anat/physio/patho 2 Flashcards
Name the 3 middle ear bones
Malleus, incus, stapes
What test should I conduct if I suspect that patient has a CN 8 palsy affecting their balance?
Romberg’s test - test for proprioception & balance
** How do I identify vagus nerve palsy?
Uvula deviation AWAY from affected side.
Vagus nerve innervates the muscles of the soft palate, in particular, the levator palatini elevates the soft palate.
When functioning normally, both sides of the levator palatini contract to lift the soft palate evenly. This gives rise to an equal level uvula.
Lesion of vagus nerve -> paralysis of the levator veli palatini muscle on one side -> failure of soft palate to elevate
Unopposed pull of soft palate towards the unaffected side -> deviation of the uvula AWAY from affected side
Differentiate between the 2 palsies causing uvula and tongue deviation
Uvula deviation:
- AWAY from affected side
- vagus nerve palsy
Tongue deviation:
- TOWARDS affected side
- hypoglossal nerve palsy
Name the 2 nuclei in the thalamus where visual and auditory information synapses
Visual -> lateral geniculate nucleus
Auditory -> medial geniculate nucleus
What branch of the ophthalmic nerve sits on top of the levator palpebrae superioris?
Frontal nerve
Which branch of trigeminal is the only one to have a motor component?
Mandibular, V3
All the muscles of the tongue is supplied by the _ nerve EXCEPT the muscle _ which is supplied by the _ nerve
Hypoglossal (CN 12), palatoglossus, vagus (CN 10)
All the muscles of the soft palate is supplied by the _ nerve EXCEPT the muscle _ which is supplied by the _ nerve
Vagus (CN 10), tensor veli palatini, mandibular (CN V3)
All the muscles of the pharynx is supplied by the _ nerve EXCEPT the muscle _ which is supplied by the _ nerve
Vagus (CN 10), stylopharyngeus, glossopharyngeal (CN 9)
In a thyroidectomy, what are the 3 vessels I am worried about affecting?
- Superior thyroid artery <-> external laryngeal nerve -> cricothyroid muscle -> high pitched sounds
- Inferior thyroid artery <-> recurrent laryngeal nerve -> posterior cricoarytenoid muscle -> abducts the vocal folds
- Cervical sympathetic trunk -> loss of sympathetic function to head and neck region -> ptosis, miosis, anhidrosis
What are the 2 key branches of the cervical plexus?
- Phrenic nerve
- Anas cervicalis -> innervation of the strap muscles (omohyoid, sternohyoid and sternothyroid) EXCEPT thyrohyoid (CN 12)
Which 2 veins combine to form the external jugular vein? How does the EJV relate to the SCM and describe its trajectory to becoming the brachiocephalic vein.
Posterior auricular vein + retromandibular vein -> external jugular vein
EJV crosses the SCM anteriorly -> subclavian vein
Subclavian (right and left) + internal jugular vein (right and left) -> (right and left) brachiocephalic vein -> superior vena cava
Name the 5 broad groups of muscles in the face & scalp
- Muscles of mastication (CN V3)
- Muscles of facial expression (CN VII)
- Muscles of the cheek - buccinator
- Orbicularis oris (mouth) & oculi (eye)
- Muscles of the scalp - occipital & occipitofrontal (forehead)
Name the deep and superficial muscles of the neck.
Deep: strap muscles (omohyoid - superior & inferior belly, sternohyoid, thyrohyoid, sternothyroid)
Superficial: platysma
Name the infra and supra hyoid muscles
Infra: strap muscles - omohyoid - superior & inferior belly, sternohyoid, thyrohyoid, sternothyroid
Supra: geniohyoid, mylohyoid, digastric (anterior & posterior), stylohyoid
State which nerves innervate the anterior and posterior belly of digastric, as well as the superior and inferior belly of omohyoid
Anterior belly of digastric: nerve to mylohyoid
Posterior belly of digastric: CN VII
Superior & inferior belly of omohyoid: anas cervicalis (C1-C4)
Between which 2 muscles does the brachial plexus lie within?
