Renal Physiology

Question 1

functional units of kidney;

that has approximately _

Answer 1

nephrons;

1 - 1.5 million

Question 2

responsible primarily for removal of waste products and reabsorption of nutrients; with make up approximately _ of nephrons

Answer 2

Cortical nephrons; 85%

Question 3

Cortical nephrons are situated primarily in the _

Answer 3

cortex of the kidney

Question 4

Their primary function is concentration of the urine. This extend deep into the _ of the kidney

Answer 4

Juxtamedullary nephrons; medulla

Question 5

nephrons clear waste products selectively from the blood and simultaneously to maintain the body’s essential _ and _ balances

Answer 5

water and electrolyte

Question 6

renal functions:

Answer 6

renal blood flow,
glomerular filtration,
tubular reabsorption,
tubular secretion

Question 7

supplies blood to the kidney

Answer 7

renal artery

Question 8

The human kidneys receive approximately _ of the blood pumped through the heart at all times.

Answer 8

25%

Question 9

blood pathway in the kidney

Answer 9

afferent arteriole -> glomerulus -> efferent arteriole -> peritubular cappilaries -> vasa recta

Question 10

what is bigger between afferent and efferent arteriole

Answer 10

afferent

Question 11

providing for the im- mediate reabsorption of essential substances from the fluid

Answer 11

proximal convoluted tubule

Question 12

final adjustment of the urinary composition

Answer 12

distal convoluted tubule

Question 13

located adjacent to the ascending and descending loops of Henle in juxtamedullary nephrons

Answer 13

vasa recta

Question 14

When dealing with kidney sizes that vary greatly from the average _ of body surface

Answer 14

1.73 m2

Question 15

the total renal blood flow is approximately _, and the total renal plasma flow ranges from _

Answer 15

1200 mL/min; 600 to 700 mL/min

Question 16

The glomerulus consists of a coil of approximately _ capillary lobes, the walls of which are referred to as the _

Answer 16

eight; glomerular filtration barrier

Question 17

glomerulus is located within _, which forms the beginning of the renal tubule

Answer 17

Bowman’s capsule

Question 18

a nonselective filter of plasma substances with molecular weights less than 70,000, several factors influence the actual filtration process

Answer 18

glomerulus

Question 19

Plasma filtrate must pass through three glomerular filtration barrier cellular layers:

Answer 19

the capillary wall membrane,
the basement membrane (basal lamina),
the visceral epithelium of Bowman’s capsule

Question 20

Cellular Structure of the Glomerulus

The endothelial cells of the capillary wall differ from those in other capillaries by containing pores and are referred to as _.

Answer 20

fenestrated

Question 21

Epithelial cells of the inner lining of Bowman’s capsule that contain foot-like processes

Answer 21

podocytes

Question 22

an autoregulatory mechanism within the _ maintains the glomerular blood pressure at a relatively constant rate regardless of fluctuations in systemic blood pressure

Answer 22

juxtaglomerular apparatus

Question 23

_ regulates the flow of blood to and within the glomerulus. The system responds to changes in blood pressure and plasma sodium content that are monitored by the juxtaglomerular apparatus, which consists of the juxtaglomerular cells in the afferent arteriole and the _ of the distal convoluted tubule

Answer 23

renin-angiotensin-aldosterone system; macula densa

Question 24

an enzyme pro- duced by the juxtaglomerular cells

Answer 24

renin

Question 25

RAAS system activation

Answer 25

renin - substrate angiotensinogen - hormone angiotensin I - angiotensin-converting enzyme (ACE) - angiotensin II

Question 26

converts angiotensin I to angiotensin II in alveoli of the lungs

Answer 26

angiotensin-converting enzyme (ACE)

Question 27

Angiotensin II cor- rects renal blood flow in the following ways:

Answer 27

• vasodilation of afferent & constriction of efferent
• reabsorption of sodium and water in the proximal convoluted tubules
• aldosterone release by adrenal cortex
• ADH release by hypothalamus

Question 28

sodium-retaining hormone

Answer 28

aldosterone

Question 29

the substance to be reabsorbed must com bine with a carrier protein contained in the membranes of the renal tubular epithelial cells

Answer 29

active transport

Question 30

is the movement of molecules across a membrane as a result of differences in their concentration or electrical potential on opposite sides of the membrane

Answer 30

Passive transport

Question 31

Passive reabsorption of water takes place in all parts of the nephron except the _, the walls of which are impermeable to water.

Answer 31

ascending loop of Henle

Question 32

plasma concentration at which active transport stops

Answer 32

renal threshold

Question 33

For glucose, the plasma renal threshold is

Answer 33

160 to 180 mg/dL

Question 34

adh is also known as

Answer 34

vasopressin

Question 35

↑Body Hydration = _ ADH = ↑Urine Volume

Answer 35

↓ADH

Question 36

eliminating waste products not filtered by the glomerulus and regulating the acid–base balance in the body through the se- cretion of hydrogen ions

Answer 36

tubular secretion

Question 37

major site for removal of these nonfiltered substances

Answer 37

proximal convoluted tubule

Question 38

The buffering capacity of the blood depends on _ ions

Answer 38

bicarbonate (HCO3–)