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SAT II BIOLOGY > Excretion > Flashcards

Flashcards in Excretion Deck (15)
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1
Q

Excretion

A

Removal of metabolic wastes

2
Q

What organs are involved in excretion in humans?

A

Kidneys, skin, lungs, liver

3
Q

Skin

A

Excretes sweat(water&salts), including urea

4
Q

Lungs

A

Excrete water vapor and CO2 from the Krebs cycle

5
Q

Liver

A
  • Doesn’t excrete anything from the body
  • Site of deamination of amino acids
  • Production of urea
6
Q

Kidneys

A
  • Excrete excess water and urea
  • Adjusts volume and concentration of urine
  • Filter 1500 liters of blood per day
  • Produce 1.5 liters of urine
7
Q

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

A
  • Under hormonal control
  • Antidiuretic hormone(ADH) targets the collecting tube of the nephrons
8
Q

Antidiuretic Hormone (ADH)

A
  • Targets the collecting tube of the nephron
  • regulates blood presure by cotnrolling how much water is reabsorbed by the kidneys
9
Q

Nephron

A
  • Basic functional unit of the kidney
  • Consists of:
    • Glomerulus
    • Bowman’s Capsule
    • Loop of Henle
  • Job:
    • Filtration
    • Secretion
    • Reabsorption
    • Excretion
10
Q

Glomerulus

A

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

11
Q

Bowman’s capsule

A

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

12
Q

Filtration

A
  • 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
13
Q

Secretion

A
  • Active, selective uptake of molecules that didn’t get filtered
  • Occurs in the tubules of the nephron
14
Q

Reabsorption

A
  • 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
15
Q

Aldosterone

A
  • 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