lect 30 & 31: renal histology

Question 1

what type of epithelium is in the thick segments of the loop of henle

Answer 1

simple low cuboidal epithelium

Question 2

what type of epithelium is in the thin segments of the loop of henle

Answer 2

simple squamous epithelium

Question 3

describe the cells of the thick ascending limb

Answer 3

have no brush border and more basal vertical striations

Question 4

what is the main function of the loop of henle

Answer 4

establish the counter-current exchange system which creates the osmotic conditions necessary to pull water out of the distal convoluted tubule and collecting duct in the presence of ADH

Question 5

What does the ascending thin limb actively pump out and why

Answer 5

chloride ion allowing sodium ions to follow

Question 6

what is the distal convoluted tubule lined with (epithelium)

Answer 6

simple cuboidal epithelium with smaller cells than those of prox conv tubule

Question 7

when is the distal convoluted tubule permeable to water

Answer 7

when ADH is present

Question 8

what is the function of ADH

Answer 8

reduces water loss

Question 9

what type of epithelium is in the walls of the collecting duct

Answer 9

simple cuboidal epithelium

Question 10

what are the 2 major specialized cell types associated with the collecting duct

Answer 10

principal cells and intercalated cells

Question 11

what are the layers of the renal pelvis, ureter and urinary bladder

Answer 11

mucosa
submucosa
muscularis
adventitia

Question 12

what are characteristics of the mucosa of the renal pelvis, ureter, and urinary bladder

Answer 12

transition epithelium
basement membrane
lamina propriar of FECT
some loose lymphoid tissue and a few smooth muscle cells

Question 13

what forms the detrusor muscle

Answer 13

layers of smooth muscle in urinary bladder

Question 14

what are characteristics of the prostatic urethra

Answer 14

secretion of urethra passing through prostate gland
mucosa lined with transitional epithelium
highly vascularized with veins with abundant elastic tissue

Question 15

what are characteristics of membranous urethra

Answer 15

tall pseudostratified columnar cells but variable

extends through urogenital diaphragm and receives striated muscle cells forming the external sphincter of the bladder

Question 16

what epithelium is in the cavernous urethra (male)

Answer 16

lined with pseudo stratified epithelium with patches of stratified squamous epithelium

Question 17

what are lucanae of morgagni

Answer 17

glands in the male urethra that are invaginations of mucous membrane containing single or groups of intraepithelial mucous cells

Question 18

what are glands of littre

Answer 18

branched tubular glands opening into the lacunae of morgagni

Question 19

what epithelium lines the mucosa of the female urethra

Answer 19

primarily with stratified or pseudo stratified columnar epithelium with intraepithelial nests of mucous glands

Question 20

where is angiotensin I primarily produced

Answer 20

in lungs

Question 21

where does ACE come from

Answer 21

pulmonary and renal endothelium

Question 22

what does the urinary system consist of

Answer 22

two kidneys and ureters

the urinary bladder and urethra

Question 23

what is the medullary area divided into

Answer 23

outer medullary area deep to the juxtamedullary cortex

inner medullary area deep to the outer medullary area

Question 24

what is the functional unit of the kidney

Answer 24

nephron

Question 25

what is each nephron composed of

Answer 25

renal corpuscle & renal tubule

Question 26

what is the renal corpuscle composed of

Answer 26

cup-shaped capsule (bowman's capsule) | glomerulus

Question 27

define glomerulus

Answer 27

capillary knot situated between 2 arterioles that lies within the indentation of the Bowman's capsule

Question 28

what is the renal tubule a continuation of

Answer 28

bowman's capsule

Question 29

where do nephrons empty into

Answer 29

collecting ducts

Question 30

where do collecting ducts empty into

Answer 30

renal pelvis

Question 31

where are the renal corpuscles of the cortical nephrons located

Answer 31

cortex

Question 32

where do the glomeruli of the cortical nephrons empty into

Answer 32

capillary networks that surround the proximal and instal convoluted tubules of their nephrons and those of surrounding nephrons

Question 33

what are the loops of henle like in cortical nephrons

Answer 33

short and do not extend deeply into the medulla

Question 34

where are the renal corpuscles of the juxtamedullary nephrons located

Answer 34

in the cortex next to cortical-medullary junction

Question 35

where do the glomeruli of juxtamedullary nephrons empty into

Answer 35

vasa recta consisting of long, straight arterioles and venues that run parallel to the loops of Henle and collecting ducts

