BIOL 261 FINAL CHP 15 Flashcards
Steroid hormones are synthesized from:
Cholesterol
Steroid hormone action:
- hormone enters cell and binds to receptor
- hormone/receptor complex enters nucleus and binds to DNA
- protein synthesis occurs
- protein alters cell function
- testosterone increasing sperm production
Function of hypothalamus:
Communicates with anterior pituitary via hypothalamic-hypophyseal portal vein
Function of anterior pituitary:
- releases 6 hormones into blood (FLAT PG)
- under hypothalamus rule via vein
Function of thyroid gland:
- regulates basal metabolic rate via thyroxine
- regulates blood Ca with the parathyroid gland by releasing calcitonin when blood Ca levels are high
Function of parathyroid gland:
Releases PTH when low blood Ca
Function of adrenal cortex:
Secretes aldosterone to regulate blood volume
Non-steroid hormone action:
- hormone does NOT enter cell
- hormone is 1st messenger; binds to receptor on cell membrane
- triggers formation of 2nd messenger (cyclic AMP) that alters cellular activities
- pituitary hormones
Function of posterior pituitary:
- releases 2 hormones into blood
- communicates with hypothalamus via nerve axons
What hormones does the hypothalamus release?
Releasing hormones that stimulate the anterior pituitary
How does the thyroid and parathyroid gland work together to regulate blood Ca?
- thyroid gland releases calcitonin when high blood Ca
- parathyroid gland releases PTH when low blood Ca
What does the zona glomerulosa secrete?
Aldosterone when blood volume is low
What does the zona fasciculata secrete?
Cortisol when under stress
What does the zona reticularis secrete?
Androgens (sex hormones)
Zones of adrenal gland from innermost to outermost?
Zona Reticularis
Zona Fasciculata
Zona Glomerulosa
Cushing’s syndrome:
- high glucocorticoid levels caused by adrenal or pituitary disease or excess glucocorticoid drugs
- store fat in cells (face and midsection) that only respond to high levels of insulin
Hypothyroidism effects:
- weight gain
- lethargy
- depression
Hyperthyroidism effects:
- hyperactivity
- insomnia
- eyeballs bulge
- goiter in through forms
Steroid hormones are:
Fat soluble which means they can go right into the cell
Nonsteroidal hormones are:
Water soluble which means they cannot go into the cell, they stay outside the cell
-cant diffuse through lipid layer
Hormone that breaks down glycogen in the liver to glucose:
Glucagon
If your cold, how does the hypothalamus communicate with the thyroid gland:
-releases thyroid releasing hormone to anterior pituitary which will release TSH-> target is thyroid-> releases T3 and T4-> causes metabolism to increase
Function of adrenal medulla:
- CNS synapses directly with adrenal medulla
- releases epi and nor epi
Blood glucose negative homeostatic feedback loop:
Stimulus: Increase in glucose
Sensor/integrator: Beta Cells in Islets of Langerhans
-Releases insulin-
Effector: Body cells, liver, adipocytes
Response: Liver stores glucose as glycogen. Adipocytes store glucose as fat.
Result: Decrease in glucose.
How does ADH regulate blood osmolarity and blood pressure?
- released into blood when blood osmolarity is high
- increase in aquaporins, increase in H20 reabsorb, increase in blood pressure
How does DM type 1 effect blood glucose?
Beta cells of pancreas are destroyed and cannot produce insulin-> high blood glucose level
Blood glucose positive homeostatic feedback loop:
Stimulus: Decrease in blood glucose
Sensor/integrator: Alpha cells of Islet of Langerhans
-release glucagon-
Effector: liver + skeletal muscle
Response: Liver converts glucagon-> glycogen->glucose
Result: Increase in blood glucose
How does DM type 2 effect blood glucose?
Resistance to insulin (liver and skeletal muscle cells don’t respond to insulin)
How do ACE inhibitors work?
Prevent conversion of angiotensin 1 to angiotensin 2
Effect of renin-angiotensin-aldosterone system on blood volume and blood pressure:
(blood volume feedback loop)
Stimulus: Decrease in BV and BP Sensor/integrator: juxtaglomerular cells of nephron-> renin->angiotensinogen->angiotensin 1->reacts with ACE to make angiotensin 2 causing vasoconstriction (increasing BV) + thirst Effector: DCT Response: Reabsorption of Na/H20 follows Result: Increase in BV and BP