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Year 2 - Renal (DP) > Histology > Flashcards

Flashcards in Histology Deck (42):
1

How does the kidney act as an endocrine gland?

Produces:
- Renin
- Erythropoietin

2

What is the kidney covered by?

Thin, strong, collagen capsule

3

What is the medulla divided into and what direction do they point in?

Pyramids:
- Apices point to hilum (papillae)

4

What is each nephron composed of?

Renal corpuscle
Renal tubules

5

What is the approximate length of each nephron?

45-65mm

6

What is the renal corpuscle formed from?

Glomerulus
Bowman's capsule

7

What epithelium makes up the Bowman's capsule?

Simple squamous

8

How many cell layers separate the blood and glomerular filtrate? What are these layers?

Two:
- Capillary endothelium
- Specialised epithelium on top of capillaries:
- Podocytes

9

What do the podocytes form?

Filtration slits (~25nm wide)

10

What lies between the cell layers separating the blood and glomerular filtrate?

Thicker basal lamina (0.3μm instead of 0.05μm):
- Made of Glycosaminoglycan (GAGs)

11

What forms the mesangium and what does it do?

Mesangial cells
Functions as connective tissue core:
- Support
- Removes debris

12

Where does the Loop of Henle lie?

In the renal medulla

13

What is the structure of the cells lining the thin descending limb of the Loop of Henle?

Simple squamous
Nuclei protrude into lumen

14

What is the structure of the cells lining the thick ascending limb of the Loop of Henle?

Simple cuboidal
Abundant mitochondria

15

Where is the distal convoluted tubule found?

Cortex

16

What lines the distal convoluted tubule?

Simple cuboidal epithelium

17

What does the DCT lack that the PCT has?

A brush border

18

Where do the collecting ducts run alongside?

Straight segments of PCT and DCT in cortex

19

Coupled with the structures collecting ducts run alongside, what is the name for these bundles?

Medullary rays:
- Parallel bundles

20

What direction do the medullary rays run?

Perpendicular to kidney surface

21

In the medulla, what do the collecting ducts run alongside?

Loops of Henle

22

What epithelium lines the collecting ducts?

Simple columnar

23

Where do the juxtaglomerula apparatuses form?

At site where DCT passes:
- Adjacent to vascular pole of same renal corpuscle

24

What are the three components of the juxtaglomerular apparatus?

Macula densa
Juxtaglomerular cells
Extraglomerular mesangial cells/Lacis cells

25

Where does the macula densa lie?

On side of DCT closest to afferent arteriole

26

What are the features of the DCT cells?

Taller
Crowded
Intensely stained nuclei

27

What do macula densa do?

Sense DCT ion composition

28

What are the juxtaglomerular cells and what do they do?

Modified smooth muscle in afferent arteriole wall
Contain and secrete renin

29

What are the extraglomerular mesangial cells?

Modified mesangial cells that extend out of the corpuscle

30

What type of the epithelium is the urothelium?

Transitional stratified epithelium (3-6 cells)

31

What are the cells at the luminal surface of the urothelium?

Umbrella cells (domed):
- Special thickened and inflexible membrane

32

Why does the urothelium have a special structure?

Variable thickness:
- Different states of distension
Apical surface of cells have a thickened membrane:
- Impermeable

33

What lies below the urothelium and what is it?

Lamina propria:
- 2-3 layers of smooth muscle

34

How long is the urethra in women?

3-5cm

35

What epithelium is the female urethra?

Transitional and then stratified squamous

36

How long is the urethra in men?

~20cm

37

How long is the prostatic urethra and what lines it?

3-4cm
Transitional epithelium

38

How long is the membranous urethra, where does it like and what lines it?

~1cm:
- From prostate to bulb of penis
Transitional -> Stratified columnar epithelium

39

How long is the penile urethra and what lines it?

~15cm
Stratified columnar (stratified squamous at tip of penis)

40

What glands form the prostate gland?

Tubulo-alveolar

41

What type of epithelium are the tubules in the prostate gland lined with?

Simple columnar secretory epithelium with fibromuscular stroma

42

What fraction of seminal fluid volume is made up of prostate gland secretions?

~1/2