Osteology And Imaging Flashcards
Functional significance of arrangement bet outer shell and inner core of bone?
Allows maximum strength with minimum weight
What ocular tissue does compact bone resemble?
Cornea stroma
Why are osteocytes interconnected by gap junctions
- allows osteocytes to communicate directly to each other through the gap junctions at the end of their long cytoplasmic processes
- allows nutrients to exchange to osteocytes in periphery
- also returns waste to Haversian canal which splits into smaller blood vessels
Which bones for the margin of the coronal suture?
Frontal and parietal
Which bones form the margin of the saggital suture
Parietal bones
Which bones form the margin of the lamboid suture
Parietal and occipital
Which are the only two skull bones not joined by sutures and why?
The temporal and mandible bones
Joint between them allows us to move the jaw in 3 planes: in and out, up and down and side to side
The movement of the joint allows us to talk and chew
What is the hypophoseal fossa
Part of the sphenoid bone where the pituitary gland sits
What specific bone forms the border between the anterior and middle cranial fossas?
Sphenoid
Where is the petrous part of the temporal bone?
Inner of ear
What nerves pass through the cribiform plate of the ethmoid bone?
Olfactory
What occupies the hypophoseal fossa and what is the bony structure that forms this space?
It’s the pituitary gland and the bony structure is the sella turcica (part of sphenoid bone)
What is the largest hole in the occipital live and what does it transmit in and out of the skull?
Foramen magnum
In= ventral artery
Out= spinal cord
Which bones contain air sinuses?
Ethmoid, maxillary, frontal and sphenoid
Which 3 motor nerves enter through the superior orbital fissure and what voluntary muscles do they innervate?
Abducent, trochlear and oculomotor
- they innervate skeleta muscle, so the EOM was which move the eye in diff directions, damage to the muscles lead to squint and double vision
What goes in/out of optic canal?
Out = optic nerve In = opthalmic artery - branches which supply to retina
What goes in/out of superior orbital fissure?
Out = superior opthalmic vein and 3 sensory neurones In = 3 motor nerves innervating somatic EOMs
What goes out of inferior orbital fissure?
sensory nerve and inferior opthalmic vein
Lacrimal gland
- produces water for tear film
Lacrimal bone
lacrimal groove and naso lacrimal gland - any tears not evaporated taken to mouth
What is enopthalmos?
Its a sunken eye, leading to diplopia, restricted up/down gaze due to trapped inferior eye muscles
What happens when para nasal air sinus is infected?
- becomes infected with bacteria, which can lead to sinusitis
- it could lead to a chronic infection where the bacteria eat through the orbital plate of the ethmoid bone and gets into the orbital cavity causing inflammation
- a potential is meningitis
- symptoms are red and swollen eyelids, ocular pain esp on eye movement
- classed as med emergency as it could lead to further potential inter cranial infection spread
