Osteology and vertebrae Flashcards
What are the two parts of the temporal bone?
Petrous and squamous
What is the central ridge on the ethmoid bone called?
Crista galli
What is the falx cerebri?
fold of dura that attaches tot eh apex of the crista galli
What is the saddle shaped part of the sphenoid bne called?
sellitursica
What is the cavernous sinus?
carotid artery, 3rd, 4th, 6th and V1 of 5th cranial artery pass through here
what is meckels cave?
shallow depression in middle cranial fossa where the three branches of the trigeminal nerve lie
what passes through the cribiform plate of the ethmoid bone?
olfactory nerve
what goes through the superior orbital fissure?
3rd, 4th, 6th and V1 of 5th cranial nerve
what goes through the optic canal?
cranial nerve 2 (optic nerve)
what passes through the foramen rotundum?
V2 (maxillary) of trigeminal nerve
what passes through the foramen ovalae?
V3 (mandibular) division of trigeminal nerve
what goes through the foramen spinosum?
middle meningeal artery (blood to dura and skull)
where do the anterior and posterior spinal arteries arise from?
vertebral arteries
where do 9th, 10th and 11th cranial nerve exits?
jugular foramina
what nerves pass through internal acoustic meatus?
7th (facial) and 8th (vestibulocochlear)
where does the facial nerve exit the skull?
stylomastoid foramen
where does the anterior circulation enter the skull?
internal carotid arteries through the carotid canal
where does the posterior circulation enter the skull?
vertebral arteries pass through foramen magnum
where does venous drainage pass through the skull?
ends in signoid sinus which passes through jugular foramen
where does the opthalmic artery pass out through the skull?
with the optic nerve through the optic canal
where does the superior opthalmic vein pass through?
superior orbital fissure
where does the labyrinthine artery pass through and whats its clinical significance?
internal acoustic meatus (disease will call pulsatile tinnitus, hear own heartbeat)
whats the role of the spinal column?
weight bearing and locomotion
what is the spinal column made up from?
7 cervical
12 thoracic
5 lumbar
5 vertebrae fuse to form sacrum
parts of vertebrae?
- vertebral body
- pedicles (pass upwards to three structures)
- transverse processes (point outwards)
- articular process (points upwards, superior and inferior one)
- lamina (forms roof over top of spinal canal
- spinous process
what makes thoracic vertebrae different?
- long downwards pointing spinous process
- articulation for ribs at the vertebral body for the head of the rib
what makes cervical vertebrae different?
- much smaller
- small transverse processes
- extra piece of bone that has fused with transverse process to create foramina (vertebral artery passes through)
- spinous process has two points (bifid)
whats another name for C1?
atlas
whats another name for C2?
axial
whats the odontoid peg?
on C2 there is a projecting part that would lie in the position of C1
whats beyond the sacrum?
coccyx
whats the curvature of the spinal column?
cervical forward
thoracic backwards
lumbar forward
whats a forward curve called?
lordosis
whats a backwards curve called?
kyphosis
what is scoliosis?
when the spinal column bends sideways
what are the layers of cartilage that connect vertebrae to intervertebral discs?
Hyaline cartilage, fibrocartilage, another layer of hyaline cartilage
whats the intervertebral discs made of?
liquid in centre called nucleus pulposus
fibrous tissie and cartilage called annulus fibrosus
whats the name of the ligament that runs down the front of vertebral bodies?
anterior spinal ligament
whats the name of the ligament that runs down the back of the vertebral boides?
posterior spinal ligament
whats the ligament called that attahces the lamina?
ligamentum flavum
how are the spinous processes connected?
interspinous ligament
how are the tips of the spinous processes connected by?
supraspinoous ligament
what is a slipped disc?
- compressant force on front of vertebral body puts tension on annulus fibrosus and it may tear
- nucleus pulposus will bulge through and compress the spinal nerve
what causes arthitis in spine?
when the dura sticks to the articular facets
where is the spinal canal widest?
cervical region
what are the meninges of the spinal cord?
dura, arachnoid, pia mater
what is a lumbar puncture?
sampling CSF by placing needle in subarachnoid space in lumbar region
what is spinal anaesthetic?