Question 36

what are the loops of Henle like in juxtamedullary nephrons

Answer 36

long and extend deeply into medulla

Question 37

where is the glomerulus inserted

Answer 37

between afferent and efferent arterioles

Question 38

where is a typical capillary bed inserted

Answer 38

between arteriole and venule

Question 39

where does the efferent arteriole feed into

Answer 39

``` Either capillary loop (vasa recta) or capillary network (peritubular capillaries) ```

Question 40

what do juxtaglomerular cells secrete

Answer 40

renin

Question 41

what is renin

Answer 41

hypertensive factor

Question 42

what type of muscle cells are at vascular pole of juxtaglomerular cell

Answer 42

circular smooth muscle cells

Question 43

what is the outer layer of the bowman's capsule and what type of epithelium is it

Answer 43

parietal layer: simple squamous epithelium | * squamous epithelium is continuous with the simple cuboidal epithelium of the proximal convoluted tubule

Question 44

what is the inner layer of bowman's capsule and what is it

Answer 44

visceral layer: inner layer of podocytes in contact with the endothelium of the glomerular capillaries

Question 45

where is the bowman's space and what is it continuous with

Answer 45

located between the parietal and visceral layers and is continuous with the lumen of the proximal convoluted tubule

Question 46

what is the renal corpuscle involved in producing

Answer 46

a filtrate of blood

Question 47

what are the three processes involved in the formation of urine and where do they occur

Answer 47

filtration (renal corpuscle) reabsorption (renal tubule) secretion (renal tubule)

Question 48

what is the mesangium formed by

Answer 48

mesangial cells embedded in a mesangial matrix

Question 49

where are intraglomerular mesangial cells located

Answer 49

located between nearby capillaries in the glomerulus and cover endothelium not covered by podocytes

Question 50

where are extraglomerular mesangial cells located

Answer 50

between the afferent and efferent arterioles at the vascular pole and are associated with the juxtaglomerular apparatus

Question 51

what are the functions of mesangial cells

Answer 51

contract, phagocytic, proliferative, synthesize, secrete, respond, provide mechanical support and regulate blood flow

Question 52

how are mesangial cells contractile

Answer 52

utlize cytoskeletal contractile proteins to modify blood flow through glomerular capillaries

Question 53

how are mesangium cells phagocytic

Answer 53

take up worn out glomerular basal lamina for recycling and also phagocytose immunoglobulins trapped in the basal lamina

Question 54

what do mesangium cells synthesize

Answer 54

matrix and collagen

Question 55

what do mesangium cells secrete

Answer 55

prostaglandins and endothelins

Question 56

what do mesangium cells respond to

Answer 56

angiotensin II

Question 57

what does endothelia do

Answer 57

causes vasoconstriction of the afferent and efferent glomerular arterioles.

Question 58

what do cytoskeletal contractile proteins do

Answer 58

modify the blood flow through glomerular capillaries by contracting mesangial cells

Question 59

what do cytokines induce

Answer 59

inflammatory reactions leading to occlusion of the capillary lumen

Question 60

what are the components of the juxtaglomerular apparatu

Answer 60

macula densa extraglomerular mesangial cells juxtaglomerular cells

Question 61

what does the macula densa respond to

Answer 61

responds to changes in sodium and chloride concentration in urine and hypotensin

Question 62

what is the macular densa involved in regulating

Answer 62

involved in regulation of fluid-electrolyte balance and blood pressure regulation

Question 63

define juxtaglomerular cells

Answer 63

modified smooth muscle cells associated with macula dense and afferent arteriole

Question 64

what are juxtaglomerular cells innervated by

Answer 64

sympathetic nerve endings which increase renin release

Question 65

what are the parts of the renal tubule

Answer 65

``` proximal convoluted tubule descending limb of henle loop of henle ascending limb of henle distal convoluted tubule ```

Question 66

what is the distal convoluted tubule continuous with

Answer 66

collecting duct

Question 67

what are the components of the renal filtration barrier

Answer 67

fenestrated endothelium of glomerular capillaries fused basal laminae of endothelial cells and podocytes filtration slits

Question 68

what does the basal lamina contain

Answer 68

type 4 collagen, fibronectin, laminin, heparin sulfate

Question 69

what are filtration slits created by

Answer 69

adjacent pedicels of podocytes

Question 70

how are the pedicels of the filtration slits attached to the basal lamina

Answer 70

via alpha 3 beta 1 integrins

Question 71

what can and cannot get through the renal filtration barrier

Answer 71

can: water, glucose, and most ions cannot: proteins and negatively charged molecules

Question 72

where does the proximal convoluted tubule extend

Answer 72

extends from urinary pole of the renal corpuscle to the beginning of the loop of henle

Question 73

what type of epithelium is in the proximal convoluted tubule

Answer 73

simple cuboidal epithelium made up of truncated pyramidal cells

Question 74

what does the proximal convoluted tubule remove

Answer 74

glucose and amino acids

Question 75

what does the proximal convoluted tubule reabsorb

Answer 75

most of filtrate (including water), most sodium and chloride ions