Anatomy Flashcards
What are the two groups of skull bones?
Cranium and facial bones
Describe the layers of the cranial bones
an external and an internal layer of compact bone, with spongy bone (diploe bone) inbetween
What are the four sutures of the cranium?
coronal suture anteriorly
sagittal suture in the midline
lambdoid suture between parietal and occipital (coronal as well)
pterion suture
What is the pterion suture bound by?
frontal bone supero-anterior
sphenoid bone infero-anterior
parietal bone supero-posterior
temporal bone infero-posterior
Which artery lies under the pterion suture?
middle meningeal artery
What are the two parts of frontal bone? and what is name of the junction between the two parts?
vertical part forming the forehead
horizontal part forming the roof of the orbits
superior orbital margin
T/F is the parietal bone completely flat?
No, it is mostly flat, but moulds to the shape of the brain
What is one prominent landmark of occipital bone
external occipital protuberance
What are the five parts of the temporal bone
1) flat squamous part
2) anterior projection, the zygomatic process
3) posterior projection, the mastoid process
4) styloid process inferiorly
5) petrous part, inward projection
Where does a depressed fracture of the cheek occur?
at the zygomatic process of the temporal bone
What is special about the mastoid process?
it is thick and full of air space
What is special about the styloid process?
gives attachment for muscles of the oral cavity and the pharynx
Sphenoid bone looks like a bat. What are the 3 major parts?
body, lesser wing antero-superiorly, greater wing inferior to lesser wing
What is found in the body of sphenoid bone, where there is a depression?
the pituitary gland
Not very relevant - body of the sphenoid is also known as?
Sella turcica
What divides the greater and lesser wings
superior orbital fissure
What are the characteristics of the two major parts of ethmoid bone in the cranial floor?
1) cribiform plate: with little holes for olfactory nerve fibres
2) crista galli, the middle segment that pokes up
What is within the
1) anterior cranial fossa
2) middle cranial fossa
3) posterior cranial fossa
1) horizontal plate of frontal bone, cribiform plate of ethmoid, lesser wing
2) greater wing, petrous part of temporal, with the wedge forming boundary to posterior cranial fossa
3) occipital bone
which cranial fossa is superior orbital fissure found?
middle
What is special about superior orbital fissure
it provides direct communication between orbit to cranial cavity
Superior orbital fissure is the beginning of an arch of foramina. What are the foraminae?
foramen rotundum, foramen ovale, foramen spinosum
Where is the optic canal?
medial to the superior orbital fissure, in the lateral body of the sphenoid
Where is foramen lacerum? What goes through the foramen?
at the medial junction between greater wing and petrous wedge. Medial to both foramen ovale and spinosum
Nothing goes through. It is covered by a membrane when meninges is intact
There are three foramens in the petrous wedge of posterior cranial fossa, what are they?
internal auditory meatus, jugular foramen inferior to the meatus, and hypoglossal foramen medial to jugular foramen
What is the central large opening found in the posterior cranial fossa?
foramen magnum
From superficial to deep, list out all layers of structures + potential spaces from the skull onward
cortical bone, diploe bone, cortical bone, extra-dural space, dura, sub-dural space, arachnoid, subarachnoid space, pia, brain tissue
Out of the three spaces in the meninges, which one is an actual space (not a potential space)
sub-arachnoid space, for CSF collection
What are dural septa?
dural projections into the sub-divisions of cranial cavity
what is the function of dural septa
restrict rotational forces and displacement of the brain in response to trauma
Name the three main dural septa
falx cerebri, tentorium cerebelli, falx cerebelli
Where is the falx cerebri? What are the attachments?
in the midline between two cerebral hemispheres
Crista galli and cribiform plate anteriorly, along the sagittal plane, then to the occipital protuberance
which plane is tentorium cerebelli in?
