Study Guide: Structure and Organization of the PNS

Question 1

The PNS includes :

Answer 1

All nervous structures outside the brain and spinal cord

Question 2

The PNS functions to:

Answer 2

Relay information between the central nervous system (CNS) and the rest of the body

Question 3

Two major communication systems of the PNS:

Answer 3

(1) Nervous system (fast targeted responses via electrical signals)
(2) Endocrine system (slower, widespread effect via hormones)

Question 4

Components of the PNS:

Answer 4

(1) Nerves
(2) Ganglia
(3) Plexuses

Question 5

Components of the PNS: Nerves:

Answer 5

Bundles of nerve fibers (axons) carrying sensory (Afferent) or motor (Efferent) signals

Question 6

Components of the CNS: Ganglia:

Answer 6

Clusters of neuron cell bodies outside the CNS

Question 7

Sensory ganglia transmit:

Answer 7

Sensory information

Question 8

Autonomic ganglia:

Answer 8

Include sympathetic (near spinal cord) and parasympathetic (near target organs)

Question 9

Components of the PNS: Plexuses:

Answer 9

Network of interwoven nerve fibers

Question 10

Spinal nerve plexuses (5):

Answer 10

(1) cervical
(2) brachial
(3) lumbar
(4) sacral
(5) Coccygeal

Question 11

Autonomic Plexuses (3):

Answer 11

(1) Cardiac
(2) Celiac
(3) Pelvic

Question 12

How is the PNS divided (2):

Answer 12

(1) Somatic nervous system
(2) Autonomic nervous system (A. Sympathetic, B. Parasympathetic, C. Enteric)

Question 13

Somatic Nervous System (SNS):

Answer 13

Voluntary control over skeletal muscles, sensory input from external stimuli

Question 14

Autonomic nervous system (ANS):

Answer 14

Involuntary control over glands and internal organs

Question 15

Sympathetic nervous system (SNS):

Answer 15

fight or flight response

Question 16

Parasympathetic nervous system:

Answer 16

“rest and digest” response

Question 17

Enteric nervous system (ENS):

Answer 17

Regulates gastrointestinal activity

Question 18

How many spinal nerve pairs do humans have?

Answer 18

31 pairs

Question 19

How many spinal nerves do rodents have?

Answer 19

33

Question 20

Spinal nerves function:

Answer 20

Connect the spinal cord to the body

Question 21

Each spinal nerve has

Answer 21

dorsal (sensory) and ventral (motor) roots

Question 22

spinal nerves form:

Answer 22

dermatomes, supplying specific skin areas

Question 23

How many cranial nerves do we have?

Answer 23

12 pairs

Question 24

The 12 cranial nerves connect directly to:

Answer 24

the brain

Question 25

What are the purely sensory cranial nerves:

Answer 25

I, II, VIII 1,2,8

Question 26

What are the purely motor nerves?

Answer 26

III, IV, VI, XII 3,4,6,12

Question 27

What are the mixed cranial nerves ?

Answer 27

V, VII, IX, X 5,7,9,10

Question 28

The ANS consists of :

Answer 28

a two-neuron chain: o Preganglionic neuron originates in CNS. o Postganglionic neuron synapses on target tissue.

Question 29

Preganglionic neuron originates in:

Answer 29

CNS

Question 30

Postganglioninc neuron synapses on:

Answer 30

Target tissue

Question 31

Sympathetic nervous system origin:

Answer 31

thoracolumbar origin (T1-L3)

Question 32

Sympathetic Nervous System: length preganglionic / post ganglionic

Answer 32

Short preganglionic Long postganglionic

Question 33

Parasympathetic Nervous System origin :

Answer 33

Craniosacral origin (CN III, VII, IX, X; S2-S4).

Question 34

sympathetic nervous system uses __ at target tissues

Answer 34

norepinephrine

Question 35

Parasympathetic Nervous System: uses _ at target tissues

Answer 35

acetylcholine

Question 36

Enteric Nervous System (ENS):

Answer 36

Independent control over digestion

Question 37

* Enteric Nervous System (ENS): Independent control over digestion via

Answer 37

myenteric and submucosal plexuses.

