HNNS Practicals Flashcards
[Dissection]
Which muscle forms the inferior boundary of the mandibular triangle?
Digastric muscle
[Dissection]
Hypoglossal nerve gives motor innervation to most of the muscles of the tongue EXCEPT for one. Which muscle of the tongue is NOT supplied by hypoglossal nerve?
A. Genioglossus
B. Hyoglossus
C. Intrinsic tongue muscles
D. Palatoglossus
E. Styloglossus
D
[Dissection]
Which nerve innervates mylohyoid muscle?
A. Ansa cervicalis
B. C1 spinal nerve
C. Mandibular branch of facial nerve (CN VII)
D. Mandibular nerve (CN V3)
D
Ansa cervicalis
- superior root (C1) + inferior root (C2-3)
- innervate omohyoid, sternohyoid & sternothyroid muscles
[Dissection]
Which nerve accompanies with the superior laryngeal artery?
A. External branch of superior laryngeal nerve
B. Internal branch of superior laryngeal nerve
C. Recurrent laryngeal nerve
B
[Dissection]
A patient complains of numbness in the anterior cervical triangle after trauma. Which nerve is most likely damaged?
A. Greater auricular nerve
B. Lesser occipital nerve
C. Supraclavicular nerve
D. Transverse cervical nerve
D
Greater auricular n.: skin behind auricle and on parotid gland
Lesser occipital n.: scalp behind auricle
Supraclavicular n.: skin over clavicle and the shoulder
Transverse cervical n.: turn around posterior border of SCM => skin of anterior cervical triangle
[Dissection]
A patient presents to a clinic with a swelling on the neck. Upon evaluation, the patient is diagnosed with an infection within the carotid sheath due to an untreated throat infection. Which of the following structures are most likely damaged?
A. Internal carotid artery and recurrent laryngeal nerve
B. Internal jugular vein and vagus nerve
C. External carotid artery and ansa cervicalis
D. Sympathetic trunk and common carotid artery
E. Vagus nerve and middle cervical ganglion
B
Carotid sheath: IJV, vagus nerve, CCA, ICA
Recurrent laryngeal n.: tracheoesophageal groove
Sympathetic trunk (with superior & middle cervical ganglia): posterior to carotid sheath
Ansa cervicalis: superficial to / in carotid sheath
[Dissection]
A patient with thyroid cancer undergoes a total thyroidectomy. Postoperatively, the patient presents with hoarseness and dysphonia. Which nerve is most likely damaged during the surgery?
A. Glossopharyngeal nerve
B. Hypoglossal nerve
C. Recurrent laryngeal nerve
D. Superior laryngeal nerve
C
Recurrent laryngeal nerve:
- posterior to thyroid gland
- damage causes ipsilateral paralysis of all muscles of larynx (except cricothyroid muscle innervated by superior laryngeal nerve)
[Dissection]
Which structure passes through mandibular foramen?
Inferior alveolar nerve, artery & vein
[Dissection]
Which structure lies on the surface of sublingual fossa?
Sublingual gland
[Dissection]
Which structure attaches to mylohyoid line?
Mylohyoid
Part of superior constrictor muscle of pharynx
[Neuroanatomy Practical]
Structures above the fornix are … while those below are …
Telencephalic
Diencephalic
[Neuroanatomy]
After a stroke, patients usually suffer dysfunctions from generating language.
What is the name of the area responsible for language production?
Broca’s area
[Neuroanatomy practical]
After a stroke, patients usually suffer dysfunctions from generating language.
Discuss which anatomical gyrus forms the affected language area.
Inferior frontal gyrus, usually left hemisphere
Brodmann 44, 45
[Neuroanatomy practical]
Which type of information is processed in transverse temporal gyri?
Auditory information
Primary auditory cortex (area 41, 42, 22)
[Neuroanatomy practical]
Which anatomical gyrus forms primary somatosensory cortex?
Postcentral gyrus of parietal lobe
Brodmann areas 3, 1, 2
Process tactile information
[Neuroanatomy practical]
Which anatomical gyrus forms primary motor cortex?
Precentral gyrus of frontal lobe
Brodmann area 4
Voluntary movements
[Neuroanatomy practical]
Which lobe of cerebrum forms primary visual cortex?
