Chapter 7: The Axial Skeleton Flashcards
What is the Axial Skeleton?
- forms the vertical, central axis of the body
- 80 bones
- skull has 22 bones
- vertebral column has 24 bones and 2 fused
- thoracic cafe had 12 pairs of ribs and the sternum
What are the 4 unique features of the skull?
1) cranial cavities
2) paranasal sinuses
3) sutures
4) fontanelles
What Are the seven cranial bones?
1) Parietal bone
2) sutural bone
3) occipital
4) frontal bone
5) sphenoid
6) ethmoid
7) temporal
What are the 6 facial bones?
1) lacrimal
2) nasal bone
3) zygomatic
4) maxilla
5) mandible
6) vomer
What are the parts of the occipital bone?
- Squamous part: forms the posterior region of the skull
- Basilar part: foramen magnum
- foramen magnum: spinal cord, vertebral, spinal arteries, and accessory nerve
- hypoglossal canal: hypoglossal nerve
What are the four functions of the paranasal sinuses?
1) Lighten skull mass
2) increase nasal surface area
3) resonating chamber
4) protection through mucus
What are the types of sutures?
1) top of skull-> coronal suture -> unites frontal to parietal bones (saggital connects parietal together)
2) posterior of skull-> lamboid suture-> unites Parietal to occipital
3) squamous -> connects parietal to temporal bones
Describe the Hyoid bone
- doesn’t articulate with any other bone
- suspended from the styloid process
- attachment site for the tongue, neck and pharynx muscles
- consists of a horizontal, rectangular body and paired projectors called the lesser and greater horns
What is the coccyx?
A triangular bone that forms 3-5 vertebral bones fusing. Fusion takes several years
What is the sacrum?
- fusion of the 5 sacral vertebrae
- happens at ~ 16-30 years of age
- transverse ridges mark fusion sites
How many vertebrae are there?
24 plus the sacrum and coccyx
What are the three regions of the vertebral column?
1) cervical (C1-C7)
2) Thoracic (T1-T12)
3) Lumbar (L1-L5)
What are the vertebral curvatures?
- primary curves in fetus = thoracic and sacral
- secondary curves = 3-4 months of age = cervical and lumbar
Describe the classification of ribs
12 pairs of ribs with their costal cartilages
- Ribs 1-7 are classified as true ribs
- ribs 8-12 are classified as false ribs with the last two peaked being floating ribs
What are the parts of the sternum?
- Xyphoid process
- Body
- Manubrium