1. Axial Skeleton Skeletal System
(Skull and Backbone)

2. Axial vs. Appendicular
The Axial skeleton consists of the skull, vertebral column and bony thorax, or thoracic cage (the sternum and ribs).
The Appendicular skeleton consists of the appendages.

3. Bones of the skull Frontal bone: the forehead
Parietal bones (2): top back half sides of skull
Maxillae (2): upper lip area where top teeth are connected
Palatine bones (2): roof of the mouth
Zygomatic bones (2): cheek bones
Lacrimal bones (2): inside the corner of the eye
Cranium

4. More Skull flat bones…. Nasal bones (2): both sides of the nose
Vomer bone: center bottom of the nose
Mandible: lower jaw, helps you chew
Temporal bones (2): sides of the head behind the eye and in front of the ear
Occipital bone: bottom back of the head
Sphenoid bone: between temporal and
zygomatic bones
Ethmoid bone: in front of sphenoid ( back of eye socket)

5. Hyoid bone: In the neck between lower jaw and larynx.
It supports the tongue and muscles attach to it to help in swallowing.
Why is the hyoid bone unique?
Not attached to any other bone!

6. Vertebral Column (Spine) extends from skull to pelvis.
26 irregular bones connected by
ligaments-> flexible and curved and
Has spinal cord down the middle Think … Meal Times
1st 7= cervical (neck) 7 am
{1st= atlas 2nd= axis concave}
12= Thoracic (chest) noon
5= Lumbar ( lower back) pm
Vertebral Column

7. More about the spine…. Fetus= 33 bones
9 vertebrae will fuse to form the Sacrum and Coccyx 
Vertebrae separated by pods of Fibrocartilage = intervertebral disks (cushions & is a shock absorber)
Young > 90% water, spongy
Adults there is less H20, harder less compressible  herniated disks “slipped”
This disks protrudes into the spinal nerves  numbess and pain
Primary curvatures --> Thoracic / sacral there at birth
Secondary curvatures--> Cervical--> baby raises head --> lumbar baby walks

8. Abnormal Spine Curvatures
Draw them below
Scoliosis
Scoliosis--> sideways Kyphosis (ex)
Lordosis (ex)

9. Vertebrae Structure Body/ Centrum-- > anterior weight bearing
Body/ Centrum-- > anterior weight bearing
Vertebral arch --> joining of all posterior extensions to body
Vertebral foramen--> canal for nerve cord
Tranverse processes --> 2 lateral projections from body
Spinous process--> single projection from arch
Articular processes --> lateral to foramen follows joints w/ adjacent vertebral

10. Subdivisions of the spine…
Cervical ( C1- C7) (C3-C7) smallest, last to process
* Have 2 foramen for cranial arteries
1. Atlas --> no body, indention’s, receive occipital condlyes-- > nod head (yes)
2. Axis --> C2 pivot for rotation of altlas (odontoid process/dense) pivot pt. “no”

11. More about the spine…
Thoracic ( T1-T2) spinous process long and hooked, larger 2 costal facets to receive ribs
Lumbar ( L1-L2) massive block bodies w/short hatched spinous process sturdiest for stress on column
Sacrum- five vertebrae fused --> posterior wall of pelvis w/sacral canal
Coccyx- 3-5 small fused. Tailbone (remnant of tail)

12. Bony Thorax
Sternum +Ribs +Thoracic Vertebrae + Thoracic Cage goes around the lung and heart
Sternum ( breastbone ) flat3 fused bones … Attaches to the 1st seven ribs.
Ribs- 12 pairs * Men don’t have one less rib than women* Tilt downward.
1st Seven Ribs are called True Ribs= attach to sternum
by costal cartilage.
The next 5 ribs are called False Ribs = indirectly to sternum or not at all
Last to Ribs are called Floating Ribs. (no attachment)
Intercostal Spaces --> filled w/ muscles to help breathing.
Bony Thorax