Nervous System 1

Question 1

What are the 2 main functional divisions of the NS?

Answer 1

Visceral or Autonomic (ANS)
Somatic (SNS)

Question 2

How many spinal cord segments are there?

Answer 2

31

Question 3

Are the nerves passing through dorsal root afferent or efferent?

Answer 3

Afferent

Question 4

Are the nerves passing through ventral root afferent or efferent?

Answer 4

Efferent

Question 5

Define meninges.

Answer 5

layers of connective tissue that envelope the CNS. Important as support the brain and allow the cerebrospinal fluid to flow around the brain and allow thermoregulation.

Question 6

What are the 3 main meninges of the brain?

Answer 6

Dura mater
Arachnoid
Pia mater

Question 7

Role of dura mater

Answer 7

tough outermost layer

Question 8

Role or arachnoid

Answer 8

layer with trabeculae projecting from the underside, creating the subarachnoid space

Question 9

Role of pia mater

Answer 9

delicate innermost layer adhered to the surface of the brain and cord

Question 10

How many pairs of cranial nerves are there?

Answer 10

12

Question 11

Name, component, role I cranial nerve

Answer 11

Olfactory, SVA, smell

Question 12

Name, component, role II cranial nerve

Answer 12

Optic, SVA, vison

Question 13

Name, component, role III cranial nerve

Answer 13

Oculomotor, GVE & GSE, pupillary constriction and eye movement

Question 14

Name, component, role IV cranial nerve

Answer 14

Trochlear, GSE, eye movement

Question 15

Name, component, role VI cranial nerve

Answer 15

Abducent, GSE, eyemovement

Question 16

Name, component, role VIII cranial nerve

Answer 16

Vestibulocochlear, SVA, balance and sound

Question 17

Name, component, role XI cranial nerve

Answer 17

Accessory, GSE, neck muscles

Question 18

Name, component, role XII cranial nerve

Answer 18

Hypoglossal, GSE, tongue muscles

Question 19

Explain the components and role of the V Trigeminal nerve.

Answer 19

SVE - branchiomotor fibres supplying the muscles of mastication in the jaw.
GSA - sensory (including pain) input from the head, including the oral cavity.
3 divisions
Ophthalmic (V1)
Maxillary (V2)
Mandibular (V3)
Branches of the V2 and V3 are the main targets for dental nerve blocking (anaesthesia)

Question 20

Explain the components and role of the VII Facial nerve.

Answer 20

GSA - general sensation from around the external ear
SVA - taste from anterior two-thirds of the tongue (hitches a lift with V part way)
SVE fibres - branchiomotor fibres supplying the muscles of facial expression
GVE - preganglionic parasympathetic fibres hitch a lift with trigeminal fibres to supply:
Lacrimal glands
Submandibular and sublingual salivary glands
Mucous membranes

Question 21

Explain the components and role of the IX Glossopharyngeal nerve.

Answer 21

GVA - carotid body & sinus (monitors blood pressure)
GVE - innervates parotid gland
GSA - general sensation in back of mouth
SVA - taste from posterior one-third of tongue
SVE - branchiomotor fibres innervating stylopharyngeus muscle (pharynx)

Question 22

Explain the components and role of the X Vagus nerve.

Answer 22

GSA - parts of the larynx and of the dura mater
GVA - sensation from the viscera
GVE - parasympathetic innervation of the viscera
SVA - taste from epiglottis and pharynx
SVE - branchiomotor fibres innervating remaining muscles of pharynx and larynx