Things found in past papers

Question 1

Innvervation of 3 salivary glands

Answer 1

• Facial nerve innervates Submandibular gland & Sublingual gland
• Facial nerve exits the skull via the Internal acoustic meatus and via the Stylomastoid foramen and passes under the parotid gland (but does not innervate it), then innervates sublingual & submandibular glands
• (Glossophargyneal nerve exits the skull via the Jugular foramen and innervates the Parotid gland)

Question 2

Function of sternothyroid

Answer 2

Depresses thyroid cartilage

Question 3

Test for trochlear nerve

Answer 3

To distinguish its muscle action from inferior rectus, we must first adduct the eye and then move it superiorly

Question 4

3 spinal curve abnormalities

Answer 4

• Lordosis – excess lumbar curvature
• Kyphosis – excess thoracic curvature
• Scoliosis – lateral deviation of the vertebral column

Question 5

List two advantages and two disadvantages of MRI over CT for visualising brain structures

Answer 5

Advantages of MRI
o	No X rays
o	Excellent soft tissue detail
o	Multiplanar acquisition
Disadvantages
o	Slow
o	Expensive
o	Noisy
o	Poor bone detail
o	Contraindications – metal implants, pacemaker

Question 6

Oculomotor palsy

Answer 6

• Ptosis – droopy eyelid due to loss of Levator palpebrae superioris
• Eye is in the “down & out” position due to opposed actions of LR & SO

Question 7

Attachments for carpal tunnel

Answer 7

• Medial attachments: Scaphoid, Trapezium

* Lateral attachments: Pisiform, Hamate

Question 8

What runs in carpal tunnel

Answer 8

• Flexor digitorum superficialis tendons X4
• Flexor digitorum profoundus tendons X4
• Flexor pollicis longus
• Median nerve

Question 9

The dorsal venous arch of the foot gives rise to which two main superficial veins?

Answer 9

• Medially – Long saphenous vein

* Laterally – Short saphenous vein

Question 10

Into which vessels do these superficial veins usually drain?

Answer 10

• Long saphenous vein drains into the Femoral vein t the Saphenous opening
• Short saphenous vein drains into the Popliteal vein at the Popliteal fossa

Question 11

What are relationships of long and short saphenous vein to the malleoli as they cross the ankle?

Answer 11

• Long saphenous vein passes anterior to medial malleolus

* Short saphenous vein passes posterior to lateral malleolus

Question 12

What is the common consequence of abnormal drainage between superficial and deep veins?

Answer 12

Varicose veins

Question 13

What is carpal tunnel normally as a result of

Answer 13

Diabetes, High blood pressure, Autoimmune disorders, fractures of the wrist

Question 14

Pathology of carpal tunnel syndrome

Answer 14

Increased pressure so entrapment of median nerve

Question 15

What nerve is affected following a blow to the lateral side of the leg, just below the knee?

Answer 15

Common peroneal

Question 16

Compartments affected and functional problem with damaged superficial peroneal

Answer 16

Lateral compartment: loss of eversion of the foot

Question 17

Compartments affected and functional problem with damaged deep peroneal

Answer 17

Anterior compartment: loss of dorsiflexion at the ankle joint

Question 18

Symptom of lateral medullary syndrome and structure associated

Answer 18

Ipsilateral cerebellar ataxia = inferior cerebellar peduncleLoss of sensation of pain and temperature face = spinal trigeminal nucleusLoss of sensation of pain/temp of contralateral body = spinothalamic tractVertigo = vestibular nucleusHorner’s syndrome = sympathetic tractHoarseness and difficulty swallowing = nucleus ambiguus

Question 19

3 neural components of a saccade

Answer 19

Optic nerve
Superior colliculus
Visual cortex
Cranial nerves and nuclei

Question 20

3 types of nystagmus

Answer 20

Vestibulo-­‐ocular reflex(vestibular nystagmus) driven by vestibular afferents. When the head is rotated the eyes move in the opposite direction (slow component) to maintain the point of visual fixation on the retina. When the limit of movement is reached the eyes flick back (fast component) and maintain a new fixation point. Slow component driven by afferents from labyrinths. If a subject is rotated and then stopped, postrotatory nystagmus occurs owing to displacement of the cupula in the opposite direction due to inertia of fluid in semi-­‐circular canals.•Optokinetic nystagmus(ocular nystagmus) driven by retinal afferents. There is a limit to the amount the eyes can be moved in the head to follow an object (slow phase of nystagmus) -­‐for example from a moving vehicle [e.g. at a tube station]. When the limit is reached the eyes flick back (quick phase) to a new fixation point.•Physiologic nystagmusalso occurs even when the subject stares at a stationary fixation point. Since the neural connections from the receptors in the eye adapt to the stimulus, physiologic nystagmus repeatedly moves the image to activate new receptors and help overcome the adaptation.ABD

Question 21

Difference of nociceptors to touch receptors

Answer 21

polymodal; high threshold; all slow adapting; all free nerve endings

Question 22

How is neuropathic pain different to nociceptive pain

Answer 22

Lesion in nervous system
No response to analgesia
Noxious stimulus absent
Abnormal pathway used
Sensation burning and throbbing rather than dull and aching

