Overview of the Urinary System

Question 1

the kidneys control blood composition and volume by

Answer 1

removing wastes and regulating water levels

Question 2

the kidneys regulate osmolarity of body fluids by

Answer 2

controlling solutes and water levels

Question 3

the kidneys regulate blood pH by

Answer 3

excreting hydrogen ions

Question 4

the kidneys regulate blood pressure by

Answer 4

activating reninangiotensin pathway

Question 5

the kidneys control oxygen-carrying capacity of blood by

Answer 5

secreting erythropoietin

Question 6

the kidneys contribute to metabolism by

Answer 6

synthesizing glucose during periods of starvation

Question 7

“waste” refers to

Answer 7

any substance that is not useful to the body

Question 8

metabolic wastes are

Answer 8

substances produced by the body

Question 9

nitrogenous wastes

Answer 9

metabolic wastes that result from breakdown of proteins

Question 10

amino groups removed from amino acids combine with

Answer 10

hydrogen ions to form ammonia, which is highly toxic and must be diluted with huge quantities of water

Question 11

ammonia

Answer 11

gets converted to less toxic urea by liver and this uses much less water

Question 12

uric acid

Answer 12

results from breakdown of nucleic acids

Question 13

creatinine

Answer 13

results from use of creatine phosphate during muscle metabolism

Question 14

the amount of nitrogenous waste in blood is expressed as

Answer 14

blood urea nitrogen (BUN)

- normal levels are 10-20 mg/mL

Question 15

azotemia

Answer 15

elevated BUN is azotemia

- it indicates renal insufficiency

Question 16

if azotemia is left untreated it can lead to

Answer 16

uremia

Question 17

uremia

Answer 17

elevated BUN

- can cause diarrhea, vomitting, dyspnea, cardiac arrhythmia, convulsions, coma, and even death

Question 18

excretion

Answer 18

the process of discharging waste materials across cell membranes

Question 19

skin- excretions and glands

Answer 19

sudoriferous glands in skin eliminate excess heat and excrete water and small amounts of salts and urea during perspiration

Question 20

lungs

Answer 20

excrete large quantities of carbon dioxide and small amounts of water vapor

Question 21

liver

Answer 21

extracts bilirubin from erythrocytes and excretes it as bile by adding it to feces

Question 22

kidneys

Answer 22

excrete nitrogenous wastes and other substances by adding them to urine

Question 23

description of kidneys

Answer 23

reddish brown organs that extend from T-12 to L-3 behind parietal peritoneum against posterior abdominal wall

Question 24

right kidney

Answer 24

slightly lower because of the liver

Question 25

adult kidney

Answer 25

larger- about 150 grams

Question 26

lateral surface of each kidney

Answer 26

is convex and the medial surface is concave | - blood vessels, lymphatic vessels, nerves, ureter attach to renal hilum

Question 27

renal capsule

Answer 27

a smooth, transparent membrane that each kidney is enclosed within

Question 28

adipose capsule

Answer 28

fatty adipose capsule cushions kidney from trauma and holds it in place

Question 29

renal fascia

Answer 29

fibrous renal fascia anchors kidney to abdominal wall

Question 30

frontal section through kidney

Answer 30

shows c-shaped parenchyma with two distinct zones

Question 31

renal cortex

Answer 31

superficial reddish zone

Question 32

renal medulla

Answer 32

deep brownish zone

Question 33

renal parenchyma

Answer 33

glandular tissue that forms urine

Question 34

portions of the renal cortex extend into the renal medulla to form

Answer 34

renal columns

Question 35

renal pyramids

Answer 35

striated, cone-shaped renal pyramids are loacted within renal medulla

Question 36

apex of each renal pyramid

Answer 36

forms renal papilla that faces hilum

Question 37

the papilla of each renal pyramid is enclosed within a

Answer 37

minor calyx that collects urine

Question 38

major calyx

Answer 38

urine from 2 or 3 minor calyces is delivered to major calyx

Question 39

renal pelvis

Answer 39

2 or 3 major calyces empty urine into renal pelvis

Question 40

each kidney contains over one million

Answer 40

nephrons, which carry out the kidney's functions

Question 41

renal corpuscle

Answer 41

consists of a glomerulus, which is a ball of capillaries that is enclosed within a two-layered Bowman's capsule

Question 42

outer parietal layer of renal corpuscle is composed of

Answer 42

simple squamous epithelium

Question 43

inner visceral layer of renal corpuscle consists of

Answer 43

podocytes that wrap around capillaries

Question 44

renal tubule

Answer 44

extends about 3 cm from Bowman's capsule to the tip of a renal pyramid

Question 45

proximal convoluted tubule

Answer 45

PCT- arises from Bowman's capsule | - it is the longest segment and contains simple cuboidal epithelium with numerous microvilli.

Question 46

microvilli

Answer 46

form a 'brush border' to increase surface area

Question 47

nephron loop of Henle

Answer 47

extends from PCT into renal medulla

Question 48

descending limb

Answer 48

a thin segment of simple squamous epithelium | - very permeable to water

Question 49

ascending limb

Answer 49

a thick segment of simple cuboidal epithelium | - involved in salt transport

Question 50

distal convoluted tubule

Answer 50

DCT- begins when loop of Henle returns to renal cortex

Question 51

macula densa

Answer 51

cluster of epithelial cells at beginning of DCT

Question 52

collecting duct

Answer 52

terminal structure of renal tubule

Question 53

several nephrons and collecting ducts

Answer 53

several nephrons empty urine into a single collecting duct | - it joins with other collecting ducts to transfer urine into a papillary duct

Question 54

cortical nephrons

Answer 54

short nephron loops that barely dip into the renal medulla

Question 55

juxtamedullary nephrons

Answer 55

have very long nephron loops that extend deep into the renal medulla

Question 56

the kidneys are richly supplied with

Answer 56

blood vessels and as much as 25% of the circulating blood supply can be in the kidneys at any moment

Question 57

blood enters a kidney from the aorta by way of

Answer 57

a renal artery that branches many times until it gives rise to a series of afferenet arterioles

Question 58

juxtaglomerular cells

Answer 58

located in wall of an afferent arterioles are modified smooth muscle juxtaglomerular (JG) cells

Question 59

juxtaglomerular apparatus

Answer 59

JG cells combine with macula densa cells to form a juxtaglomerular apparatus

Question 60

at the end of each afferent arteriole

Answer 60

is the collection of glomerular capillaries

Question 61

the blood that supplies a nephron passes through

Answer 61

two capillary beds

Question 62

glomerular capillaries reunite to form

Answer 62

efferent arteriole that drains them after they produce filtrate

Question 63

efferent arteriole divides to form

Answer 63

peritubular capillaries that surround each cortical nephron | - reclaim most filtrate

Question 64

efferent arterioles divides to form _______ _____ that surround each juxtamedullary nephron

Answer 64

vasa recta

Question 65

blood exits these capillaries and enters

Answer 65

venules, which form a series of veins that eventually merge to form the renal vein that delivers blood to the inferior vena cava