Homeostasis Of Body Temperature

Question 0

What does a falling body temperature prompt?

Answer 0

Changes in blood flow to skin - vasoconstriction. Allows less heat to be lost via skin. Controlled by sympathetic.
Increased metabolism - hypo stimulates ant lobe which secretes TSH, to release thyroxine.
Shivering - hypo stimulates parts of brain that increase muscle tone to start moving to produce heat.
Behavioural responses - huddling, warm clothes, heating.

Question 1

What does a rising body temperature prompt?

Answer 1

Change in blood flow to skin - vasodilation. Allows heat loss via conduction, convection, radiation and evaporation. Controlled by autonomic.
Deceased metabolism - reduced secretion of thyroxine.
Sweat - cools by evaporating from body. Controlled by sympathetic.
Behavioural responses - staying still, shade, aircon.

Question 2

How does the body control thermoregulation?

Answer 2

Hypothalamus monitors temperature of blood and receives impulses from peripheral theremoreceptors in skin and mucus membrane.

Question 3

What is thermoregulation?

Answer 3

Maintaining balance between heat production and heat loss.

Question 4

Describe the feedback loop for falling body temperature.

Answer 4

Stimulus - falling body temp.
Receptor - theremoreceptors.
Modulator - hypothalamus.
Effector - shivering, vasoconstriction, increased metabolic rate.
Response - body temp rises.

Question 5

Describe the feedback loop of a rising body temperature.

Answer 5

Stimulus - rising body temperature.
Receptor - theremoreceptors.
Modulator - hypothalamus.
Effector - sweating, decreased metabolic rate, vasodilation.
Response - body temp decreases.

Question 6

Name two mechanisms the nervous system would control to maintain core temperature of a biologist in Antarctica.

Answer 6

Shivering - contraction of skeletal muscles producing heat.

Vasoconstriction - reduced diameter of blood vessels reduces blood flow to skin.

Question 7

What is the modulator for control of body temperature?

Answer 7

Hypothalamus.