Anterior and middle scalene muscles of the neck
Name the 2 types of orbicularis oculi muscle
- Palpebral - close eye gently
- Orbital - close eye tightly
Name the layers of the scalp and name which layer is the most vascular
Skin
Connective tissue (dense)
Aponeurosis
Loose connective tissue (**Most vascular layer)
Pericranium
Describe the sensory innervation to the face
Anterior to vertex ear chin line: Trigeminal nerve
Posterior: branches of superficial cervical plexus
Name the 3 sutures of the skull and roughly where they are
Anterior left to right: coronal
Posterior (occipital region) left to right: lambdoid
Anterior to posterior: sagittal
The pterion is the junction between which 4 boenes?
Frontal
Parietal
Sphenoid (greater wing)
Temporal
What is the needle looking bone of the skull near the ear canal and what is the other closely related bony part where many muscles attach to?
Needle: styloid process
Point of muscular attachment: mastoid process
Name the 3 dural infoldings and where is each located
Falx cerebri - separate right and left cerebral hemispheres
Tentorium cerebelli - separate occipital lobe & cerebellum
Falx cerebelli - separate right and left cerebellar hemispheres
**Describe CSF drainage
- Produced by choroid plexus in lateral and 3rd ventricle
- 3rd to 4th ventricle via cerebral aqueduct
- 4th ventricle has openings which allows CSF to enter subarachnoid space
For recycling,
4. Arachnoid granulations absorb the CSF (more is found in transverse sinus and superior sagittal sinus)
5. Arachnoid granulations drain to dural venous sinuses
Name the 6+1+2 (parasym) muscle of the eye
Extraocular muscle (6):
- Superior, inferior, lateral, medial rectus
- Superior and inferior oblique
Levator palpebrae superioris
Parasym (2):
- Sphincter pupillae
- Ciliary muscle
What opening is the same level as the inferior concha in the nasal cavity?
Eustachian (auditory) tube
What opening is the same level as the superior concha in the nasal cavity?
Spheno-ethmodial recess
Name the 4 paranasal sinuses and which is the largest
- Frontal
- Ethmoidal
- Sphenoidal
- *Maxillary (LARGEST & also the most commonly infected)
What are the 3 ligaments that support the TMJ joint?
- Temporomandibular
- Stylo mandibular
- Spheno mandibular
The _ palatine nerve/artery innervates the _ palate while the _ palatine nerve/artery innervates the _ palate
GREATER -> HARD
LESSER -> SOFT
What is the main artery of the tongue and oral cavity?
Lingual artery which is the 3rd branch of the ECA
What muscles am I using to close my mouth (elevation of mandible)?
Temporalis, masseter and medial pterygoid
What muscles am I using to open my mouth (depression of mandible)?
Lateral pterygoid and supra and infrahyoid muscles
What muscles am I using to protude my mandible?
Lateral and medial pterygoid, masseter
What muscles am I using to retract my mandible?
Temporal and masseter
Describe the histology of salivary glands
Sublingual - purely mucinous (highest concentration of clear cells)
Submandibular - mix of mucinous and serous
Parotid - purely serous (looks the most compact)
What 2 nerves is the submandibular gland closely related to?
Lingual nerve and CN 12
What vessels is closely related to parotid gland?
**FACIAL NERVE
Posterior auricular artery
Name the muscles of the pharynx (internal and external), state the special exception of innervation
Internal (elevate and widen pharynx during swallowing and speaking) – *stylopharyngeus, salpingopharyngeus, palatopharyngesus
*All muscles of pharynx is innervated by pharyngeal branches of CNX except stylopharyngeus which is innervated by CN IX
External (constrict walls of pharynx during swallowing) – superior, middle and inferior constrictor
What are the 2 muscles in the ear and their function
Tensor tympani and stapedius
When sound is too loud, the 2 muscles contract reflexively to pull the ossicles away from the external ear. This reduces the amount of sound transmitted and hence protects the ossicles.
