Lesson 2

Question 1

What is the spinal cord?

Answer 1

• Long, thin tubular bundle of nervous tissue and support cells that extends from the brain
• Protected by spinal column

Question 2

What does spinal cord do?

Answer 2

• Transmits neural signals between brain and rest of body
• Contains neural circuits that can independently control numerous reflexe

Question 3

Describe structure of spinal cord

Answer 3

• Central area of grey matter which contains nerve cells and transmit bodies
• Surrounded by white matter which consists of nerve fibres surrounded by axons
• Cord itself surrounded by membranes called meninges

Question 4

Where are neurone fibres found in spinal cord?

Answer 4

• Sensory fibres from PNS enter spinal cord on dorsal root
• Cell bodies of sensory fibres found in the dorsal root ganglia
• Motor fibres leave via ventral roots

Question 5

What is the simplest type of response?

Answer 5

• Simple reflex arc which is an inborn response to a stimulus and is rapid, automatic and beneficial
• Doesn’t involve brain because it is involuntary

Question 6

Describe the reflex arc

Answer 6

• Stimulus detected by receptor
• Sensory carries impulsr from receptor to relay neurone in CNS
• Relay transmits impulse from sensory to motor
• Motor carries impulse to effector
• This causes muscle contraction or hormone release