PNS

Question 1

How do motor (efferent) neurons and sensory (afferent) neurons differ in structure and function?

Answer 1

motor (efferent) neurons —> carry toward PNS, effectors

sensory (afferent) neurons-> carry away from PNS toward CNS, sensory receptors

Question 2

What is a ganglion?

Answer 2

In the CNS a cluster of cell body’s of neurons is called “nuclei”

Within the PNS a cluster of cell body’s is referred to as a ganglion

Question 3

Explain the two main divisions of the PNS and the 4 branches it breaks into

Answer 3

The sensory/afferent division

- > somatic sensory division-> muscles, bones, joints, special 	senses  
- > visercal sensory division-> signals from internal organs 	(viscera ) 

The motor/efferent division

- > somatic motor division-> skeletal muscles 
- > visceral motor division, aka autonomic nervous system

Question 4

What are the functions of the anterior, posterior, and lateral horn in the grey matter of the spinal cord.

Answer 4

Anterior-> somatic motor functions

Posterior-> somatic & visceral sensory stimuli

Lateral-> present from 1st thoracic vertebrae to lumbar portion of the cord—> visceral Motor functions (autonomic nervous system)

Question 5

What is the limbic system and what are its functions?

Answer 5

Fornix, hippocampus, amygdala, limbic lobe

“The visceral brain” ‘butterflys In stomach”

Memory, learning, emotion, behaviour

Question 6

Define the term decussate.

Answer 6

When they crossover and switch sides

Question 7

What takes place at a sensory receptor?

Answer 7

Sensory transduction-> where a receptor potential is generated which may trigger an action potential

Question 8

________ detect stimuli originating inside your body

________ detect stimuli originating from outside your body

Answer 8

Interoreceptors & exteroreceptors

Question 9

How do each of these receptors work?

A) mechanoreceptors

B) thermoreceptors

C) chemoreceptors

D) photoreceptors

E) nociceptors

Answer 9

A) detect stimuli that mechanically deform the tissue

B) detect thermal stimuli

C) detect the presence or concentration of chemicals

D) detect light

E) detect painful stimuli

Question 10

What would you use to measure the receptive field of a nueron?

Answer 10

Assessing two point discrimination

Question 11

_____ and _____ detect the sensory portion of reflexes and they help to monitor and control movement

Answer 11

• Muscle spindles-> contain interfusal muscle fibres, detect stretch
• golgi tendon organs-> detect the tension generated by a muscle contraction

Question 12

The _____ root of the spinal nerve transmits sensory stimuli from the PNS to the CNS, whereas the ________ root transmits motor impulses from CNS to the PNS

Answer 12

Posterior root

Anterior root

Question 13

First order somatic sensory neurons are ______ neurons whose cell bodies are located in the ______

A) bi polar; anterior horn

B) pseudounipolar; posterior root ganglion

C) Multipolar; posterior horn

Answer 13

B) pseudounipolar; posterior root ganglion

Question 14

What is the sensory receptor in the knee-jerk reflex?

Answer 14

Muscle spindles are the sensory receptors in the knee-jerk reflex

Question 15

What is the correct order of events for a reflex arc?

A) stimulus detection and delivery-> motor response-> integration in the CNS

B) motor response-> stimulus detection and delivery-> integration in the CNS

C) stimulus detection and delivery-> integration in the CNS-> delivery of motor response

D) integration in the CNS-> motor response-> stimulus detection and delivery

Answer 15

C) stimulus detection and delivery-> integration into the CNS-> delivery of motor response