osteology and cervical vertebre

Question 1

identify the osteological features/foramina of the typical and atypical cervical vertebrae

(which is atypic, typical?)

Answer 1

3rd–6th >> “typical” cervical vertebrae;

1st, 2nd, and 7th>> “atypical.”

Question 2

which is the strongest cervical vertebrae?

Answer 2

AXIS

cuz atlas, carrying th eskull, rotates on it!

Question 3

what stabilzes the Atlanto-axial joint?

Answer 3

Question 4

What structure passes through the foramina in the transverse processes of the cervical vertebrae?

Answer 4

They give passage to the vertebral artery, vein and sympathetic nerves.

Question 5

The cervical vertebrae have 3 features which distinguish them from thoracic vertebrae:

Answer 5

Question 6

vertebral foramen get _____as we go down the cervical vertebrae

Answer 6

SMALLER

Question 7

describe shape of atlas

Answer 7

a ring-like, kidney-shaped bone lacking a spinous process or body

consisting of 2 lateral masses connected by anterior and posterior arches.

Its concave superior articular facets receive the occipital condyles.

Question 8

name joints unique to Cervical Spine

Answer 8

• -atlanto-axial
• -atlanto-occipital

Question 9

why does the cervical vertebrae can dislocate or “slip-off” at much less force than is required for them to fracture?

Answer 9

The articular surfaces of the cervical vertebrae are more horizontally orientated than in other vertebrae

Question 10

would a Slight dislocation damage the spinal cord in the cervical region? why?

Answer 10

Slight dislocation may not damage the spinal cord because of the large vertebral canal in the cervical region.

Question 11

where r the most common sites of cervical spine injuries?

Answer 11

C2, C6, C7

Question 12

where do the most severe (fatal) injuries occur? why

Answer 12

upper part of spine, C1-C4

where damage can lead to quadriplegia and cessation of respiratory movements.

Question 13

How might an anterior view of C1 and C2 be obtained?

Answer 13

Question 14

How many bones does the skull have?

Answer 14

The skull is a collective term referring to the complete skeleton of the head,

which includes the cranium and mandible.

Question 15

divisions of Cranium & key feautres of each

Answer 15

Question 16

What is the difference between the “viscerocranium” and the “neurocranium”?

Answer 16

Answer 17

Question 18

difference btw a hole and a fissure in the skull?

Answer 18

roundish>> hole

narrow slit>> fissure

Question 19

what does the neurocranium consist of?

Answer 19

Question 20

bones of the neurocranium

Answer 20

Question 21

what do the bones of the calvaria consist of?

Answer 21

2 layers of compact bone

separated by a layer of spongy bone, known as the diploe

(in adults inner most lay of compact bone is particularly brittle )

Answer 22

Question 23

what is the thinnest part of the calvaria?

Answer 23

Question 24

which artery lies right beneath the perterion? why is this signficant?

Answer 24

beneath this bone is the middle meningeal artery (its anterior branch),

Bleeding from this artery will cause an extradural haematoma,

blood accumulates btw the periosteal layer of the dura mater and the bone.

The haematoma exerts pressure on the underlying brain!

Question 25

what is a suture? what is its function? structure?

Answer 25

immobile, fibrous Joints btw bones, the interlocking btw the bones make sit hard for bones to dislocate! *As we age, these suture lines begin to ossify.*

Question 26

what r the sutures of the calvaria?

Answer 26

coronal, sagittal and lambdoid)

Question 27

now we move on to cranial floor, describe it!

Answer 27

Question 28

shade the anterior middle and posterior fossa how do u know which ones which?

Answer 28

Anterior\> lesser wing of sphenoid bone middle\> petrous part of temporal bone Posterior\> other part of petrous bone

Question 29

What are the **fontanelles** and why is their presence important in the fetal/infant skull

Answer 29

**Sutures,** which are soft but tough membranous connections, lie in the junctions where there is incomplete fusion of the bones.

