Kidneys deel 1

Question 1

What are 3 Functions of kidneys?

Answer 1

• Osmoregulation: Maintaining optimal composition of fluids.
• Waste excretion (nitrogen)
• Production of hormones (repin, epo)

Question 2

What happens during Excretion of nitrogen waste? (2)

Answer 2

• Breakdown of proteins and nucleic acids into less toxic substances.
• Amino acids can turn into ammonia, urea (ureum) an uric acid.

Question 3

What are four factors of kidneys?

Answer 3

• Outer layer = cortex, inner layer = renal medulla, middle = renal pelvis
• Renal artery supplies blood, renal vein drains blood
• Almost all of the fluid is reabsorbed in blood vessels and exits through the renal vein
• Urine is collected in renal pelvis, nierbekken

Question 4

What are 4 important processes in the kidneys leading up to excretion?

Answer 4

• Filtration
• Reabsorption
• Secretion
• Excretion

Question 5

What happens during filtration?

Answer 5

Small molecules can pass through endothelial membrane because of blood pressure

Question 6

What happens during reabsorption?

Answer 6

Useful molecules are reabsorbed by active transport

Question 7

What happens during secretion?

Answer 7

Non-essential molecules and waste products are actively excreted in the filtrate

Question 8

What happens during excretion?

Answer 8

The filtrate leaves the body as urine. The amount of solutes determines whether more or less water enters the filtrate.

Question 9

What is the nephron? (5)

Answer 9

• Functional units of the kidney
• Run through both cortex and medulla of the kidney
• 1 kidney contains 1 million of nephrons, mostly in the cortex
• Long tube with twists/loops and contains glomerulus’
• Bowmans’s capsule surrounds glomerules

Question 10

Where in the nephron does filtration take place?

Answer 10

In Glomerulus

Question 11

What happens in the Nephron? (4)

Answer 11

-small molecules can move freely between glomerulus and bowman’s capsule
-every day 1600L flows through kidneys
-180L of filtrate is formed
-99% of this is reabsorbed

Question 12

What happens in the proximal tube? (4)

Answer 12

• Reabsorption of ions, water and valuable nutriens (glucose, aminoacids)
• Water follows due to osmosis
• PH regulation
• The farther into the proximal tubule, the more concentrated the filtrate

Question 13

What does excretion of toxins depend on? (4)

Answer 13

• Size of substance
• Water/fat solubility
• Saturation of toxin excretion pathways
• Functionality of renal mitochondria

Question 14

What happens in the descending Loop of Henle? (2)

Answer 14

• Water leaves filtrate, filtrate becomes more concentrated
• Descending limb contains aquaporins, but no channels for NaCl or other small soluble molecules

Question 15

What happens in the Ascending loop of Henle? (3)

Answer 15

• No aquaporins, Nacl leaves the filtrate
• Active transport
• Lower osmolarity that in the descending loop of Henle

Question 16

What is the function of the Distal tubule? (2)

Answer 16

• Regulate concentration of NaCl and K ions
• Ph regulation

Question 17

What happens in the collecting duct? (2)

Answer 17

-filtrate becomes urine
-determines how concentrated the urine will be