Homeostasis - Fluid Regulation

Question 1

Where are the locations where fluid is distributed in the body?

Answer 1

1. Intracellular fluid
2. Extracellular fluid

Question 2

What is extracellular fluid?

Answer 2

The fluid outside the cells.

Question 3

What is intracellular fluid?

Answer 3

The fluid inside the cells. Also known as cytosol.

Question 4

What is included in the extracellular fluid?

Answer 4

1. Intravascular fluid
2. Interstitial fluid
3. Transcellular fluid

Question 5

What is intravascular fluid?

Answer 5

Is blood plasma located within the blood vessels.

Question 6

What is interstitial fluid?

Answer 6

The fluid found between cells.

Question 7

What is transcellular fluid

Answer 7

The fluid is found in specific body regions such as the spinal cord and eyes.

Question 8

Define osmotic concentration

Answer 8

Osmotic concentration is the concentration of solutes.

Question 9

What else is osmotic concentration also known as?

Answer 9

Osmolarity.

Question 10

What is osmotic pressure?

Answer 10

Osmotic pressure is the tendency of a solution to take in the pure solvent. The greater the difference in osmotic concentrations between two solutions, the greater the osmotic pressure.

Question 11

What is metabolic water?

Answer 11

Is water formed as a by-product of cellular respiration.

Question 12

What is excretion

Answer 12

Excretion is the removal of waste products of metabolism from the body.

Question 13

Where are four excretions that occur in the body?

Answer 13

1. Lungs
2. Sweat glands
3. Alimentary canal
4. Kidneys

Question 14

Describe how the lungs are involved in the process of excretion.

Answer 14

The lungs are involved in the excretion of carbon dioxide. The body cannot use carbon dioxide and it is carried in the blood until it reaches the lungs where it is excreted.

Question 15

Describe how the sweat glands are involved in the process of excretion.

Answer 15

Sweat glands in the skin secrete water containing by-products of metabolism such as salts, urea and lactic acid.

Question 16

Describe how the alimentary canal is involved in the process of excretion.

Answer 16

The alimentary canal passes out bile pigments that entered the small intestine with bile. They leave the body with faeces. The faeces are not considered excretory products as they have not been produced by cells.

Question 17

Describe how the kidneys are involved in the process of excretion.

Answer 17

The kidneys will remove urea, which is produced in the liver during the breakdown of proteins.

Question 18

What is the function of antidiuretic hormone (ADH) in a nephron?

Answer 18

ADH is produced by the hypothalamus and released from the posterior lobe of the pituitary gland. ADH increases the permeability of the distal convoluted tubule and collecting tubule, increasing the reabsorption of water in the blood.

Question 19

What do high levels of ADH mean?

Answer 19

There is a low volume of water in urine which leads to a decrease in urine output.

Question 20

What do low levels of ADH mean?

Answer 20

There is a high volume of water in urine which leads to increased urine output.

Question 21

What is the aldosterone hormone also referred to as?

Answer 21

The “salt retaining” hormone.

Question 22

What is the function of aldosterone in a nephron?

Answer 22

Aldosterone is secreted by the adrenal cortex and acts on the distal convoluted and collecting tubules to increase sodium ions reabsorbed into the bloodstream and the amount of potassium secreted in the urine.

Question 23

Where is aldosterone secreted from?

Answer 23

The Adrenal cortex.

Question 24

What are four responses aldosterone is secreted from the adrenal cortex?

Answer 24

1. Decrease in the concentration of sodium ions in the blood
2. Decrease in blood pressure
3. Decrease blood volume
4. Increase in the concentration of potassium ions in the blood

Question 25

Write an SRMERF for the thirst response.

Answer 25

S - Decrease in water concentration/Increase in osmotic pressure.
R - Osmoreceptors in the thirst centre of the hypothalamus.
M - Thirst centre in Hypothalamus.
E - Hypothalamus causes a person to feel thirsty.
R - The person responds to feeling thirsty by drinking water. Water drunk is absorbed into the blood from the alimentary canal.
F - Increase in water concentrations/decrease in osmotic pressure.

Question 26

Define dehydration.

Answer 26

Dehydration is the excessive loss of water and accompanying salts from the body. Dehydration occurs when the body loses more fluid than it takes in.

Question 27

Define water intoxication.

Answer 27

Water intoxication is caused by drinking too much water when the amount of salt in the body is low.

Question 28

What proportion of total body fluid is intracellular fluid?

Answer 28

2/3 of total body water.

Question 29

What proportion of total body fluid is extracellular fluid?

Answer 29

1/3 of total body fluid.

Question 30

What proportion of total body fluid is intravascular fluid?

Answer 30

Approximately 1/4 of extracellular fluid.

Question 31

What proportion of total body fluid is interstitial fluid and transcellular fluid?

Answer 31

Approxmetialy 3/4 of extracellular fluid.

Question 32

Write an SRMERF on how ADH responds to an increase in osmotic pressure/decrease in water concentration.

Answer 32

S - Increase in osmotic pressure/decrease in water concentration.
R - Osmoreceptors in the hypothalamus.
M - Hypothalamus
E - Hypothalamus stimulates the release of ADH from the posterior lobe of the pituitary gland.
R - ASH works on the DCT and CD in the nephron to increase the permeability to water and increase the reabsorption of water in the blood.
F - Decerase in osmotic pressure/increase in water concentration.