Renal Anatomy and Histo

Question 1

Blood flow through kidney

Answer 1

Aorta
Renal a.
Segmental a.
Interlobar a.
Arcuate a.
Cortical radiate a.
Afferent arteriole
Glomerulus
Efferent arteriole
Peritubular capillary
Vasa recta
Cortical radiate v.
Arcuate v.
Interlobar v.
Segmental v.
Renal v.
IVC

[afferent arteriole thru vasa recta are nephron-associated]

Question 2

2 major components of a nephron

Answer 2

Glomerulus

Renal tubule

Question 3

2 major components of renal corpuscle

Answer 3

Glomerulus
Glomerular capsule (Bowman's)

Question 4

3 layers of glomerular capsule and associated histo

Answer 4

Parietal layer - simple squamous epithelium

Visceral layer - podocytes

Glomerular space - contains primary filtrate

Question 5

What are the 2 poles of the renal corpuscle?

Answer 5

Vascular pole = associated with afferent and efferent arterioles

Urinary pole = origin of PCT

Question 6

Renal corpuscles are only found in the _____ of the kidney

Answer 6

Cortex

Question 7

Bowman’s capsule is continuous with the first portion of the _____

Answer 7

Nephron

Question 8

______ = single layer of cells having pedicles that interdigitate and make filtration like barrier; filtration slits have ultrathin _______ made of several EC protein molecules critical in regulating filtration

Answer 8

Podocytes; diaphragm

Question 9

________ cells are phagocytic, and also have the ability to regulate GFR by preventing glomerular distension (contractile properties)

Answer 9

Mesangial

Question 10

Albuminia is characterized by albumin in the urine. It indicates damage to which of the following:

A. Filtration barrier
B. Glomerular basement membrane
C. Podocytes
D. Nephrons

Answer 10

B. Glomerular basement membrane

Question 11

What is the most abundant kidney tubule and is found only in the renal cortex

Answer 11

PCT

Question 12

Describe epithelium of PCT

Answer 12

Simple cuboidal to columnar epithelium with abundant microvilli (brush border)

Basal and lateral cell membranes are highly folded to increase surface area

Question 13

What differentiates PST from PCT

Answer 13

PST is not as tall as PCT with less well developed brush border. PST is equipped with high affinity sodium glucose transporter

[PCT has abundant mitochondria, most active in resorption and secretion, has Na/K pumps, aquaporins, numerous types of glucose and amino acid transporters]

Question 14

Describe epithelium of the LOH

Answer 14

Thin limb = thin, permeable simple squamous epithelial wall lacking brush border, some nuclei bulge into lumen

Thick ascending segment = simple cuboidal epithelium with numerous microvillia but no visible brush border

Question 15

The loop of henle sets up the _______ gradient

Answer 15

Hyperosmotic

Question 16

The DCT is confined to the ______

Answer 16

Cortex

Question 17

Describe epithelium of DCT

Answer 17

Lined with simple cuboidal epithlium with sparse microvilli

Luminal surface is smoother than the PCT and fewer in number. Cells are taller than the thick ascending LOH

Question 18

________ influences Na+ resorption at the DCT

Answer 18

Angiotensin II

Question 19

Describe epithelium of collecting ducts

Answer 19

Lined with simple cuboidal epithelium but are simple columnar at their ends

Question 20

What are the 2 individual cell types of the collecting duct epithelium

Answer 20

Light cells = principal cells (target of aldosterone)

Dark cells = intercalated cells (H+ and bicarb transport)

Question 21

What is the primary target of aldosterone in the kidney

Answer 21

Principal cells (light cells) of the collecting duct

Question 22

Function of juxtaglomerular granular cells

Answer 22

Mechanosensory, secrete renin if BP is low

Question 23

Location and Function of macula densa

Answer 23

Distal end of thick ascending LOH; acts as chemoreceptor by monitoring salt levels; signals release of renin from JG granular cells if Na+ is low

Question 24

Describe epithelium lining of most of the urinary tract, including its 3 layers

Answer 24

Transitional epithelium = urothelium

Layers:
Superficial (stretched and relaxed)
Intermediate (sliding layer)
Basal (stem cells)

Fusiform vesicles (fuse with PM when cell is distended, endocytosed when not distended)

Urothelial plaques (form impermeable barrier)

Question 25

Describe histology of ureters

Answer 25

Transitional epithelium with 3 indistinct muscularis layers:

Inner longitudinal
Outer circular
Outer longitudinal

Adventitia = typical CT

Question 26

Describe epithelium of urethra

Answer 26

Changes with location:

Transitional epithelium - possible near origin of urethra at bladder

Majority of urethra is pseudostratified columnar

Distal end is stratified squamous

Question 27

3 named regions of male urethra

Answer 27

Prostatic urethra - passes through prostate gland

Membranous urethra - through the urogenital diaphragm; homologous to that found in the female

Spongy (penile) urethra - passes through the length of the penis; longest part encased in cylindrical erectile tissue (corpus spongiosum) in the penis to reach external urethral orifice