Week 3.1 - Osteology

Question 1

Name the curvatures of the spine

Answer 1

• Cervical and lumbar are secondary curvatures

- Thoracic and sacral and primary curvatures

Question 2

State 3 distinguishing features of a typical cervical vertebrae

Answer 2

• Bifid spinous process
• Transverse foramen
• Large vertebral foramen

Question 3

Which cervical vertebrae are atypical?

Answer 3

-1, 2, 7

Question 4

What is different about atlas?

Answer 4

-No body or spinous process (concentric ring)

Question 5

What is the main distinguishing feature of axis?

Answer 5

-Odontoid process (the dens)

Question 6

What is the main distinguishing feature of C7 which makes it atypical?

Answer 6

-Prominent spinous process which is not bifid

Question 7

Which movement of the head does atlas permit?

Answer 7

-Yes movement

Question 8

Which movement of the head does axis permit?

Answer 8

-No movement

Question 9

Why are there many ligaments between the vertebrae?

Answer 9

-To strengthen

Question 10

On an anteroposterior radiograph of the cervical spine, from which vertebrae can you see?

Answer 10

-C3

Question 11

On an lateral radiograph of the cervical spine, from which vertebrae can you see?

Answer 11

-C1

Question 12

Describe a burst fracture (Jefferson fracture)

Answer 12

-Between 2-4 fractures within C1 (atlas) resulting from occiput condyles being driven into C1 eg head first fall from a height/diving into shallow water

Question 13

Describe a hangmans fracture

Answer 13

• Bilateral fracture of C2

- Caused by hyperextension of the head on the neck -> compresses the brain stem

Question 14

What does the skull refer to?

Answer 14

-Cranium + Mandible

Question 15

How many bones in the skull?

Answer 15

-22

Question 16

How are most bones of the skull joined?

Answer 16

-Fibrous joint (symphysis) known as a suture

Question 17

What is the only movable joint in the skull?

Answer 17

-TMJ

Question 18

What is the name for the major opening into the skull?

Answer 18

-Foramen magnum

Question 19

How are sutures specialised for their function?

Answer 19

-Serrated edges allows bones to firmly interlock with one another resisting force in one direction

Question 20

What gives the skull its protective function?

Answer 20

• The bones are flat bones which means they are dense and strong
• They are arranged in a trilaminar structure with 2 plates of compact bone and 1 middle layer of spongy bone

Question 21

What is thought to be the function of the layer of spongy bone in the skull?

Answer 21

-Reduce the weight of the cranium

Question 22

Is the cranium the same thickness all the way around?

Answer 22

-No it varies in thickness eg occiput and frontal bone are thick and pterion is thin

Question 23

How does the mandible form?

Answer 23

-Two separate bones which fuse together by a midline fibrou joint known as the mental symphysis

Question 24

What is the calvaria?

Answer 24

-Bony housing of the brain made up by 8 bones

Question 25

What are the main bones of the cranial cap?

Answer 25

- Frontal - Parietal - Occipital - Temporal

Question 26

Describe the sutures of the cranial cap

Answer 26

-Coronal, saggital and lamboid suture with point lines bregma and lambda

Question 27

What is the cranial fossa?

Answer 27

-The cranial floor

Question 28

How is the cranial fossa divided and state the cranial nerves associated with each part?

Answer 28

- Anterior fossa 1 - Middle fossa 2-6 - Posterior fossa 7-12

Question 29

State the main bones of the cranial fossa

Answer 29

- Frontal - Ethmoid - Sphenoid - Temporal - Occipital - Palatine plate

Question 30

What is the purpose of the foramina in the cranial fossa?

Answer 30

- Lessen weight of skull | - Allow anatomical structures to pass in and out of cranial cavity

Question 31

Where is the frontal bone?

Answer 31

- Anterior of skull vault | - Contributes to superior orbit

Question 32

Where is the ethmoid bone?

Answer 32

-Midline of anterior cranial fossa

Question 33

What is specialised about the ethmoid bones?

Answer 33

- Contains cribriform plate to allow passage of olfactory nerves - Contains ethmoidal air cells

Question 34

Describe the sphenoid bone | Where is it located?

Answer 34

- Butterfly shaped bone (greater and lesser wings) with central body containing sphenoid sinus - Median of middle cranial fossa, forms back of orbit

Question 35

Where is the parietal bone?

Answer 35

-Forms a large part of the roof and sides of cranial cavity

Question 36

Describe the temporal bone

Answer 36

-6 parts to the bone: | squamous, mastoid, tympanic, styloid process, zygomatic process, petrous part

Question 37

To which sense does the parietal bone contribute?

Answer 37

-Hearing (and balance)

Question 38

Describe the occiput

Answer 38

-4 parts arranged around foramen magnum: Squamous (posterior) L+R Condylar (edges of foramen) Basilar (anterior)

Question 39

What are the differences between a neonate and adult skull?

Answer 39

- Cranial sutures are open - Adjacent bones held together by thick connective tissue matrix in the bregma and lamba regiones and are known as fontanelles

Question 40

Explain how the neonate skull is specialised for full-term birth

Answer 40

- Open sutures allow movement during partum | - Cranial bones pushed together and serrated edges temporarily interlock to protect brain

Question 41

Explain how the neonate skull can cause problems at pre-term birth

Answer 41

- Cranial sutures too wide open | - Pressures from birthing process do not result in interlocking of sutures leaving a probability of brain damage

Question 42

How many cervical vertebrae?

Answer 42

-7