Question 30

At what age do the anterior and posterior fontanelles fuse?

Answer 30

The _anterior_ fontanelle\> closed By ~18 months – **2** years\> becomes the site of the ***bregma.*** The *_posterior_* fontanelle\> closes within first 2 -3 months\> becomes site of the ***lambda.*** **Fontanelles are therefore only an anatomical feature of the fetal/ infant skul**l.

Question 31

How might the presence of the fontanelles be helpful when assessing an unwell newborn or infant?

Answer 31

1. A **sunken** fontanelle can give an indication of hydration status \> *_dehydration_* 2. A **tense/bulging** fontanelle \> raised intra-cranial pressure; infections such as meningitis can also cause a bulging fontanelle. ## Footnote * can also provide a “window” for imaging the brain using ultrasound (very safe form of imaging but cannot penetrate bone)* * Note that fontanelles may appear to bulge slightly when a newborn/infant is crying or when lying flat and this is entirely normal. The ‘bulging’ returns to normal when the newborn/infant is calm and in a head-up position.*

Question 32

how do the sutures appear on a CT scan?

Answer 32

chna fracture!

Question 33

what is ur main concern if someone had a skull fracture or trauma?

Answer 33

risk of **intracranial injury** (i.e. injury to brain, blood vessels, cranial nerves) *BUT can still have intracranial injury without skull fracture!* ***_CT scanning should be performed in all patients with known or suspected skull fractures to identify any intracranial injuries_***

Question 34

what r the types of skull fractures?

Answer 34

2 main fracture types: – **Linear** pass full thickness of skull, fairly straight, involve no bone displacement – **Depressed**: fragment is displaced inwards towards the brain Fractures involving the cranial base = **basilar skull fractures**

Question 35

most common facial fractures include? (4)

Answer 35

Fractures of the nasal bones (cuz of the prominence of the nose), zygomatic bone and arch and mandible are common

Question 36

A hard blow to the **lower jaw (mandible)** often results in a **fracture of the neck** of the mandible and its body and may be associated with the dislocation of the **TMJ.**

Question 37

what is the cheek bone? what does it articulate w/?

Answer 37

zygomatic bone! ## Footnote they inferolateral sides of the orbit articulate with the **frontal**, **sphenoid**, **temporal** bones and the **maxillae**.

Question 38

ok.. moving on to the viserocranium how many bones and name them!

Answer 38

is formed by bones enclosing the orbits, nasal cavity, oral cavity, paranasal sinuses and includes the maxillae (the upper jaw) and the mandible (the lower jaw); the jaws house the teeth.

Question 39

just above the orbital margin is a sharp bony ridge called\_\_\_\_\_\_\_\_. what is the significance of this area?

Answer 39

***the supraciliary arc*** ## Footnote The skin overlying this area can be easily split when there is a blunt force in jury to this area of the head.

Question 40

why is the mandible movable?

Answer 40

becauseitarticulateswiththecranial base at the ***temporomandibular joint (TMJ),***

Question 41

Answer 41

Question 42

Xray

Answer 42

Question 43

Xray sinus

Answer 43

Question 44

Where is the vomer bone?

Answer 44

A boner is in the middle. (So the vomer) is in the middke forming nasal septum!

Question 45

Explain the ethmoid bone in all views of the skull?

Answer 45

Question 46

Label the zygoma and zygomatic arch paranasal sinuses - frontal, nasal/ethmoid, and maxillary

Answer 46

Question 47

Why is **CT** imaging, rather than a skull x-ray, is the preferred modality when investigating patients with *head injuries and/or suspected skull fractures?*

Answer 47

dunno

Question 48

Describe the process that leads to the fusion of the fontanelles (i.e. how do they become ossified).

Answer 48

Question 49

in the adult skull what is the anatomical point to the site of the anterior & posterior fontanelle in the infant skull?

Answer 49