Question 23

Loss of sight in one eye

Answer 23

Anopia

Question 24

How is acuity increased in middle ear

Answer 24

) The lever system of articulated ossicles between the malleus, incus and stapes, therefore the vibration and
conduction between the bones creates a better intensity
b) The ratio of area of tympanic membrane to oval window (17:1), therefore the sound would be mo

Question 25

A patient had an acoustic schwannoma and has deafness. Describe why, if left untreated, later on the patient will have ataxia, dizziness, loss of facial sensation and facial movement. • Growing in the internal acoustic meatus = sensorineural deafness due to pressing

Answer 25

• Growing in the internal acoustic meatus = sensorineural deafness due to pressing on the cochlear part of the nerve, dizziness due to pressing on vestibular part of CN8 • Ataxia = further growth puts pressure on cerebellum and brainstem, raising the ICP and causing ataxia• Loss of facial sensation = the tumour may grow into the posterior fossa, press on the V nerve which is responsible for facial sensation • Loss of facial movement = the tumour stretches the facial nerve which innervates the facial muscles (leaves the same foramen)

Question 26

Cranial nerves with parasympathetic association

Answer 26

Occulomotor Vagus Facial Glossopharyngeal

Question 27

Upper pontine lesion effects

Answer 27

2) Swallowing (no): the nerves that control swallowing are: a) Glossopharyngeal CN9 (medulla): innervates stylopharyngeus via nucleus ambiguus b) Vagus CN10 (medulla): innervates muscles of the soft palate, pharynx, larynx, and upper oesophagus for swallowing c) NB: chewing would be affected because the trigeminal nerve emerges on the pons and innervates the muscles of mastication including the masseter, medial and lateral ptergoids and temporalis 3) Horizontal eye movements (yes): the abducens nerve CN6 controls the lateral rectus muscle for horizontal version and originates at the ponto-medullary junction. 4) Facial expression (yes): the facial nerve CN7 emerges at the pontomedullary junction lateral to CN6 and controls the muscles of facial expression

Question 28

Syringomyelia effects

Answer 28

Spinothalamic level: disruption of pain and temperate as the fibres decussate at the level of input - loss of nociception from the upper limbs à pt presents with cuts on hands disrupts fibres crossing over at the midline • Severe pain and UMN lesions; disrupted ANS • Dorsal columns: Joint position and vibration senses are spared • If enters the brainstem: dysarthria, dysphagia, tongue wasting, ataxia and nystagmus

Question 29

Structures associated with aggression

Answer 29

Brain stem (PAG) Hypothalamus Amygdala

Question 30

Limbic system affected disorders

Answer 30

Amygdala (aggression, fear, fight, flight) à Kluver Bucy | Hypothalamus (memory and learning) à Alzheimer’s, epilepsy

Question 31

What are 2 types of relfex seen in knee jerk

Answer 31

Monosynpatic to the same muscle (effector muscle) Polysynaptic to the antagonist muscle (knee flexor) Is a postural reflex

