Homeostasis

Question 1

Define homeostasis

Answer 1

Maintenance of a constant internal environment despite external changes; a system in dynamic equilibrium

Question 2

What are the 8 human functional characteristics?

Answer 2

1. Maintaining boundaries
2. Movement
3. Responsiveness
4. Digestion
5. Metabolism
6. Excretion
7. Reproduction
8. Growth

Question 3

What are the 5 human survival needs?

Answer 3

1. Nutrients
2. Oxygen
3. Water
4. Normal body temperature
5. Appropriate atmospheric pressure

Question 4

What are the 3 components of a homeostatic control system?

Answer 4

1. Receptor
2. Control centre
3. Effector

Question 5

What is the function of the receptor?

Answer 5

Detects changes in the environment and informs the control centre via the afferent pathway

Question 6

What is the function of the control centre?

Answer 6

Receives information and determines what the response will be

Question 7

What is the function of the effector?

Answer 7

Decides how the response is executed by receiving information from the control centre via the efferent pathway

Question 8

What is the afferent pathway?

Answer 8

Stimulus –> Receptor –> Control centre

Question 9

What is the efferent pathway?

Answer 9

Control centre –> Effector –> Response

Question 10

How does negative feedback work?

Answer 10

• When a stimulus causes conditions to change, the effectors counteract this change to reduce/stop it
• When the desired level has been reached, negative feedback shuts off the original stimulus to maintain homeostasis

Question 11

Give 5 examples of negative feedback mechanisms

Answer 11

1. Thermoregulation
2. Blood pressure
3. Blood glucose
4. Hunger physiology
5. Exercise

Question 12

Describe the process of thermoregulation

Answer 12

Stimulus - external temperature decreases
Receptor - thermoreceptors in hypothalamus and skin
Control Centre - hypothalamus
Effectors - muscles, organs and glands
Response - vasoconstriction, increase in cellular metabolism, shivering

Question 13

Describe the process of maintaining blood pressure

Answer 13

Stimulus - blood pressure increases
Receptor - pressure receptors in carotid arteries
Control Centre - medulla
Effectors - heart muscle
Response - HR decreases so pressure is reduced

Question 14

How does positive feedback work?

Answer 14

When a stimulus causes conditions to change, positive feedback increases the effect of the stimulus so that the reactions occurs at a faster rate

Question 15

Give 4 examples of positive feedback mechanisms

Answer 15

1. Blood clotting
2. Childbirth
3. Breastfeeding
4. Menstrual cycle

Question 16

Describe the process of childbirth

Answer 16

Stimulus - baby moving further down birth canal
Receptor - pressure receptors in cervix
Control Centre - hypothalamus
Effector - posterior pituitary gland
Response - more oxytocin is released, causing the uterus to contract more vigorously to push the baby out

Question 17

What is anatomy?

Answer 17

The study of body shape and structure

Question 18

What is physiology?

Answer 18

The study of bodily functions

Question 19

What is cytology?

Answer 19

The study of plant and animal cells

Question 20

What is epidemiology?

Answer 20

The study of the spreading and incidence of diseases

Question 21

What is metabolism?

Answer 21

The chemical processes that occur in the body

Question 22

What is histology?

Answer 22

The study of tissue structure

Question 23

What is anabolism?

Answer 23

Synthesis of complex molecules

Question 24

What is catabolism?

Answer 24

Breaking down of complex molecules