Decrease hormone regulation july 2018 bios256 midterm

Decrease.
Hormone regulation
July 2018

BIOS256 Midterm Study Guide
TYPE OF
REGULATION MAJOR STIMULUS
MECHANISM AND SITE OF
ACTION
EFFECT
ON GFR
Angiotensin II Decreased blood volume or blood
pressure stimulates production of
angiotensin II.
Constriction of afferent and efferent
arterioles.
Decrease.
Atrial natriuretic
peptide (ANP)
Stretching of atria of heart
stimulates secretion of ANP.
Relaxation of mesangial cells in
glomerulus increases capillary
surface area available for filtration.
Increase.

 (Ch. 26) Tubular reabsorption and secretion
 (Ch. 26) Table 26.4
HORMONE
MAJOR STIMULI THAT
TRIGGER RELEASE
MECHANISM AND SITE
OF ACTION EFFECTS
Angiotensin
II
Low blood volume or low
blood pressure stimulates
renin-induced production
of angiotensin II.
Stimulates activity of Na + –
H + antiporters in proximal
tubule cells.
Increases reabsorption of
Na + , other solutes, and
water, which increases
blood volume and blood
pressure.
Aldosterone Increased angiotensin II
level and increased level
of plasma K + promote
release of aldosterone by
adrenal cortex.
Enhances activity of sodium–
potassium pumps in
basolateral membrane and
Na + channels in apical
membrane of principal cells
in collecting duct.
Increases secretion of
K + and reabsorption of
Na + , Cl − ; increases
reabsorption of water,
which increases blood
volume and blood
pressure.
Antidiuretic
hormone
(ADH)
Increased osmolarity of
extracellular fluid or
decreased blood volume
promotes release of ADH
from posterior pituitary
gland.
Stimulates insertion of water
channel proteins (aquaporin-
2) into apical membranes of
principal cells.
Increases facultative
reabsorption of water,
which decreases
osmolarity of body fluids.
Atrial
natriuretic
peptide (ANP)
Stretching of atria of
heart stimulates ANP
secretion.
Suppresses reabsorption of
Na + and water in proximal
tubule and collecting duct;
inhibits secretion of
aldosterone and ADH.
Increases excretion of
Na + in urine (natriuresis);
increases urine output
(diuresis) and thus
decreases blood volume
and blood pressure.
Parathyroid
hormone
(PTH)
Decreased level of
plasma Ca 2+ promotes
release of PTH from
parathyroid glands.
Stimulates opening of
Ca 2+ channels in apical
membranes of early distal
tubule cells.
Increases reabsorption of
Ca 2+ .

 (Ch. 26) Formation of concentrated urine
 (Ch. 26) Evaluation of kidney function
Short Answer Questions