Occipital lobe
Brodmann area 17
Visual information
[Neuroanatomy practical]
What is the function of Brodmann area 6?
Premotor cortex - plan movements
[Neuroanatomy practical]
Name 3 association areas and their functions.
- Prefrontal cortex
- complex behaviour, decision-making, personality - Parietal association cortex
- integrate sensory information to form a single perception - Temporal association cortex
- recognition of objects and faces, memory
[Neuroanatomy practical]
The spinal cord is a cylindrical structure, greyish-white in colour.
Name the anatomical space in which the spinal cord travels.
Vertebral canal
[Neuroanatomy practical]
Name three membranes which protect the spinal cord.
- Dura mater
- Arachnoid mater
- Pia mater
[Neuroanatomy practical]
In which meningeal space is the cerebrospinal fluid found?
Subarachnoid space
[Neuroanatomy practical]
The spinal cord is segmental. How many segments form the spinal cord?
31 segments
Cervical: C1-C8
Thoracic: T1-T12
Lumbar: L1-L5
Sacral: S1-S5
Coccygeal: Co1
[Neuroanatomy practical]
What is the name of the last part of the spinal cord?
Conus medullaris
[Neuroanatomy practical]
Observe the posterior median sulcus. What is the name of its counterpart on the front?
Anterior median fissure
[Neuroanatomy practical]
How is the filum terminale formed?
Continuation of pia mater
From tip of conus medullaris to coccyx
- Meningeal layer of dura and subarachnoid space ends at S2
[Neuroanatomy practical]
What is the common name for a bundle of spinal nerve rootlets that arise from conus medullaris?
Cauda equina
[Neuroanatomy practical]
What is held inside central canal?
Cerebrospinal fluid
[Neuroanatomy practical]
How many branches does a typical spinal nerve have?
4
- Ventral ramus
- Dorsal ramus
- Meningeal branch
- Communicating rami (to sympathetic trunk)
[Neuroanatomy practical]
Why can we observe a widened area at C4-T1 level of spinal cord?
Cervical enlargement
Increased volume of motor neurons in ventral horn
Anterior rami of spinal nerves -> brachial plexus -> upper limbs
[Neuroanatomy practical]
Why can we observe a widened area at T11-L1 level of spinal cord?
Lumbar enlargement
Anterior rami of spinal nerves -> lumbosacral plexus -> lower limbs
[Neuroanatomy practical]
Compare the sizes of anterior, posterior and lateral horns of spinal cord. Explain the difference in size
Anterior > posterior > lateral
Anterior horn:
- motor neurons
- enlarged in cervical and lumbar regions
Posterior horn:
- sensory neurons
- relatively constant size
Lateral horn:
- ANS neurons
- Only found in T1-L2 (sympathetic) & S2-S4 (parasympathetic)
[Neuroanatomy practical]
What is the approximate circulating volume of CSF?
150 mL
[Neuroanatomy practical]
What is the approximate daily production volume of CSF?
500 mL
[Neuroanatomy practical]
What produces CSF?
Ependymal cells in choroid plexus in ventricles
[Neuroanatomy practical]
Describe the functions of CSF.
- Buoyancy
- Protection: shock absorber
- Regulation of intracranial pressure by altering CSF volume
- Homeostasis (pH, electrolyte, temperature)
- Clearance of metabolic waste: glymphatic system (glia + lymph) -> CSF -> blood
Brain Protection Relies Heavily on CSF
[Neuroanatomy practical]
What is the clinical importance of CSF analysis?
- Appearance
- turbid: infection
- blood-stained: subarachnoid haemorrhage
- xanthochromic (clear yellow): breakdown products of blood (e.g. after subarachnoid haemorrhage) - Glucose
- Normal: 2/3 of blood
- Often lowered in infections - Protein
- Minimal normally
- Often elevated in infections, inflammation and demyelinating diseases - Cell counts
- Normal: no RBC, WBC <5/mm^3 - Electrolytes
- Normal: less Ca2+ and K+, more Cl-
[Neuroanatomy anatomy]
Where can you perform lumbar puncture?
Subarachnoid space at L3-L5
For diagnosis / regional anesthesia
L4: iliac crest
[Neuroanatomy practical]
Which anatomical structures form the walls of lateral ventricle?
