Clinical Anatomy NB Flashcards
What are the benefits if anterior and posterior frontanelles?
They are used assess growth
Important for skull and brain growth as well as moulding during normal vaginal birth
When does the bregma close?
18 months
When does the lambda close?
At 6 months
What is the highest point of the transverse sinus?
Asterion
What is the anatomical position pterion?
Meeting point of parietal, frontal, squamous part of temporal and greater wing of sphenoid bone & lies 4 cm above middle of the zygomatic arch and 3 1/2 cm behind the frontozygomatic suture
What is an epicranial aponeurosis?
flat tendon of occipitofrontalis muscle
Where can gapping and profuse bleeding occur?
Epicranial aponeurosis injury
What is the dangerous area of the scalp and why?
it is the dangerous area of scalp because infection can pass into the cranial cavity via the emissary veins present in it.
Haemorrhage here is large and seperates the scalp from the skull bones
What is the radiological apperance of bone marrow hyperplasia?
seen as hair on end appearance; trabeculae are oriented perpendicular to the inner table
What does pituitary adenoma cause?
Causes bitemporal hemianopia
What does anemia do to the diploic layer?
thickens is it due to bone marrow hyperplasia
What is the most common origin of the subdural hemotoma?
venous origin
What causes subdural hemotoma and what can be some pathological causes?
Caused by a tear in bridgig veins in the subdural space
Can happen due to brain shrinkage in neurodegenerative diseases especially Alzheimer’s disease
What does head trauma to the ethmoid bone lead to?
Will affect the cribriform plate leading to rhinorrhea due to the leak of CSF from the anterior cranial fossa into the nasal cavity
What do patients feel when they hae head trauma to the ethmoid bone?
Feel warm water dripping from their nose
What does head trauma to petrous part of temporal bone lead to?
Will lead to otorrhea due to leak of CSF from middle cranial fossa into the middle ear then externanal auditory meatus
What do patients feel when they get head trauma to the petrous part?
Patient feels warm water dripping from ear
What causes thrombs to the cavernous sinus?
Infection from the dangerous area of th e face via direct or indirect pathways
What are the direct/indirect pathways of spread of infection from the dangerous area of the face?
Direct: Facial to superficial opthalamic to cavernous
Indirect: Deep facial to ptyrgoid to emissary to cavernous
What is the function of the emissary veins?
Equalizes intercranial and extra cranial pressure
What are the contents found inside the cavernous sinus?
ICA and abducent nerve (6th cranial nerve)
Wha are the contents embedded in the lateral wall of the cavernous sinus content?
3rd occulomotor nerve
4th trochlear nerv
OPthalamc and maxllary nerves (2 divisions of the 5th nerve)
What are the symptoms of cavernous sinus thrombosis ?
Fever and internal squint due to paralysis of abducent nerve
The eye becomes congested (black eye) and oedematous due to obstruction of its venous drainage and later on the eye is bulging to the outside (proptosis)
How can pelvic tumors directly metastis to the brain?
Through the basilar venous plexus as it is directly connected to vertebral venous structure
What is the motor nerve supply of the face?
Facial nerve
What is the sensory supply of the face?
From the trigeminal nerve except for a small area of skin covering the angle of the mandible and the parotid gland which is supplied by the great auricular nerve (C2-3)
What does buccinator paralysis lead to?
Auccumulation of food in the vestibule of the mouth and dripping food from the angle of the mouth
How and why should an incision to the face be preformed?
Horizontally to avoid injury to facial nerve branches
What is bell’s palsy ?
Lower motor neuron lesion of trigeminal
What happens in bell’s palsy?
The entire ipsilateral side of the face is affected and patients cannot close their eyes or smile
Dryness of the ey and maybe ulceration
Due to inflammation of the facial nere while the facial canal in the petrous bone
What happens in upper motor neuron lesion of trigeminal nerve ?
Contralateral affection
upper part of the face is spared (forehead sparing) but lower part is affected so patient can close their eyes but not smile
Where is the superficial temporal artery pulse felt?
Against the zygomatic arch
Why does forehead sparring occur?
Due to the corticonuclear fibers supplying the forehead but not the lower half of the face
Which nerve do dentist apply anesthesia to?
Inferior alveolar nerve
where does the parotid duct open?
It is 5cm long
and opens in the vestibule of mouth opposite the upper 2nd molar tooth
What are the structures of the parotid gland?
Facial nerve
Retromandibular vein
External carotid artery
DEep parotid lymph nodes
Auriculotemporal nerve
What is the parasympathetic supply of th eparotid gland?
The glossopharyngeal nerve
Where do preganglion fibers arise from and what are their pathways?
Arise from inferior salivary nucleus in the medulla and pass in tympanic branch of glossopharyngeal nerve which enters the middle ear cavity to form the tympanic plexus
Where do the postganglionic fibers end up?
They join the auriculotenporal nerve which carries them to the parotid gland
What does the tympanic plexus give rise to?
The lesser superficial petrosal nerve which passes through foramen ovale to relay to the otic ganglion