HOMEOSTASIS

Question 1

what is homestatis?

Answer 1

-Homeostasis is the ability to maintain a constant
internal environment.

-This involves keeping certain physiological variables within a normal range, to allow cells to function at optimal conditions.

Question 2

what is homeostatis controlled by?

Answer 2

Homeostasis is controlled by the nervous system and/or endocrine system (hormones).

Question 3

examples of homestatis in the human body?

Answer 3

• body temperature
• water balance
• blood pH
• CO2 concentration
• blood glucose levels

Question 4

what is negative feedback?

Answer 4

In negative feedback systems, when a deviation from the ‘norm’ is detected, it will initiate a response to return the system to its ‘norm’. (If conditions are too high then there are responses to lower it, or if conditions are too low there are responses to raise it)

Question 5

what is thermoregulation?

Answer 5

Thermoregulation is control of body temperature to

ensure optimum temperature for enzymes.

Question 6

what is the temp for thermoregulation for humans?

Answer 6

37C

Question 7

If body temperature falls too low…?

Answer 7

reactions become too slow for cells to survive.

Question 8

If body temperature rises too high…?

Answer 8

the body’s enzymes are at risk of denaturing.

Question 9

what are changes in body temp deceted by cold/warm skin?

Answer 9

thermoreceptors

Question 10

what is the hypothalamus?

Answer 10

The hypothalamus is the area of your brain
responsible for controlling temperature. Within the
hypothalamus the thermoregulatory centre detects
changes in blood temperature.

Question 11

cooling mechanism, sweating?

Answer 11

• Sweat glands open ensuring that water is lost to the skin

- The evaporation of this water from the skin causes a cooling effect on the body

Question 12

cooling mechanism, dialtion of arterioles (vasodilation) in the skin?

Answer 12

This results in more blood being carried to the surface of the skin so that heat can be lost by radiation to the environment.

Question 13

cooling mechanism, behavoirs?

Answer 13

• taking off clothes
• limiting excess movement
• air conditioning

Question 14

warming mechanism, increased rate of metabolism?

Answer 14

• Shivering.

- Muscular contractions require respiration to occur, thus releasing heat as a by-product.

Question 15

warming mechanism, contriction of arterioles (vascontriction) in the skin?

Answer 15

• This results in less blood being transferred to the skin and more blood transferred to internal organs
• Less heat is lost by raditation

Question 16

warming mechanism, contraction of erector pill muscles?

Answer 16

-raised hairs (goose bumps/pimples) trap an insulating layer of air

Question 17

warming mechanism, behavoirs?

Answer 17

• increased movement
• huddling
• reduction of exposed surfaces