What is the main artery supplying the inner ear?
Labyrinthine artery (branch of basilar artery <- vertebral arteries)
Briefly describe how sound is perceived (pathway)
- Vibration of fluid in cochlear passed from external -> middle -> inner ear
- Displacement of stereocilia of hair cells in the cochlea
- Depolarisation and generation of action potential -> generate an electrical impulse
- Cochlear branch of CN VII transmits this impulse to medial geniculate nucleus in thalamus then to auditory cortex
What kind of epithelium normally lines the larynx and vocal fold?
The vocal fold is the only part of the larynx that is lined by stratified squamous epithelium while the rest of it is by respiratory epithelium (pseudostratified ciliated columnar cells with goblet cells).
Which muscle of the larynx is responsible for high pitched sounds and how?
Cricothyroid muscle - tenses the vocal folds
Which muscle in the larynx ABDUCTS the vocal folds?
Posterior cricoarytenoid muscle
Which 2 cartilages articulate to form the adam’s apple?
Left and right thyroid cartilage
Describe the UMN and LMN of the corticospinal tract
UMN: Axons descend from motor cortex (THROUGH THE INTERAL CAPSULE) to ventral horn of spinal cord
LMN: Ventral horn of spinal cord -> effector muscle
Describe the UMN and LMN of the corticobulbar tract
UMN: Axon descends from motor cortex to cranial nerve motor nuclei in brainstem
LMN: Cranial nerve motor nuclei in brainstem -> effector muscle in the head and neck region
Do all corticospinal nerve fibres decussate? and at where?
No, about 10% do not decussate. If they do decussate, it is at the level of the medulla.
Name the type of influence in the corticobulbar tract and name the exception to this rule
Bilateral influence (ie. UMN signals come from both sides of the brain).
Except for the lower half of the face of CN VII which receives contralateral LMN signals.
Name the motor nucleus for CN V
Trigeminal motor nucleus
Name the motor nucleus for CN VII
Facial motor nucleus
Name the motor nucleus for CN IX & cranial part of CN X
Nucleus ambiguus
Name the motor nucleus for spinal part of CN X
Spinal accessory nucleus
Name the motor nucleus for CN XII
Hypoglossal nucleus
What is the function of the frontal eye field? What happens if there is a lesion to it?
FEF controls eye movements to focus on a central object. Each FEF causes conjugate eye movement towards the opposite side.
If the right FEF is damaged, it will not be able to oppose the action of the left FEF which thus pushes both eyes towards the right.
Lesion results in conjugate deviation of the eyes towards the side of lesion.
What do the limbic system control?
Components include hippocampus, amygdala
ELMO - emotion, learning, (long term) memory and olfaction
Which part of the brain is linked to aggression?
Amygdala
**Where does the ACA supply (ie what brain part and hence what function)
Medial surface of frontal & parietal lobes
Motor & sensory cortices of lower limbs
**Where does the MCA supply (ie what brain part and hence what function)
Lateral surface of frontal, parietal & temporal lobes
Motor, sensory cortices of upper limb, auditory cortices
**Where does the PCA supply (ie what brain part and hence what function)
Inferior surface of temporal lobe and occipital lobe
Visual cortex
What is the watershed area?
An area of lack of collateral circulation, thus patients with severe episodes of hypotension = poor perfusion to the brain = are at risk of infarction occuring at these watershed regions.
**Name the branches of the basilar artery
- Posterior cerebral artery - temporal and occipital lobe
- Superior cerebellar arteries - cerebellum
- Pontine arteries - pons
- Labyrinthine arteries - inner ear
- Anterior inferior cerebellar arteries - cerebellum
**What would I expect to see in a patient with ACA occlusion?
Contralateral hemiparesis and hemisensory loss involving mainly the leg and foot (ie. face and upper limb spared/not as affected).
Damage to frontal lobe - apathy, personality changes and astereognosis (inability to identify objects correctly)
**What would I expect to see in a patient with MCA occlusion?
Contralateral hemiparesis and hemisensory loss in the face and arm but spares the leg.
