Renal system 2 of 2

Question 1

a specialization of the nephron involved in the blood pressure regulation. What are the main structures? Cells (just list them)

Answer 1

juxtaglomerulat apparatus (JGA)

JGA is a specialized region near the renal corpuscle that is important in the regulation of systemic blood pressure

1. main structures
   
   1. afferent arteriole
      
      1. just before it enters the bowmans capsule
   2. posrtion of the DCT
      
      1. the same nephron that loops back against the afferent arteriole
2. special cell types
   
   1. juxtaglomerular cells
   2. macula densa
   3. extraglomerular mesangial cells

Question 2

List, locate and define the cells of the juxtaglomerular aparatus

Answer 2

1. juxtaglomerular cells
   
   1. location
      
      1. modified smooth muscle cells layered around the afferent arteriole immedietly before it enters the glomerulus
   2. content/funtcion
      
      1. posess
         
         1. renin
            
            1. enzyme contained within the cytoplasmic granules
         2. mechanoreceptors
            
            1. sensing arteriole blood pressure
2. macula densa- specialized cells of the JGA
   
   1. location
      
      1. modified cells of the DCT immidietly adjacent to the renal corpuscle at the vascular pole
      2. appear as thin columnar cells and are thus taller and most tightly packed than other cells of DCT
   2. content/function
      
      1. posess
         
         1. chemoreceptors
            
            1. sensitive to Na+ level of DCT FILTRATE
3. extraglomerular mesangial cells ( lacis, polkissen cells)
   
   1. location
      
      1. lie between the macula densa and bowman’s capsule
   2. contents/function
      
      1. they perform the same functions as the other mesangial cells
         
         1. supportive
         2. contractile
         3. defensive

Question 3

modified smooth muscle cells, posses renin and sense arteriole blood pressure

Answer 3

juxtaglomerular cells

Question 4

appwar as thin columnar cells in the DCT

Answer 4

macula densa

Question 5

have supportive function, similar to mesangial cells. Where are they located though?

Answer 5

Question 6

Which ones are how do the cells of the JGA affect a drop in blood pressure?

Answer 6

1. decreased blood pressure - triggered two ways
   
   1. first trigger- pressure receptors in afferent arterioles
      
      1. JUXTAGLOMERULAR CELLS to release
         
         1. renin : INTO BLOOD STREAM OF AFFERENT ARTERIOLE
   2. second trigger-chemoreceptors in the MACULA DENSA sense a change in the Na+ concentration. Decreased concentration indicates a decrease in GFR which is read as a drop in blood pressure

Question 7

describe the regulation of blood pressure through renin system

Answer 7

1. blood pressure drop is sensed by
   
   1. Juxtaglomerular cells
      
      1. pressure receptors on afferent arterioles
   2. macula densa cells
      
      1. sensitive to the GFR rate via Na+ concentration, which decreases with blood pressure drop
2. renin is released by juxtaglomerular cells into the afferent arteriole
3. Renin acts on the plasma globulin->angiotensinogen**, producing 10 amino acid polypeptide called **angiotensin 1
4. angiotensin 1 is cleaved by angiotensin converting enzyme(ACE)**, into **angiotensin 2
   
   1. ACE is secreted by lung endothelium
5. angiotensin 2
   
   1. powerful vasoconstrictor
      
      1. increasing BP by constricting peripheral blood vessels
   2. stimulates release of aldosterone from the adrenal cortex.
      
      1. aldosterone promotes the reabsorption of Na+ in the DCT and water follows, this increases plasma volume = increasing blood pressure

Question 8

what are the two ways that angiotensin 2 increases blood pressure?

Answer 8

1. acts as a power vasoconstrictor for peripheral blood vessels
   
   1. allowing blood to stay in a “central/trunk” region
2. stimulates aldosterone release from the adrenal cortex
   
   1. aldosterone promotes the reabsorption of Na+ in the DCT and water follows.
   2. this increases the

Question 9

describe the blood flow to the glomerulus from the aorta

Answer 9

1. aorta
2. renal artery
3. segmental artery
4. interlobar arteries
5. arcuate arteries
6. interlobar arteries
7. afferent arterioles
8. glomerulus
9. efferent arteriole
10. peritubular capillaries
11. interolobar v
12. arcuate v
13. interlobar v
14. renal v

Question 10

what happens right when the renal arteries enter the kidney?

Answer 10

branch in to segmental arteries

Question 11

formed of interlobar arteries at the corticomedullary junction

Answer 11

arcuate arteries are formed of interlobar arteries at cortico medullary junction

Question 12

segmental arteries give rise to what and where to they travel?

Answer 12

segmental arteries give rise to interlobar arteries that travel up renal columns between its pyramids

Question 13

each of these enters the bowman capsule to form the glomerulus

Answer 13

each of the afferent arterioles enters a bowmans capsule to from a glomerulus

Question 14

what surround the PCT and DCT in the cortex?

