Excretion

Question 1

Excretion

Answer 1

Removal of metabolic wastes

Question 2

What organs are involved in excretion in humans?

Answer 2

Kidneys, skin, lungs, liver

Question 3

Skin

Answer 3

Excretes sweat(water&salts), including urea

Question 4

Lungs

Answer 4

Excrete water vapor and CO₂ from the Krebs cycle

Question 5

Liver

Answer 5

• Doesn’t excrete anything from the body
• Site of deamination of amino acids
• Production of urea

Question 6

Kidneys

Answer 6

• Excrete excess water and urea
• Adjusts volume and concentration of urine
• Filter 1500 liters of blood per day
• Produce 1.5 liters of urine

Question 7

Why is the kidney able to respond quickly to changing requirements of the body?

Answer 7

• Under hormonal control
• Antidiuretic hormone(ADH) targets the collecting tube of the nephrons

Question 8

Antidiuretic Hormone (ADH)

Answer 8

• Targets the collecting tube of the nephron
• regulates blood presure by cotnrolling how much water is reabsorbed by the kidneys

Question 9

Nephron

Answer 9

• Basic functional unit of the kidney
• Consists of:
  
  • Glomerulus
  • Bowman’s Capsule
  • Loop of Henle
• Job:
  
  • Filtration
  • Secretion
  • Reabsorption
  • Excretion

Question 10

Glomerulus

Answer 10

A cluster of capillaries that sits inside the BOwman’s capsule

Sieve that only amino acids and glucose can pass through, not blood or proteins

Question 11

Bowman’s capsule

Answer 11

Cup-like structure around the glomerulus and forms the starting end of the tubule

Question 12

Filtration

Answer 12

• Diffusion through the glomerulus to the Bowman’s capsule; Passive and nonselective
• Glucose, salts, vitamins, wastes(rea)
• Glomerulus — Bowman’s capsule —- loop of Henle —— collecting duct/tubule —- ureter and urinary bladder(temporary storage) —- urethra — out of body

Question 13

Secretion

Answer 13

• Active, selective uptake of molecules that didn’t get filtered
• Occurs in the tubules of the nephron

Question 14

Reabsorption

Answer 14

• Most of the water and solutes (glucose, amino acids, vitamins) that entered during filtration are transported back into the capillaries and back to body
• Occurs in tubule, loop of Henle, collecting tubule
• Longer the loop of Henle, greater reabsorption of water

Question 15

Aldosterone

Answer 15

• Produced by adrenal cortex
• Stimulates reabsorption of Na+ and secretion of K+
• Leads to a rise in blood volume and blood pressure
• secreted in response to low extracellular sodium
• Conserve water and sodium