Question 38

Herniated discs

Answer 38

Compression of spinal nerves leading to pain and weakness.

Question 39

Shingles:

Answer 39

Viral infection affecting dorsal root ganglia, causing dermatome-specific rashes.

Question 40

Brachial Plexus (C5-T1) → Controls

Answer 40

the upper limb

Question 41

Lumbar Plexus (L1-L4) → Controls

Answer 41

the anterior thigh

Question 42

Sacral Plexus (L4-S4) → Controls

Answer 42

the posterior thigh and lower leg

Question 43

Coccygeal Plexus (S4-Co1) → Innervates

Answer 43

the skin over the coccyx

Question 44

sciatic nerve is found in which plexus?

Answer 44

sacral

Question 45

1. Which of the following is NOT a component of the PNS? A) Nerves B) Ganglia C) Spinal cord D) Plexuses

Answer 45

C) Spinal cord

Question 46

2. The autonomic nervous system is responsible for which of the following? A) Voluntary movement B) Skeletal reflexes such as the knee-jerk reflex C) Involuntary regulation of internal organs D) Sensory processing in the cortex

Answer 46

C) Involuntary regulation of internal organs

Question 47

3. Which cranial nerve is responsible for facial expression? A) Cranial Nerve III (Oculomotor) B) Cranial Nerve VII (Facial) C) Cranial Nerve IX (Glossopharyngeal) D) Cranial Nerve X (Vagus)

Answer 47

B) Cranial Nerve VII (Facial)

Question 48

4. What is the function of the dorsal root of a spinal nerve? A) Motor output B) Sensory input C) Autonomic regulation D) Reflex coordination

Answer 48

B) Sensory input

Question 49

5. The enteric nervous system primarily controls: A) Heart rate B) Blood pressure C) Digestive processes D) Voluntary muscle movement

Answer 49

Digestive processes

Question 50

6. Which of the following statements about spinal nerves is TRUE? A) They all contain only motor fibers. B) They all contain only sensory fibers. C) They contain both sensory and motor fibers. D) They are only found in the cervical region.

Answer 50

C) They contain both sensory and motor fibers

Question 51

7. The sympathetic nervous system is most active during: A) Digestion B) Sleep C) “Fight or flight” responses D) Resting states

Answer 51

C) “Fight or flight” responses

Question 52

8. Which neurotransmitter is used by postganglionic parasympathetic neurons? A) Dopamine B) Norepinephrine C) Acetylcholine D) Glutamate

Answer 52

C) Acetylcholine

Question 53

9. Which of the following cranial nerves is purely sensory? A) Cranial Nerve III (Oculomotor) B) Cranial Nerve VII (Facial) C) Cranial Nerve VIII (Vestibulocochlear) D) Cranial Nerve XII (Hypoglossal)

Answer 53

C) Cranial Nerve VIII (Vestibulocochlear)

Question 54

10. The brachial plexus supplies nerves to the: A) Head B) Abdomen C) Upper limbs D) Lower limbs

Answer 54

C) Upper limbs

Question 55

11. The ventral root of a spinal nerve carries: A) Sensory input B) Motor output C) Both sensory and motor signals D) Autonomic ganglia

Answer 55

B) Motor output

Question 56

12. Damage to the vagus nerve (Cranial Nerve X) would most likely affect: A) Vision B) Balance C) Heart rate and digestion D) Facial expressions

Answer 56

C) Heart rate and digestion

Question 57

13. The sciatic nerve originates from which plexus? A) Brachial B) Cervical C) Lumbar D) Sacral

Answer 57

D) Sacral

Question 58

14. The parasympathetic division of the ANS is also known as the: A) Thoracolumbar division B) Craniosacral division C) Enteric division D) Somatic division

Answer 58

B) Craniosacral division

Question 59

15. What type of neurons are found in the dorsal root ganglia? A) Motor neurons B) Sensory neurons C) Interneurons D) Autonomic neurons

