Osteology And Imaging

Question 1

Functional significance of arrangement bet outer shell and inner core of bone?

Answer 1

Allows maximum strength with minimum weight

Question 2

What ocular tissue does compact bone resemble?

Answer 2

Cornea stroma

Question 3

Why are osteocytes interconnected by gap junctions

Answer 3

• 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

Question 4

Which bones for the margin of the coronal suture?

Answer 4

Frontal and parietal

Question 5

Which bones form the margin of the saggital suture

Answer 5

Parietal bones

Question 6

Which bones form the margin of the lamboid suture

Answer 6

Parietal and occipital

Question 7

Which are the only two skull bones not joined by sutures and why?

Answer 7

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

Question 8

What is the hypophoseal fossa

Answer 8

Part of the sphenoid bone where the pituitary gland sits

Question 9

What specific bone forms the border between the anterior and middle cranial fossas?

Answer 9

Sphenoid

Question 10

Where is the petrous part of the temporal bone?

Answer 10

Inner of ear

Question 11

What nerves pass through the cribiform plate of the ethmoid bone?

Answer 11

Olfactory

Question 12

What occupies the hypophoseal fossa and what is the bony structure that forms this space?

Answer 12

It’s the pituitary gland and the bony structure is the sella turcica (part of sphenoid bone)

Question 13

What is the largest hole in the occipital live and what does it transmit in and out of the skull?

Answer 13

Foramen magnum
In= ventral artery
Out= spinal cord

Question 14

Which bones contain air sinuses?

Answer 14

Ethmoid, maxillary, frontal and sphenoid

Question 15

Which 3 motor nerves enter through the superior orbital fissure and what voluntary muscles do they innervate?

Answer 15

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

Question 16

What goes in/out of optic canal?

Answer 16

Out = optic nerve 
In = opthalmic artery - branches which supply to retina

Question 17

What goes in/out of superior orbital fissure?

Answer 17

Out = superior opthalmic vein and 3 sensory neurones 
In = 3 motor nerves innervating somatic EOMs

Question 18

What goes out of inferior orbital fissure?

Answer 18

sensory nerve and inferior opthalmic vein

Question 19

Lacrimal gland

Answer 19

• produces water for tear film

Question 20

Lacrimal bone

Answer 20

lacrimal groove and naso lacrimal gland - any tears not evaporated taken to mouth

Question 21

What is enopthalmos?

Answer 21

Its a sunken eye, leading to diplopia, restricted up/down gaze due to trapped inferior eye muscles

Question 22

What happens when para nasal air sinus is infected?

Answer 22

• 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