Question 32

Function test and nerve of each ocular muscle

Answer 32

``` Superior rectus • Movement = elevation and adduction • Superior ramus of CN3 • To test = abduct then elevate Inferior rectus • Movement = depression and adduction • Inferior ramus of CN3 • To test = abduct then depress Medial rectus • Movement = adduction • Inferior ramus of CN3 • To test = adduct Lateral rectus • Movement = abduction • CN6 • To test = abduction Superior oblique • Movement = depression and abduction • Trochlear nerve CN4 • To test = adduct then depress Inferior oblique • Movement = elevation and abduction • Inferior ramus of CN3 • To test = adduction then elevate ```

Question 33

Innervation of ciliary muscle, cornea, levator palpebrae and lacrimal gland

Answer 33

. Ciliary muscle – parasympathetic post-ganglionic fibres (short ciliary nerve) from ciliary ganglion. NB: CN3 is the pre-ganglionic parasympathetic nerve fibre synapsing in the edinger westphal nucleus. 2. Cornea – trigeminal, V1 (nasociliary of ophthalmic branch). NB branches of ophthalmic include: frontal (scalp + forehead), nasociliary (orbit and nasal mucosa), lacrimal (lacrimal gland) 3. Levator palpebrae superioris – superior ramus of CN3 N.B. the tarsal muscle is innervated by sympathetic fibres of superior cervical ganglion from T1 [also innervates vascular SM for vasoconstriction and radial muscle for dilation]. 4. Lacrimal gland – post-ganglionic parasympathetic fibres from facial nerve (CN7) from pterygopalatine ganglion (superior salivatory nucleus within the pons). Sensory innervation is via lacrimal nerve of trigeminal V1

Question 34

Corticospinal pathway

Answer 34

* Sensory input to the Betz cells in layer 5 * Cell bodies arise in layer 5 of the cerebral cortex via Betz cells * Axons project to white matter below * Axons project through the posterior limb of the internal capsule * UMN fibres go to brainstem * Travel via cerebral peduncles à fibres come together as the pyramids * 80% of the fibres decussate at the medullary pyramids (those 20% that don’t = anterior corticospinal) * Synapse in the ventral horn of the spinal cord * Lower motor neurones innervate voluntary muscles

Question 35

Where does 4th ventricel receive CSF from

Answer 35

Central canal of spine | Aqueduct

Question 36

5 components of reflex arc

Answer 36

Sensory receptor – responds to stimulus by producing receptor potential • Sensory neurone – conducts impulse from receptor to integrating centre • Central integrating centre: interneurone in spinal cord, relay impulse sensoryàmotor • Motor neurone: impulse from integrating centreàeffector • Effector muscle or gland: responds to motor impulse from motor nerve

Question 37

Diseases which affect motor system and how they do

Answer 37

Motor neurone disease • Affects the UMN and LMN of the corticospinal tract • Chromatolysis = disconnection of the neurons from target muscle fibres • Mosaic patterns with a decrease in myosin ATP • Muscle atrophy • Myasthenia gravis • Antibodies bind to the nicotinic AChR of the neuromuscular junction

Question 38

Branches of laryngeal nerve and effect of damage

Answer 38

Superior laryngeal nerve à internal and external laryngeal nerves • Internal à loss of sensation to larynx above the vocal cords • External à loss of inferior constrictor muscle and cricothryoid (forward and downward rotation of thyroid cartilage to tense the vocal cords) Recurrent laryngeal nerve 1. Loss of intrinsic laryngeal muscles excluding the cricothyroid 2. On the LEFT: bronchial or oesophageal tumour/swollen mediastinal lymph nodes can damage recurrent laryngeal 3. Hoarseness, breathlessness, aphonia

Question 39

How are loud noises dampened down

Answer 39

There is a reflex contraction of the stapedius muscle (attached to stapes) and the tensor tympani muscle (attached to malleus) to loud noises à reduces leverage through the ossicle bridge. • NB: swallowing opens up the Eustachian tube which is connected to the nasopharynx à equalises membrane pressure either side of the tympanic membrane.

Question 40

What is responsible for auditory reflexes

Answer 40

Inf colliculus

Question 41

Action and supply of sternothyroid, geniohyoid, digastric, thyrohyoid, mylohyoid and stylohyoid muscles

Answer 41

• Nerve supply = ansa cervicalis (nerve fibres forming a loop from C1-C3 and innervating many infrahyoid muscles) • Action = depress the larynx bone • NB: thyroid muscles (sternothyroid and thyrohyoid depress/raise the larynx respectively). The omohyoid and sternohyoid depress the hyoid bone. • Anterior belly digastric opens mouth by lowering the mandible. • Posterior belly digastric pulls hyoid upward and back = facial nerve • Mylohyoid elevates the hyoid bone = V3 • Stylohyoid elevates hyoid in postero-superior direction = facial nerve • Geniohyoid pulls mandible downward and inward, or hyoid bone forward if mandible fixed = C1 fibres

Question 42

Which nerve is at risk when clamping the inferior thyroid vessels for thyroid surgery and what are the likely consequences of damaging the nerve?

Answer 42

Vagus supplies larynx. • Superior laryngeal nerve – internal (sensation above cords) and external branches (cricothyroid and inferior constrictor muscle). Superior thyroid artery from external carotid and runs with internal branch à thyrohyoid membrane. • Recurrent laryngeal nerve (sensation below vocal cords, most intrinsic laryngeal muscles). Inferior thyroid artery from the thyrocervical trunk of subclavian • Right recurrent laryngeal most vulnerable as it has a direct course (left arches around aorta). • Consequence = loss of sensation below the vocal cords and paralysis of the ipsilateral laryngeal muscles except cricothyroid. • Unilateral = hoarseness; bilateral may mean loss of voice (aphonia) and difficulty breathing

Question 43

Consequence of poor drainage between superficial and deep veins in leg

Answer 43

Swelling of superficial veins (i.e. varicose veins) If a deep vein problem à DVT, post-phlebitic syndrome If superficial à ulcers, superficial thrombophlebitis

Question 44

What prevents hip from over-extending

Answer 44

All ligaments limit extension Ischio-femoral ligament = limits medial rotation Pubofemoral ligament = limits abduction Iliofemoral ligament = limits lateral rotation They spiral together and become taut when the hip extends Minimises energy required to maintain the standing position

Question 45

Carpal tunnel syndrome

Answer 45

Pins and needles/paraesthesiae in the hand Weakness of the thumb muscles Loss of muscle bulk of the thumb muscles *Sensation preserved as palmar cutaneous branch of median nerve comes off before *Swelling of the tendons or cysts in the carpal joints (RA, hypothyroid) à pressure on the median nerve

Question 46

Landmark femoral artery

Answer 46

3-4cms above the mid-point of the inguinal ligament

Question 47

What does phospholipase A2 break daiglycerol into

Answer 47

arachidonic acid