Skeletal System Overview

Skeletal System

Overview

• The skeletal system is the system of bones, joints, and ligaments that provide structure, support, and protection to the body.
• It consists of 206 bones that form the skeleton.

Functions

• Support: provides a framework for the body to maintain its shape and posture.
• Protection: protects internal organs, such as the brain, heart, and lungs, by encasing them in a protective cage of bones.
• Movement: acts as a system of levers and joints that enable movement and locomotion.
• Blood cell production: bones 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.

Divisions of the Skeletal System

• Axial skeleton: includes the bones of the skull, spine, ribs, and sternum.
• Appendicular skeleton: includes the bones of the upper and lower limbs, pelvis, and shoulder girdle.

Types of Bones

• Long bones: characterized by a shaft and two ends, e.g. femur (thigh bone) and humerus (upper arm bone).
• Short bones: cube-shaped bones, e.g. carpals (wrist bones) and tarsals (ankle bones).
• Flat bones: thin, flat bones, e.g. ribs and sternum.
• Irregular bones: bones that do not fit into any of the above categories, e.g. vertebrae and pelvis.

Joints

• Types of joints:
  • Synovial joints: freely movable joints, e.g. knee and elbow.
  • Cartilaginous joints: joints connected by cartilage, e.g. joints between vertebrae.
  • Fibrous joints: joints connected by fibrous connective tissue, e.g. joints between bones of the skull.
• Functions of joints:
  • Movement: enables movement between bones.
  • Stability: provides stability to the skeletal system.

Other Important Concepts

• Bone growth and development: bones grow and develop through a process called ossification.
• Bone remodeling: the process by which old bone tissue is replaced with new tissue.

Skeletal System

Overview

• The skeletal system provides structure, support, and protection to the body through its 206 bones.

Functions

• Supports the body's framework, maintaining shape and posture.
• Protects internal organs like the brain, heart, and lungs with a protective cage of bones.
• Enables movement and locomotion through levers and joints.
• Produces blood cells, including red blood cells, white blood cells, and platelets.
• Acts as a storage site for minerals like calcium and phosphorus.

Divisions of the Skeletal System

Axial Skeleton

• Includes the skull, spine, ribs, and sternum bones.

Appendicular Skeleton

• Comprises the bones of the upper and lower limbs, pelvis, and shoulder girdle.

Types of Bones

• Long Bones: characterized by a shaft and two ends, e.g. femur (thigh bone) and humerus (upper arm bone).
• Short Bones: cube-shaped bones, e.g. carpals (wrist bones) and tarsals (ankle bones).
• Flat Bones: thin, flat bones, e.g. ribs and sternum.
• Irregular Bones: bones that don't fit into the above categories, e.g. vertebrae and pelvis.

Joints

Types of Joints

• Synovial Joints: freely movable joints, e.g. knee and elbow.
• Cartilaginous Joints: joints connected by cartilage, e.g. joints between vertebrae.
• Fibrous Joints: joints connected by fibrous connective tissue, e.g. joints between bones of the skull.

Functions of Joints

• Enables movement between bones.
• Provides stability to the skeletal system.

Other Important Concepts

• Bone Growth and Development: bones grow and develop through ossification.
• Bone Remodeling: the process of replacing old bone tissue with new tissue.

Skeletal System

Functions

• Provides structural support and protection for internal organs, such as the brain and heart
• Facilitates movement through joints and attachments for muscles, enabling activities like walking and running
• Produces blood cells, including white blood cells to fight infection and red blood cells to carry oxygen, in bone marrow
• Stores essential minerals like calcium and phosphorus, crucial for bone growth and development

Components

Bones

• The adult human skeleton comprises 206 bones
• Long bones, such as the femur and humerus, have a shaft and two ends
• Short bones, like the carpals and tarsals, are cube-shaped and provide support
• Flat bones, such as the ribs and sternum, are thin and curved
• Irregular bones, including the vertebrae and pelvis, have complex shapes

Joints

• Joints connect bones and allow for movement
• Synovial joints, like the knee and elbow, have a space between bones and are lubricated by synovial fluid
• Cartilaginous joints, such as those in the spine, are connected by cartilage
• Fibrous joints, like those in the skull bones, are connected by fibrous connective tissue

Ligaments and Tendons

• Ligaments connect bones to each other, providing stability
• Tendons connect muscles to bones, facilitating movement

Divisions

Axial Skeleton

• Comprises the skull, spine, ribs, and sternum
• Supports and protects the head, neck, and torso

Appendicular Skeleton

• Includes the upper and lower limbs, pelvis, and shoulder girdle
• Facilitates movement and supports the body

Interesting Facts

• Bone fusion reduces the number of bones from 206 at birth to 206 in adulthood
• The femur is the longest bone in the human body, measuring around 19-20 inches in length
• The skeletal system accounts for approximately 15% of an adult's total body weight

Learn about the skeletal system, its functions, and the 206 bones that form the human skeleton. Discover how it provides support, protection, and facilitates movement in the body.