Human Skeletal System Overview

Study Notes

The skeletal system is a complex system of 206 bones that provide support, protection, and movement for the body.
It is also known as the osteological system.

Support: provides a framework for the body's muscles, organs, and tissues.
Protection: shields internal organs, such as the heart, lungs, and brain, from injury.
Movement: works with the muscular system to facilitate movement and locomotion.
Blood cell production: bones are responsible for producing blood cells, including red and white blood cells.
Storage of minerals: bones act as a storage site for minerals such as calcium and phosphorus.

Long bones: longer than they are wide, found in the arms and legs. Examples: femur, humerus.
Short bones: cube-shaped, found in the wrists and ankles. Examples: carpals, tarsals.
Flat bones: thin and flat, found in the skull, ribs, and sternum. Examples: frontal bone, ribcage.
Irregular bones: do not fit into any of the other categories. Examples: vertebrae, pelvis.
Sesamoid bones: small, round bones embedded within tendons. Examples: patella.

Compact bone: dense, compact bone tissue that makes up the majority of the bone.
Cancellous bone: spongy, porous bone tissue found at the ends of long bones.
Periosteum: a layer of connective tissue that covers the bone surface.
Endosteum: a layer of connective tissue that lines the bone marrow cavity.

Ossification: the process of bone formation.
Intramembranous ossification: bone formation within a membrane, occurs in the skull.
Endochondral ossification: bone formation from cartilage, occurs in long bones.

Osteoporosis: a condition characterized by brittle and porous bones.
Osteoarthritis: a condition characterized by joint inflammation and cartilage degeneration.
Rickets: a condition characterized by softening of the bones in children, often caused by vitamin D deficiency.
Fractures: breaks in the bone, can be classified as open or closed.

The skeletal system comprises 206 bones that provide support, protection, and movement for the body.
It is also known as the osteological system.

Long bones are longer than they are wide, found in the arms and legs, e.g., femur, humerus.
Short bones are cube-shaped, found in the wrists and ankles, e.g., carpals, tarsals.
Flat bones are thin and flat, found in the skull, ribs, and sternum, e.g., frontal bone, ribcage.
Irregular bones do not fit into any of the other categories, e.g., vertebrae, pelvis.
Sesamoid bones are small, round bones embedded within tendons, e.g., patella.

Compact bone is dense, compact bone tissue that makes up the majority of the bone.
Cancellous bone is spongy, porous bone tissue found at the ends of long bones.
Periosteum is a layer of connective tissue that covers the bone surface.
Endosteum is a layer of connective tissue that lines the bone marrow cavity.

Ossification is the process of bone formation.
Intramembranous ossification is bone formation within a membrane, occurs in the skull.
Endochondral ossification is bone formation from cartilage, occurs in long bones.

Osteoporosis is a condition characterized by brittle and porous bones.
Osteoarthritis is a condition characterized by joint inflammation and cartilage degeneration.
Rickets is a condition characterized by softening of the bones in children, often caused by vitamin D deficiency.
Fractures are breaks in the bone, can be classified as open or closed.