the horizontal plane
tentorium cerebelli provides the roof for _______, separating _______ above from ________ below
posterior cranial fossa
occipital lobe
cerebellum
Falx cerebelli is found beneath the __________, and is also in the ________ plane, same as _________
tentorium cerebelli
sagittal
falx cerebri
Do the dural septa separate the hemispheres completely?
no, they only project part-way
What is the name of the dural fold over the body of sphenoid?
diaphragma sellae
What structure does diaphragma sellae enclose? What pierces through it?
pituitary gland
the infundibulum of the pituitary
what are the two layers of dura mater?
outer periosteal layer and inner meningeal layer
What are dural venous sinuses?
endothelial lined spaces that exist between the outer and inner layers of dura which are associated with dural projections
Where do dural venous sinus receive blood from? What is the significance of it?
veins of the brain
spongy bones via diploic veins
exterior skull via emissary vein
infection of skull wound can spread into venous sinus to meningitus or encephalitis
What is the name of dural sinus at the top of falx cerebri?
superior sagittal sinus
where is the inferior sagittal sinus?
at the inferior margin of falx cerebri
Inferior sagittal sinus joins the ________ to form the _________
great cerebral vein
straight sinus
where does the straight sinus run?
in the inferior margin of falx cerebri, where it meets the tentorium
where does the superior sagittal sinus meet the straight sinus?
at the confluence of sinuses
T/F a lot more blood is collected posteriorly
True
Where do the right and left transverse sinuses run?
around the margin of tentorium
where do the transverse sinuses drain from?
the confluence of sinuses
What is the major branch of transverse sinus. Where does it drain into?
sigmoid sinus down the jugular foramen into the internal jugular vein
What are the two minor branches of the transverse sinus?
superior and inferior petrosal sinuses
Where does the superior petrosal sinus drain into
into the cavernous sinus
what gives the vascular supply for the skull and meninges?
Small meningeal artery
Which artery provides the most important supply for the skull and meninges? It is a branch of which artery?
Middle meningeal artery
maxillary artery
Middle meningeal artery is likely to be damaged with a fractured ______
pterion suture
How do arteries from outside the skill enter the brain?
via the foramen spinosum into the middle cranial fossa
How does middle meningeal artery branch out from the pterion?
it splits into anterior and posterior divisions and groove the interal aspect of the skull
Where does the middle meningeal artery lie? A fractured pterion is likely to cause _________
in the extra-dural space
extra-dural haematoma
Why can a tear in superior sagittal sinus be self-limiting
a tear will cause sub-dural haemorrhage, and because it’s venous blood, it is at a much lower pressure, therefore it can be self-limiting
What are the borders of the scalp?
it extends from external occipital protuberance to supraorbital margin, over the zygomatic arches laterally
What are the five layers of the scalp?
skin connective tissue aponeurosis loose connective tissue pericranium
Which layer contains the neurovascular structure?
the connective tissue
what is the aponeurosis layer of the scalp made of?
occipital-frontalis, with an anterior frontalis belly and a posterior occipital belly
What is the function of occipital-frontalis
it’s the layer of muscle that moves the scalp. I.e raise the eyebrow
what is the function of loose connective tissue?
allow the superficial layers to slide over the pericranium
What is the significance of the rich blood supply over the connective tissue layer?
with laceration, there can be profuse bleeding
What are the three reasons contributing to severe bleeding due to surface laceration?
Rich anastamoses
frontalis and occipitalis pull the wound apart
tissue fibrous septa adhere to vessels so they are unable to constrict and promote clotting
What is the difference between the layers of scalp and face
the face does not have loose connective tissue
facial muscles replace the aponeurosis
what are the groups of facial muscles?
circular muscles as sphincters
longitudinal muscles as dilators, which can be either depressors or levators
What are the attachments of the facial muscles
skin superficially and fascia deeply
What is the embryonic origin of facial muscle? Where nerve supplies the muscles?
from the 2nd pharyngeal arch, supplied by CNVII
Describe the sensory supply for the head
trigeminal nerve supplies everything in front of the ear, C2 and C3 supply everything behind the ear
(cervical plexus was not mentioned)
What is trigeminal neurogia?
