urinary system - week 4 TISSUE BIOLOGY

Question 1

What does the urinary system consist of?

Answer 1

2 kidneys
2 ureters
bladder
urethra

Question 2

What are the major connections of the kidney?

Answer 2

• renal artery (unfiltered blood)
• renal vein (filtered blood)
• ureter (urine exits to bladder)

Question 3

What are the functions of the kidney?

Answer 3

• extensive
• ventilation (lungs)
• osmoregulation (brain via angiotensin 2)
• blood pressure (heart)
• calcium (bones)
• metabolism (muscles)
• tissue oxygenation (blood platelets)

Question 4

What does the medulla do?

Answer 4

• regulates concentration of urine

Question 5

What does the papilla do?

Answer 5

• sieve-like, facilitates passage of urine

Question 6

What is the cortex?

Answer 6

• location where filtering begins

Question 7

Describe the kidney histology

Answer 7

capsule -> cortex -> medulla -> papilla -> calyces

Question 8

Describe the capsule

Answer 8

• made of connective tissue
• supported by underlying stratal cells (fibroblasts and myofibroblasts)
• capsule preserves hydrostatic pressure needed for filtrations
• strong cells can help repair injured kidney

Question 9

Describe the cortex

Answer 9

• directly underlying capsule
• contains filtration units (renal corpuscle of nephron)
• typically nephrons being in cortex and convolute through medulla and end up in papilla

Question 10

what is the nephron?

Answer 10

• functional unit of the kidney - production of urine

Question 11

How many nephrons are there approximately in each kidney?

Answer 11

1 mio

Question 12

What cells do nephrons consist of?

Answer 12

simple, single layer epithelium along their entire length

Question 13

Describe the renal corpuscle

Answer 13

• dense, ball-like structure enclosing tuft of capillaries (glomerulus)
• surrounded by Bowman’s capsule (urinary capsule)
• site of blood filtration - ultrafiltration
• always located in cortex

Question 14

Describe the renal tubule

Answer 14

1. proximal convoluted - in renal cortex
2. loop of hence - mostly medulla
3. distal convoluted - renal cortex
4. collection tubules/ducts - medulla

Question 15

How many litres of filtrate does a human produce a day and how much urine?

Answer 15

180 litres of filtrate
1-2 litres of urine

Question 16

If only 1% of filtrate becomes urine, what happens to the other 99%?

Answer 16

becomes reabsorbed

Question 17

how many types of nephrons are there and how are their differentiable?

Answer 17

• 3 types
• originate in different parts of cortex

Question 18

What characterises a nephron?

Answer 18

long (juxtamedullary) and short (cortical) loops of henle

Question 19

SILDE 15/43