Homeostasis And Response

Question 1

What is Homeostasis?

Answer 1

Maintaining a constant internal environment.

Question 2

What’s a stimuli?

Answer 2

Change in internal/external environment.

Question 3

What is a receptor?

Answer 3

Cells that detect a stimuli.

(Sense organ)

> skin
nose
eyes

Question 4

Function of coordination Centre?

Answer 4

Decides how to respond to stimuli.

> spinal chord
hypothalamus (brain)

Question 5

Function of Effector?

Answer 5

Causes a response.

>nervous= muscle
>endocrine= gland

Question 6

What is a response?

Answer 6

Returns body or cell back to normal.

Question 7

How does the body respond to internal/external changes?

Answer 7

Endocrine system

Nervous system

Question 8

What is a neuron?

Answer 8

Nerve cells which are adapted to carry electrical impulses from one place to another.

Question 9

What is a reflex?

Answer 9

Involuntary response to a stimuli

> breathing, digestion and dropping hot pan

Question 10

Importance of a reflex? (Unconscious response)

Answer 10

• Safety mechanism/protective
• Quick
• Unconscious=doesn’t require thought
• Innate= not learnt
• Prevent overloading in brain

Question 11

What is a reflex arc?

Answer 11

Nerve pathway that bypasses conscious part of the brain.

Question 12

Sensory neurone?

Answer 12

Sends electrical messages from receptor to relay neurone.

Question 13

Relay neurone?

Answer 13

Passes an electrical message from sensory neurone to motor neurone.

Question 14

Motor neurone?

Answer 14

Sends electrical messages to effector (muscle) to cause a response.

> muscle contracts to move hand away from stimuli

Question 15

What is the synapse?

Answer 15

Microscopic gap between end of 2 neurons where chemical messengers (neurotransmitter) travel across.

Question 16

What is a neurotransmitter?

Answer 16

Chemicals which help to pass nerve impulses from one nerve cell to the next across across synapse.

Question 17

What is the synapse process?

Answer 17

1- An electrical message causes a neurotransmitter to move to the membrane of the sensory neurone.

2- Neutransmitters released into synapse

3- They diffuse across synapse.

4- Neurotransmitters bind with specific receptors of membrane of next neurone.

5- Stimulates posy synaptic neurone to transmit electrical impulse.

Question 18

What are nerve cells?

Answer 18

> Specialised cells adapted to rapidly carry electrical impulses.

> Carry information over large distances

> One of longest cells in body.

Question 19

What is the brain?

Answer 19

> Organ which controls complex behaviours.

> Made from billions of interconnected neurones.

> 4 Regions

> Involved in hormonal and reflex response

Question 20

What is cerebral cortex? Function?

Brain

Answer 20

Outer layer of main sections of brain and responsible for more complex activities.

> Consciousness, language, intelligence + memory

Question 21

What is the cerebellum? Function?

Brain

Answer 21

Located at bottom of brain

> Muscular activities= balance

Question 22

What is the medulla? Function?

Brain

Answer 22

Located at bottom of brain

Responsible for unconscious activities

> Heart rate, breathing + digestion

Question 23

What is thermoregulation?

Answer 23

Process that allows body to maintain its core internal temperature.

> 36.5°C

Question 24

How is theemoregulation controlled?

Answer 24

Monitored and controlled by hypothalamus in brain.

HYPOTHALAMUS:

Contains temperature receptors which detect deviations in blood temp.

Question 25

What is the nervous system?

Answer 25

Central nervous system= brain + spinal chord

Peripheral nervous system= nerve cells which carry electrical impulses to or from CNS.

> Messages travel in nerves (neurones)

> Fast response

> Short lasting