- injection of local anaesthetic into subarachnoid space in lumbar or sacral region
whats the last bit of spinal cord called and how does it finish?
conus medullaris
how and where does the spinal cord end?
finished in a tube of pia mater called phylum terminalis at the end of the coccyx
where do sensory pathways enter spinal cord?
dorsal aspect (dorsal horn)
where do motor pathways exit the spinal cord?
ventral aspect of spinal cord
whats the cauda equina?
collection of sensory and motor neurons entering and exiting spinal cord below the end of the spinal cord
how are the spinal nerves name?
-cervical nerves named from vertebra theyre above
-thoracic and lumbar nerves exit below their numbered vertebrae
whats the lower limit of the spinal cord?
approximately L1 and L2
- damage at L2 would not damage spinal cord
whats different about the thoracic spinal cord?
has an intermediade horn that contains components of sympathetic nervous system
whats the name of the motor pathway of the spinal cord?
corticospinal tract
what is the pathway of the corticospinal tract in the brain?
arises in motor cortex, passes through internalcapsule and through midbrian and pons
where does the lateral corticospinal tract first decussate?
pyramid of medulla
whats the name of the corticospinaltract that does not decussate and what does it supply?
anterior/ventral
- axial muscles of trunk, neck and shoulders
whats the name of the three sensory pathways of the spinal cord?
spinocerebellar
spinothalamic
dorsal medial lemniscus
what sensory information does the spinothalamic tract carry?
temperature change, pressure and pain (ends in thalamus)
where does decussation happen in the spinothalamic tract?
in the spinal cord
what sensory information from the spinocerebellar tracts carry?
balance and position sense
what is the mnemonic for the ventral and dorsal spinocerebllar tracts?
COVID (contralateral info is ventral tract, ipsilateral info is the dorsal tract)
what sensory information does the dorsal column medial lemniscis pathway carry?
fine touch, vibration, two point discrimination
what are the gracile and cuneate fasiculi?
gracile: mid thoracic and lower limbs
cuneate: upper limbs
where does decussation occur in dorsla column medial lemniscus pathway?
in the medulla
where do the second order neurons go to in dorsal medial lemniscus pathway?
medial lemniscus in the thalamus
where do the third order neurons terminate in the dorsal medial lemniscus pathway?
primary somatosensory cortex
what are the symptoms of raised intracranial pressure?
headache, nausea, visual disturbances, later altered consciousness levels
what are the signs of raised intracranial pressure?
papilloedema, increased blind spot on visual field testing
what is jugular foramen syndrome?
compression of multiple lower cranila nerves (9, 10 and 11)
what are the signs and symptoms of jugular foramen syndrome?
dysphonia (disorder of voice), loss of gag reflex and unlilateral wasting of sternocleidomastoid and trapezius muscles
what is foramen magnum syndrome?
compression of spinal cord, lower brainstem or cerebellum
what are the symptoms of foramen magnum syndrome?>
pain in head, neck, limbs and trunk made worse by straining
- cerebellar symptoms: vertigo, gait disturbance
what are the signs of foramen magnum syndrome?
decerebrate posture, cardiorespiratory failure, pyramidal signs
what is radiculopathy?
nerve root pathology: most commonly compression due to prolapsed intervertebral disc
what is sciatica?
-compression or irritaion of sciatic nerve (L5)
what are signs and symptoms of sciatica?
- pain radiating down the buttock, into leg and down to the calf
- weakness in dorsiflexion causes foot drop leading to abnormal gait
what is cauda equine syndrome?
- compression of nerve roots below level of spinal cord termination
what are signs and symptoms of cauda equina syndrome?
-low back pain
- bladder dysfucntion
-faecal incontinence
what is a lumbar puncture used for?
- diagnosis and treatment of idiopathic intracranial hypotension
- MS diagnosis (oligoclonal bands)
- diagnose infectious meningitis and encephalitis
- diagnose subarachnoid haemorrhage
