The Urinary System - Herron Flashcards Preview

Renal Physiology > The Urinary System - Herron > Flashcards

Flashcards in The Urinary System - Herron Deck (91)
1

What is the pathway of urine?

The kidney produces urine.
Urine passes to the ureters.
Then to the bladder for storage until discharged through urethra.

2

What does the hilum consist of?

Renal artery
Renal Vein
Nerves
Renal Pelvis

3

What is the parenchyma of the kidney divided into?

Cortex (outer layer)
Medulla (Inner Layer)

4

Where are the pyramids located?

In the medulla

5

What is the apex of the pyramid?

Renal Papilla

6

What is the tissue between adjacent pyramids?

renal column

7

What is a lobe?

a medullary pyramid and the overlying cortex plus 1/2 of the renal columns on each side of the pyramid

8

What are calyces?

Extensions of the renal pelvis into the proper kidney

9

How many renal papilla does a minor calyx surround?

One

10

What is a major calyx?

The combination of two or more minor calyces

11

What is the function of the minor calyx?

Drains the urine from the papilla of the pyramid into the major calyx (beginning of renal pelvis)

12

How many lobes does each kidney have?

8-10

13

What does the structure of the kidney allow the kidney to do (functions)?

remove waste from the blood and excrete it as urine
regulate electrolyte balance (na, k, h, ca)
regulate plasma volume and bp
produce hormones

14

what hormones does the kidney produce?

EPO, for rbc formation
renin, involved in water retention for bp and volume regulation
converts vit d precursor to active form of vit d.

15

what is the structural and functional unit of the kidney

the nephron

16

what does the nephron consist of

renal corpuscle and its tubules

17

where does the renal corpuscle's tubules end?

at the collecting duct

18

How many nephrons does the human kidney have?

800k to 1 mill

19

What percentage of cardiac output goes to the kidney?

25%

20

What are the four main segments of the nephron tubule?

Proximal thick segment
Thing segment
Distal thick segment
loop of henle

21

what are the segments of the proximal thick segment?

proximal convuluted tubule
proximal straight tubule

22

what are the segments of the thin segment?

thin limb

23

what are the parts o the distal thick segment

Medullary thick ascending limb (mtal)
cortical thick acscending limg (ctal)
macula densa (md)
disetal convoluted tubule (dct)
connecting segment (ct)

24

what is the dividing point between the proximal and distal tubules?

the macula densa

25

What is the collecting duct?

NOT part of the nephron
Conducts urine from the nephron tubule to the renal papillae
Consists of the cortical collecting duct and the medullary collecting duct

26

what does the collecting duct consist of?

cortical collecting duct
medullary collecting duct

27

what are the ducts of bellini?

the papillary duct or collecting duct

28

how do you distinguish between different tubular segments and dcuts?

PCT are larger, have a lot of microvilli (increases the SA), which forms the distinctive brush border
DCT don't ahve brush border, smaller, sharper luminal void and a higher [ ] of cells

29

How can you identify collecting ducts on histo?

they are like ice cube trays and you can see the border between adjacent cells

30

how can you identify the thin segment of the loop of henle?

seen by squamous cells, flattened with thin and small lumen

31

what type of cells do collecting ducts and thick segments both have? (in contrast to squamous cells of the thin segment of the loop of henle?

cuboidal cells

32

describe the shapes of the lumen of dct and pct

pct have a star shaped lumen, with a brush border
dct have a round lumen with a distinct border

33

describe the diameters of dct vs proximal tubules

the outside diameters of prox tubules are larger than those of distal tubules

34

do proximal or distal tubules have more nuclei in their cross sections?

the distal tubules have more, but have less than CDs.

35

describe the walls of the collecting ducts

they are cuboidal and smaller than those of proximal tubules. they also display a relatively larger number of nuclei than do comparable segmetns of proximal tubules.

36

what two cells types can make the walls of the thin segments?

low cuboidal cells or simple squamous

37

when looking at a histo slide near a corpuscle, will more of the visible areas be proximal or distal?

proximal

38

What is the beginning of the nephron?

the renal corpuscle

39

what brings blood directly to teh renal capillaries? away from them?

afferent arteriole
efferent arteriole (STILL artery)

40

Is the afferent or efferent arteriole alrger?

afferent is always larger

41

What does the renal corpuscle consist of?

glomerulus ( a tuft of capillaries)
bowman's capsule (two layers, visceral and parietal)
urinary space (between visceral and parietal layers)

42

where does the ultrafiltrate drain to WITHIN the renal corpuscle?

the urinary space

43

what and where are the mesangial cells?

that phagocytose debris, provide structural support, and secrete substances (il1) for repair of the glomerulus
they are located amongst the cappilaries

44

what are the different types of nephrons?

cortical nephrons
juxtamedullary nephrons
intermediate neprhons

45

what are cortical nephrons

have a short loop of henle, located near the surface of the kidney

46

what are juxtamedullary neprhons

close to the medullary boundary, and have long loops of henle

47

what are intermediate nephrons

those with intermediate loops of henle

48

what separates the cortex from the medulla?

the arcuate artery

49

what are the subdivisions of the cortex?

cortical labyrinths
medullary rays

50

what are the cortical labyrinths

one of the subdivisions of the cortex
consist of renal corpuscles, proximal convoluted and distal convoluted tubules

51

what are medullary rays?

subdivision of the cortex, consisting of aggregation of straight tubules and collecting ducts, lies between the cortical labyrinths.

