Short Bones Function Quiz and Flashcards

Study Notes

Bone Structure and Types

The outer shaft of long bones consists of compact bone, encased in a periosteum, a connective tissue sheath.
Ends of long bones feature cancellous (spongy) bone enveloped by a thin layer of compact bone.
Articular surfaces at the ends of bones are covered with hyaline cartilage for smooth joint movement.

Short Bones

Found in hands and feet, such as tarsal and carpal bones.
Roughly cuboidal in shape, consisting of cancellous bone with a thin outer layer of compact bone.
Covered with periosteum, with their articular surfaces also lined with hyaline cartilage.

Flat Bones

Located in the vault of the skull, including frontal and parietal bones.
Comprised of two thin layers of compact bone with a layer of cancellous bone in between.
Scapulae are categorized as flat bones despite their irregular shape.

Irregular Bones

Include bones that don't fit into other classifications, like vertebrae, pelvic bones, and certain skull bones.
Characterized by a thin outer layer of compact bone surrounding cancellous bone.

Sesamoid Bones

Small nodules found within certain tendons where they glide over bony surfaces.
Function to improve leverage and protect tendons from wear.

Bone Composition

Compact bone appears as a dense, solid structure.
Cancellous bone consists of a network of trabeculae, arranged to withstand stress and strain effectively.

Bone Classification

Regional Classification:
- Axial Skeleton (80 bones): Includes cranial (8), facial (14), auditory ossicles (6), hyoid (1), vertebrae (26), and thoracic cage (1 sternum, 24 ribs).
- Appendicular Skeleton (126 bones): Comprises the pectoral girdle (4 bones), upper extremities (32 bones), pelvic girdle (2), and lower extremities (30 bones).
Classification by Shape:
- Long Bones: Found in limbs (e.g., humerus, femur), longer than they are wide, with a tubular shaft (diaphysis) that typically contains a marrow cavity.
- Short Bones: Similar in length and width, mainly provide support and stability.
- Flat Bones: Thin and flat, primarily serve protective roles.
- Irregular Bones: Complex shapes not fitting other categories.
- Sesamoid Bones: Embedded within tendons for mechanical advantage.

Description

This quiz covers the anatomy of long and short bones, discussing the composition of the outer part of the shaft, the structure of the ends of long bones, and the characteristics of short bones found in the hand and foot.