Gaze deviation to ipsilateral side (due to frontal eye field)
Expressive dysphasia (Broca’s area affected)
Hemineglect (due to inferior parietal lobe damage)
Dressing apraxia
Which vessel is the most commonly affected in ischemic stroke?
MCA
**What would I expect to see in a patient with PCA occlusion?
Contralateral homonymous hemianopia with macular sparing (due to primary visual cortex damage)
Macular sparing is due to dual supply by MCA and PCA to the portion of the visual cortex representing the macula.
Dominant hemisphere: patient may exhibit difficulty in naming objects and inability to read.
What would I expect to see in a patient if there is an occlusion in their superior cerebellar arteries?
Vertigo, nausea, vomiting, cerebellar signs eg. finger nose dysmetria, ipsilateral ataxia, dysdiadochokinesia
What would I expect to see in a patient if there is an occlusion in their pontine arteries?
Pons affected.
Cranial nerve impairment
- CN 3 - diplopia, ptosis and impaired eye movements
- CN 7 - ipsilateral facial weakness
- CN 10 - dysphagia and hoarseness
- CN 12 - tongue deviation
Unilateral or bilateral hemiparesis (as most of the motor nerve fibres pass through the brainstem to reach the cerebral cortex)
Name the 3 components of the blood brain barrier and what is its function
Components:
1. Endothelium (capillary walls) with tight junctions
2. Basement membrane
3. **Astrocytes
Function:
1. Provides neurons with a relatively constant biochemical and metabolic environment
2. Protects against toxins and infective agents.
What is the name of the nucleus involved in pupillary light reflex?
Edinger Westphal
Describe the pupillary light reflex
Bright light -> photoreceptors on retina -> pretectal nucleus in midbrain
On ipsilateral side:
Pretectal nucleus -> Edinger Westphal nucleus -> ciliary ganglion -> constriction of sphincter pupillae
On contralateral side:
Pretectal nucleus -> **posterior commissure -> Edinger Westphal nucleus -> ciliary ganglion -> constriction of sphincter pupillae
What is the name of the nucleus involved in accommodation for near objects?
Superior colliculus in midbrain
Describe the accommodation for near objects
Primary -> secondary visual cortex -> superior colliculus in midbrain
CN 3,4,6 nuclei -> extra ocular muscles -> eyes converge
Edinger westphal nucleus -> ciliary ganglion -> constriction of sphincter pupillae & ciliary muscle relax -> lens thickens
What nerve is the patellar reflex testing for? Nerve root?
Femoral
L2-4
What nerve is the Achilles tendon reflex testing for? Nerve root?
Tibial (branch of sciatic)
S1
**Name some signs of cerebellar dysfunction
- Nystagmus
- Finger nose dysmetria
- Dysdiadochokinesis
- Heel shin test positive - unable to carry out the movements
- Ataxic gait
- Inability to maintain posture
Which lobe in the cerebellum is responsible for motor?
Spinocerebellum
Which lobe in the cerebellum is responsible for balance, posture, coordination?
Vestibulocerebellum
Which lobe in the cerebellum is responsible for speech?
Cerebrocerebellum
The highest number of arachnoid granulations is found in the _
Superior sagittal sinuses
Transverse sinuses
Describe venous drainage of the brain
Cerebrum/cerebellum/
brainstem -> deep veins -> **DURAL VENOUS SINUSES (no valves) -> internal jugular vein
Which artery has the highest chance of berry aneurysm?
Anterior communicating artery
How does hypertension result in intraparenchymal haemorrhage?
Elevated blood pressure causes mechanical stress on small arteries of the brain.
When prolonged, this could damage the vascular endothelium and cause it to be more prone to rupture.
Microaneurysm rupture leads to blood extravasation into the brain parenchyma, forming a haematoma that disrupts tissue and increases intracranial pressure (ICP).
Depending on which section of the brain is affected -> determines which functions will be compromised.