52

on a histological slide, why are medullary rays so easy to identify?

they are multiple straight lines surrounded on each side by normal looking histology

53

what is a lobule?

consists of the medullary ray and adjacent half of labyrinths
parallels the organization of lobes (which are medullary pyramids and overlying 1/2 of renal columns)

54

where in the kidney does the majority of cardiac output go?

90% goes to the cortex

55

Which artery carries blood to the kidney?

the renal artery

56

what is the arterial pathway and divisions?

renal artery - lobar arteries - interlobar arteries - arcuate arteries - interlobular arteries - afferent arterioles - tuft of capillaries - efferent arterioles - peritubular capillaries -

57

explain the different formations of efferent arterioles in the cortical vs juxtamedullary areas?

those in cortical area produce the peritubular capillary network that surrounds local tubules
those in the juxtamedullary glomeruli descend into medulla to from arteriole rectae

58

LOOK UP EFFERENT ARTERIOLES MAKING PERITUBULAR CAPILLARY AND ARTERIOLE RECTAE

YEA..... DO IT

59

where are interlobular arteries?

between lobules...as the name implies

60

what are the three principal functions of nephrons?

filtration of blood making ultrafiltrate
reabsorption (mostly in pct)
secretion

61

where does filtration primarily occur

glomerulus, bc it contains the filtration apparatus

62

how much do the two kidneys filter per day

180 l/day or 125 ml/min

63

what are the three components of the filtration apparatus?

1. fenestrated endothelium of glomerulus
2. basement membrane of the glomerulus (loops of cpaillaries)
3. basement membrane of the podocytes

64

what do podocyte processes form?

numerous secondary processes called pedicels (or foot processes) around glomerulus

65

what are the elongated spaces between pedicels called?

filtration slits

66

What part is considered the ultimate barrier?

the ultimate barrier is the lamina densa

67

why is the lamina densa considered such a good barrier?

only molecules that are neutrally charged and less than 70000 daltons can pass through the lamina densa

68

why and proteins generally excluded by the lamina densa?

the lamina densa is made of heparin, which is negatively charge. likewise most proteins are negatively charged. so albumin, which is small enough to pass through, will not because of the charge of the protein

69

How is the basal lamina different in diabetes mellitus?

it is thicker than normal and functionally leaky so an excessive amount of protein gets lost in the urine.
May lead to low blood albumin (leading to edema)
all of this together is called nephrotic syndrome

70

Where do reabsorption and secretion occur?

tubules

71

What is reabsorption?

when filtered products in the renal tubules are reabsorbed back into the peritubular capillaries

72

what is secretion?

when prodcues (h k nh3 etc) from peritubular capillaries are secreted into the provisional urine of the tubules and collecting ducts

73

what is the major site of reabsorption

proximal convuluted tubule (where most h20 and electrolytes and all glucose is reabsorped)

74

Where does secretion largely occur?

distal part of nephron (thin limb and distal tubules) and collecting ducts

75

what types of interactions largely manage reabsorption and secretion?

electrochemical reactions

76

what does the juxtamedullary apparatus consist of?

macula densa, juxtaglomerular cells (on afferent and efferent arterioles), and extraglomerular mesangial cells

77

what does juxtaglomerular apparatus do?

regulates blood pressure

78

how are the macula densa cells different from the adjacent tubule cells?

they are narrower, usually taller and more crowded

79

what do the macula densa cells do?

they monitor blood volume and sodium concentration

80

Under what conditions do jg cells activate a system for restoring homeostasis?

Under low sodium intake or decreased volume of circulating blood, jg cells active renin-angiotensin-aldosterone system.

81

Give an overview of regulation of blood pressure by jg cells

macula densa cells monitor physiological conditions and communicate with jg cells
jg cells contain granules of renin which is released when signaled to by macula densa cells.

82

where are the jg cells located?

they are located on the exterior of the afferent arteriole

83

what do all excretory pathways except the urethra contain in terms of general structure?

mucosa, muscularis, adventitia or serosa

84

all excretory passages except the lower part of the urethra are lined by ___________?

transitional epithelium

85

what is the lower part of the urethra lined with

stratified or pseudostratified columnar epithelium

86

Make sure you are practicing for the practical

yep

87

In the kidney, papillary ducts:
a. release urine into renal pelvis
b receive ultrafiltrate from urinary space
c release urine into minor calyces
d receive urine from distal convoluted tubules
e release urine into straight connecting ducts

c

88

what tubular segment contains the macula densa?
proximal convoluted tubule
distal convoluted tubule
distal straight tubule
proximal straight tubule
thin limb

c

89

podocytes form?

the visceral layer of bowmans capsule

90

cells in which structure are responsible for the repair of the glomerulus?

mesangium

91

the macula densa is a specialized region of the

distal straight tubule