Lecture 20 - Histology of the kidney and urinary system Flashcards Preview

1060 Human form and function > Lecture 20 - Histology of the kidney and urinary system > Flashcards

Flashcards in Lecture 20 - Histology of the kidney and urinary system Deck (18):
1

What is the urinary system composed of ?

 

 
 

Two kidneys

Two ureters

One bladder

One urethra

 
 

2

Short summary of how the urinary system works 

 

Urine produced in the kidneys is conducted by the ureters to the bladder where it is stored until voided via the urethra

 

3

What is the Hilum?

 

The hilum (in the kidney): site of entry and exit of the renal blood vessels and ureter. 

 

4

What is a nephron?

 

A nephron is the functional unit of the kidney; consists of renal corpuscle and renal tubule

 

Renal corpuscle – plasma filtration. consists of 2 structures:

Bowman’s capsule; distended, blind end

of the renal tubule

Glomerulus; packed capillaries that

invaginate Bowman’s capsule derive

from the afferent arteriole

 

Renal tubule – reabsorption.

extends from Bowman’s capsule to the

collecting duct. Convoluted in shape,

four histological-physiological zones

a: proximal convoluted tubule (PCT)

b: loop of Henle

c: distal convoluted tubule (DCT)

d: collecting tubule

 

 

5

Plasma filtrate from the glomerular capillaries passes through 3 layers before entering the renal tubule, which ?

 

Capillary endothelium – fenestrated

Glomerular basement membrane – thick (~ 300 nm) as formed by 2 basal laminae of podosomes & endothelia. Otherwise normal composition (collagen IV, laminin, proteoglycan rich in heparin sulphate)

Podocytes – interdigitating pedicels (primary and secondary processes). The secondary pedicels attach directly to the glomerular basement membrane.

Gaps between pedicels are filtration slits.

 

 

6

What is the ureter?

 

A muscular tube that conduct urine from the kidney to the bladder

 

7

What is the ureter formed of ?

 

Two layers of smooth muscle: Longitudinal (L); inner layer and really an elongated spiral. Circular (C); outer layer and also a (tight) spiral.

Lumen of ureter is lined by transitional epithelium, with deep lamina propria rich in collagen (LP).

An adventitia surrounds ureter: note the arteries (A) and veins (V).

 

 

8

What are the 3 layers of the bladder ?

 

Wall of bladder consists of 3 smooth muscle layers (as does lower section of ureter) and abundant elastic fibres.

IL:   inner longitudinal

OC: outer circular

OL:  outermost longitudinal

The adeventitia (A) contains arteries, veins and lymphatics

 

9

 

 

Pyramid

 

10

 

 

Papilla

 

11

 

 

Acuate artery

 

12

 

 

Interlobular artery

 

13

 

 

Cut edge of capsule

 

14

 

 

Interlobar artery

 

15

 

 

Renal artery 

 

16

 

 
 

Renal vein

 
 

17

 

 

Renal pelvis

 

18

 

 

Cut edge of pelvis