Chapter 32 Renal anatomy/physiology/pathophys & A managment

Question 1

main function of kidneys

Answer 1

excreting end products of metabolism and controlling the concentration of constituents of body fluids

Question 2

kidney facts

Answer 2

• extend from 12th thoracic vertebrae to the 3rd lumbar vertebrae
• weighs approx. 125-170 g in men & 115-155g in women
• 11.25 cm long
• 5 to 7.5 cm wide
• 2.5 cm thick
• d/t hepatic displacement the right kidney’s position is slightly lower than the left

Question 3

what structures enter or exit the kidney at the hilus

Answer 3

renal artery & vein, nerves, lymphatics, and urters

Question 4

pyramids have a striated appearance d/t

Answer 4

presence of the loop of Henle and collecting ducts of the nephron

Question 5

medulla is divided into how many triangular wedges called __

Answer 5

8 to 18 pyramids

Question 5

the base of the pyramids is directed toward the renal cortex, and the apexes converge toward the

Answer 5

renal pelivis

Question 6

apex of each pyramid is called the

Answer 6

papilla

Question 7

papillary ducts empty into

Answer 7

minor calyx –> several minor calyces empty into –> major calyces —> come together to form renal pelvis

Question 8

functional unit of the kidney

Answer 8

nephron

Question 9

how many nephrons reside in each kidney

Answer 9

1,250,000

Question 10

filtered blood flows through the nephrons, which, in turn, retained filter fluid know as

Answer 10

filtrate

through this process, end-products of metabolism are excreted, and metabolically important substances like water and electrolytes are reabsorbed as needed

Question 11

formation of urine begins with the

Answer 11

nephron

begins in the cortex at the glomerulus and ends where the tubule joins the collecting duct at the papilla

Question 12

glomerulus

Answer 12

tuft of capillaries derived from afferent arteriole

blood is transported to the glomerulus via the afferent arteriole

Question 13

blood that is not filtered in the nephron returns to

Answer 13

the systemic circulation via efferent arteriole

Question 14

the filtrate from the glomeruli enters the __ __ or __ __

Answer 14

bowman capsule; capsula glomeruli

then flows through a torturous pathway in the proximal convoluted tubule, to the loop of Henle, the distal convoluted tubule, and finally to the collecting duct

Question 15

cortex contains:

Answer 15

bowman capsule, glomerulus, & proximal and distal tubules

Question 16

descending loop of Henle comes from

Answer 16

the proximal tubule and extends toward the pyramid

Question 17

kidneys have 2 types of nephrons:

Answer 17

cortical nephrons:
- extend only partially into the medulla

juxtamedullary nephrons:
- lie deep in the cortex and extend deep into the medulla
- compromise 1/5 to 1/3 of total nephrons
- important role in the concentration of urine !!

Question 18

how much blood per minute do the kidneys recieve?

Answer 18

1,100 - 1,200 mL of blood

or 20% to 25% of the cardiac output

Question 19

renal artery divides into several __ arteries and then subdivides again into __ arteries, which run between the pyramids

Answer 19

lobar; interlobar

Question 20

interlobar arteries reach the __ zone, they make well-defined arches over the bases of the __

Answer 20

corticomedullary; pyramids

Question 21

arcuate arteries divide into a series of arteries known as

Answer 21

interlobular arteries

Question 22

where do interlobular arteries terminate?

Answer 22

may terminate as an afferent arteriole or as a nutrient artery to the tubule

Question 23

the afferent arterioles form the

Answer 23

high-pressure capillary bed within the bowman capsule that is called the glomerulus

Question 24

little or no O2 is removed in the __, blood that is not filtered begins its passage to the __ __ via the __ __

Answer 24

glomerulus; venous system; efferent arteriole

Question 24

T/F the efferent arteriole is smaller than the afferent arteriole

Answer 24

true *thereby affording some resistance to blood flow*

Question 25

efferent vessel becomes a plexus of capillaries AKA

Answer 25

peritubular capillary bed low-pressure bed

Question 26

the cardiac output portion that passes through the kidney is called the

Answer 26

renal fraction normal renal fraction of CO is between 20% & 25%

Question 27

T/F renal medulla has a larger distribution of renal blood flow compared to the renal cortex

Answer 27

FALSE renal cortex receives larger distribution of renal blood flow

Question 28

blood flow to any organ is determined by

Answer 28

the arteriovenous pressure difference across the vascular bed

Question 29

RPF

Answer 29

renal plasma flow

Question 30

how is renal blood flow regualed

Answer 30

- intrinsic autoregualtion - neural regulation: the sympathetic nervous system innervates afferent & efferent arterioles, acute sympathetic stimulation will have associated vasoconstriction & can decrease renal blood flow

