Excretory System

Question 1

Glomerulus filtration

Answer 1

Occurs at renal corpuscle
Plasma, fluid and some nutrients from blood are forced out of glomerulus and then collected by glomerular capsule
Afferent to efferent arteriole- increase pressure and forces fluid out
Glomerular capsule and glomerulus= 1 cell thick and allows rapid collection of fluid
Fluid forced out of glomerulus and collected by glomerular capsule= filtrate

Question 2

Reabsorption

Answer 2

Many components of plasma that is filtered out is useful
Water, glucose, amino acids, ions (Na, Cl, Ca, K) and some waste (Urea, Co2)
Proximal/distal convoluted tubule and loop of henle- increases surface area and therefore increase reabsorption

Question 3

Facultative reabsorption

Answer 3

Active process
Regulation of reabsorption of water depending on body’s requirements
Affects concentration of urine

Question 4

Tubular secretion

Answer 4

Adding of material to filtrate from blood
Potassium, hydrogen, ammonia, urea, creatinine, some drugs (penicillin)
Active process
Removes unwanted fluid from body
Controls pH of blood- to increase blood pH, hydrogen and ammonia is secreted

Question 5

Excretion of lungs

Answer 5

Waste- carbon dioxide and water

Process- cellular respiration

Question 6

Excretion of kidney

Answer 6

Waste- water, ions including potassium and sodium, urea, uric acid
process- deamination

Question 7

Excretion of sweat glands

Answer 7

Waste- salt, urea, lactic acid, water

Process- sweat released

Question 8

Excretion of alimentary canal

Answer 8

Waste- bile and undigested chyme

Process- digestion

Question 9

Role of liver in excretion

Answer 9

Deamination= because Proteins unable to be stored, amino acids are converted into urea to be eliminated
Amino acid + oxygen -> Co2 + ammonia -> urea + water
Amino acid- amine- ammonia- urea
Ammonia= toxic
Liver cells rapidly convert ammonia into urea

Question 10

Nephron suited to its function

Answer 10

-Glomerular capsule surrounds glomerulus
Allows filtered out to be quickly collected
-Arteriole leading out of glomerulus has smaller diameter
Increases pressure and Allows more fluid to be filtered out
-2 convoluted tubule and loop of henle
Increases surface area which allows more reabsorption to take place
-millions of nephron and 2 kidneys
More excretion to take place

Question 11

Urine formation 3 steps

Answer 11

1) glomerulus filtration
2) reabsorption
3) tubular secretion