- Anterior wall
- Superior: foramen of Monro
- Inferior: optic chiasm - Posterior wall
- Superior: Suprapineal recess
- Inferior: cerebral aqueduct - 2X Lateral walls
- Medial aspects of thalamus and hypothalamus
[Neuroanatomy practical]
Which structure continues the fourth ventricle in spinal cord?
Central canal
[Neuroanatomy practical]
Follow the blood flow from internal jugular vein to the heart.
Internal jugular vein -> join subclavian vein to form brachiocephalic vein
L & R brachiocephalic veins join to form superior vena cava -> right atrium
[Neuroanatomy practical]
Cavernous sinus drains into internal jugular vein via …
Inferior petrosal sinus
[Neuroanatomy practical]
What tissue lines the lumen of the dural venous sinuses?
Endothelium
The lumen is the space between periosteal and meningeal layers of dura mater
[Neuroanatomy practical]
What is the main function of arachnoid villi (granulations)?
CSF reabsorption into blood
[Neuroanatomy practical]
What are emissary veins?
Valveless veins that connect extracranial with intracranial veins
[Neuroanatomy practical]
In which space are cerebral veins found?
Subarachnoid space
[Neuroanatomy practical]
What are the tributaries of great cerebral vein (of Galen)?
Paired internal cerebral veins
Paired basal cerebral veins (of Rosenthal)
[Neuroanatomy practical]
Into which sinus does great cerebral vein drain into?
Straight sinus (with inferior sagittal sinus)
[Neuroanatomy practical]
Venous drainage ensures that blood volume in the brain is not excessive since sinuses are housed in non-expandable bony structures and will not place the brain under pressure. A blood clot in the cavernous sinus (cavernous sinus thrombosis) can place pressure on the cranial nerves.
Which cranial nerves may be affected?
CN III -> ptosis
CN IV -> vertical diplopia
CN VI (most common) -> horizontal diplopia
CN V1
CN V2
-> loss of sensation in forehead and cheeks
[Neuroanatomy practical]
Describe the position of caudate nucleus in relation to lateral ventricle.
Caudate nucleus is lateral to lateral ventricle
[Neuroanatomy practical]
Name 3 major areas of white matter in the brain.
- Internal capsule
- External capsule (separates claustrum from putamen)
- Anterior commissure (connects 2 cerebral hemispheres)
[Neuroanatomy]
Name 5 major basal ganglia structures.
- Caudate nucleus
- Putamen
- Globus pallidus
- Subthalamic nuclei
- Substantia nigra
[AR/VR]
What are the structures that pass through the substance of the parotid gland?
From deep to superficial (AVN)
1. External carotid artery
2. Retromandibular vein
3. Facial nerve (divides superficial & deep lobes)
[AR/VR]
What are the 4 muscles of mastication and their actions on the mandible?
- Medial pterygoid: elevation, protrusion
- Lateral pterygoid: depression, protrusion
- Temporalis: elevation, retraction
- Masseter: elevation, retraction
[AR/VR]
The sphenopalatine foramen gives passage to …
Sphenopalatine artery (terminal branch of maxillary artery)
Nasopalatine nerve (which goes down and passes through incisive foramen)
Nasal branches of PPG
[AR/VR]
How to locate sphenopalatine foramen in nasal cavity?
Posterior to superior meatus on lateral wall
[AR/VR]
What structures form the nasal septum?
Septal cartilage
Perpendicular plate of ethmoid bone
Vomer
[AR/VR]
Name the 4 contributors to the Kiesselbach’s area.
- Sphenopalatine artery
- Greater palatine artery (terminal branch of maxillary artery): goes down via greater palatine foramen, along hard palate, then up via incisive foramen
- Septal branches of anterior & posterior ethmoidal arteries (from ophthalmic artery)
- Septal branch of superior labial artery (from facial artery)
[AR/VR]
Pituitary gland is located in …, a part of … bone.
Sella turcica
Sphenoid
[AR/VR]
What are three passages into the orbit closely related to sphenoid bone?
Superior orbital fissure
Inferior orbital fissure
Optic canal
[AR/VR]
Which surface(s) of sphenoid bone help to form temporal fossa?
Greater wing
[AR/VR]
Which surface(s) of sphenoid bone help to form infratemporal fossa?
Infratemporal surface of greater wing
Lateral pterygoid plate
[AR/VR]
Which surface(s) of sphenoid bone help to form middle cranial fossa?