syndrome characterised by brief episodes of intense pain over one of the division of CNV
where is the CNV ganglion?
in the apex of the petrous part of the temporal bone
CNV has three divisions, which foramina do they go through?
opthalmic - superior orbital margin
maxillary - foramen rotundum
mandibular - foramen ovale
what are the main arteries from internal carotid that are supplying the face?
supra-orbital branch and supra-trochlear branch
They are branches of opthalmic artery
What is the most important branch from the external carotid artery supplying the face? Describe its course
facial artery
it runs in a tortuous course from the inferior angle of mandible to the medial angle of the eye
What are the four branches of the external carotid artery beyond the facial artery?
posterior auricular artery
occipital artery
superficial temporal artery
maxillary artery
what is the major venous drainage for the face? How is it different to facial artery?
the facial vein, which is posterior to facial artery
it is straighter
Where are emissonary veins located on the face? What is the significance?
in a triangular area in the centre of the face
some blood drains into the cavernous sinus so the wounds within the area must be carefully treated
from front to back, list the lymph nodes of the face
submental, under the chin submandibular, under the mandible pre-auricular parotid posterior auricular occipital
Where do the lymph drainage of the face go to?
all drain into cervical nodes in the neck
what is the function of parotid gland?
secretion of saliva
where is it located?
inferior to zygomatic process anterior to mastoid process superior to angle of mandible posterior to masseter superficial to styloid process
what is it wrapped in? what is the significance?
it is wrapped in parotid fascia
in patients with mumps, there can be extreme pain because the fascia allows the internal pressure to build up
describe the course of the parotid duct
emerge from the anterior border of the parotid gland and runs superficial to masseter until its anterior edge. It then pierces the buccinator to enter the oral cavity near the second upper molar
what are the structures wtihin the parotid gland from superficial to deep
facial nerve
retro-mandibular vein
external carotid artery
where are the lymph nodes in the parotid? what is the significance?
scattered throughout the gland.
In patient with cancer, if the surgeon needs to operate on the parotid, the nerve, vein and artery can potentially be in danger
where does the facial nerve exit
stylomastoid foramen between mastoid and styloid process
what branches does the facial nerve give?
posterior auricular branch to back of the scalp
pes anserinus anteriorly in the substance of parotid
what muscles does the posterior auricular branch innervate?
occipitalis, digastric and stylohyoid
what are the five branches of pes anserinus
temporal zygomatic buccal mandibular cervical
what is the retromandibular vein formed by?
superficial temporal artery superiorly and maxillary vein anteriorly
what does facial nerve injury cause?
facial droop, partial or complete paralysis
what’s the most common cause of facial nerve injury?
bell’s palsy
What causes cleft lip and palate?
failure of the facial process to merge around either side of the pre-maxilla
What are the three major components of outer ear?
auricle, lobule, and external auditory meatus
What is the function of the auricle?
collecting sound and directing it to the ear
T/F the entire external auditory meatus is cartilaginous
False, the medial 2/3 is bony
What is the sensory supply for the external auditory meatus?
vagus - posterior and inferior
auriculotemporal nerve of trigem - anterior and superior
What is the significance of trigeminal nerve innervating the external auditory meatus?
pain can refer the to teeth, or vise versa
T/F tympanic membrane is concaved so the middle is deeper into the ear
True, and this is important for the collection of sound
If you shine some light down to the membrane, where will the light defect to?
the antero-inferior quadrant, if the ear is healthy
what are the two cavities of the middle ear?
tympanic cavity proper
epitympanic recess superiorly
What can you find in the epitympanic recess?
lots of air space, and it communicates with mastoid process
What is the direction of the auditory tube?
antero-inferior to nasopharynx
What is the function of auditory tube?
equalisation of pressure
Why shouldn’t you sky dive when you have a cold?
mucus can block up the auditory tube to prevent equalisation of pressure, so there may be excessive movement of the TM and pain
What are the three bones of the middle ear?
malleus
incus
stapes
Why are middle ear infection more common in children?
the auditory is more horizontal, allowing bacteria to migrate
What are the two muscles of the middle ear, and what are their nerve supply?
tensor tympani - Trigem
Stapedius - facial
What is the function for the muscle of the middle ear?
auditory reflex - they contract when the sound amplitude is too high, preventing excessive energy from entering the inner ear
What is the function of chorda tympani?
