Module 3: Peripheral Nervous System

Question 1

What are the different types of nerves in the PNS and how many?

Answer 1

1. Cranial (12)
2. Spinal (31)

Question 2

What does the PNS control?

Answer 2

1. cranial/spinal nerves
2. ganglia
3. enteric plexuses (GIT)
4. other nerve plexuses
5. sensory receptor

Question 3

What is sciatica?

Answer 3

a range of symptoms including, extreme back pain, pain in lower limbs

Question 4

What is the organisation of the PNS?

Answer 4

CNS - PNS
|
sensory - motor
|
somatic - autonomic

Question 5

What is afferent?

Answer 5

1. sensory
2. nerves carry info from sensory receptors to CNS
3. reflex

Question 6

What is efferent?

Answer 6

1. motor
2. nerves carry info away from CNS to efferent organs
3. parasympathetic and sympathetic

Question 7

are somatic and autonomic voluntary or involuntary?

Answer 7

somatic - voluntary

autonomic - involuntary

Question 8

what is the sympathetic nervous system?

Answer 8

fight or flight

Question 9

what is the parasympathetic nervous system?

Answer 9

rest and digest

Question 10

What are examples of parasympathetic ?

Answer 10

1. pupil constriction
2. slow heartbeat
3. bladder constriction
4. airway constriction
5. saliva stimulation

Question 11

What are examples of sympathetic?

Answer 11

1. pupil dilation
2. saliva inhibition
3. airway dilation
4. fast heartbeat
5. bladder release

Question 12

what are sensory neurons?

Answer 12

activated by external physical or chemical stimuli

Question 13

what are motor neurons?

Answer 13

found in spinal cord that connect to organs, muscles, and different types of glands in the body

Question 14

what are interneurons?

Answer 14

connect to motor neurons to sensory neurons, allowing signalling between the two

Question 15

What are the three layers of connective tissue?

Answer 15

1. endoneurium
2. perineurium
3. epineurium

Question 16

What is endoneurium?

Answer 16

1. Surround individual axons with a fascicle
2. innermost tissue

Question 17

What is perineurium?

Answer 17

1. wraps around each fascicle
2. Middle tissue

Question 18

What is epineurium?

Answer 18

1. encases all the fascicles to the whole nerve
2. outer tissue

Question 19

What and how many nerves are in the spinal cord?

Answer 19

1. cervical - 8
2. thoracic - 12
3. lumbar - 5
4. sacral - 5
5. coccygeal - 1

total 31

Question 20

What is dorsal rami?

Answer 20

1. dorsal root - sensory (afferent)
2. innervation to skin and back muscles
3. smaller

Question 21

What is ventral rami?

Answer 21

1. ventral root - motor (efferent)
2. innervation to the rest of the trunk and limbs
3. larger

Question 22

what is a nerve plexus?

Answer 22

multiple spinal nerves interacting together to perform a function

Question 23

why is there several nerves working together to form a plexus

Answer 23

if 1 nerve is broken or damaged complete loss of function doesn’t occur

Question 24

What are the 4 plexuses?

Answer 24

1. cervical: under sternocleidomastoid (sternum-skull) muscle: innervates skin
2. brachial: neck, shoulder: innervates upper limbs
3. lumbar:innervates psoas muscle (attached to lumber spine-femur): innervates ab wall, anterior and medial thigh
4. sacral: posterior lumbar plexus: innervates lower limbs, buttox and pelvis