Lesson 1

Question 1

What is a stimulus?

Answer 1

Detectable change in the external or internal environment of an organism

Question 2

What is a receptor?

Answer 2

Detects stimuli (one form of energy) and converts to electrical energy to send information as electrical impulse to CNS via neurones

Question 3

What is an effector?

Answer 3

Receives electrical impulses from CNS and brings about a response

Question 4

Describe the sensory neurone

Answer 4

• Carries impulses from receptor to CNS
• Cell body in middle of axon
• Long dendron

Question 5

Describe the motor neurone

Answer 5

• Carry impulses from CNS to effector organs (muscles/glands)
• Cell body at start of axon
• Have longer axon

Question 6

Describe relay neurone

Answer 6

• Cell body at the start of axon
• Have no myelin sheath
• Longer axon

Question 7

What is the axon?

Answer 7

Extension of the cell that transmitted impulses away from cell body to axon endings

Question 8

What are dendrites?

Answer 8

Many thin extension of cytoplasm that receive impulses from other nerve cells and transmit impulses toward cell body

Question 9

What is the cell body of neurone?

Answer 9

Contains nucleus and groups ribosomes called Nissl granules in the cytoplasm

Question 10

What do Nissl granules do?

Answer 10

Synthesis neurotransmitters

Question 11

What are synaptic end bulbs?

Answer 11

Swelling at the end of axon in which neurotransmitter is stored

Question 12

What do axon ends do?

Answer 12

Secrete neurotransmitter by exocytosis into synaptic cleft

Question 13

What do Schwann cells do?

Answer 13

Surround peripheral neurones in vertebrates and grow around axon to form multi-layered myelin sheath

Question 14

What does the myelin sheath do?

Answer 14

Provides electrical insulation to speed up nerve impulse transmission

Question 15

What are nodes of Ranvier?

Answer 15

Interval in myelin sheath between adjacent Schwann cells