Chapter 7 Axial skeleton

Question 1

How many bones of the axial skeleton are?

Answer 1

Skeletal system: 206
1) axial skeleton: 80
2) appendicular skeleton: 126

Question 2

The categories of the axial skeleton

Answer 2

1) skull and associated bones: 29
a) skull
cranium: 8/ face: 14
b) associated bones
auditory ossicles: 6/ hyoid: 1
2) thoracic cage: 25
a) sternum: 1
b) ribs: 24
3) vertebral column: 26
a) vertebrae: 24
b) sacrum: 1
c) coccyx: 1

Question 3

what are skull and associated bones?

Answer 3

1) skull and associated bones: 29
a) skull
- cranium: 8
- face: 14
b) associated bones
- auditory ossicles: 6
- hyoid: 1

Question 4

what is a thoracic cage?

Answer 4

2) thoracic cage: 25
a) sternum: 1
b) ribs: 24
*you can observe costal cartilages (cartilages of ribs)

Question 5

what is a vertebral column?

Answer 5

3) vertebral column: 26
a) vertebrae: 24
b) sacrum: 1
c) coccyx: 1
*you can observe intervertebral discs (cartilages)

Question 6

List the facial bones (8)

Answer 6

1. maxillae: 2
2. palatine bones: 2
3. nasal bones: 2
4. inferior nasal conchae: 2
5. zygomatic bones: 2
6. Lacrimal bones: 2
7. vomer: 1
8. mandible: 1
   total= 14

Question 7

List the cranium bones

Answer 7

1. occipital bones: 1
2. parietal bones: 2
3. frontal bone: 1
4. temporal bones: 2
5. sphenoid: 1
6. ethmoid: 1
   total= 8

Question 8

What do the associated bones contain?

Answer 8

1) Hyoid bone: 1
2) auditory ossicles enclosed in temporal bones: 6
total= 7

Question 9

Make sure that you know the exact locations of those bones!

Question 10

List 6 cranial bones and identify which have two

Answer 10

1. frontal bone
2. parietal bone = 2
3. occipital bone
4. temporal bone = 2
5. sphenoid
6. ethmoid

Question 11

Name 3 sutures of the skull

Answer 11

sutures: fibrous joints that are unique to the skull.
- immovable and completely fuse around the age of 20.

1) coronal suture: runs from ear to ear, fusing the frontal bone to the parietal bones
2) sagittal suture: runs along the tops of the skull, fusing the two parietal bones together
3) squamosal suture: fuses the squamous part of the temporal bone to the parietal bones

Question 12

6 process of the skull:

Answer 12

1. the zygomatic process of temporal bones
2. the temporal process of zygomatic bones
3. Alveolar process: joints between the teeth
4. condylar process (part of temporo-mandibular joints)
5. mastoid process: a bony projection on the temporal bone located behind your ears on each side of your skull
6. styloid process: a bony projection on the temporal bone that helps move the tongue, larynx, pharynx, mandible and hyoid bone

Question 13

Where does sound enter?

Answer 13

External acoustic meatus
: a tube that carries sound waves from the outer ear to the eardrum
(the ear canal)

Question 14

The bones of chin

Answer 14

Mandible
- mental protuberance: the front part
- mandibular angle: the triangular region where the lower back of the mandible curves upwards

Question 15

The bones of the nasal complex: What is ethmoid sinus?

Answer 15

ethmoidal air cells in the ethmoid bone
- a hollow space in the bones around the nose
- cribriform plate in the ethmoid bone, which houses olfactory nerves for smelling
- shaped like butterflies
(related to the respiratory (nasal cavity))

Question 16

The bones of the nasal complex: What is vomer

Answer 16

: the small, thin bone separating the left and right nasal cavities in humans and most vertebrates
(in the middle of nose)

Question 17

what are the cranial vault and base of the cranial cavity?

Answer 17

cranial vault + the cranial base = neurocranium

cranial vault: the space in the skull within the neurocranium, occupied by the brain
(including frontal, parietal, occipital, and temporal bones and the greater wings of the sphenoid bone)

the cranial base:
1) posterial cranial fossa
2) middle cranial fossa
3) anterior cranial fossa

Question 18

Can you see the frontal sinuses inside the frontal bone?

Answer 18

yes, but you can feel them by pressing upward just under your eyebrows

The frontal sinuses are located in the frontal bone, which is in the forehead, above the eyebrows and eye sockets.

Question 19

Can you see the sphenoidal sinuses inside the frontal bone?

Answer 19

no, they are located behind the eyes and deeper into the skull, while the frontal sinuses are located above the eyes and in the forehead

Question 20

What is the hyoid bone?

Answer 20

supports your tongue and plays a key role in speaking and swallowing
- the styloid process is connected to the hyoid bone

3 parts of the hyoid:
- greater horn
- lesser horn
- body

Question 21

What is fontanelle?

Answer 21

a space between the bones of the skull in an infant or fetus, where ossification is not complete, and the sutures are not fully formed.

