Axial Skeleton

Question 1

How many cranial and facial bones are in the skull?

Answer 1

8 cranial, used to protect brain and attachments for head and neck muscles
14 facial bones for openings for food and supports teeth

Question 2

How many auditory ossicles are there and what are their names?

Answer 2

6, malleus, incus and stapes

Question 3

What are connective tissues made of?

Answer 3

Cells and Extra-cellular matrix

Question 4

What does the matrix contain?

Answer 4

Fibres and ground substance

Question 5

Three types of cartilage connective tissues are?

Answer 5

➢ Hyaline cartilage
➢ Fibrocartilage
➢ Elastic cartilage

Question 6

Cells of cartilage and where are they found?

Answer 6

Chondrocytes and lacunae

Question 7

Matrix of a cartilage contains?

Answer 7

Ground substance composed of proteoglycans which
create flexible & resilient structures
➢ Many collagenous fibres (for tensile strength)

Question 8

Cells of the bone tissue?

Answer 8

➢ Osteoblast – cell that builds bone
➢ Osteocyte - mature cell that maintains bone
➢ Osteoclast – cell that breaks down bone

Question 9

Matrix of the bone tissue

Answer 9

Approximately 1/3 of bone matrix is collagenous fibres
➢ Provides strength & some flexibility
Approximately 2/3 of bone matrix is inorganic matter
➢ 85% calcium phosphate salt (Hydroxyapatite)
➢ 10% calcium carbonate

Question 10

What are the two types of bone tissues and key characteristics?

Answer 10

1. Compact (Cortical / Dense) bone
   ➢ Makes up the dense outer layer of bones
   ➢ Main structural unit is the osteon
2. Spongy (Cancellous / Trabecular) Bone
   ➢ Consists of interconnecting plates of bone called trabeculae
   ➢ Contains spaces filled with bone marrow

Question 11

Name of hollow cylinders that surround haversian canal?

Answer 11

Lamellae

Question 12

How do blood vessels and nerves gain access from in the bones?

Answer 12

Haversian and Volkmann’s canals

Question 13

What is the canaliculi?

Answer 13

Links osteocytes to blood supply

Question 14

What is the spongy bone made of?

Answer 14

Trabeculae

Question 15

What is the axial skeleton made of?

Answer 15

Skull, bony thorax and vertebral column

Question 16

Describe the epiphyses

Answer 16

Expanded ends of long bones
➢ Exterior is compact bone, interior is spongy bone
➢ Joint surface lined with articular (hyaline) cartilage
➢ In immature bones, the epiphyseal plate separates the
diaphysis from the epiphyses

Question 17

Endochondral ossification

Answer 17

Produces most bones of the skeleton below the skull
➢ Uses hyaline cartilage “bones” as template material
➢ Epiphyseal plate facilitates lengthwise growth of long
bones until puberty

Question 18

What are the 3 cranial fossas?

Answer 18

Anterior fossa: supports frontal lobe of brain
➢ Middle fossa: supports temporal lobes of brain
➢ Posterior fossa: supports cerebellum

Question 19

What is the nasal cavity composed of?

Answer 19

➢ Constructed of bone & cartilage
➢ Dived into right & left parts by nasal septum
➢ Helps warm, moisten & purify air

Question 20

What are the sutures of the skull?

Answer 20

Sagittal suture
Links the left & right parietal bones
Coronal / Frontal suture
Links the frontal bone to both the parietal bones
Lambdoidal suture
Links the occipital bone to the parietal bones

Question 21

What does the paranasal sinuses do?

Answer 21

➢ Lighten skull / humidify air
➢ Lined by pseudostratified ciliated columnar (respiratory)
epithelium.

Question 22

What are the paranasal sinuses?

Answer 22

➢ frontal (2 or more)
➢ maxillary (2)
➢ ethmoidal (many)
➢ sphenoidal (2)

Question 23

What are the bones of the orbits?

