The Axial Skeleton

Question 1

What makes up the Axial Skeleton?

Answer 1

Skull, vertebral column, and bony thorax

Question 2

What are the three subgroups of the skull?

Answer 2

Cranium, facial bones, and associated bones (hyoid bone and ear ossicles)

Question 3

Function of the cranium

Answer 3

Enclose and protect the fragile brain tissue

Question 4

Function of the facial bones

Answer 4

Support the eyes and position them anteriorly. Also provide attachment sites for facial muscles.

Question 5

Frontal bone

Answer 5

Anterior portion of cranium; forms the forehead, superior part of the orbit, and floor of anterior cranial fossa

Question 6

Parietal bones

Answer 6

Posterolateral to the frontal bone, forming sides of cranium

Question 7

Temporal bones

Answer 7

Inferior to parietal bone on lateral skull. 3 parts: Squamous, tympanic, and petrous

Question 8

Sagittal suture

Answer 8

Midline articulation point of the two parietal bones

Question 9

Coronal suture

Answer 9

Point of articulation of parietals with frontal bone

Question 10

Squamous suture

Answer 10

Point of articulation of the temporal bone with the parietal bone

Question 11

Zygomatic process

Answer 11

Bridgelike projection joining the zygomatic bone (cheekbone) anteriorly.

Question 12

Mandibular Fossa

Answer 12

Rounded depression on the inferior surface of the zygomatic process (anterior to the ear); forms the socket for the condylar process of the mandible, where the mandible joins the cranium

Question 13

External acoustic meatus

Answer 13

Canal leading to eardrum and middle ear

Question 14

Styloid Process

Answer 14

Needlelike projection inferior to external acoustic meatus; attachment point for muscles and ligaments of the neck.

Question 15

Zygomatic Arch

Answer 15

Zygomatic bone and zygomatic process

Question 16

Mastoid Process

Answer 16

Rough projection inferior and posterior to external acoustic meatus; attachment site for muscles.

Question 17

Occipital bone

Answer 17

Most posterior bone of cranium - forms floor and back wall. Joins sphenoid bone anteriorly via its narrow basilar part.

Question 18

Foramen Magnum

Answer 18

Large opening in base of occipital, which allows the spinal cord to join with the brain

Question 19

Occipital Condyles

Answer 19

Rounded projections lateral to the foramen magnum that articulate with the first cervical vertebra (atlas)

Question 20

Sphenoid bone

Answer 20

Bat-shaped bone forming the anterior plateau of the middle cranial fossa across the width of the skull. Is the keystone of the cranium because it articulates with all other cranial bones.

Question 21

Greater wings of Sphenoid

Answer 21

Portions of the sphenoid seen exteriorly anterior to the temporal and forming a part of the eye orbits

Question 22

Sella Turcica

Answer 22

A saddle-shaped region in the sphenoid midline. Hypophyseal fossa surrounds pituitary gland (hypophysis)

Question 23

Lesser wings of Sphenoid

Answer 23

Bat-shaped portions of the sphenoid anterior to the sella turcica

Question 24

Optic Canal (optic foramen)

Answer 24

Openings int he bases of the lesser wings through which the optic nerves (cranial nerve II) enter the orbits to serve the eyes.

Question 25

Ethmoid Bone

Answer 25

Irregularly shaped bone anterior to the sphenoid. Forms the roof of the nasal cavity, upper nasal septum, and part of the medial orbit walls.

Question 26

Crista galli

Answer 26

Vertical projection providing a point of attachment for the dura mater, helping to secure the brain within the skull

Question 27

Cribriform plates

Answer 27

Bony plates lateral to the crista gallithrough which olfactory fibers (cranial nerve I) pass to the brain from the nasal mucosal through the cribriform foramina.

