3.17.25 lecture: ADH and intro to anterior pituitary

what does ADH stand for?

antidiuretic hormone

what does a diuretic do?

increases urine production

ADH is a __________________ hormone

water-conserving

how does ADH decrease urine production?

by reabsorbing water in the kidneys

________________ in the kidneys are sensitive to salt concentrations in the blood

osmoreceptors

we mainly find osmoreceptors in the _______________ and ___________________

hypothalamus (dendrites and soma, neural regulation) and kidneys (distal tubules of the nephrons, humoral regulation)

ADH plays a role in the _______________ system

renin-angiotensin-aldosterone system (RAAS)

yeah he didn't mention it in class, but you'll appreciate this connection later

what is the trigger to secrete ADH?

high solute concentrations

what happens when your fluids are diluted?

decrease ADH

ADH also stimulates _________________

thirst

ADH AT THE KIDNEYS

cause that's where the pee is

a ____________ is the functional unit of the kidney

nephron

nephrons are where we regulate _________________

body water

water is brought to the nephrons via __________ which supply a specific portion of the nephron called the ____________________

capillaries; glomerulus

from the capillaries, ______________ and ______________ will pass into the nephron, travel through, into the collecting ducts, then down to form urine

water and small solutes (like sodium)

the _______________________________ is analagous to a funnel, and it catches any fluid and any solute that leaves the blood vessels

glomerular capsule

in the ____________________________, right after the glomerulus, we have means that automatically reabsorb some water

proximal convoluted tubule

after the proximal convoluted tubule, the fluid passes through the _____________________, where we absorb more water

loop of henle

once the water passes the loop of henle, the fluid passes through the ____________________ and then is dumped into the ______________________

distal convoluted tubules; collecting ducts

ADH triggers the production of ___________ in the __________________

aquaporins; collecting ducts

ADH recovers water from the ______________________ of the neprons

collecting ducts

true/false: ADH ONLY triggers water reabsorption, NOT salt reabsorption or anything else

true! it is strictly water

The automatic water reabsorption in the nephrons (no ADH) follows the principle of ________________, driven by ______________

osmosis; solute gradients

briefly describe how the tubules leverage solute gradients for automatic water reabsorption

the nephron actively transports sodium out of the tubules, causing water to passively follow

true/false: we have an automatic way to reabsorb water in the absence of ADH, it's just not very efficient

true! The automatic way is like ~60% reabsorption where ADH is like ~95%

what common drug inhibits ADH secretion?

alcohol

ADH deficiency characterizes the disorder _______________________

diabetes insipidus

diabetes insipidus is an abnormal increase in _________________, _____________________, and ___________________

urine output, fluid intake, and often thirst

what are the symptoms of diabetes insipidus

dilute urine

increased urinary frequency

bedwetting

low urine osmolality is the technical term for ________________

dilute urine

what is the word for waking up a lot to go pee?

nocturia

what's the word for bedwetting?

enuresis

what causes ADH hyposecretion

death of ADH producing cells in the hypothalamus and posterior pituitary gland

true/false: diabetes insipidus causes low urine osmolality but high blood osmolality

true! because remember, ADH has NOTHING to do with salts!

what disorder characterizes ADH overproduction?

Syndrome of inappropriate ADH secretion (SIADH)

what normally causes SIADH?

a tumor resulting in the overproduction of ADH

what are the symptoms of SIADH? (4)

1. hyponatremia

2. elevated urine osmolarity

3. excessive urine sodium secretion

4. decreased serum osmolality

why does SIADH cause elevated sodium excretion?

because there's small amounts of urine and the urine you do produce will be hyperconcentrated with sodium

_____________________ is the proper name for the anterior lobe of the pituitary gland

adenohypophysis

is the adenohypothesis considered a proper gland?

yes

there are __ hormones secreted by the anterior pituitary

6

the _____________________ is the network of blood vessels that feeds the adenohypophysis

hypophyseal portal system

the hypothalamus releases regulatory hormones which feed into the _______________________________

primary capillary plexus

in the adenohypophysis, blood flows through the _________________________ , and responds by releasing its own hormones (ACTH, TSH, GH, etc.) into circulation via the __________________________________

hypophyseal portal veins; secondary capillary plexus