Answer 23

Frontal bone
Sphenoid bone
Ethmoid bone
Lacrimal bone
Palatine bone
Zygomatic bone
Maxilla

Question 24

Features of the parietal bones

Answer 24

Squamosal suture
Temporal lines- thickened regions of bones arcing across parietal and frontal bones
Points of attachment for temporalis muscle

Question 25

Features of temporal bones

Answer 25

1. Mastoid process Conical process that acts as attachment point for sternocleidomastoid muscle. 2. Styloid process slender process anterior & medial to mastoid process Attachment point for muscles & ligaments. 3. External acoustic meatus Canal which terminates at tympanic membrane (eardrum) adjacent to middle ear.

Question 26

Features of the occipital bone

Answer 26

``` Foramen magnum surrounds spinal cord ➢ Skull rests on atlas at occipital condyles ➢ Jugular foramen: allows passage for cranial nerves & blood vessels (e.g. internal jugular vein). ```

Question 27

Features of the sphenoid bone

Answer 27

A butterfly-shaped bone that spans the width of the middle cranial fossa ➢ Articulates with all other cranial bones ➢ Contains sella turcica which houses pituitary gland ➢ Characterised by greater & lesser wings ➢ Contains air sinuses & numerous foramina

Question 28

Features of the ethmoid bone

Answer 28

``` ➢ Located medial to orbits ➢ Forms lateral walls & roof of nasal cavity ➢ Contain air sinuses ➢ Perpendicular plate forms part of nasal septum ➢ Contain superior & middle conchae ```

Question 29

Features of the Maxillae

Answer 29

➢ 2 medially fused bones that form the superior jaw ➢ All facial bones except mandible articulate with it ➢ Holds upper teeth & contains air sinuses ➢ Palatine process contributes to hard palate (roof of mouth)

Question 30

Features of the mandible

Answer 30

``` ➢ Only moveable bone of skull ➢ Holds the lower teeth ➢ Coronoid process: attachment points for muscles of mastication ➢ Mandibular condyles: form articulations with mandibular fossa of temporal bone ```

Question 31

Nasal bones

Answer 31

2 medially fused bones that form the bridge of the nose

Question 32

Lacrimal Bones

Answer 32

2 bones that contribute to | medial walls of orbits

Question 33

Palatine Bones

Answer 33

2 bones that form portions of the hard palate, orbits & lateral walls of nasal cavities

Question 34

Vomer

Answer 34

A plough-shaped bone that forms part of | nasal septum

Question 35

Inferior Nasal Conchae

Answer 35

2 curved bones that form part of the lateral | walls of the nasal cavity

Question 36

Bones of the vertebral Column

Answer 36

7 cervical vertebrae 12 thoracic vertebrae 5 lumbar vertebrae Sacrum and coccyx

Question 37

3 main physical features of the Vertebrae

Answer 37

``` 1. Body ➢ Disk- shaped anterior portion ➢ Weight bearing structure of vertebra 2. Vertebral arch ➢ Extends posteriorly from body ➢ Surrounds vertebral foramen (spinal cord) 3. Processes ➢ Normally seven processes arise from arch ➢ Points of attachment for muscles ➢ Articulate with other vertebrae ```

Question 38

Thoracic vertebrae features

Answer 38

``` ➢ Heart shaped body ➢ Long spinous processes angled inferiorly ➢ Costal facets for articulation with ribs ```

Question 39

Lumbar features

Answer 39

➢ Large kidney shaped bodies | ➢ Relatively short processes

Question 40

Sacrum features

Answer 40

➢ Formed by 5 fused vertebrae ➢ Articulates with coxal bones of pelvis

Question 41

Coccyx features

Answer 41

Formed by 4 fused | vertebrae

Question 42

3 elements of the adult sternum are

Answer 42

1. Manubrium Sterni 2. Body/Corpus 3. Xiphisternum (Xiphoid process)

Question 43

Hyoid bone

Answer 43

``` Lies inferior to mandible. Provides attachment for neck muscles involved with raising larynx during speech & swallowing Only bone in body that does not articulate with another bone. ```