The Middle Cranial Fossa

Question 1

What are the different modalities of the cranial nerves

Answer 1

Somatic sensory (sensory info from the body wall to the brain)
Somatic motor ( from cns to skeletal muscle)
Parasympathetic motor
Special sensory
Mixed
Visceral sensory

Question 2

Explain what is meant by somatic sensory and motor nerve s

Answer 2

Sensory - from skin etc to CNS, mental nerve

Motor – to skeletal muscle form CNS, spinal accessory

Question 3

Explain what is meant by the parasympathetic nerves and special sensory

Answer 3

Parasymp motor - rest and digest, glands get secretomotor innervation
Special sensory - from sense organ, optic nerve

Question 4

Explain what a mixed nerve is nd what a visceral sensory nerve I

Answer 4

Mixed - mix of a few modalities, trigeminal

Visceral sensory - from carotid body, Glossopharyngeal

Question 5

What are the cranial nerves

Answer 5

Olfactory
Optic 
Oculomotor
Trochlear 
Trigeminal
Abducens 
Facial 
Vestibulocochlear 
Glossopharyngeal 
Vagus 
Spinal accessory 
Hypoglossal

Question 6

What are the modalities of the cranial nerves

Answer 6

Some say marry money my brother says big brains matter more

Question 7

Explain some features of the olfactory nerve

Answer 7

Special sensory
Smell
Olfactory receptors in the crubiform plate
Olfactory tract and bulb

Question 8

Explain some feature of the optic nerve

Answer 8

Special sensory
Sight
Passes through optic canal thro the formina
Optic nerves meet at chiasms and cross over

Question 9

What are the two main structures of the eye

Answer 9

Pupil - hole the centre where light passes through
Iris coloured part
associciated circular smooth muscle sphincter pupillae
And radial is dilator pupillae

Question 10

What causes the pupil to constrict

Answer 10

Parasympathetics

Oculomotor nerve reached to eye

Question 11

What causes the pupil to dilate

Answer 11

Sympathetics

Reach the orbit following arteries

Question 12

How do u clinically test the optic nerve

Answer 12

Flashing light in eyes 
See pupillary light reflex 
Both eyes hold constrict 
Sensory is from optic nerve 
Moto pr is from oculomotor

Question 13

Describe some features of the oculomotor nerve

Answer 13

Mixed
Somatic motor - muscles of eye in orbit extra ocular
Parasympathetic - sphincter pupillae muscle

Question 14

What does the trochlear nerve suppl

Answer 14

One extra ocular muscle = superior oblique muscle
Very delicate
Only cranial nerve that emerges form midbrain
Called trochlear as Ct tubing where muscle is called trochlea

Question 15

What does the abducens nerve supply

Answer 15

Somatic motor
Of one extra ocular eyes the lateral rectus muscle which helps abduct the eye
Leaves the brain from the junction between the pons and medulla

Question 16

What does the trigeminal nerve innervate

Answer 16

Mixed
Somatic motor - root shoes rate joins with sensory part of Vc at foramen ovale
Sensory - Va sensory to upper face, Vb sensory to mid face
Vc - mixed as has sensory to lower face and motor for muscles of mastication

Question 17

What are all the foraminae that the cranial nerves exit out of

Answer 17

Olfactory- crubiform 
Optic - optic canal 
Oculomotor - superior orbital fissure 
Trochlear - superior orbital fissure
Trigeminal - Va and Vb (foramen rotundum) Vc (foramen ovale) 
Abducens - superior orbital fissure 
Facial - internal acoustic meatus 
Vestibulocochlear - internal acoustic meatus 
Glossopharyngeal - jugular foramen 
Vagus - hypoglossal canal 
Spinal accessory - spine
Hypoglossal -  hypoglossal canal

Question 18

What nerves pass thought the lateral walls of the cavernous sinus

Answer 18

Oculomotor, trochlear and the Opthalmic and maxillary divisions of the trigeminal nerve

Question 19

What things pass through the actual cavernous sinus

Answer 19

Internal carotid artery
Abducens
(Submerged in venous blood)

Question 20

What are the subdivisions of the cranial fossa

Answer 20

Anterior - frontal, ethmoid, sphenoid

Middle - sphenoid and temporal

Posterior - temporal and occipital