The axial skelton is composed of:

- the skull

- the vetrebal column

- the thoracic cage

The appendicular skeleton consists of:

- upper and lower limbs

- the bones that hold the limbs to the trunk of the body

What does the cranial bones form?

forms the rounded cranium, which completely surrounds and encloses the brain

What does facial bones form?

the bones of the face

Facial bones also...

- protect the entrances to the digestive and respiratory stystems

- provide attachment sites for facial muscles

What is the largest cavity in the skull and what are its functions?

- Cranial cavity

- Functions = encloses, cusions and supports the brain

"houses the brain"

List the smaller cavities in the skull

- orbits (eyes)

- oral cavity (mouth)

- nasal cavity

- paranasal sinuses

Numerous bone markings

- canals

-fissures

- foramina (passageways for blood vessels and nerves

Sutures

-immovable fibrous joints that form the boundaries b/t the cranial bones

- allows the skull to grow/expand

-sutures fuse in adulthood

4 types of sutures

- coronal

- lamboid

-saggital

- squamosal

sutural bones

represent independent bone ossfication

Sinuses

- have a mucuos lining that helps to humidifiy and warm inhaled air

What causes the skull bones to be lighter and provides resonance tot he voice?

Sinuses

Fontanels

 - "soft spots" on babys head

- close by 15 months of age

Hyoid Bone

- slender curved bone located inferior to the skull b/t the mandible and the larynx

- does not articulate w/ any other bone in the skeleton

- serves as sites for attachment  for tongue and larynx muscles and ligaments

How many bones composes the vertebral column?

26

How many individual vertebrae are there in the vertebral column?

`

24 individual vertebrae

What two bones are fused vertebrae?

sacrum and coccyx

Functions of the vertebral column

- providing the vertical support for the body

- supporting the weight of the head

- houses and protects the delicate spinal cord

- provides a passageway for spinal nevers connecting  to the spinal chord

Three Main Spinal Curvature Deformities

- kyphosis

- lordosis

- scoliosis

Kyphosis

an exaggerated thoracic curvature that is directed posteriorly

"hunchback"

Lordosis

an exaggerated lumbar curvature that is observed as a protrusion of the abdomen and buttocks

"swayback"

Scoliosis

an abnormal lateral curvature that sometimes results during development when both the vertebral arch and body fail to form on one side of a verebrae

What is the most common spinal curvature deformity?

Scoliosis

All vertebrae share common structural features:

- Body = weight bearing portion

-Vertebral Arch

-

Pedicles/Laminae

-Spinous process

- Transverse processes

-Articular processes

-Intervertebral discs

Vertebral Arch

- posterior to the body

- when stacked together the forament form the verebral canal which houses the spinal chord

Pedicles/ Laminae

forms the verebral arch

Spinous process

projects posteriorly from the left/right laminae

Transverse processes

lateral projections from both sides of the vertebral arch

Articular processes

inferior articular processes articulates w/ the superior articular process of the verebrae immediately below

Intervertebral discs

-annulus fibrosis - fibrocartilage outer ring

- nucleus pulposis - inner circular region w/ a high water content giving a gelatinous consistency

- allows a person to bend

Thoracic Cage

consists of the thoracic verebrate (posteriorly)

- ribs (laterally)

- sternum (anteriorly)

What is the function of the thoracic cage?

acts as a protective cage around vital organs, such as the lungs, heart, trachea and esophagus

True Ribs

- Ribs 1-7

- connect indiviudally to the sternum by seperate cartilagionous extensions called costal cartilages

False Ribs

- Ribs 8-12

- costal carilages do not attach directly to the sternum

Floating Ribs

- last two pairts of false ribs (11 and 12)

- no connection w/ the sternum