Question 22

List 4 fontanelles:

Answer 22

1) sphenoid fontanelle
2) anterior fontanelle
3) posterior fontanelle
4) mastoid fontanelle
: close to the lower jaw associated w/ mastication or chewing

Question 23

the anterior fontanelle

Answer 23

In picture…
the anterior fontanelle(“soft spot”) and associated sutures in the skull of an infant (sagittal/ coronal/ frontal sutures)&raquo_space; typically after the age of 9 = adult head

Question 24

how does occipital (posterior) fontanelle work?

Answer 24

In picture…
the occipital fontanelle and associated sutures in a posterior view of the skull of an infant (sagittal suture/ lambdoid suture)

Question 25

How many bones in the vertebral column (spine)

Answer 25

consists of 26 bones (24 vertebrae, the sacrum, and the coccyx); designated to support the upper body and protect the spinal cord

Question 26

5 regions of vertebrae

Answer 26

1) cervical region (curvature) (C1-C7) = 7 am - atlas/ axis 2) thoracic region (curvature) (T1-T12) = 12 noon 3) lumbar region (curvature) (L1-L5) = 5 pm 4) sacrum (5 fused bones) 5) coccyx (4 fused bones)

Question 27

The factors of the vertebrae

Answer 27

each region forms a curvature that allows flexibility & maximal weight-bearing - to support the weight of your body

Question 28

What is intervertebral discs?

Answer 28

vertebrae articulate with one another on their superior and inferior surfaces with a unique cartilage joint called an **intervertebral discs**

Question 29

the distinguishable part of thoracic vertebrae

Answer 29

1) transverse process (side) 2) intervertebral foramen (fused to body) 3) spinous process (you can feel it on your spine) also can see. - a facet of superior articular process between the vertebrae - an intervertebral disc

Question 30

The term of vertebra

Answer 30

the general structure of each vertebra is conserved throughout the column. However, each region is specialized for specific functions if you can imagine an animal through the shape = a superior view

Question 31

What is vertebral foramen

Answer 31

where spinal cord is going in = you can observe it through the superior view

Question 32

what is transverse process

Answer 32

serve as muscle attachment sites. the muscles will... - maintain posture - induce rotation and lateral flexion of single vertebrae and the spine as a whole

Question 33

what is the spinous process

Answer 33

a bony projection that extends from the back of each vertebra in the spine, where it attaches to back muscles and ligaments

Question 34

what is the superior/ inferior articular process

Answer 34

the superior and inferior articular processes of cervical vertebrae have fused on either or both sides to form articular pillars, columns of bone that project laterally from the junction of the pedicle and lamina

Question 35

the structure of the cervical vertebra

Answer 35

C1 (atlas) - groove for vertebral artery and first cervical nerve C2 (axis) - dens of the axis (odontoid process) C7 (vertebra prominens) - a bit thicker than the previous Cs

Question 36

The first two cervical vertebrae

Answer 36

1. atlas - anterior arch of atlas - ligament that enables rotation (as in shaking the head to indicate "no") - posterior arch of atlas - joint that permits nodding (as in indicating "yes") 2. axis - dens (odontoid process)

Question 37

what is atlas

Answer 37

: is specialized to articulate superiorly with the occipital condyles of the skull and permit nodding of the head - anterior arch of atlas - ligament that enables rotation (as in shaking the head to indicate "no") - posterior arch of atlas - joint that permits nodding (as in indicating "yes")

Question 38

what is the axis

Answer 38

: acts as a pivot (central point) for the rotation of the atlas - dens (odontoid process)

Question 39

how do you distinguish which vertebral region?

Answer 39

1. cervical - transverse foramen (transverse process) - bifurcated spinous process 2. thoracic: look-alike with giraffe - articulating with ribs - the body is smaller than the lumbar - the spinous process of vertebra 3. lumbar: look-alike with moose - the body is much larger - the surrounding of the spinous process looks like a crown = 더 화려함

Question 40

How herniated or slipped disc happens?

Answer 40

: occurs when the disc bulges abnormally or breaks apart as a result of injury, normal wear & tear, or disease With 2 components: - nucleus pulposus - annulus fibrosus (intervertebral disc - fibrocartilage) causes... - pain, numbness, weakness if pressed on nerve roots - called sciatica if in the lower back; causes pain down the buttock & leg treatment... : rest/ ice and then light exercise

Question 41

How many curves the vertebral column has?

Answer 41

the vertebral column has four (4) curves: 1) cervical 2) thoracic 3) lumbar 4) sacral

Question 42

what are the primary curves?

Answer 42

the thoracic and the sacral curves - they present at birth

Question 43

what are the secondary curves?

Answer 43

the lumbar and cervical curves - they develop within the first few years of life - is achieved by changes in the intervertebral discs rather than through changes in the vertebrae

Question 44

what happens to the vertebrae during aging?

Answer 44

intervertebral discs tend to lose water, become... - thinner/ less elastic this can cause... - the secondary curves to diminish, leading to postural abnormalities such as **kyphosis** (increased thoracic curvature) >> this is worsened by other factors such as **osteoporosis**

Question 45

what is lordosis

Answer 45

: an exaggerated lumbar curvature - temporary lordosis associated with a large/ heavy "front load" >> If you are pregnant/ if you have quite a larger beer belly, that can cause "lordosis"