Excretion

Question 1

Excretion:

Answer 1

The removal of the waste substances of metabolic reactions from the body

Question 2

Skin excretes:

Answer 2

Water, Mineral Ions

Question 3

Lungs excrete:

Answer 3

Carbon Dioxide, Water

Question 4

Kidneys excrete:

Answer 4

Water, Mineral Ions, Urea

Question 5

Role of the Kidney:

Answer 5

Regulate water (and salt) content of blood
Excrete toxins and nitrogenous wastes

Question 6

Osmoregulation:

Answer 6

The process of maintaining water and salt concentrations across membranes within the body

Question 7

Kidney Explanation:

Answer 7

Two bean-shaped organs that filter the blood

Question 8

Ureter Explanation:

Answer 8

Tube connecting the kidney to the bladder

Question 9

Bladder Explanation:

Answer 9

Organ that stores urine produced by the kidney

Question 10

Urethra Explanation:

Answer 10

Tube that connects the bladder to the exterior, where urine is released.

Question 11

Urine is composed of:

Answer 11

Water, salts(ions) and urea

Question 12

Renal Pelvis:

Answer 12

Links the kidney to the ureter

Question 13

Cortex contains
What occurs:

Answer 13

1. Tiny blood vessels 2. Nephrons
   Ultrafiltration

Question 14

Medulla contains
What occurs:
Connects to:

Answer 14

1. Nephrons 2. Capillaries
   Osmoregulation
   Renal Pelvis

Question 15

Parts of the Nephron in order

Answer 15

Glomerulus (Ball of Capillaries)
Bowman’s Capsule (Ultrafiltration)
Proximal Convoluted Tubule
Loop of Henle
Distal Convoluted Tubule
Collecting Duct

Question 16

Ultrafiltration:

Answer 16

The capillaries in the glomerulus get narrower further on, forcing blood through under high pressure
This forces smaller molecules carried in the blood out of the capillaries and into the Bowman’s capsule (Glomerular filtrate)
Substances forced out: Glucose, water, urea, salts
Substances remaining: Cells and large proteins

Question 17

Water is reabsorbed at:

Answer 17

Loop of Henle, Collecting Duct

Question 18

Salts are reabsorbed at:

Answer 18

Loop of Henle

Question 19

Glucose is reabsorbed at:

Answer 19

Proximal Convoluted Tubule (via active transport)

Question 20

Less water means urine is more:

Answer 20

Concentrated

Question 21

Adaptation of the nephron for glucose:

Answer 21

Many mitochondria to provide energy for active transport

Question 22

Diabetes:

Answer 22

At a normal blood glucose level, there are enough gates in the PCT to remove all the glucose from the filtrate
People with diabetes cannot control their blood glucose levels and they are often very high
Hence, not all the glucose can be filtered out, and it continues in the filtrate and ends up in the urine
This is why doctors test urine for presence of glucose to check for diabetes

Question 23

Role of ADH

Answer 23

Negative Feedback
The Hypothalamus detects low water content, stimulating the pituitary gland
The pituitary gland secretes increased amounts of ADH
ADH is carried in the blood
ADH arrives at the collecting duct, and causes it to become more permeable to water
More water is reabsorbed into the blood, less urine is produced, more concentrated