CT is a branch of facial nerve. It provides the special sensory for anterior 2/3 of the tongue
What are the two openings to the inner ear?
oval window connecting to cochlea
round window for releasing pressure within the inner ear
What is the promontary?
a large swelling on the medial surface of the middle ear. It is used as a landmark
Where is the inner ear chamber in relation to the surrounding bony structure?
It is enclosed in the petrous temporal bone
What are the structures within the cochlea?
there is a space called the bony labyrinth, filled with perilymph, and a suspended membranous labyrinth, filled with endolymph
Where is the vestibule?
it is between the semicircular canal and the cochlea, communicating with the round window
Which arterial systems make up the circle of Willis?
the internal carotid system and the vertebrobasilar system
T/F Circle of Willis looks almost identical in most people
False, the CoW is very variable in reality
What is the function of the anastomoses in CoW
where there is a blockage, blood can be diverted to from other arteries
Describe the course of the internal carotid artery
It comes off the common carotid, then enter the carotid canal into the middle cranial fossa lateral to the optic chiasm. It will then give off its branches
Describe the course of the vertebral artery
comes off the subclavian and traverse through transverse foramina of the vertebral column into the foramen magnum. It then joins to form the basilar artery
What is the functional territory of anterior cerebral artery
Medial part of frontal and parietal lobes
Most importantly, the motor and somatosensory area for the lower limbs
Describe the course of anterior cerebral artery
it is the anterior branch for the CoW, which travels anteriorly initially, but then does a sharp turn posteriorly and splits into two branches. Pericallosal branch around corpus collosum, and callosomarginal brnach higher up in the longitudinal fissure
What would a lesion most likely cause?
contralateral hemi-paresis and hemisensory loss of the lower limbs
Which lobes does the middle cerebral artery supply?
Lateral parts of frontal, parietal, temporal and occipital lobes
insula
What is the functional territory of MCA?
motor and sensory cortices for most of the body
parietal-occipital association
language area in temporal
What functions can be lost with a lesion in MCA
contralateral sensory loss for upper limb + face
hemiparesis
some aphasia
Which lobe does the posterior cerebral artery supply?
medial and inferior surfaces of temporal and occipital lobes
What is the main functional territory of PCA?
the visual cortex
What will a lesion in PCA most likely lead to ?
visual problem, homonymous hemianopia
Which main artery branch do pontine arteries come off
the basilar artery
What do the small perforating branches usually supply ?
deep structures, the core of cerebrum and the associated deep nuclei
What do the anterior perforating branches supply?
optic chiasm
anterior hypothalamus
What do the posterior perforating branches supply?
ventral midbrain
posterior hypothalamus
some thalamus
The lenticulostriate arteries are branches of ______
middle cerebral artery
What do the lenticulostriate arteries supply?
mainly the basal ganglia and internal capsule
The anterior choroidal artery comes off the ________
internal carotid artery (after opthalmic)
What does the anterior choroidal artery supply?
deep lateral hemisphere
optic tract
lateral ventricles
hippocampus
PICA is a branch of _______ while AICA is a branch of _______. While they mostly the ______, they also supply parts of the _________. Just before the posterior cerebral artery, ________ comes off the basilar artery, which gives a little branch to supply the ______ of the midbrain
vertebral artery basilar artery cerebellum brainstem superior cerebellar artery inferior colliculi
The medulla gets three separate blood supplies. What are they, and which area do they supply?