Answer 14

efferent arterioles of cortical nephrons are small in diameter and form the peritubular capillary network that surround the PCT and DCT in the cortex

Question 15

formation and names of the long, straight vessels that form a haripin loop

Answer 15

Efferent arterioles of the juxtamedullary nephrons are larger and course into the medulla where they branch into many blood vessel, thus forming the vasa recta

vasa recta

1. long, straight vessels that form hairpin-U turns at various levels in the medulla turning back and running close to the descending limb of loop of Henle as well as other bbranches of vasa recta

Question 16

describe the route, function, and portions of the vasa recta

Answer 16

vasarecta

1. route
   
   1. long, straight vessels that form hairpin-U turns at various levels in the medulla.** turning bakc and running close to the **descending limb of loop of Henele as well as other branches of vasa recta
2. function
   
   1. counter current exchange
   2. preserving osmolality of the medullary interstitium
      
      1. blood and interstitium osmolality equilibriate
3. portions- 2 main
   
   1. descending portion of vasa recta
      
      1. arterial and is composed of small diameter vessels with continuous endothelium
   2. ascending venous side
      
      1. larger diameter vessels with thin, fenestrated walls
      2. the ascending venous limb drains into interlobular veins->arcuate vein-> interlobar vein->renal vein

Question 17

what would happen if the vasa recta were straight vessels coursing quickly through the medulla?

Answer 17

if the vasa were straight vessels coursing through the medulla, the interstitial salts would quickly be carried away in the bloodstream, leading to no water(solvent) drag, or very little = blood and urine osmolality would not be even

Question 19

only 2% of renal blood flow enter the medulla through the

Answer 19

vasa recta

Question 20

Answer 20

Question 21

where do the ureters pierce the bladder?

Answer 21

ureters are hollow, cylindrical tubes that drain urine collected at the major calyce. Each ureter pierces the base of the urinary bladder

Question 22

describe the histology of the ureter

3 layers and important aspects involved

Answer 22

1. mucosa
   
   1. transitional epithelium
      
      1. lining the lumen surface, usually about 3-5 cell layers thick
   2. lamina propria
      
      1. composed of relatively dense irregular fibroelastic connective tissue
2. muscularis
   
   1. proximal 2/3, near kidney
      1. 2 smooth muscle layer
         
         1. inner circular layer
         2. outer longitudinal layer
      2. distal- near bladder (distal 1/3)3 layers
         
         1. inner circular
         2. outer longitudinal
         3. another outer longitudinal
3. the outter connective tissue
   
   1. covering blends with the connective tissue of the kidney capsule at one end and the bladder wall at the other end.

Question 23

describe the ureter middle layer: mucularis. how does it change between the kidney and the bladder?

Answer 23

1. muscularis
   
   1. proximal 2/3, near kidney
      
      1. 2 smooth muscle layer
         
         1. inner circular layer
         2. outer longitudinal layer
   2. distal- near bladder (distal 1/3)
      
      1. 3 layers
         
         1. inner circular
         2. outer longitudinal
         3. another outer longitudinal

Question 24

describe the histology of the urinary bladder

Answer 24

1. layers
   
   1. transitional epithelium
   2. lamina propria
   3. muscular layer- two longitudinal layers between a middle circular layer
      
      1. muscular coat-deep to lamina propria
      2. middle layer
      3. detrusor muscle-smooth muscle
   4. adventitia
      
      1. dense irregular collagenous connective tissue

Question 25

what is deep to the lamina propria, in the urinary bladder?

Answer 25

deep to the lamina propria = muscular coat

Question 26

what is the smooth muscle of the urinary bladder?

Answer 26

detrusor muscle

Question 27

where is the muscular layer of the urinary bladder easy to visualize and what is seen?

Answer 27

neck of the bladder

1 circular layer sandwhiched between two longitudinal layers

Question 28

what is the outer covering of the urinary bladder?

Answer 28

the outer covering, adventitia= dense irregular collagenous connective tissue

Question 29

compare the male and female urethra

1. function

Answer 29

1. males
   
   1. function: passage for
      
      1. urine
      2. sperm
   2. regions-3
      
      1. prostatic
         
         1. 3-4 cm long
         2. lies entirely within the prostate gland.
         3. lined by transitional epitheliumand has oprning for
            
            1. ducts of the prostate
            2. paired ejaculatory ducts
      2. membranous
         
         1. short segment lined by stratified squamous or pseudocolumnar epithelium
      3. spongiosa
         
         1. lined by
            
            1. stratified squamous epithelium
            2. patches of psudostratified columnar epithelum
         2. smoothe muscle deep to mucosa in two layers- continuous with the bladder
            
            1. inner longitudinal
            2. outer circular
         3. skeletal muscle surrounds portion of urethra, allowing for voluntary micturition
2. female
   
   1. bladder to external orifice
   2. lined
      
      1. stratified squamous epithelium
      2. patches of pseudostratified columna epithelium
   3. smooth muscle i same as males
   4. skeletal muscle lines the urethra premitting voluntary control of micturition

Question 30

generate a concept map describing the flow of blood and urine.

Answer 30