Homeostasis

Question 1

What is homeostasis?

Answer 1

process by which we adapt and adjust to changes in our environment to maintain our functional integrity

Question 2

How does homeostasis occur?

Answer 2

1) receptors detect a change in internal/external environment
2) afferent information is sent to our control centre
3) afferent information is integrated after being received by the control center
4) control center sends out efferent information to effectors to negate or amplify the change

Question 3

what are the two main homeostatic patterns?

Answer 3

• tight control (values always close to set point)

- loose control (values fluctuate around set point)

Question 4

What are the 3 feedback systems

Answer 4

• negative feedback loop
• positive feedback loop
• forward feedback system

Question 5

What happens in a negative feedback system

Answer 5

• change is opposed

- bring variable back to its set point

Question 6

What happens in a positive feedback system

Answer 6

• change is amplified

- bring variable further away from the set point

Question 7

what happens in a forward feedback system

Answer 7

change occurs in anticipation to an event

Question 8

What is gain of a regulated variable?

Answer 8

a measure of how precisely a control system can prevent deviation from homeostasis
- larger gain: more sensitive and is better maintaining a better state of homeostasis

Question 9

How does a reflex response occur

Answer 9

• requires knowledge from an integrating centre

- integration centres can connect the receptors to the effectors

Question 10

How does a local response work?

Answer 10

• occurs separate from an integrating centre

- it allows individual body parts to self-regulate their internal environment

Question 11

What things are involved in reflex responses?

Answer 11

• hormones + bloodstream
• nerves + neurotransmitters
• all of the above working together

Question 12

What things are involved in local responses?

Answer 12

• local cell only

- local cell + target cell

Question 13

What happens in the body when there is a change in arterial pressure pressure of oxygen

Answer 13

• chemosensors (in carotid and aortic bodies) detect change
• send afferent information to brainstem where it is integrated + processed
• efferent information is sent to respiratory muscles -> tidal volume + breathing freq increases/decreases

Question 14

What happens in the body when there is a change in the mean arterial pressure?

Answer 14

• mechanosensors in carotid sinus and aortic arch detect change in arterial pressure
• send afferent information to medulla, info is integrated + processed
• medulla sends efferent information -> effectors
• heart rate + periphery resistance decreases/increases

Question 15

What happens in the body when there is a change in blood glucose concentration

Answer 15

• chemosensors in pancreas (fed state) / pancreas + hypothalamus (fasting state) detect change in blood [gluc]
• send afferent info -> pancreas
• efferent info sent from pancrease -> liver, adipose tissue/skeletal muscles
• increased metabolism/storage of glucose

Question 16

What happens in the body when there is a change in core body temperature

Answer 16

• thermoreceptors detect change in body temperature
• afferent information is sent to the hypothalamus to be processed and integrated
• efferent information is sent out to the effector (sweat glands, smooth muscles in blood vessels, skeletal muscles) to nullify the change to maintain body temperature