Week 4 - kidney

Question 1

What does the urinary system consist of?

Answer 1

• 2 kidneys
• 2 ureters
• bladders
• urethra

Question 2

What are the major connections to 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

• ventilation, acid-base homeostasis
• osmoregulation, thirst, ventilation
• blood pressure and cardiac rhythm
• blood pressure potassium
• calcium, phosphate acid -base homeostasis in bones
• metabolism - potassium
• calcium, phosphate
• metabolism, detoxification in liver
• tissue oxygenation in blood platelets

Question 4

name the kidney histology complex

Answer 4

Capsule
Cortex
Medulla
Papilla
Calyces

Question 5

What is the capsule

Answer 5

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

Question 6

What is the cortex?

Answer 6

• Directly underlies capsule
• contains filtration units (renal corpuscle of nephron)
• typically nephrons begin in cortex and convolute through medulla, end up in papilla

Question 7

What is a nephron?

Answer 7

• funcitonal unit of kidney - production of urine - approx. 1 mio nephrons in each kidney
• consists of simple, single-layer epithelium alonf their entire length

Question 8

What is the renal corpuscle?

Answer 8

• dense, ball like structure enclosing a tuft of capillaries (glomerulus)
• site of blood filtration - ultrafiltration
• always located in cortex

Question 9

What is the renal tubule?

Answer 9

• Proximal convoluted tubule (PCT) - found in renal cortex
• loop of henle - mostly in medulla
• distal convoluted tubule - renal cortex
  Collecting tubules/ducts - in medulla

Question 10

How much urine is produced by humans in a day?

Answer 10

1-2 litres of urine

Question 11

How many types of urine are there?

Answer 11

3 - in different parts of the cortex

Question 12

What characterises a nephron?

Answer 12

Long and short loops of henle

Question 13

How do nephrons alter urine content?

Answer 13

• afferent arteriole
• reacts to pressure
• low = produces renin that cleaves angiotensisn 2
• constricts the efferent arterioles results in higher pressure more filtration
• renin stored in granules in smooth muscle cells of arteriole
• negative feedback can reduce renin