Nervous Coordination And Muscles

Question 1

What is a stimulus?

Answer 1

Change in internal or external environment

Question 2

What is a receptor?

Answer 2

Detects a stimulus(specific to one stimulus)

Question 3

What is a coordinator?

Answer 3

Formulated a suitable response to a stimulus

Question 4

What is an effecter?

Answer 4

Produces a response

Question 5

What is a neurone?

Answer 5

A nerve cell can carry an impulse

Question 6

What is a nerve?

Answer 6

Many nerve fibres (neurone extensions) wrapped in connective tissue

Question 7

What is a cell body?

Answer 7

Part containing the nucleus lists of rough endoplasmic reticulum for making neurotransmitters

Question 8

What is a dendron?

Answer 8

Extensions of a cell body which subdivide into smaller branches fibres, called dendrites that carry nerve impulses away from the cell body

Question 9

What is an axon?

Answer 9

Single long fibre that carries a nerve impulse away from cell body

Question 10

What is the myelin sheath?

Answer 10

Covers the axon and is made up of membranes of Schwann cells. These membranes are rich in a lipid called myelin. Neurones with is are called myelinated neurones

Question 11

What is a node of ranvier?

Answer 11

Constrictions between adjacent Schwann cells where there is no myelin sheath.
constrictions are 2-3um long and occur every 1-3mm in humans

Question 12

What is a Schwann cell?

Answer 12

Surround axon to protect and insulate
Cells are made from myelin
At intervals where Schwann cells meet axon is unprotected-node of ranvier
Some neurones have no Schwann cells eg autonomic nerves
Impulses are slower as a result