nephron anatomy and physiology

Question 1

the functional unit of the kidney?

Answer 1

nephron

Question 2

what is a nephron

Answer 2

long tubular structure and associated blood vessels

Question 3

where are most nephrons found

Answer 3

in the renal cortex but some extends into the medulla

Question 4

how many nephrons does each kidney contain

Answer 4

1.3 million

Question 5

two major portions of each nephron

Answer 5

renal corpuscle and the renal tubule

Question 6

what does the renal corpuscle contain

Answer 6

glomerulus- a ball of capillaries and the bowman’s capsule- a hollow cup shaped structure surrounding the glomerulus

Question 7

what does the renal tubule contain

Answer 7

a 3cm long tube with 3 segments- proximal and distal convoluted tubule and the nephrons loop

Question 8

3 major processes of urine formation

Answer 8

glomerular filtration
tubular reabsorption
tubular secretion

Question 9

What happens during glomerular filtration

Answer 9

Blood enters through the afferent arteriole.
Fluid and solutes from the blood pass through specialized filtration cells called podocytes into the Bowman’s capsule.
Once in the capsule, the fluid is called filtrate.
The remaining blood leaves through the efferent arteriole and the filtrate continues into the renal tubule.

Question 10

what happens during tubular reabsorption

Answer 10

Most of the water (80%) and many ions and nutrients are reabsorbed into the blood through both passive and active transport.
This occurs mostly in the proximal convoluted tubule.

Question 11

what happens during tubular secretion

Answer 11

Additional substances are actively removed from the blood (drugs, steroids).
H+ and K+ are fine-tuned to control blood pH.