Physiology

Question 1

Define minimal-change nephropathy?

Answer 1

LOSS of negative charges on basement membrane (lesion of glomerulus)

Question 2

Define hydronephrosis?

Answer 2

distention and dilation of renal pelvis and calyces

Question 3

Factors influencing glomerular capillary colloid osmotic pressure.

Answer 3

arterial plasma colloid osmotic pressure

filtration fraction

Question 4

Factors INCREASING glomerular colloid osmotic pressure

Answer 4

INCREASING filtration fraction

Question 5

Factors that determine glomerular hydrostatic pressure

Answer 5

arterial pressure

afferent arteriolar resistance

efferent arteriolar resistance

Question 6

Factors that determine renal blood flow

Answer 6

tubular Na+ reabsorption

Question 7

Substances that are actively secreted into renal tubules

Answer 7

creatinine

para-aminohippuric acid

Question 8

Define “transport maximum”

Answer 8

limit to the rate at which the solute can be transported (due to saturation of transport system)

Question 9

Define “solvent drag/bulk transport”

Answer 9

passive H2O reabsorption is coupled to Na+ reabsorption

Question 10

Define “Addison’s disease”

Answer 10

absence of aldosterone

Question 11

Define “Conn’s syndrome”

Answer 11

extra aldosterone

Question 12

What is the maximum urine concentration that kidneys can produce?

Answer 12

1200-1400 mOsm/L

Question 13

What is required by kidney tubules for formation of concentrated urine?

Answer 13

presence of ADH

high osmolarity of renal medullary interstitial tubule

Question 14

Where in kidney tubules are MOST of the filtered electrolytes reabsorbed?

Answer 14

proximal tubule (65%)

Question 15

What is the role of osmoreceptor-ADH feedback mechanism?

Answer 15

controls extracellular fluid [N+] and osmolarity

Question 16

Where is ADH formed?

Answer 16

hypothalamus (in magnocellular neurons)

Question 17

What is the function of osmoreceptor cells?

Answer 17

detect changes in osmotic pressure

Question 18

What is the normal extracellular concentration of K+?

Answer 18

4.2 mEq/L

Question 19

What is the clinical significance of EXCESS extracellular K+?

Answer 19

high concentration = cardiac arrest or fibrillation

Question 20

What is the overall effect of aldosterone secretion on K+ secretion?

Answer 20

INCREASED extracellular K+ = INCREASED aldosterone secretion

Question 21

What is the relationship between tubular flow rate and K+ secretion?

Answer 21

HIGH K+ intake = INCREASED K+ secretion rate

Question 22

What is the normal pH range of venous blood?

Answer 22

pH = 7.35-7.45

Question 23

What is the normal pH range of arterial blood?

Answer 23

pH = 7.37-7.44

Question 24

List the major systems that regulate pH?

Answer 24

acid-base buffer system

respirator system

kidneys

Question 25

What is the organ that primarily regulates bicarbonate buffer system?

Answer 25

kidneys

Question 26

What is the primary method for removing nonvolatile acids?

Answer 26

via renal excretion

Question 27

What must happen BEFORE filtered bicarbonate is reabsorbed?

Answer 27

must react with secreted H+ (to form H2CO3 before reabsorption)

Question 28

List the mechanisms by which kidneys regulate extracellular H+

Answer 28

1- reabsorb filtered HCO3- 2- secrete H+ 3- produce NEW HCO3-

Question 29

What is the role of carbonic anhydrase?

Answer 29

formation of NEW HCO3- (from CO2 + H2O)

Question 30

What is the LOWEST limit of pH that can be achieved by normal kidneys?

Answer 30

pH = 4.5

Question 31

What buffers are important in allowing larger [H+] to be excreted?

Answer 31

phosphate buffer system ammonia buffer system

Question 32

Which agents dilate pulmonary arterioles?

Answer 32

- isoproterenol | - AcH

Question 33

Which agents constrict pulmonary arterioles?

Answer 33

- norepinephrine - epinephrine - angiotensin II - prostaglandins

Question 34

Which agents constrict pulmonary venules?

Answer 34

- serotonin - histamine - E. Coli endotoxin

Question 35

What are the factors that control [O2] in alveoli?

Answer 35

- rate of O2 absorption into blood | - rate of NEW O2 entry into lungs (alveolar ventilation)

Question 36

What are the factors that control [CO2] in alveoli?

Answer 36

- rate of CO2 excretion | - alveolar ventilation

Question 37

What does "Va/Q" ratio refers to?

Answer 37

ventilation-perfusion ratio

Question 38

What factors allow the diffusion capacity of O2 to INCREASE during exercise?

Answer 38

INCREASED surface area of capillaries

Question 39

What factors determine tissue pO2?

Answer 39

- rate of O2 transport to tissues | - rate of O2 consumption by tissues

Question 40

List the ways CO2 is transported in blood.

Answer 40

1- dissolved in blood (7%) 2- transported as H2CO3 (70%) 3- transported as carbamino hemoglobin (23%)

Question 41

Which respirator center establishes ramp signals?

Answer 41

DRG

Question 42

What is the function of Hering-Breuer inflation reflex? and where does it begin?

Answer 42

prevent excess inflation of lungs

Question 43

Define "apneusis"

Answer 43

failure to turn off inspiration

Question 44

Define "chemosensitivity"

Answer 44

a lab test that measures number of tumor cells killed by chemotherapy

Question 45

What are some of the diseases that LOWER glomerular capillary filtration coefficient?

Answer 45

chronic uncontrolled hypertension diabetes mellitus (HIGH blood sugar)