Homeostasis and Response

Question 1

What is the CNS and what does it consist of?

Answer 1

Central Nervous System - the brain and spinal cord

Question 2

What does the peripheral nervous system consist of?

Answer 2

Nerve cells that carry information to or from the CNS.

Question 3

What is an effector?

Answer 3

Parts of the body (e.g muscles and glands), that produces response to a detected stimulus.

e.g a muscle contracting to move an arm.

Question 4

What are receptors?

Answer 4

Specialised cells that can detect change in the environment and produce electrical impulses in response.

Question 5

What are Motor neurons and what do they do?

Answer 5

The nerve cell that carries electrical impulses from the CNS to effectors such as muscles or glands.

Question 6

What is a sensory Neurone and what does it do?

Answer 6

The nerve cell that transmits electrical impulses from receptors in the sense organs to the CNS.

Question 7

What is the Stimulus?

Answer 7

Something that sets off a reaction in the nervous system e.g light or heat.

Question 8

How does the information pass through the nervous system?

Answer 8

1) Information from receptors passes along cells
(neurones) as impulses to the central nervous
system,
.
2)The CNS coordinates the response of effectors
which may be muscles contracting or glands
secreting hormones.

stimulus -> receptor ->coordinator -> effector
-> response

Question 9

What are Reflex actions?

Answer 9

Actions that are automatic and rapid; they do

not involve the conscious part of the brain.

Question 10

Name a simple reflex action?

Answer 10

The pain withdrawal reflex

Question 11

What is a Reflex Arc?

Answer 11

When a nerve pathway is followed by a reflex action

Question 12

Explain the Reflex Arc that would occur when you touch something hot?

Answer 12

1) Receptor in the skin detects a stimulus (the change in temperature).
2) Sensory neurone sends impulses to relay neurone.
3) Motor neurone sends impulses to effector.
4) Effector produces a response (muscle contracts to move hand away).

Question 13

What is the synapse?

Answer 13

The tiny gap where two neurons meet.

Question 14

How do impulses travel across this gap?

Answer 14

They diffuse across the gap and make the other neurone transmit an electrical impulse.

Question 15

What is meant by Homeostasis?

Answer 15

Homeostasis is the maintenance of a constant internal environment

Question 16

Name 3 internal conditions kept constant by Homeostasis?

Answer 16

1) Water Content
2) Body Temperature
3) Blood Sugar Level