Topic 5a- Homeostatis/ thermoregulatory

Question 1

What is homeostatis?

Answer 1

Homeostatis is the regulation of the conditions inside your body (and cells) to maintain a stable internal environment in response to changes in both internal and external conditions.

Question 2

Which part of the brain controls body temperature?

Answer 2

Thermoregulatory centre

Question 3

How does the thermoregulatory centre function?

Answer 3

• Recieves information about body temperature from receptors in the skin
• Receptors in the thermoregulatory centre in the brain measure the temperature of the blood running through it

Question 4

How is body temperature maintained? How does the body respond to a rise in body temperature?

Answer 4

A negative feedback system
1. When receptors detect the core body temperature is too high, they send impulses to the thermoregulatory centre, which acts as a coordination centre.
2. The thermoregulatory centre processes the information from the temperature receptors and triggers the effectors automatically.
3. The effectors produce a response that increases the amount of heat lost from the body causing the body to cool down.

Question 5

What are responses that reduce core body temperature?

Answer 5

1. Hairs on the skin lie flat to prevent air being trapped near the skin and insulating the body.
2. Sweat is produced by the sweat glands. Sweat evapourates from the skin, transferring energy to the environment.
3. Vasodilation- blood vessels supplying the skin capillaries dilate so more blood flows closer to the surface of the skin.

Question 6

How is body temperature maintained? How does the body respond to a drop in body temperature?

Answer 6

A negative feedback system
1. When receptors detect the core body temperature is too low, they send impulses to the thermoregulatory centre, which acts as a coordination centre.
2. The thermoregulatory centre processes the information from the temperature receptors and triggers the effectors automatically.
3. The effectors produce a response that reduces the amount of heat lost from the body causing the body to warm up.

Question 7

What are responses that decrease core body temperature?

Answer 7

1. Hairs on skin stand up- this traps insulating air next to the skin.
2. No sweat is produced.
3. Vasoconstriction- blood vessels supplying the skin capillaries constrict so less blood flows close to the surface of the skin and less energy is transferred from the skin to the environment.
4. Shivering- muscles automatically contract requiring respiration which transfers some energy to warm the body.