Untitled Quiz

Study Notes

Students should be able to describe the divisions of the skeletal system.
Students should be able to identify different types of bones.
Students should be able to describe the structure of a long bone and the periosteum.

Bone consists of bone cells, an intercellular matrix made of collagen fibers, inorganic salts, and minerals.

Compact (Hard) Bone: Dense and ivory-like, forming the surface of bones.
Cancellous (Spongy) Bone: Found inside bones, consisting of trabeculae (tiny beams of bone) with spaces like a sponge.

Axial Skeleton: Contains bones along the longitudinal axis of the body. Includes the skull, sternum, ribs, vertebral column, and hyoid bone.
Appendicular Skeleton: Consists of bones of the upper and lower limbs (extremities) and the girdles connecting the limbs to the axial skeleton.

Cervical Region: Contains the cervical vertebrae (C1-C7).
Thoracic Region: Contains the thoracic vertebrae (T1-T12).
Lumbar Region: Contains the lumbar vertebrae (L1-L5).
Sacrum: A triangular bone formed by the union of five sacral vertebrae (S1-S5).
Coccyx: Formed by the fusion of four coccygeal vertebrae.

Shoulder Girdle: Consists of the scapula and clavicle. Connects the upper limb to the trunk at the sternoclavicular joint.
Arm: Contains the humerus.
Forearm: Contains the radius and ulna.
Hand: Composed of the carpal (8), metacarpals (5), and phalanges (3 in each finger except thumb, which has 2).

Pelvic Girdle: Consists of the hip bone and connects the lower limb to the axial skeleton at the sacroiliac joint.
Thigh: Contains the femur.
Leg: Contains the tibia and fibula.
Foot: Composed of the tarsal bones (7), metatarsals (5), and phalanges (3 in each toe except the big toe, which has 2).

Long Bones: Examples include the humerus, femur, metacarpals, and phalanges.
Short Bones: Examples include the carpal and tarsal bones.
Flat Bones: Examples include the vault of the skull, ribs, sternum, and scapula.
Irregular Bones: Various shapes, e.g., vertebrae, hip bone.
Pneumatic Bones: Contain air spaces, e.g., maxilla, frontal bones.
Sesamoid Bones: Small bones embedded in tendons, e.g., patella (kneecap).

Diaphysis: Shaft of the bone, formed of outer compact bone covered by periosteum and an inner medullary cavity.
Epiphysis: Two ends of the bone, composed of cancellous bone covered by compact bone. The articular surface is covered by hyaline cartilage.
Metaphysis: Part of the diaphysis close to the epiphysis.
Epiphyseal Plates: Cartilaginous discs between the epiphysis and diaphysis that allow for the growth of bone in length.

A fibrous connective tissue covering the surrounding bone, except at the site of articular cartilage.
Highly sensitive due to its rich nerve supply.
Functions:
- Provides attachment for muscles, tendons, and ligaments.
- Provides a source of blood supply to the bone.
- Contributes to bone growth in width.
- Helps in the healing of fractured bones.

It is a fatty, vascular tissue found in the medullary cavity of long bones and the spaces of cancellous bone.
Involved in the formation of blood cells.
The type of bone marrow changes with age:
- At birth: All marrow cavities are filled with red bone marrow.
- During childhood: Yellow bone marrow replaces red bone marrow in the distal long bones.
- In adults: Red bone marrow is only present in the spaces of spongy bones (in the skull, vertebrae, sternum, ribs, hip, upper end of the femur, and humerus). The medullary cavities of all long bones contain only yellow bone marrow.

Membranous Ossification: Bone develops from a membrane of connective tissue called mesenchymal ossification. Examples include the skull bones, shaft of the clavicle, and facial bones.
Cartilaginous Ossification: Bone develops from cartilage. Examples include all other bones of the body.