Anatomy Flashcards
what are the 3 parts of the brain stem?
midbrain
pons
medulla oblongata
the spinal cord is an inferior continuation of what part of the brain?
medulla oblongata
what is the diencephalon made of?
thalamus + hypothalamus
what i the diencephalon?
the central core of the cerebrum
has connections to left and right cerebral hemispheres and the midbrain
what connects the hypothalamus to the pituitary gland?
the infundibulum
/pituitary stalk
what are the 2 lobes of the pituitary gland?
posterior lobe
anterior lobe
what fossa does the pituitary gland sit in?
the pituitary fossa
what bone is the pituitary fossa in?
the sphenoid bone
what region of the sphenoid bone does the pituitary fossa lie within?
the sella turcica
turkish saddle
what bounds the anterior cranial fossa anteriorly?
frontal bone
what bounds the anteiror cranial fossa posteriorly?
the lesser wing of the sphenoid
what bounds the middle cranial fossa anteriorly?
the lesser wing of the sphenoid
what bounds the middle cranial fossa posteriorly?
the petrous part of the temple bones
what bounds the posterior cranial fossa anteriorly?
the petrous part of the temple bones
what part of the visual pathway lies just superior to the pituitary gland?
optic chiasm
light rays from the temporal side of the visual field will be perceived by what retina?
nasal retina
light rays from the nasal side of the visual field will be perceived by what retina?
temporal retina
what nerves is the optic chiasm formed by?
left and right optic nerves
what happens at the optic chiasm?
APs from the temporal retina will remain on the same side and continue through on the same optic tract
APs from the nasal retina will cross to the other side of the optic tract at the chiasm
after passing through the optic chiasm, where do the APs from the retina synapse?
pass posteriorly from the chiasm and synapse at the thalamus
after synapsing in the thalamus, where do the APs from the retina synapse?
pass posteriorly from the thalamus and synapse in the visual cortex
what bone is the visual cortex within?
occipital bone
what do the axons in the chain from the thalamus to the visual cortex pass via?
the optic radiation
what does early compression of a pituitary tumour cause to the visual pathway?
bitemporal hemianopia
blindness in temporal field will occur
why does bitemporal hemianopia occur by an early pituitary tumour?
tumour causes midline compression of the optic chiasm. this disrupts the APs coming from the nasal retina bilaterally as they try to cross at the chiasm.
therefore temporal side of visual field is lost bilaterally
what are the 2 main ways of surgical access to the pituitary fossa?
transcranial approach (subfrontal- under the frontal lobe)
transsphenoid approach (via nasal cavities and sphenoid sinus)
what 2 bones make up the midline nasal septum?
perpendicular plate of the ethmoid (superiorly)
vomer (inferiorly)
what is the roof of the nasal cavity?
the cribiform plate of the ethmoid bone
what bone is the hard palate mostly made of?
maxlla
where does the paranasal air sinus sit in relation to the pituitary gland?
paranasal air sinus sits anteriorly to the pituitary gland
what bones are the superior, middle and inferior nasal conchae components of?
superior and middle conchae are components of the ethmoid bone
inferior conchae is a bone in it’s own right
what are the 4 paranasal sinuses?
frontal sinuses (frontal bone) maxillary sinuses (maxillae) ethmoidal air cells (ethmoid bone) sphenoid sinuses (sphenoid bone)
what cells line the paranasal sinuses?
mucous-secreting respiratory mucosa
what are the largest paranasal sinuses?
maxillary sinuses
where are the ethmoid air cells located?
3 groups- inferior, middle, superior- located between the nasal cavity and the orbit
where is the fracture in a Le Fort 1 fracture?
fracture passes horizontally across the maxilla
what does a Le Fort 1 fracture separate?
the hard palate from the maxilla
where is the fracture in a Le Fort 2 fracture?
fracture between maxillae and zygomatic bones
and
fracture between maxilae and nasal bones
what does a Le Fort 2 fracture separate?
the maxilla from the rest of the skull
what does a Le Fort 3 fracture separate?
neurocranium from viscerocranium
where does the olfactory (CN I) nerve leave the skull?
cribiform plate
where does the optic (CN II) nerve leave the skull?
optic foramen
where does the oculomotor (CN III) nerve leave the skull?
superior orbital fissure
where does the trochlear (CN IV) nerve leave the skull?
superior orbital fissure
where does the opthalmic division of the trigeminal (CN V1) nerve leave the skull?
superior orbital fissure
where does the maxillary division of the trigeminal (CN V2) nerve leave the skull?
foramen rotundum
where does the mandibular division of the trigeminal (CN V3) nerve leave the skull?
foramen ovale
where does the abducens (CN VI) nerve leave the skull?
superior orbital fissure
where does the facial (CN VII) nerve leave the skull?
internal auditory canal
where does the vestibulocochlear (CN VIII) leave the skull?
internal auditory canal
where does the glossopharyngeal (CN IX) leave the skull?
jugular foramen
where does the vagus (CN X) nerve leave the skull?
jugular foramen
where does the spinal accessory (CN XI) nerve leave the skull?
jugular foramen
where does the hypoglossal (CN XII) nerve leave the skull?
hypoglossal canal
what is the entire cranial cavity lined internally with?
dura mater
what is the tentorium cerebelli?
a tough sheet of dura mater which ‘tents’ over the cerebellum
which cranial fossa is the tentorium cerebelli in?
posterior cranial fossa
why is there a central gap within the tentorium cerebelli?
to permit the brainstem to pass through
what is the diaphragm sellae?
a tough sheet of dura mater forming a roof over the pituitary fossa
what is formed in the areas where the 2 sheets of dura mater have a gap between them instead of being so tightly adhered?
dural venous sinuses
where do the dural venous sinuses drain blood from?
most of the venous blood from the cranial cavity (including brain)
where do the dural venous sinuses drain blood to?
internal jugular veins
where do dural venous sinuses drain venous blood to the internal jugular veins?
at the jugular forminae in the floor of the posterior cranial fossa
what is the name for the dural venous sinuses that surround the pituitary gland?
cavernous sinuses and intercavernous sinuses
what connects the left and right cavernous sinuses?
the intercavernous sinuses
what are the 5 cranial nerves at risk in pituitary gland surgery?