Question 28

Mandible

Answer 28

The lower jawbone, which articulates with the temporal bones in the only freely movable joints of the skull

Question 29

Condylar head (process)

Answer 29

Articulation point of the mandible with the mandibular fossa of the temporal bone

Question 30

Mental foramen

Answer 30

Prominent opening on the body (lateral to the midline) that transmits the mental blood vessels and nerve to the lower jaw

Question 31

Mandibular foramen

Answer 31

On the medial aspect of the mandibular rams. Foramen permits passage of the nerve involved with tooth sensation (mandibular branch of cranial nerve V)

Question 32

Maxilla

Answer 32

Two bones fused in a median suture; form the upper jawbone and part of the orbits. All facial bones, except mandible, join the maxilla.

Question 33

Palatine process

Answer 33

Form the anterior hard palate; meet medially in the inter maxillary suture

Question 34

Palatine bones

Answer 34

Paired bones posterior to the palatine processes; form posterior hard palate and part of the orbit; meet medially at the median palatine suture

Question 35

Zygomatic bones

Answer 35

Lateral to the maxilla; forms the portion of the face commonly called the cheekbone, and forms part of the lateral orbit. Its three processes are named for the bones with which they articulate

Question 36

Lacrimal bones

Answer 36

Fingernail-sized bones forming a part of the medial orbit walls between the maxilla and the ethmoid. Each lacrimal bone is pierced by an opening, the lacrimal fossa, which serves as a passageway for tears.

Question 37

Nasal bones

Answer 37

Small rectangular bones forming the bridge of the nose

Question 38

Vomer

Answer 38

Blade-shaped bone in median plane of nasal cavity that forms the posterior and inferior nasal septum

Question 39

Inferior nasal conchae

Answer 39

Thin curved bones protruding medially from the lateral walls of the nasal cavity; serve the same purpose as the turbinate portions of the ethmoid bone.

Question 40

What are the paranasal sinuses?

Answer 40

Frontal sinus, ethmoid air cells, sphenoidal sinus, and maxillary sinus

Question 41

Hyoid bone

Answer 41

Located in the throat above the larynx. Serves as a point of attachment for many tongue and neck muscles. Does not articulate with any other bone.

Question 42

Lambdoid suture

Answer 42

Site of articulation of occipital bone and parietal bone

Question 43

Vertebral column function

Answer 43

Forms the body's major axial support. Surrounds and protects the spinal cord while allowing spinal nerves to emerge.

Question 44

Body (Centrum) of vertebra

Answer 44

Rounded central portion of the vertebra, which faces anteriorly in the human vertebral column

Question 45

Vertebral arch

Answer 45

Composed of pedicles, laminae, and a spinous process, it represents the junction of all posterior extensions from the vertebral body

Question 46

Vertebral foramen

Answer 46

Opening enclosed by the body and vertebral arch; a passageway for the spinal cord

Question 47

Transverse processes

Answer 47

Two lateral projections from the vertebral arch

Question 48

Spinous process

Answer 48

Single medial and posterior projection from the vertebral arch

Question 49

Superior and inferior articular processes

Answer 49

Paired projections lateral to the vertebral foramen that enable articulation with adjacent vertebrae. The superior articular process typically face toward the spinous process (posteriorly), whereas the inferior articular processes face (anteriorly) away from the spinous process.

Question 50

Intervertebral foramina

Answer 50

The right and left pedicles have notches on their inferior and superior suffices that create openings, the intervertebral foramen, for spinal nerves to leave the spinal cord between adjacent vertebrae

Question 51

Intervertebral disc

Answer 51

A pad of fibrocartilage that cushions the vertebrae and absorbs shock.

Question 52

5 division of the vertebral column

Answer 52

Cervical, thoracic, lumbar, sacrum, and coccyx

Question 53

Number of cervical vertebrae

Answer 53

7

Question 54

Number of thoracic vertebrae

Answer 54

12

Question 55

Number of lumbar vertebrae

Answer 55

5

Question 56

Number of sacral vertebrae

Answer 56

5

Question 57

Number of coccygeal vertebrae

Answer 57

Usually 4