major androgen of testes:
- Major secretion of ovaries (2):
- Major androgen of testes:
Testosterone - Major secretion of ovaries (2):
Estrogens (estradiol-17beta) and progesterone (which comes solely from the ovaries and placenta)
Placenta (as a endocrine gland):
- Placenta specific hormones:
- Placenta specific hormones:
Human Chorionic Gonadotropin (hCG, this is what a pregnancy is searching for)
Somatomammotropin: similar in action to growth hormone and prolactin
Paracrine define:
Autocrine define:
Paracrine define:
A ligand is produced by a cell, it diffuses through the ECM and effects a neighboring cell of a DIFFERENT type
Autocrine define:
A ligand is produced by a cell, it diffuses through the ECM and effects a neighboring cell of the SAME type
Most diverse group of paracrine regulators?
Prostaglandins
