Exam 5: Chapter 20

Question 1

what is sensible water loss?

Answer 1

urine & feces

Question 2

what is insensible water loss?

Answer 2

skin & lungs

Question 3

what is the medullary gradient? what is it created by?

Answer 3

created by the countercurrent exchange system
-as we go down the medulla, there is a higher concentration

Question 4

what two tubules are apart of the countercurrent exchange system?

Answer 4

LOH & vasa recta
-close in proximity to eachother
-fluids move in opposite directions

Question 5

what happens at the descending LOH in the countercurrent exchange system?

Answer 5

water leaves and enters vasa recta
-makes sure it doesn’t dilute the medulla
-LOH filtrate becomes more concentrated

Question 6

what happens at the ascending LOH in the countercurrent exchange system?

Answer 6

solute leaves and stays in the interstitial fluid
-creates the medullary gradient

Question 7

what are the collecting ducts permeable to?

Answer 7

BOTH water and solutes
-depends on situation

Question 8

what is dilute urine?

Answer 8

large volume (more H2O), low solute
-solutes are reabsorbed

Question 9

what is concentrated urine?

Answer 9

small volume (less H2O), high solute
-water is reabsorbed

Question 10

what is diuresis?

Answer 10

increase water excretion

Question 11

what is ADH/vasopressin released by?

Answer 11

posterior pituitary

Question 12

what does ADH/vasopressin do?

Answer 12

stops water excretion (antidiuretic)
-promotes water reabsorption
-more concentrated urine

Question 13

how does ADH/vasopressin act on collecting ducts?

Answer 13

1. ADH binds to a receptor on collecting duct MB
2. activates cAMP pathway
3. aquaporins (AQP2) are inserted on apical MB
4. water enters and exits on basolateral MB
5. water goes into bloodstream

Question 14

what triggers ADH/vasopressin release?

Answer 14

-low BP, low blood volume
-increase in osmolarity (high solute conc.)

Question 15

what is the circadian rhythm of ADH/vasopressin?

Answer 15

increase ADH secretion at night

Question 16

what happens to volume when osmolarity increases?

Answer 16

volume does not change

Question 17

what happens when there is a high osmolarity?

Answer 17

too concentrated
-hypothalamus initiates thirst drive (bring osmolarity back down through dilution)
-initiate AHD/vasopressin release

Question 18

what is aldosterone released by?

Answer 18

adrenal cortex

Question 19

what are the effects of aldosterone release?

Answer 19

increase Na+ reabsorption
increase H2O reabsorption
increase K+ secretion

Question 20

what are triggers for aldosterone release?

Answer 20

• high K+ (we need to get rid of it)
• low osmolarity (need more solutes)
• low BP (triggers RAAS)

Question 21

how does aldosterone act on the collecting ducts?

Answer 21

1. aldosterone is released and enters principle cells (P cell)
2. aldosterone binds to cytoplasmic receptor
3. creates new channels on the MB
4. modifies existing channels on MB (increase opening time or speed of pumps)
5. Na+ enters ECF to be reabsorbed into blood
6. K+ enters nephron to be secreted

Question 22

what is the renin-angiotensin-aldosterone system (RAAS)?

Answer 22

1. decrease in BP
2. sympathetic NS acts on granular cells of kidney
3. constriction causes renin to release into the blood
4. angiotensinogen -> angiotensin 1
5. angiotensin 1 -> angiotensin 2 (enzyme: ACE)
6. angiotensin 2 constricts vessels (increase R = increases blood volume)
7. MULTIPLE FACTORS (next flashcards)
8. increase BP

Question 23

what is the impact of the medulla oblongata in RAAS?

Answer 23

increase symp NS
-constriction

Question 24

what is the impact of the proximal tubules in RAAS?

Answer 24

increase Na+ reabsorption
increase water reabsorption

Question 25

what is the impact of the adrenal cortex in RAAS?

Answer 25

release aldosterone -increases Na+ reabsorption -increases H2O reabsorption -increase K+ secretion

Question 26

what is the impact of the posterior pituitary in RAAS?

Answer 26

release ADH -increase water reabsorption

Question 27

what is the impact of the hypothalamus in RAAS?

Answer 27

initiate thirst drive -increase H2O intake initiate ADH release from the posterior pituitary -increase water reabsorption

Question 28

what are the two types of naturetic peptides?

