Physiology 2

Question 1

When does the body temperature rise?

Answer 1

When heat production exceeds heat loss

Question 2

When does the body temperature decrease?

Answer 2

When heat loss surpasses heat production

Question 3

What is heat a by product of?

Answer 3

Metabolism

Question 4

Name 3factors heat is influenced by?

Answer 4

• Basal metabolic rate of body cells
• Increased metabolism from muscle activty
• Effects of hormones like throxyine, growth hormones and testtosterone

Question 5

Name and describe the 2 steps heat transfer occurs

Answer 5

1. Conducting heat from internal organs to the skin.

2.Transferring heat from the skin to the surroundings

Question 6

Name insulators in the insulator system and their role

Answer 6

• Skin, subcutaneous tissues and fat
• They reduce the heat loss

Question 7

What is the role of insulation system

Answer 7

It allows skin temperature to mach the surroundings while maintaining stable internal core temperatures

Question 8

Explain how the blood vessels in the skin work

Answer 8

-Skin has a venous plexus beneath it, recieving blood from the capillaries
- In hands, feet and ears arteriovenous anastomes direclty supply bood to the plexus.

Question 9

What is the role of High blood flow?

Answer 9

• It effectively conducts heat from the body core to the skin

Question 10

What is the function of reduced blood flow

Answer 10

• Minimizes heat transfer

Question 11

What is the blood flow to the skin regulated by and controlled by?

Answer 11

-It is regulated by vasoconstriction of arterioles and arteriovenous anastomoses.
Controlled by the sympathetic nervous system in response to changes in body core and environmental temperature.

Question 12

Name the 3 methods of heat loss

Answer 12

• Radiation
• Conduction
• Evaporation

Question 13

What happens in Radiation?
When does heat loss occur ?

Answer 13

• Heat radiates as infrared rays
• Heat loss occurs if the bodys temperature is higher than its surroundings ?

Question 14

What happens in conduction?

How is heat transferred ?
When does heat transfer stop?

Answer 14

• Heat transfers via direct contact
• Heat transfer stops when air temperature equals skin temperature unless the heated air is replaced

Question 15

What happens in convection?

How is heat transferred?

Answer 15

• Heat is transferred from the skin to air and carried away by moving air currents