Endocrine 1
What are three potential causes of Primary Hyposecretion?
1. Partial destruction of the gland
2. Dietary deficiency
3. Enzyme deficiency
What are two differences between T3 and T4 hormones?
T4 is more abundant, but T3 is more potent
What are the structures the urine formed in the nephrons must pass through in order to get to the urinary bladder?
Minor Calyx --> Major Calyx --> Renal Pelvis --> Ureter --> Urinary Bladder
List the regions of the nephron in order, starting with where the filtrate crosses into the renal corpuscle:
Bowman's space --> Proximal tubule --> descending Loop of Henle --> ascending Loop of Henle --> distal tubule --> collecting duct
What is the main role of the submucosal/Meissner's plexus in the GI tract?
Describe the regulation of Growth Hormone Secretion.
Pulsatile - lower secretion during the day with the highest amount just after sleep
Stimulated by starvation, stress, exercise
Peak levels during puberty
What are the layers of the adrenal gland and what hormones are produced in each layer?
Glomerulosa - aldosterone
Fasciculata - cortisol
Reticularis - androgens
Medulla - epinephrine
What are the two types of nephrons and what is the important function difference between them?
Cortical and juxtamedullary; juxtamedullary is important for concentrating urine
Which renal processes apply to glucose?
If a person has primary hypocortisolism their level of cortisol would be _______ and their level of ACTH would be _______.
Low, High
What are the four types of hypercortisolism?
Pituitary - cushing's disease
Adrenal form - cushing's syndrome
Ectopic - non-pituitary ACTH secreting tumor
Iatrogenic - long term glucocorticoid therapy (drug related)
What are the four pancreatic endocrine cell types, and what do each of them produce?
A cells - glucagon
B cells - insulin
D cells - somatostatin
F cells - pancreatic polypeptide
What are the three layers of the glomerular filtration barrier?
1) Capillary endothelium (Fenestrated)
2) Basement membrane
3) Podocytes that have foot processes that create filtration slits
What are the three muscles of micturition and which division of the nervous system stimulates each one?
Detrusor - parasympathetic
Internal urethral sphincter - sympathetic
External urethral sphincter - somatic
What is the role of the hepatic portal vein?
The hormone Prolactin causes milk production while the hormone Oxytocin causes milk ejection. The type of interaction between these two hormones is considered a(n) ______ relationship
Permissive
Type I DM is characterized by increased appetite but loss of weight.
Type I DM is characterized by autoimmune destruction of pancreatic alpha cells.
Statement 1 is true, statement 2 is false
PT = 65%
LoH = 15%
DT & CD = 20%
1) High levels of ADH
2) Hyperosmotic medullary interstitium due to the action of the Countercurrent Multiplier System and juxtamedullary nephrons
What are the four ways that the pancreas is stimulated to release more insulin?
Increased glucose, amino acids, and parasympathetic activity, as well as release of incretins.
Which of these effects is produced by cortisol?
1. Increased blood fatty acid levels
2. Increased immune system activity
3. Stimulation of protein synthesis
4. Hypoglycemia
1. increased blood fatty acid levels
Which of the following would be a result of Primary Hyperaldosteronism?
1. Myxedema
2. Hypokalemia
3. Hypotension
4. Hyperlglycemia
2. Hypokalemia
Assuming normal GFR, what renal processes are occuring for a substance with these values?
UX = 250 mmole/L
PX = 5 mmole/L
V = 3 mL/min
(250 mmole/L * 3 mL/min) / 5 mmole/L = 150 mL/min
Filtration and secretion
Under what conditions would Na+ reabsorption be increased? Decreased? Explain what hormones are involved.
Increased: by aldosterone, as part of RAAS in response to decreased NaCl in the thick ascending loop of Henle filtrate, decreased pressure in the afferent arteriole, sympathetic nerve activity, (or increased K+). Acts on principal cells of distal tubules and collecting ducts to cause Na+ reabsorption (and K+ secretion).
Decreased: by ANP, in response to distention of atrial wall (increased BP). Closes Na+ channels in apical membrane (also dilates afferent arteriole and constricts efferent arteriole to increase GFR).
What conditions cause ADH secretion? What is the mechanism for ADH function?
ADH is secreted when blood volume/MAP decrease, or plasma osmolarity increases. It affects the principal cells of the distal tubule and collecting duct, increasing permeability to water and allowing for reabsorption by following the concentration gradient established by the countercurrent multiplier system.