BIOM 1060 (Module 3)

Classifications of bones

Long bones

• Longer than wide

• Help with movement

• Examples: femur, humerus

Short bones

• Small and cube-shaped (equal length, width, and thickness)

• Give stability

• Examples: wrist (carpals), ankle (tarsals)

Flat bones

• Thin, flat, and usually curved

• Protect organs

• Examples: skull, ribs, sternum

Irregular bones

• Odd-shaped

• Have special jobs (support/protection)

• Examples: vertebrae, pelvis

Sesamoid bones

• Small bones in tendons

• Help reduce friction

• Example: kneecap (patella)

Gross structure and key anatomical features of long bones

Compact bone: Dense outer layer

Spongy bone: Honeycomb like bone found within

Connective tissue:

• Periosteum covers outside of the impact bone

• Endosteum covers the inside portion

Long Bone structure:

• Diaphysis: Forms long axis, tubular shaft

• Epiphyses: The end of long bones, made up of compact bone and spongy bone

• Metaphysis: Region between diaphysis and epiphysis and contains the growth plate

The axial skeleton

1. Cervical: 7 vertebrae
2. Thoracic: 12 vertebrae
3. Lumbar: 5 vertebrae
4. Sacrum: one bone formed from fusion of
several (5) bones, articulates with hip
5. Coccyx: fused (4) bones

Common structure of all vertebrae

Cervical: Small oval body, large vertebral foramen

Thoracic: Heart shaped body, smaller vertebral foramen, large transverse process

Lumbar: Large oval body, triangular vertebral foramen, small transverse

Joints of the vertebral column

Intervertebral discs – cushion-like pad between vertebrae that act as shock absorbers

Thoracic cage

Composed of ribs, sternum and thoracic cage

Protects the organs and support upper limbs

Upper limbs

Arms: Hummeruss

Forearm: radius and ulna

Hand: carpals (8), metacarpals (5), phalanges (14)

Lower limbs

Thigh: Femur and patella
Leg: Tibia and Fibula
Foot: tarsals (7), metatarsals (5), phalanges (14)

Understand changes to the skeleton during development, ageing, and disease.

Development

• Skeleton starts as cartilage → ossifies in embryo

• Long bones start ossifying at 8 weeks and finish at 25 weeks

• Growth continues in childhood/adolescence and stop around 25 years

Age-related bone changes

• Children: more bone formation than resorption (bone growth)

• Young adults: formation = resorption (stable)

• Adults: less bone formation than resorption (bone loss begins)

Osteoporosis

• Resorption > formation → low bone mass

• Common in elderly (especially women)

• Prevention: weight-bearing exercises