Renal 7

Question 1

aldosterone

Answer 1

a steroid hormone responsible for altering Na+ reabsorption and K+ excretion

Question 2

renin-angiotensin-aldosterone system

Answer 2

an endocrine pathway that regulates blood Na+ levels

Question 3

hyperkalemia

Answer 3

elevated levels of potassium in blood

Question 4

decreased blood pressure controls..

Answer 4

aldosterone secretion that results in production angiotensin II

Question 5

angiotensin II

Answer 5

triggers aldosterone release

Question 6

Modifiers of aldosterone release

Answer 6

• increased osmolarity during dehydration inhibit release

- large drops in plasma Na+ directly stimulate aldosterone secretion

Question 7

renin-angiotensin-system (RAS)

Answer 7

a multi-step pathway for maintaining blood pressure

Question 8

renin

Answer 8

an enzyme involved in salt and water balance; main role to convert inactive plasma protein angiotensinogen to angiotensin I

Question 9

renin is secreted by..

Answer 9

granular cells

Question 10

3 stimuli for renin secretion

Answer 10

• low blood pressure
• sympathetic neurons activated by CVCC when blood pressure decreases terminate on granular cells
• paracrine feedback (prostaglandins) from macula densa cells signal to granular cells

Question 11

angiotensin converting enzyme (ACE)

Answer 11

an enzyme produced in blood vessel endothelium that converts angiotensin I to angiotensin II

Question 12

angiotensin II

Answer 12

travels to adrenal cortex and stimulates production of aldosterone

Question 13

angiontensin II effects

Answer 13

• increases vasopressin secretion
• stimulates thirst
• one of the most potent vasoconstrictors
• ANG II receptors activated in CVCC increase sympathetic output to heart and blood vessels
• increase proximal tubule Na+ reabsorption

Question 14

Pharmaceutical companies now use ____ inhibitors for the treatment of hypertension

Answer 14

angiotensin converting enzyme (ACE)

Question 15

preventing the conversion of ANGI to ANGII leads to…

Answer 15

relaxation of the vasculature and lower blood pressure

Question 16

atrial natriuretic peptide (ANP)

Answer 16

peptide hormone produced and secreted by specialized myocardial cells primarily in atria of the heart that promotes Na+ and water excretion

Question 17

natriuresis

Answer 17

loss of Na+

Question 18

brain natriuretic peptide (BNP)

Answer 18

a second type of natriuretic peptide produced in ventricles and in some neurons in the brain

Question 19

How are ANPs released?

Answer 19

-increased blood volume stretches atrial wall during filling and atrial myocytes release ANP due to stretch

Question 20

Aldosterone plays a critical role in K+ homeostasis by..

Answer 20

enhancing excretion in P cells

Question 21

Range that K+ needs to be maintain within

Answer 21

3.5-5 mM

Question 22

Alteration in K+ levels affects…

Answer 22

resting membrane potential of all cells

Question 23

avoidance behaviours

Answer 23

prevent need for behavioural responses

-desert animals avoiding heat of day and becoming active at night