SUPPORT AND MOVEMENT: THE SKELETAL SYSTEM REVIEWClinical Health

J. Sugahara

Bare Bones

• Skeletal System = joints and bones (206)• Provide a framework for the body• Protect vital organs like the brains and spinal cord

• Serve as levers, when muscles are attached to help us lift and move

• Store calcium, which may be reabsorbed into the blood if there isn’t enough in the diet

• Produce blood cells in the red bone marrow.

Two kinds of Bones• Compact

• Homogeneous

• Spongy• Cancellous bones - • Spaces or honeycombed

Bone Structure

Categories of Bones

•Long•Short•Flat•Irregular•Sesamoid

Long Bones

Short Bones• Small, cube-shaped bones of wrists, ankles and toes• Consist of an outer layer of compact bone w/ inner layer

of cancellous bone (latticework structure)• Provide support/stability w/ little to no movement

Flat Bones• Large, somewhat flat surface that cover organs or provide

a surface for large areas of muscle

Irregular Bones• Specialized bones with specific shapes• Ears, vertebrae, face

Sesamoid Bones• Bones embedded in tendon (tough, connective tissue that

connects muscle to bone)• Knee, hands and feet

Interior – Red and Yellow Marrow• Marrow – tissue comprising center of large bones• Red Marrow

• at birth all marrow red• Produces red blood cells, platelets and most white blood cells

• Yellow Marrow• Produces some white blood cells• Color due to fat• More and more marrow becomes yellow as you age

Bones of the Head (cranial bones)• Form skull• Protects brain/structures inside skull• Join at points called sutures• Frontal – forehead, roof of eye sockets• Ethmoid – nasal cavitiy and orbits of eyes• Parietal – top and upper parts of the sides of the skull• Temporal – lower part of the skull and the lower sides,

incl. openings for ears• Occipital – back and base of the skull• Sphenoid – base of the cranium, holds frontal, occipital

and ethmoid bones

Spinal Column

• 5 sets of vertebrae• Cervical – 7 vertebrae of neck• Thoracic – 12 vertebrae that

connect to ribs• Lumbar – 5 bones of middle

back• Sacrum – curved bone of the

lower back, 5 separate bones at birth = fuse in early childhood

• Coccyx – tailbone, 4 fused bones

• Vertebra separated by a thick cartilaginous disc, helps in movement and flexibility

Bones of the Chest• Top

• Clavicle (collarbone) • Scapula

• Sternum (breastbone)• 12 pairs of ribs

• 7 joined to both vertebral column and sternum – “True ribs”

• 3 joined to vertebral column and 7th rib – “False ribs”• Last two – “false/floating ribs” – do not attach to

sternum or other ribs

Bones of the Pelvis

• Pelvic girdle – large bone that forms hips and supports the trunk of the body• Ilium, ischium and pubes• Point of attachment for

legs• Area where two pubic

bones join = “pubic symphysis”

Bones of the Extremities

• Humerous (upper arm) -> ulna and radius (lower arm) -> eight carpals (wrist) -> metacarpals (palm) -> phalanges (fingers)• Attaches at scapula, clavicle

• Femur (thigh) ->patella (kneecap -> tibia (shin) and fibula -> tarsals (ankle) -> phalanges (toes)

Joints• Points where bones connect• Connected to other bones with ligaments (bands of

fibrous tissue)• Movement

• Diarthroses – joints that move freely – knee• Amphiarthroses – cartilaginous joins that move slightly – between

vertebrae• Synarthroses – do not move – between skulls bones• Symphyses cartilaginous joints that unit two bones firmly – pubic

symphysis• Synovial – covered in a membrane that secretes a fluid lubricant

and helps joint move easily - hip

Take C. Notes on Skeletal System

1. Pp192 – 196

2. Don’t forget to write your summary (on the bottom of the first page if possible)

3. Include colored drawings of the following structures:

1. Bone Structure (figure 6-23)

2. Different types of fractures *You will need to look up pictures of the fractures that are not listed as well.

Sources• http://www.emsjunkie.com/anatomy-physiology/skeletal-sy

stem/