Bones of the Skeleton

2 Divisions:

28. Axial Skeleton A. Purpose – protect vital organs and hold body upright B. Includes - skull, vertebral columns, rib cage

Skull C. Made up of 22 Bones: – Facial bones = 14 – Cranium =8

a. Cranium – bones that enclose the brain

Cranial bones Frontal – (1) forms the forehead frontal

Cranial bones Parietal – (2) forms most of top and sides of head parietal

Cranial bones Occipital – (1) forms back of head occipital

Cranial bones Temporal – (2) temporal

Cranial bones Sphenoid – (1) keystone of cranium, butterfly shape sphenoid

Cranial bones Ethmoid – (1) internal bone that forms nasal cavity ethmoid

Review

c. Facial bones – bones not enclosing the brain

Facial bones Mandible – (1) lower jaw, only moveable face bone mandible

Facial bones Maxillae – (2) upper jaw maxillae

Facial bones Zygomatic – (2) cheekbones zygomatic

Facial bones Nasal – (2) bridge of the nose nasal

Facial bones Lacrimal – (2) medial wall of eye lacrimal

Facial bones Vomer – (1) nasal septum vomer

Facial bones Palantine – (2) hard palate of mouth

Facial bones Inferior nasal concha – (2) lateral walls of nasal cavity Inferior nasal concha

Review

Vertebral Column D. (spine) 28 inches long, contains 26 bones

5 Divisions

Cervical vertebrae – 7 bones of neck

Thoracic vertebrae – 12 bones of upper back

Lumbar vertebrae – 5 bones of lower back

Sacrum – 5 fused vertebrae

Coccyx – 4 fused vertebrae, tail bone

Issues with the spine Kyphosis – hunchback – exaggerated thoracic curve

Issues with the spine Lordosis - exaggerated lumbar curvature

Issues with the spine Scoliosis: abnormal lateral curvature (side to side)

Ribcage E. Made of sternum and ribs

Sternum a. Breast bone, 3 fused bones

Ribs – 12 pair

True ribs – 1-7 attach to sternum by costal cartilages False ribs – 8-12 attach indirectly or not at all to sternum – Floating ribs – no anterior attachment

29. Appendicular Skeleton A. Purpose – enables most movement B. Includes - pectoral and pelvic girdle, limbs, hands and feet

Pectoral girdle C. Connects upper limbs (arms) to axial skeleton

a. Clavicle – (2) thin collar bone

b. Scapula – (2) flat shoulder blades

Upper limb a. Humerus – (2) arm bone

Upper limb b. Ulna – (2) pinky side, makes up elbow

Upper limb c. Radius – (2) thumb side, supports wrist

Hand a. Carpals – (16) wrist bones, 8 each hand

Hand b. Metacarpals – (10) hand bones, 5 each hand

Hand c. Phalanges – (28) finger bones, 14 each hand

Pelvic girdle F. Connects lower limbs (legs) to axial skeleton, coxal bones (hip bone)

a. Ilium – superior region of coxal

b. Ischium – inferior region, part we sit on

c. Pubis – anterior region

Male vs. Female

Male or Female Angle > 90 or < 90 degrees Sacrum forward or backward Pelvic Outlet Small or Large

Male or Female Angle > 90 or < 90 degrees Sacrum forward or backward Pelvic Outlet Small or Large

Lower limb a. Femur – thigh bone, longest, largest, strongest bone in body

Lower limb b. Patella – knee cap

Lower limb c. Tibia – shin bone

Lower limb d. Fibula – stick like, does not bear weight

Foot a. Tarsals – (14) ankle bones, 7 each foot

Foot b. Metatarsals – (10) foot bones, 5 each foot

Foot c. Phalanges – (28) toe bones, 14 each foot

Review