Answer 59

B) Sensory neurons

Question 60

16. The enteric nervous system is primarily responsible for regulating: A) The heartbeat B) Blood pressure C) Gastrointestinal function D) Breathing rate

Answer 60

C) Gastrointestinal function

Question 61

17. Which of the following describes a mixed nerve? A) A nerve that carries only sensory signals B) A nerve that carries only motor signals C) A nerve that carries both sensory and motor signals D) A nerve that is found only in the brainstem

Answer 61

C) A nerve that carries both sensory and motor signals

Question 62

18. The function of autonomic ganglia is to: A) Process skeletal reflexes such as the knee-jerk reflex B) Relay signals from the CNS to peripheral organs C) Generate voluntary movements D) Transmit sensory information to the brain

Answer 62

B) Relay signals from the CNS to peripheral organs

Question 63

19. Which division of the PNS controls voluntary skeletal muscle movements? A) Autonomic Nervous System B) Somatic Nervous System C) Enteric Nervous System D) Sympathetic Nervous System

Answer 63

B) Somatic Nervous System

Question 64

20. The sympathetic nervous system is primarily responsible for which response? A) Rest and digest B) Fight or flight C) Reflexes D) Homeostatic balance

Answer 64

B) Fight or flight

Question 65

21. How many spinal nerve pairs do humans have? A) 12 B) 24 C) 31 D) 33

Answer 65

C) 31

Question 66

22. Which type of neuron has their cell bodies in autonomic ganglia? A) Sensory neuron B) Preganglionic neuron C) Interneuron D) Postganglionic neuron

Answer 66

D) Postganglionic neuron

Question 67

23. Which neurotransmitter is released by postganglionic sympathetic neurons? A) Acetylcholine B) Glutamate C) Dopamine D) Norepinephrine

Answer 67

D) Norepinephrine

Question 68

24. The vagus nerve (Cranial Nerve X) is primarily involved in: A) Eye movement B) Facial expression C) Parasympathetic regulation of the heart and digestion D) Hearing and balance

Answer 68

Parasympathetic regulation of the heart and digestion

Question 69

25. Which of the following describes the structure of the autonomic nervous system? A) Single neuron from CNS to target B) Two-neuron chain with a synapse in a ganglion C) Sensory neuron directly connecting to CNS D) Motor neuron directly controlling glands

Answer 69

Two-neuron chain with a synapse in a ganglion

Question 70

26. Which cranial nerve is purely sensory? A) Cranial Nerve III (Oculomotor) B) Cranial Nerve V (Trigeminal) C) Cranial Nerve VII (Facial) D) Cranial Nerve II (Optic)

Answer 70

D) Cranial Nerve II (Optic)

Question 71

27. Which nerve is responsible for the sensation of touch in the face? A) Facial nerve B) Trigeminal nerve C) Hypoglossal nerve D) Vagus nerve

Answer 71

B) Trigeminal nerve

Question 72

28. Which structure carries motor signals from the spinal cord to skeletal (striated) muscles? A) Dorsal root B) Ventral root C) Dorsal horn D) Thalamus

Answer 72

B) Ventral root

Question 73

29. A dermatome is best described as: A) A motor neuron connecting to a muscle B) A region of skin supplied by a specific spinal nerve C) A cluster of interneurons in the spinal cord D) A type of autonomic ganglion

Answer 73

B) A region of skin supplied by a specific spinal nerve

Question 74

30. Which of the following is a function of the parasympathetic nervous system? A) Increasing heart rate B) Dilating pupils C) Stimulating digestion D) Triggering sweating

Answer 74

C) Stimulating digestion

Question 75

31. The thoracolumbar division refers to which autonomic subdivision? A) Sympathetic B) Parasympathetic C) Enteric D) Somatic

Answer 75

A) Sympathetic

Question 76

32. Which cranial nerve is responsible for eye movement? A) Cranial Nerve II (optic) B) Cranial Nerve III (oculomotor) C) Cranial Nerve VII (facial) D) Cranial Nerve XII (hypoglossal

Answer 76

B) Cranial Nerve III (oculomotor)