Axial Skeleton- LECTURE

cranial bones create what?

cranial cavity

what is a protective membrane in between bones and brain ?

meninges

What are the cranial bones, how many of each?

• 1 frontal bone

• 2 parietal bones

• 2 temporal bones

• 1 occipital bone

• 1 sphenoid bone

• 1 ethmoid bone

facial bones have no direct contact with?

the brain or meninges

List the facial bones and how many of each there is.

• 2 maxillae bones

• 2 palatine bones

• 2 zygomatic bones

• 2 lacrimal bones

• 2 nasal bones

• 2 inferior nasal conchae 

• 1 vomer bone

• 1 mandible bone

sinuses in the skeletal system are _________________ in bone

cavities or chambers

what are the roles of sinuses?

• lighten weight of skull

• produce mucus

• sound resonation

What are the 4 paranasal sinuses?

1. frontal sinus

2. maxillary sinus

3. sphenoid sinus

4. ethmoidal sinus (air cells)

What are fibrous regions between the cranial bones of developing skull known as?

fontanels

What is the function of fontanels?

• flexibility for growing brain

• allow distortion of skull during birth

When are most fontanels usually fused by?

12 months

what is known as the soft spot on a baby’s head?

anterior fontanel

when does the anterior fontanel close?

18 to 20 months

how many cervical bones are there?

7

How many thoracic bones are there?

12

how many lumbar bones are there?

5

are sacral and coccyx unfused?

no, they are fused

what kind of curvature is the cervical curvature?

secondary curvature (2 degree)

What kind of curvature is the thoracic curvature?

primary curvature (1 degree)

What kind of curvature is the lumbar curvature?

secondary curvature (2 degree)

What kind of curvature is the sacral curvature?

primary curvature (1 degree)

How many vertebrae are there?

33

How many individual bones and how many fused in vertebrae?

• 24 individual

• sacrum (5 fused)

• coccyx (4 fused)

What is particular about the thoracic vertebrae?

has costal facets for attachment of ribs 

what is C1 of cervical vertebrae called?

atlas

What is C2 of cervical vertebrae called?

axis

what does C1 (atlas) articulate with?

occipital condyles

What is particular about C1 (atlas)?

has a “ring” like structure, no body

What does C2 (axis) articulate with?

atlas

What is particular about C2 (axis)?

has odontoid process (dens)

What are ribs 1-7 known as?

true ribs

What are ribs 8-12 called?

false ribs

what are ribs 11-12 also known as?

floating ribs

How many bones make up the orbit (eye socket)?

10

What are the bones that make up the orbit (eye socket)?

1. supraorbital notch

2. orbital surface

3. optic canal

4. superior orbital fissure

5. inferior orbital fissure 

6. lacrimal glands

7. zygomatic process

8. infraorbital foramen

9. zygomatic process

10. supraorbital margin