Chapter 4.3

Question 1

Where are interneurons found

Answer 1

• they are found predominantly in the spinal cord and the brain
• > often linked to reflexive behavior

Question 2

Contrast white matter and grey matter. Specifically what each is made up of.

Answer 2

White matter
->consists of axons encased in myelin sheaths

Grey matter
->unmyelinated cell bodies and dendrites

Question 3

What are the divisions of the spinal cord

Answer 3

-cervical, thoracic, lumbar and sacral

Question 4

What two neurons in the autonomic nervous system work to transmit messages from the spinal cord

Answer 4

1) preganglionic neuron
- >soma is in the CNS
- >its axon travels to a ganglion in the PNS

2)postganglionic neuron

Question 5

What type of reflex is the knee-jerk reflex

Answer 5

• it is a monosynaptic reflex arc
• > there is a single synapse between the sensory neuron and the motor neuron
• > no interneurons required

Question 6

What type of reflex is the withdraw reflex

Answer 6

• it is a polysynaptic reflex arc

- >there is at least one interneuron between the sensory and motor neurons

Question 7

Where is the white matter and the grey matter in the spinal cor

Answer 7

• the white matter lies on the outside of the spinal cord
• grey matter is deep within the spinal cord
• sensory neurons come through the dorsal side
• motor neurons exit the spinal cord ventrally

Question 8

What neurotransmitters are responsible for the parasympathetic nervous system

Answer 8

-acetylcholine is released by both the preganglionic nervous system and the postganglionic nervous system

Question 9

What neurotransmitters are responsible for the sympathetic nervous system

Answer 9

-preganglionic neurons release acetylcholine and postganglionic neurons mostly release norepinepherine