Practical 1 - station 2 - PNS

Question 1

What are the 12 cranial nerves?

Answer 1

Olfactory
Optic 
Oculumotor
Trochlear
Trigeminal
Abducent
Facial
Vestibulocochlear
Glossopharngeal
Vagus
Accessory
Hypoglossal

Question 2

What is each cranial nerve for?

Answer 2

Olfactory - sensory smell
Optic - sensory sight
Oculomotor - motor eye movements (intrinsic and extrinsic)
Trochlear - motor eye movements
Trigeminal - 3 sensory branches to face, motor for mastication
Abducent - motor eye movement
Facial - motor facial expression, sensory taste and parasympathetic glands
Vestibulocochlear - sensory balance and hearing
Glossopharyngeal - tongue and pharynx
Vagus - parasymp to Gi tract, motor to palate, pharynx, larynx
Accessory - motor to SCM and trapezius
Hypoglossal - motor to tongue

Question 3

Which cranial nerves are sensory?

Answer 3

Olfactory, optic, vestibulocochlear

Question 4

Which cranial nerves are motor?

Answer 4

Hypoglossal, accessory, abducent, trochlear, oculomotor

Question 5

Which cranial nerves are mixed?

Answer 5

Trigeminal, glossopharyngeal, vagus, facial

Question 6

Which cranial nerves attach on to the forebrain?

Answer 6

Olfactory and optic

Question 7

Where do most cranial nerves originate from?

Answer 7

Brainstem

Question 8

What are the branches of the trigeminal nerve?

Answer 8

Opthalmic, maxillary, mandibular

Question 9

What muscles are innervated by the mandibular branch?

Answer 9

Muscles of mastication - masseter, temporal, lateral and medial pterygoid

Question 10

What are the branches of the facial nerve?

Answer 10

Temporal, zygomatic, buccal, marginal mandibular, cervical

Question 11

What nerve allows taste of the anterior 2/3 of the tongue?

Answer 11

Chorda tympani

Question 12

What nerve allows taste of the posterior 1/3 of the tongue?

Answer 12

Glossopharyngeal

Question 13

What nerve allows general sensation of the oral cavity?

Answer 13

Trigeminal

Question 14

Which blood vessels enter the carotid canal, jugular foramen and the foramen spinosum?

Answer 14

Carotid canal - internal carotid artery
Jugular foramen - ascending pharyngeal artery
Foramen Spinosum - Middle meningeal artery

Question 15

How many spinal nerves are there in each section?

Answer 15

31 pairs in total
8 cervical
12 thoracic
5 lumbar
5 sacral
1 coccygeal

Question 16

Which nerve allows tongue movements?

Answer 16

Hypoglossal innervates intrinsic and extrinsic muscles of the tongue

Question 17

Which nerves are responsible for the gag reflex?

Answer 17

Initiation - glossopharyngeal (sensory)

Execution - vagus (motor)

Question 18

What gland does the facial nerve supply?

Answer 18

Parotid

Question 19

Which nerves supply the parotid, submandibular and sublingual glands?

Answer 19

Parotid - glossopharyngeal

Submandibular and sublingual - facial

Question 20

Where does the vagus nerve travel in the neck?

Answer 20

Through the carotid sheath, inferior to IJV and common carotid
Right - anterior to subclavian and posterior to sternoclavicular joint
Left - inferior to common carotid and subclavian arteries, posterior to sternoclavicular joint

Question 21

What does the vagus nerve give rise to in the neck?

Answer 21

Recurrent pharyngeal, superior pharyngeal, pharyngeal

Question 22

Where does the vagus enter the abdomen?

Answer 22

Through oesophageal hiatus (opening in diagphragm)

Question 23

What does the accessory nerve supply?

Answer 23

SCM and trapezium

Question 24

What would accessory nerve palsy lead to?

Answer 24

Pain and weakness in shoulder
Droop shoulder
Weakness when lifting
Trapezius muscle atrophy

Question 25

What does a spinal nerve divide into and where?

Answer 25

It emerges from the intervertebral foramen and divides into small dorsal ramus and large ventral ramus (both mixed)

Question 26

What is different about ventral rami T2-T12?

Answer 26

They don't converge to form plexi

Question 27

Where are dermatomes C5,6,7,8, T5,12, L3,4,5, S1?

Answer 27

``` C5 - shoulder down arm C6 - thumb C7 - middle finger C8 - little finger T5 - below nipples T12 - pubis L3 - inner thigh L4 - knee L5 - big toe S1 - little toe ```

Question 28

What is the difference between the roles of the afferent and efferent divisions of the PNS?

Answer 28

Afferent (sensory) - sensory receptors to CNS | Efferent (motor) - CNS to effector organs

Question 29

What are the types of afferents?

Answer 29

Somatic - skin, joints, muscles | Visceral - organs

Question 30

What are the 2 parts of the motor division?

Answer 30

Somatic - voluntary to skeletal muscle | ANS - involuntary to SM, cardiac, glands

Question 31

What are the 3 divisions of the ANS?

Answer 31

Enteric - gut function Sympathetic - 4F's (flight, fight, fright, sex) Parasympathetic - rest relaxation recuperation

Question 32

Which nerves are involved in the parasympathetic and which in the sympathetic?

Answer 32

Para - craniosacral (cranial - oculomotor, facial, glossopharyngeal, vagus), S2-S4 Symp - T1-L2 (lumbosacral)

Question 33

What do the cranial nerves do in parasympathetic control?

Answer 33

Oculomotor - pupil constriction Facial - pupil constriction and salivary production Glossopharyngeal - salivary production Vagus - reduces heart rate and force of contraction and constricts bronchi SM

Question 34

How do fibres get from the spinal nerves to the sympathetic trunk?

Answer 34

From the spinal cord ventral roots leave and become preganglionic sympathetic fibres which pass through white rami communicantes (myelinated) to the sympathetic trunk

Question 35

Where does a sympathetic preganglionic axon synapse?

Answer 35

- paravertebral (in the same chain ganglion from the spinal segment that they arose from or higher or lower in the chain with postganglionic neurons) - prevertebral (pass through the trunk and synapse along the abdominal aorta)

Question 36

Which nerves synapse prevertebrally?

Answer 36

Splanchnic

Question 37

Where are grey rami?

Answer 37

From the sympathetic trunk once synaptic contact has been established forming postganglionic neurons

Question 38

What is the exception with some sympathetic preganglionics?

Answer 38

They project directly to the adrenal cortex (essentially is a postganglionic neuron) to release adrenaline directly into circulation

Question 39

Pre and post ganglionic neurotransmitter of symp and para

Answer 39

Symp pre - Ach, post - Noradrenaline except at sweat glands | Para - pre - ach, post - Ach or NO or noradrenaline