Question 31

if mean systemic pressure falls below 50 mm Hg

Answer 31

filtration ceases

Question 32

T/F direct relationship between RBF & glomeruli filtration

Answer 32

true

Question 33

reduction of glomerular filtration leads to dilation of

Answer 33

afferent arteriole an increase in blood flow to the glomerulus returns glomeruli filtrations to normal

Question 34

myogenic mechanisms

Answer 34

arterial pressure rises, the arterial walls are stretched, the vessel constricts, & blood flow remains normal * when arterial pressure decreases the opposite effect occurs

Question 35

renal physiology:

Answer 35

filtration, reabsorption, and tubular secretion

Question 36

filtration

Answer 36

results from pressures forcing fluids and solutes through the glomerulus, is the first step in the formation of urine

Question 37

GFR

Answer 37

quantity of glomerular filtrate formed each minute in all nephrons

Question 38

filtration fraction

Answer 38

quantity of renal plasma flow that becomes filtrate and is defined as GFR divided by the flow to one kidney

Question 39

regulation of GFR

Answer 39

- the pressure inside the glomerular capillaries - the pressure in the bowman capsule - the colloid osmotic pressure of the plasma proteins

Question 40

pressure of the glomerulus

Answer 40

60 mm Hg is an outward force

Question 41

colloid osmotic pressure

Answer 41

28 mm Hg created by proteins and is an inward force that tends to hold fluid within the glomerulus

Question 42

pressure in the bowman capsule

Answer 42

18 mm Hg opposes filtration

Question 43

filtration pressure is the pressure that forces __ through the __ __ and is equal to the glomeruli pressure minus the sum of the glomerular colloid osmotic pressure and the capsular pressure

Answer 43

fluid; glomerular membrane

Question 44

normal filtration pressure is

Answer 44

10 mm Hg

Question 45

factors that can alter GFR

Answer 45

- increased renal blood flow - dilation of the afferent arteriole - increased resistance in the efferent arteriole all increase GFR

Question 46

what structure regulates GFR

Answer 46

juxtaglomerular complex *distal convoluted tubule lies between the afferent and efferent arterioles *

Question 46

what decreased GFR

Answer 46

afferent arteriole constriction and efferent arteriole dilation

Question 47

cells of the distal tubule encountering the arterioles are __, and therefore are referred to as the __ __

Answer 47

dense; macula densa

Question 48

smooth muscle cells of both aff & eff arterioles consist of

Answer 48

juxtaglomerular cells, which contain renin

Question 49

decreased glomeruli filtration causes

Answer 49

overabsorption of Na and Cl in the ascending limb of the loop of Henle resulting in a reduction in the delivery of these ions to the macula densa

Question 49

macula densa function

Answer 49

detect small changes in osmolarity

Question 49

the structure is arranged to allow fluid in the distal tubule to alter aff & eff arteriole

Answer 49

tone and thus regulate GFR

Question 50

decreases in Na and Cl concentrations causes __ arterioles to dilate, thus increasing ___ & __

Answer 50

afferent; RBF; GFR

Question 51

permeability at the glomerulus is __ to __ times greater than most capillaries

Answer 51

100 to 150

Question 52

glomeruli capillary containes

Answer 52

negatively charged pores freely permeable to water and small molecules

Question 52

glomerulus is almost impermeable to all

Answer 52

plasma proteins but highly permeable to most other dissolved substances

Question 53

conversion of glomeruli filtrate to urine is the result of

Answer 53

filtration at the glomerulus, tubular reabsorption, or transport from the tubular lumen to the renal cell, and secretion or transport from the renal cell to the filtrate

Question 54

approx __% if plasma filtrate is reabsorbed in the nephron

Answer 54

99%

Question 56

once blood has reacherd the peritubullary capillary

Question 69

tubular reabsorption permits conservation of substances such as:

Answer 69

water, glucose, amino acids, and electrolytes water and Na are reabsorbed throughout the nephron

Question 70

proximal tubule

Answer 70

- active transport of NA is the primary function - reabsorption of water leaves an increased concentration of urea within the tubular lumen - hydrogen ions are actively secreted in exchange for Na

Question 71

Loop of Henle

Answer 71

- function is to establish a hyperosmotic state within the medullary area --> vital to conserve salt and water - the longer the loop, the greater the concentration gradient --> as the gradient increases, the movement of water is enhanced

Question 72

late distal tubule

Answer 72

- Na under the influence of aldosterone is reabsorbed - K is excreted into the lumen in exchange for Na - secretes H ions against a concentration gradient --> role in acid/base balance and determines the final degree of urine acidification - area is permeable to H2O only in the presence of ADH