anterior spinal artery - medial strip of medulla
vertebral artery - the olives and ventral-lateral medulla
PICA - dorsal lateral medulla
What is medial medullary syndrome caused by?
cerebrovascular accident associated with anterior spinal artery
What will a stroke in anterior spinal artery damage?
hypoglossal nucleus - ipsilateral atrophy of tongue
medial lemniscus - contralateral somatosensory hemideficit
pyramids - contralateral hemiparesis
Anteriorly, the _______ runs down the _________ of the spinal cord. Posteriorly, there are two branches of ________ . These arteries are all reinforced by _______ from the aorta, and they send _______ to supply the inner grey matter
anterior spinal artery ventral medium fissure posterior spinal arteries segmental arteries perforating branches
What are the bony and cartilagenous structures forming the external nose
frontal process of maxilla laterally
two nasal bones in the midline
2 lateral and two alar cartilages, with a septal cartilage in the midline
T/F ethmoid bone is located in the posterior nasal cavity
False, the sphenoid forms the posterior cavity with palantine and ethmoid anterior to it
T/F vomer is in the midline of the basal cavity
True, the vomer in the midline forms the nasal septum
What is rhinorrhea?
leakage of CSF out of the meninges, via the cribiform holes and into the nasal cavity
What are the functions of the highly vascular mucosa of the nasal cavity?
trap foreign particle
humidify air
warm up the air so it’s closer to body temperature
What is the function of the cilia in the inferior respiratory area of the nasal cavity?
actively encourage mucous to be expelled
Where is the vestibule and how is it different to the rest of the nasal cavity?
it’s the bit where fingers can easily reach
It’s lined by skin and hair so it’s a lot stronger
What’s the function of concha? Which wall is it found on?
creates turbulent air flow
three conchi on the lateral wall
T/F conchi take up a lot of space in the nasal cavity
True, hence why nose can be so easily blocked up if there is excessive mucous
What’s the name of the space inferior the conchi
meatus, and there are three of them - superior, middle, and inferior
What can be found in the meatus?
paranasal sinuses
What is the function paranasal sinuses?
to lighten the head so we can keep our heads up against gravity. This is an energy saving mechanism
What is the clinical significance of paranasal sinuses?
they are direct openings of the nasal cavity, so bacteria can migrate into it to cause inflammation and pain
T/F sinusitis generally occurs in the ethmoid sinus
False, it generally occurs in the maxillary sinus, because it’s the only one that’s not located superiorly, and draining is more difficult
What’s the nerve supply for the 4 sinuses?
frontal, ethmoid and sphenoid sinuses are supplied by V1
Maxillary sinus by V2
Where is the opening to sphenoid sinus?
posteriorly in the nasal cavity, inferior to the superior concha
It opens via a recess called sphenoethmoidal recess
Where are the openings for ethmoid sinus?
posterior - under the superior meatus, anterior to sphenoid sinus opening
middle - bulla ethmoidalis, inferior to middle concha
anterior - anterior hiatus semilunaris
Which sinus openings are located in the hiatus semilunaris?
frontal
anterior ethmoidal
maxillary
What’s located inferior to the inferior meatus?
the orifice of nasolacrimal duct
Where is the lacrimal gland?
supero-lateral part of the orbit
What is the blood supply to the inferior quadrant of nasal cavity?
greater palatine artery
what is the blood supply to the superior quadrant of the nasal cavity?
ethmoidal arteries
what is the blood supply to the posterior quadrant of the nasal cavity?
sphenopalatine artery
The rupture in which artery will cause the most severe nose bleed?
sphenopalatine artery
what is the blood supply to the anterior quadrant of nasal cavity?
the lateral wall - facial artery
medial aspect - supply by vessels to the lips
Where is the anastomoses for all nasal vessels?
posterior to vestibule
What is the nerve supply to the nasal cavity?
the antero-superior half is supplied by V1
the posto-inferior half is supplied by V2
Where’s the palantine gland?
at the roof of the oral cavity directly under the mucosa
What is it importance to have an oral cavity roof?