Answer 28

ANP (atrial) BNP (brain)

Question 29

what is the process of ANP after it is released?

Answer 29

1. increase BP = stretch 2. ANP released 3. MULTIPLE IMPACTS 4. decrease BP

Question 30

what is the effect of the hypothalamus due to ANP?

Answer 30

decrease ADH -increase water secretion

Question 31

what is the effect of the kidney due to ANP?

Answer 31

afferent arteriole dilates -increase GFR -decrease renin proximal tubule -increases Na+ secretion -increases water secretion

Question 32

what is the effect of the adrenal cortex due to ANP?

Answer 32

decrease aldosterone -increase Na+ secretion -increase water secretion -increase K+ reabsorption

Question 33

what is the effect of the medulla oblongata due to ANP?

Answer 33

decrease SYMP -dilation

Question 34

what hormone keeps K+ in it's narrow range?

Answer 34

aldosterone -increases K+ secretion if levels are too high

Question 35

what is hypokalemia?

Answer 35

low K+ -muscle weakness, failure of respiratory muscles and heart

Question 36

what is hyperkalemia?

Answer 36

high K+ -cardiac arrhythmias

Question 37

what are the effects of dehydration?

Answer 37

low volume low BP high osmolarity

Question 38

how does the body fix dehydration?

Answer 38

1. decrease in BP 2. increase SYMP NS 3. constriction 4. decrease GFR 5. increase RAAS 6. inhibit adrenal cortex (do not want to increase osmolarity)

Question 39

what do buffers do?

Answer 39

binds to H+ if its too acidic, and lets go of H+ if too basic -fast working and make small changes

Question 40

what are the three molecules that use ICF mechanisms for buffers?

Answer 40

cellular proteins phosphate ions hemoglobin

Question 41

what molecule uses ECF mechanisms for buffers?

Answer 41

bicarbonate

Question 42

what two molecules are kidney/urine buffers?

Answer 42

phosphate ions ammonia

Question 43

what does the respiratory system do when the pH is too low? (too acidic)?

Answer 43

HYPERventilation -need to decrease CO2 = decrease H+ -creates an alkaline state to increase pH

Question 44

what does the respiratory system do when the pH is too high (too basic)?

Answer 44

HYPOventilation -need to increase CO2 = increase H+ -creates an acidosis state to decrease pH

Question 45

what does the kidney do when pH is too high (too basic)?

Answer 45

H+ reabsorption and HCO3- secretion -overall decreases pH

Question 46

what does the kidney do when pH is too low (too acidic)?

Answer 46

H+ secretion and HCO3- reabsorption -overall increases pH

Question 47

what does the proximal tubule do to H+ and HCO3-?

Answer 47

secretes H+ reabsorbs HCO3-

Question 48

what does type A distal tubule cells do to H+ and HCO3-?

Answer 48

secretes H+ reabsorbs HCO3- *wants to make pH more basic*

Question 49

what does type B distal tubule cells do to H+ and HCO3-?

Answer 49

reabsorbs H+ secretes HCO3- *wants to make pH more acidic*

Question 50

what is respiratory acidosis caused by?

Answer 50

HYPOventilation -CNS depressants

Question 51

what is respiratory alkalosis caused by?

Answer 51

HYPERventilation -anxiety

Question 52

what is metabolic acidosis accompanied by?

Answer 52

HYPERventilation -increased acid production in the body

Question 53

what is metabolic alkalosis accompanied by?

Answer 53

HYPOventilation -increased action of getting rid of acids (vomitting)

Question 54

what is happening to H+, pH, and HCO3- during respiratory acidosis?

Answer 54

increase H+ decrease pH (more acidic) increase HCO3- (high CO2 in the body)

Question 55

what is happening to H+, pH, and HCO3- during metabolic acidosis?

Answer 55

increase H+ decrease pH (more acidic) decrease HCO3- (low CO2 in the body)

Question 56

what is happening to H+, pH, and HCO3- during respiratory alkalosis?

Answer 56

decrease H+ increase pH (more basic) decrease HCO3- (low CO2 in the body)

Question 57

what is happening to H+, pH, and HCO3- during metabolic alkalosis?

Answer 57

decrease H+ increase pH (more basic) increase HCO3- (high CO2 in the body)