Homeostasis

Question 1

What is homeostasis?

Answer 1

When the internal remains relatively constant

Question 2

What are stressors?

Answer 2

Changes in the internal(pH balance, high/low blood sugar)/external(heat, noise, lack of
o2) environment

Question 3

What homeostatic function does the integumentary system do?

Answer 3

Controls body temp with sweat glands

Question 4

What homeostatic function does the musculo/skeletal system do?

Answer 4

Maintains calcium in blood, ensures nutrition, smooth muscle does blood pressure and cardiac muscle circulates blood.

Question 5

What homeostatic function does the nervous system do?

Answer 5

Communicates/assesses stressors. Instructs other mechanisms.

Question 6

What homeostatic function does the endocrine system do?

Answer 6

Regulates metabolic activities and blood levels.

Question 7

What homeostatic function does the Circulatory system do?

Answer 7

Transports o2, nutrients and hormones. Removes waste and maintains water and ionic tissue balance.

Question 8

What homeostatic function does the Respiratory system do?

Answer 8

Maintains blood oxygen content, eliminates co2.

Question 9

What homeostatic function does the Digestive system do?

Answer 9

maintains food molecules and building materials.

Question 10

What homeostatic function does the urinary system do?

Answer 10

Regulates blood chemistry with endocrine system.

Question 11

What homeostatic function does the reproductive system do?

Answer 11

Passes on genes and maintains sex characteristics.

Question 12

What are the 3 parts of the system control model?

Answer 12

The control centre, receptor and effector.

Question 13

What does the control centre do?

Answer 13

Determines set point/range and analyses information to choose response. Variable maintained.

Question 14

What does the receptor do?

Answer 14

Detect change, sends information to control centre through afferent pathway.

Question 15

What does the effector do?

Answer 15

Carries out response along efferent pathway.

Question 16

What is negative feedback?

Answer 16

Depresses stimulant so control is shut off. Returns body from out of steady to steady state.

Question 17

What is positive feedback?

Answer 17

Enhances stimulus so reaction continues at faster rate.

Question 18

How does the homeostasis of a rise in body temp change fix itself?

Answer 18

Temperature rises, the change is sensed by hypothalamus which sends nueral messages to sweat glands in skin. Sweat glands respond by increasing perspiration which when evaporates, heat is lost.

Question 19

How does the homeostasis of a low body temp change fix itself?

Answer 19

Temperature lowers, hypothalamus senses change, brain tells body to begin muscle contractions which makes the body shiver. Also capillaries in skin constrict and there is a hormonal change.

Question 20

How does the homeostasis of blood glucose levels occur?

Answer 20

If the sugar levels are high, the pancreas releases insulin, glycogen is then formed from glucose in the liver and inturn the cells uptake the glucose lowering the level.
If the sugar level is low, the pancreas releases glucagon which breaks down to glucose and increases level.

Question 21

How does the positive feedback mechanism of blood clotting occur?

Answer 21

Blood vessel damage occurs, platelets then cling to the injured site in which they release a chemical that attract more platelets. From here the pile of platelets grow forming a clot.

Question 22

How does the positive feedback mechanism of labour contractions occur?

Answer 22

Baby moves down birth canal which puts pressure on cervix. This excites pressure receptors in uterine wall and the receptors send message to the brain. Brain responds by releasing oxytocin hormone which is transported to uterus. Oxytocin stimulates uterine walls to contract and increase of contractions moves baby down canal.

Question 23

What is allostasis?

Answer 23

Remaining stable by being variable. Is stable by physiological and behavioural changes.