09.09 Kidney

Question 1

Answer 1

Located retroperitoneally, between T12 and L3 vertebrae

cortex: outer light granular layer from capsule to the base of pyramids.

Medulla: inner dark striated layer with piramids

Sinus/pelvis: connective and adipose tissue

Question 2

Answer 2

calyces: minor (8-18/kidney) and major (2-3/kidney)

Pelvis: joining of the major calyces

hilum: includes vessels nerves and ureter

Question 3

Question 4

Question 5

Question 6

Answer 6

1. Aorta → renal artery (through hilum)→ segmental artery → lobar artery → arcuate artery → interlobular artery (between columns) → afferent arteriole (surrounds glomerulus)→ glomerulus (capillaries) → efferent arteriole (surrounds glomerulus) → peritubular capillaries (surrounds convoluted tubules) and vasa recta (bundles of thin vessels that carry blood to and from medulla) → interlobular vein → arcuate vein → lobular vein → renal vein → interior vena cava.

Question 7

Question 8

Answer 8

i. Renal Corpuscles (in cortex)
a. Bowman’s capsule: parietal layer (outer wall) and visceral layer (inner wall)

Question 9

Answer 9

Podocytes:

Modified squamous epithelial cells. They sit on top of the glomerular capillaries not quiet touching each other and the spaces between the podocytes are called slits through which blood can be filtered.

Question 10

Answer 10

where blood and urine leave the corpuscle

Question 11

Answer 11

where blood and urine leave corpuscle

Question 12

Answer 12

• podocytes surround capillary loops and their foot processes form slits
• negative charge on the podychtes keep negatively charged protein from filtering through

Question 13

Answer 13

1. capillray network for filteration
2. includes afferent and efferent arterioles
3. capillary loops are supported by mesangium: for filteration and phagocytes
4. capillaries have a fenestrated endothelium.
5. urine consisting of water and waste products collects initially in Bowman’s space in the glomerulus

Question 14

Answer 14

Juxtaglomerular apparatus (JGA) in cortex

• regulates renal blood flow and filteration rate.
• located between vascular pole and distal convulted tubule of the same nephron

Question 15

Answer 15

granular renin-producing cells sit on afferent and efferent arteriole and can sense arterial BP, sodium concentration, or renal sympathetic nerve activity

Question 16

Answer 16

Macula densa cells are sensitive to sodium concentration in the distal tubule

Question 17

Answer 17

Proximal tubule in the cortex

• microvilli makes brush border
• eosinophilic cytoplasm (lots of mitochondria)
• cuboidal cells
• gets urine from Bowman’s space
• 80% of filtered urine is reabsorbed here

Question 18

Question 19

Answer 19

Distal Tubules

• Distinct apical ends ⇒ distinct lumen

• Less mitochondria ⇒ less eosinophilic (means it can be dyed pink)
• Cuboidal cells (increased mitochondria makes cytoplasm more eosinophilic.
• Secretion of ions due to hormonal control
• Aldosterone mediates reabsorption of Na+ and H2O as needed to regulate BP.

Question 20

Answer 20

D=distal

P=proximal

Question 21

Question 22

Answer 22

Medulla has no glomeruli.

Contains portions of proximal and distal convulated tubules.

Question 23

Answer 23

CD= collecting ducts

TS = thin segments of the Loop of Henle

DT = distal tubules

Question 24

Answer 24

a. Descneding: thin (simple squamous)
b. Ascending : thick (simple cuboidal)
c. Absorbs Na+ ⇒ increase in [Na+] in surrounding parenchyma

Question 25

Answer 25

a. Simple cuboidal and clear cytoplasm
b. Further adjust urine volume and solute concentration

• Antidiuretic hormone (ADH) from posterior pituitary gland makes cell more permeable to water → absorption of free H2O → more concentrated urine.
• Increase in [Na+] in medulla draws water out once cells are permeable.

Question 26

Answer 26

series of straight capillaires that lies parellel to the Loop of Henle

Question 27

Question 28

Answer 28

1. Papillary duct (of Bellini)
   
   • convergence of collecting ducts
   • tall columnar cells with clear cytoplasm
   • large lumen taht open into calyces
2. Calyx: transitional epithelium

Question 29

Question 30

Answer 30

1. Carry urine from renal pelvis to trigone of bladder
2. Located inferior to the blood vessels
3. Has transitional epithelium
4. Thin lamina propria

Question 31

Answer 31

• inner longitudinal and outer circular layer of smooth muscle
  
  • Lower third has another outer longitudinal layer of smooth muscle
  • For continuous peristalsis
  • Ureter is convoluted at resting which allows for easy expansion by fluid.

Question 32

Question 33

Answer 33

• Ureters enter the bladder at an angle at the trigone, producing one-way valve . This prevents reflux of urine.
• transitional epithelium produces a mucoid secretion with natural anti-bacterial properties to prevent infection

Question 34

Answer 34

• think lamina propria
• submucosa
• detrusor muscle contracts bladder
  
  • inner longitudinaNext >>l, middle circular and outer longitudinal

Question 35

Answer 35

1. Exits the bladder below the trigone
2. Males longer (prostatic urethra extends through the prostate, penile urethra and urethral meatus)
3. Females: shorter

Question 36

Answer 36

4. Upper 1/3 is transitional epithelium. Lower 2/3 is stratified squamous epithelium.
5. Lamina propria with vessels (more in males)