Human Skeletal System

Study Notes

Overview

The skeletal system is a complex system of 206 bones that provide support, protection, and movement for the human body.

Functions

Support: Provides a framework for the body's muscles, organs, and tissues.
Protection: Protects internal organs, such as the heart, lungs, and brain, by encasing them in a cage of bones.
Movement: Acts as a system of levers and joints, allowing for movement and locomotion.
Blood cell production: The bones in the skeletal system are responsible for producing blood cells, including red blood cells, white blood cells, and platelets.
Storage of minerals: Bones act as a storage site for minerals such as calcium and phosphorus.

Types of Bones

Long bones: Characterized by a long shaft and two ends, example: femur (thigh bone) and humerus (upper arm bone).
Short bones: Cube-shaped bones, example: carpals (wrist bones) and tarsals (ankle bones).
Flat bones: Thin, flat bones, example: sternum (breastbone) and ribs.
Irregular bones: Bones that do not fit into any other category, example: vertebrae and pelvis.
Sesamoid bones: Small bones embedded within tendons, example: patella (kneecap).

Bone Structure

Compact bone: Dense, compact bone tissue that forms the outer layer of bones.
Cancellous bone: Spongy, porous bone tissue that forms the inner layer of bones.
Bone marrow: The spongy tissue found inside the cavities of bones, responsible for producing blood cells.
Periosteum: A layer of connective tissue that covers the surface of bones.
Endosteum: A layer of connective tissue that lines the inner surface of bones.

Joints

Fixed joints: Joints that do not allow for movement, example: joints between bones in the skull.
Partially movable joints: Joints that allow for limited movement, example: joints between vertebrae.
Freely movable joints: Joints that allow for a wide range of movement, example: shoulder and hip joints.

Disorders and Diseases

Osteoporosis: A condition characterized by a loss of bone density, leading to brittle and fragile bones.
Osteoarthritis: A condition characterized by the wear and tear of joints, leading to pain and stiffness.
Rickets: A condition characterized by softening of bones in children, often due to a lack of vitamin D.
Fractures: Broken bones, which can be caused by trauma, osteoporosis, or other conditions.

Description

Learn about the human skeletal system, its functions, types of bones, structure, joints, and common disorders and diseases. Test your knowledge of the skeletal system and its importance in the human body.