9 - excretory system

Question 1

organs of excretion

Answer 1

• lungs: get rid of carbon dioxide and water
• skin: get rid of water, salt, small amounts of urea
• waste: get rid of ammonia
• waste: get rid of urine

Question 2

the role liver plays in excretion

Answer 2

the liver transforms material into removable wastes

Question 3

deamination

Answer 3

• the removal of nitrogen containing amino groups in proteins forming ammonia.
• the ammonia combines with the carbon dioxide in the liver forming urea

Question 4

uric acid is formed by

Answer 4

the breakdown of amino acids

Question 5

Primary functions of the urinary system

Answer 5

1. removes salts and nitrogenous wastes from the blood
2. maintains water balance,
3. maintains PH
4. controls red blood cell production and blood pressure

Question 6

the kidneys

Answer 6

• kidneys filter blood

- blood is carried to the kidney by the renal artery and carried back to the heart by the renal vein

Question 7

kidney - capsule

Answer 7

an outer layer of connective tissue that surrounds the kidney

Question 8

kidney - renal medulla

Answer 8

the inner layer of the kidney, found beneath the cortex

Question 9

kidney - renal pelvis

Answer 9

the centre chamber of each kidney, that connects to the ureters

Question 10

kidney - renal vein

Answer 10

veins that branch from the kidney to the inferior vena cava they carry deoxygenated blood to the heart

Question 11

kidney - renal artery

Answer 11

arteries that branch into the kidney from the aorta they carry oxygenated blood from the heart

Question 12

kidney - nephrons

Answer 12

the site of blood filtration

Question 13

nephron - afferent arteriole

Answer 13

branches from the renal artery and carries blood to the glomerulus

Question 14

nephron - efferent arteriole

Answer 14

carries blood away from the glomerulus

Question 15

nephron - glomerulus

Answer 15

a tuft of capillaries that is surrounded by the Bowmans capsule
- the site of filtration

Question 16

nephron - Bowmans capsule

Answer 16

• a cup like structure that surrounds the glomerulus

- receives the filtered fluids from the glomerulus

Question 17

nephron - proximal tubule

Answer 17

joins the Bowman’s capsule with the loop of Henle

- the site of reabsorption from the nephron back to the blood

Question 18

nephron - distal tubule

Answer 18

the last segment of the nephron

• connects the loop of Henle to the collecting duct
• reabsorption can occur here

Question 19

nephron - loop of Henle

Answer 19

takes urine from the proximal tubule to the distal tubule

• descending part is permeable to water and ions and is the site of some reabsorption
• ascending part is impermeable to water so sodium ions are actively transported out

Question 20

nephron - collecting duct

Answer 20

collects urine from many nephrons and carries the urine to the renal pelvis

Question 21

stage 1 - Filtration

Answer 21

• the pores in the glomerulus are large enough to allow some substances in the blood plasma to pass easily into the Bowmans capsule to form the filtrate
• force filtration relies on blood pressure

Question 22

stage 2 - reabsorption

Answer 22

proximal tubules: water, amino acids, sodium, glucose
descending  loop of henle: water
ascending loop of henle: salt 
distal tubules: salt and water
collecting duct: water

Question 23

stage 3 - secretion

Answer 23

• opposite of reabsorption (gets rid of)
  proximal convoluted tubules: hydrogen, urea, uric acid, creatin
  loop of henle: urea
  distal convoluted tubules: Hydrogen, potassium, ammonium

Question 24

maintaining blood PH at 7.4

Answer 24

if blood is too acidic, kidneys will excrete hydrogen ions and bicarbonate is reabsorbed
if blood is too basic, kidneys will not excrete hydrogen ions and bicarbonate is not reabsorbed

Question 25

water balance

Answer 25

when blood plasma becomes too concentrated (deydration) osmotic pressure increases

Question 26

what do osmorecpetors do

Answer 26

they send an signal to the pituitary gland to release ADH (antidiuretic hormone)

Question 27

Balance of salt - adolsterone

Answer 27

• the kidneys regulate salt balance

- adolsterone stimulates the distal tubule and collecting ducts to reabsorb sodium into the blood