SKELETAL SYSTEM

HAP Chapter 7.1 – 7.5 Notes

I. Introduction

A. Living…not deadB. Functions…

1. structure2. attachment for muscles3. protection4. produce blood cells5. store salts (calcium)6. house nerves and blood vessels

II. Long Bone structure (pg. 127)A. Epiphysis

1. Def – the end of the bonea. Forms a jointb. Proximal and distalc. Covered in articular cartilage

B. Diaphysis1. Def – the shaft of the bone

a. Periosteum – outer covering-forms and repairs bone

tissue

b. Processes – bony projections -allow attachments, room for blood

vessels and nerves, acts as a puzzle piece with another bone.

c. Compact bone – tightly packed-wall of diaphysis

d. Spongy bone – loosely packed-found in epiphysis-light weight

*c and d are resistant to bending and are stronge. Medullary cavity – opening for blood

vesselsf. Endosteum – layer that lines medullary

cavityg. Marrow – (yellow and red)

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C. Microscopically Speaking…1. Bone cells (osteocytes) are located

within lacunae that lie in concentric circles around Central/Haversion canals.

a. Volkmann’s Canals – connect central canals2. Osteocytes pass nutrients and gasses. 3. Stores…

a. Collagen – gives bones their strength

b. Salts – gives bones their hardness

III. Bone Growth and Dev.A. Development of bone

1. Intramembranous Bones a. Broad and flat bones b. Location – skull c. Process…

1.connective tissue appears2. osteocytes osteoblasts

(bone makers)3. create spongy bone…

periosteum next4. compact bone is then made

2. Endochondral Bones a. Long bones b. Location legs, arms, ribs…

c. Process…1. Begins as hyaline cartilage2. cartilage grows3. bone forms in diaphysis (primary ossification center)4. spongy bone is laid + periosteum

forms5. spongy bone turns to compact bone6. band of cartilage remains in epiphysis epiphyseal plate (2nd ossification

center)7. bone continues to grow in length

IV. Fractures

A. Def – partial or complete break in the bone1. Classifications

a. Open – the bone exits and through the skin.

aka – compoundb. Closed – the bone does not

exist through the skin aka – simple

B. Types of fractures

1. Greenstick – incomplete fracture; bone is not completely broken

2. Transverse - the break is in a straight line across the bone

3. Spiral – the break spirals around the bone. Caused by a twisting motion.

4. Oblique – diagonal break across the bone

5. Compression – the bone is crushed causing it to look flatter in shape

6. Comminuted – the bone is broken into three or more pieces

7. Avulsion – a tendon/ligament pulls a bone fragment off of the bone

Medial epicondylar avulsion

V. Skeletal OrganizationA. Axial Skeleton

1. supports head, neck and trunk2. Bones

a. Skull (cranium)-facial bones and brain case

b. Hyoid bone-found in the neck-supports tongue

c. Vertebral column-vertebrae, sacrum, coccyx

d. Thoracic cage-ribs and sternum

B. Appendicular Skeleton1. consists of upper and lower limbs1. Bones

a. Pectoral girdle-scapula, clavicle

b. Upper limbs-humerous, radius, ulna,

carpalsmetacarpals, phalanges

c. Pelvic Girdle-coxa (hipbones)-form pelvis (connection b/t

appendicular and axial

d. Lower limbs-femur, tibia, fibula, patella,

tarsals, metatarsals, phalanges

C. Bone breakdown…1. pg. 135 – 206 bones

a. Terms…17 descriptions