Greater wing
Anterior clinoid process
Sella turcica
[AR/VR]
Which surface(s) of sphenoid bone help to form anterior cranial fossa?
Lesser wing
[AR/VR]
Which surface(s) of sphenoid bone help to form nasal cavity?
Body
Sphenoidal sinus
Medial pterygoid plate
[AR/VR]
Name the contents of pterygopalatine fossa.
- Maxillary nerve (branches: zygomatic, ganglionic, alveolar, meningeal)
- PPG
- 3rd part of maxillary artery and accompanying veins
[AR/VR]
Which nerve passes through foramen rotundum?
CN V2
[AR/VR]
Transphenoidal surgery is used to remove tumours of pituitary gland. Describe the path of endoscope and/or surgical instruments after insertion into nasal cavity.
Nasal cavity -> along nasal septum -> sphenoid sinus inside body of sphenoid bone -> sella turcica -> pituitary gland
[AR/VR]
What are the four parasympathetic ganglia in head?
CN III -> ciliary ganglion
CN VII -> pterygopalatine ganglion, submandibular ganglion
CN IX -> otic ganglion
[AR/VR]
How is lobotomy performed?
Insert needle transorbitally -> sever the connections between prefrontal cortex and thalamus
[AR/VR]
Describe the contents of the greater palatine canal.
Greater & lesser palatine nerves & arteries
[AR/VR]
Name the boundaries of the pterygopalatine fossa.
- Anterior: maxilla
- Posterior: pterygoid plate of sphenoid bone
- Medial: perpendicular plate of palatine bone
- Roof: infratemporal surface of greater wing of sphenoid bone
- Floor: pyramidal process of palatine bone
[Surgical cadaveric dissection]
In thyroidectomy, the posterior part of each lobe is usually preserved to protect …
Recurrent laryngeal nerve
Superior laryngeal nerve
Parathyroid gland
[Surgical cadaveric dissection]
Name the layers cut through during parotidectomy.
Skin -> subcutaneous fascia -> (platysma) -> parotid fascia (investing layer of deep cervical fascia) -> superficial lobe
[Dissection]
Which nerve gives motor innervation to the buccinator muscle?
A. Facial nerve (CNVII)
B. Ophthalmic branch of mandibular nerve (CN V1)
C. Maxillary branch of mandibular nerve (CN V2)
D. Mandibular branch of mandibular nerve (CN V3)
A
Buccal branch of CN VII
[Dissection]
Which nerves transmit the nerve fibers that innervates the parotid gland?
Parasympathetic: lesser petrosal nerve
Inferior salivatory nucleus -> Tympanic branch of glossopharyngeal nerve (CN IX) -> Lesser petrosal nerve -> Otic ganglion
Sensory: auriculotemporal nerve (CN V3: mandibular)
Sympathetic: internal carotid plexus (from superior cervical ganglion)
X facial nerve
IT has Lesser Options Anywhere
[Dissection]
In the event of facial artery bleeding, where should direct pressure be applied to achieve hemostasis?
A. On the frontal bone
B. On the inferior margin of the body of the mandible
C. On the nasal bone
D. On the ramus of mandible
B
Facial artery
- ascend deep to post. belly of digastric & stylohyoid in neck
- cross body of mandible anterior to masseter
- palpation: inferior margin of body of mandible, anterior border of masseter
[Dissection]
A patient accidentally cut the scalp when shaving the head. The scalp wound appears modest but bleeds profusely. In what layer of the scalp do the severed vessels reside?
A. Skin
B. Dense subcutaneous connective tissue
C. Occipitofrontalis and aponeurosis
D. Loose connective tissue
E. Periosteum of the skull
B
Contains nerves and vessels
[Dissection]
Which layer of the scalp does traumatic scalping occur?
A. Skin
B. Dense subcutaneous connective tissue
C. Occipitofrontalis and aponeurosis
D. Loose connective tissue
E. Periosteum of the skull
D
Allow upper 3 layers to move freely as a unit
Spread of infections via emissary (epiploic) veins to intracranial venous sinuses
[Dissection]
When does the anterior and posterior fontanelle close?
Anterior fontanelle (larger): usually by 12-18 months of age
Posterior fontanelle: usually by 2-3 months of age