- oculomotor nerve
- trochlear nerve
- trigeminal nerve a + b
- abducens nerve
what arteries are at risk in pituitary gland surgery?
internal carotid arteries
what dural venous sinuses are at risk in pituitary gland surgery?
cavernous sinuses
what happens when there is injury to the trigeminal (CN V) nerve?
sensory symptoms on the face
difficulty chewing
what happens when there is iatrogenic injury to the abducent (CN VI) nerve?
problems with specific eye movements
what happens when there is iatrogenic injury to the cavernous sinus?
venous haemorrhage
what happens when there is iatrogenic injury to the internal carotid artery?
catostrophic haemorrhage
what happens when there is iatrogenic injury to the dura mater?
cerebrospinal fluid leak
what does the thyroid gland consist of?
a right and left lobe
an isthmus joining to the 2 lobes
what are the lobes of the thyroid gland attached to?
the lateral aspects of the thyroid and cricoid cartilage and
the trachea
the isthmus of the thyroid gland lies anteriorly to which cartilages of the trachea?
2nd/3rd cartilages of the trachea
what surface of the thyroid gland’s lateral lobes are the parathyroid glands located?
on the posteiror surface of the thyroid gland’s lateral lobes
what 2 pyramidal shaped bits of cartilage attach to the superior surface of the posterior cricoid cartilage?
arytenoid cartilage
what extra lobe of thyroid gland can sometimes be present?
pyramidal lobe
most frequently, which lobe is the pyraimdal lobe of the thyroid gland a superior extension of?
the left lobe
where do most pyramidal lobes of the thyroid gland attach superiorly?
to the thyroid cartilage
where is the foramen caecum of the tongue?
at the junction between the anterior 2/3rds and the posteiror 1/3rd of the tongue
where does the thyroid begin its embryological development?
at the junction between the anterior 2/3 of the tongue and the posterior 1/3 of the tongue
in embryology, the thyroid gland migrates inferiorly from the tongue to the adult anatomical position following what duct?
thyroglossal duct
in what week of development does the thyroid gland reach it’s final position?
7th week
what muscles are present in the superficial fascia of the neck?
the right and left platysma
what is the function of the platysma muscles?
muscles of facial expression
brings corners of mouth down into a sad face
what is the nerve supply of the platysma muscle?
facial nerve (CN VII)
what are the 4 deep fascia compartents of the neck?
investing deep fascia
prevertebral deep fascia
carotid sheaths (2)
pretracheal deep fascia
what is the most superficial of the deep fascia layers of the neck?
investing deep fascia
what muscles are enclosed in the investing deep fascia of the neck??
trapezius (descending)
sternocleidomastoid
what muscles are enclosed in the prevertebral deep fascia of the neck?
posural neck muscles
what do the carotid sheaths enclose?
internal jugular vein
carotid artery
vagus nerves
deep cervical lymph nodes
what does th epretracheal deep fascia of the neck enclose?
strap muscles thyroid gland trachea oesophagus recurrent laryngeal nerves
where does the sternal head of the sternocleidomastoid attach?
to the manubrium of the sternum
where does the clavicular head of the sternocleidomastoid attach?
to the medial end of the clavicle
what is the common attachment of the sternocleidomastoid?
the mastoid process of the temporal bone
what does the anterior jugular vein drain into?
external jugular vein
what does the external jugular vein drain into?
subclavian vein
what muscle belly does the external jugular vein cross?
sternocleidomastoid
what blood vessel do the superior thyroid arteries come from?
external carotid arteries
what blood vessel do the inferior thyroid arteries come from?
subclavian arteries
what do the superior thyroid veins drain into?
internal jugular veins
what do the middle thyroid veins drain into?
internal jugular veins
what do the inferior thyroid veins drain into?
both into left brachiocephalic vein
what structure does the right recurrent laryngeal nerve (from the vagus nerve) hook up round?
the right subclavian vein
what structure does the left recurrent laryngeal nerve (From the vagus nerve) hook up round?
arch of the aorta
do the right and left vagus nerves pass anteriorly or posteriorly to to the lung root?
posteriorly
what structure do the vagus nerves pass through the diaphragm with?
the oesophagus
what are the 4 strap muscles? indicate which 2 are more superficial and which 2 are more deep?
sternohyoid + omohyoid
(superficial)
thyrohyoid + sternothyroid
what are the 2 bellies of the omohyoid?
superior belly and inferior belly
what are the attachments of the omohyoid?
scapula and hyoid bone
what are the attachments of the sternohyoid?
sternum and hyoid bone
what are the attachments of the thyrohyoid?
thyroid cartilage and hyoid bone
what are the attachments of the sternothyroid?
sternum and thyroid cartilage
what deep fascia column do the strap muscles sit within?
pretracheal deep fascia
what traingles does the sternocleidomastoid split the neck into?
posterior triangle and anterior triangle
compare unilateral and bilateral recurrent laryngeal nerve injury in terms of symptoms?
unilateral- hoarsenss
bilateral- aphonia
why can bilateral recurrent laryngeal cause aspiration and inability to produce a good cough?
inability to close rima glottidis