Food doesn’t enter the nasal cavity
important for producing suction, important for infant feeding
Which muscles are found in the floor of the oral cavity?
Mylohyoid laterally
Geniohyoid medially
digastric inferiorly
Which nerve gives off the lingual nerve?
mandibular nerve of CNV
What are the four types of papillae on the tongue?
fungiform in anterior 2/3
foliate in the posto-lateral aspect
valate along the sulcus
filiform for grip
Where are the taste buds?
embedded in cells of the papillae (except for filiform papillae)
Where is the lingual tonsil?
in the posterior 1/3 of the tongue
What are the four extrinsic muscles of the tongue? What are their actions?
palatoglossus - elevation
styloglossus - retraction
hyoglossus - depression
genioglossus - protraction
Which nerves supply the muscles of the tongue?
Hypoglossal, except for palatoglossus supplied by vagus
What are the three intrinsic muscles of the tongue?
superior longitudinal
inferior longitudinal
transverse/vertical
What are the four types of teeth we have?
incisors
canine
premolar
molar
Which nerves supply the teeth?
Inferior alveolar and superior alveolar
What are the three salivary glands?
parotid
submandibular
sublingual
Where does the duct of submandibular gland run?
run in the floor of the lingual frenulum
What are the three internal muscles of the pharynx?
salpigopharyngeus
palatopharyngeus
stylopharyngeus
What is the action of salpingopharyngeus
attaches to the auditory tube. Contraction elevates pharynx and help equalising pressure of auditory tube
What is the action of palatopharyngeus
elevate/depress the soft palate
also pull the pharynx up
what are the two arches of the oropharynx? What can be found between them?
palatoglossal arch
palatopharyngeus arch
palatine tonsil inbetween
Which nerves supply the muscles of the pharynx?
All supplied pharyngeal branch of the vagus, except for stylopharyngeaus (CNIX)
What are the two muscles of the soft palate? What are their actions?
levator veli palatini
tensor veli palatini
Both to elevate the palate. TVP exaggerates the movement of LVP by putting tension on soft palate
Which muscles will depress the soft palate?
palatoglossus
palatopharyngeus
What is the nerve supply for tensor veli palatini
T for T
trigeminal
From top to down, what are the tonsils of the Waldeyer’s ring?
adenoid
tubal
palatine
lingual
Where is the superior and inferior boundaries of the larynx
epiglottis superiorly
C6 inferiorly
From the anterior view, list out the structures of the larynx from top to bottom
hyoid bone thyrohyoid membrane thyroid cartilage cricothyroid membrane cricoid cartilage
How is cricoid cartilage different to tracheal cartilage?
It is a complete ring, but there are also other structural differences
What is found posteriorly on the cricoid cartilage
arytenoid cartilage
What are the two movements of the vocal muscles?
slide
abduction/addiction
what is the name of the superior mucosal fold?
vestibular fold, the false vocal fold
What are the six intrinsic muscles of the larynx
lateral cricoarytenoid posterior cricoarytenoid transverse/oblique arytenoid lateral cricoarytenoid cricothyroid vocalis
What does the superior laryngeal nerve supply?
Internal - mucosa above vocal ligament
external - cricothyroid muscle
What happens when we damage the external laryngeal branch?
lose control of cricothyroid, which is responsible for lengthening the vocal ligament. Damage = unable to hit high pitch
Which nerve supplies most of the vocal muscles? What happens if we damage the nerve
recurrent laryngeal nerve
hoarse voice and stridor
Why do we get stridor in damaging recurrent laryngeal nerve?
because there is a lot more effort needed to produce voice
what are the arterial supplies for the thyroid?
superior thyroid artery (external carotid)
inferior thyroid artery (subclavian)
Where should an emergency airway be?
in the cricothyroid membrane, between the thyroid and cricoid
