Skeletal System PDF | PPT
Keywords: Skeletal system, bones, joints, axial skeleton, appendicular skeleton, cranium, vertebrae, ribs, sternum, anatomy, physiology.
This resource provides comprehensive notes and presentations (PDF and PPT) on the skeletal system, covering its anatomy, functions, and classification of bones. It is an essential study material for students and professionals in biology, medicine, and related fields.
The Skeletal System
Functions of the Skeletal System
The skeletal system serves as the body's structural framework and performs several critical functions:
- Support: Provides a rigid framework that supports the body and maintains its shape.
- Protection: Protects vital organs such as the brain, heart, and lungs.
- Movement: Works with muscles to enable movement through joints.
- Mineral Storage: Stores calcium and phosphorus, which are essential for various physiological processes.
- Blood Cell Production: The bone marrow produces red blood cells, white blood cells, and platelets.
Anatomy of the Skeletal System
The skeletal system is divided into two main parts: the axial skeleton and the appendicular skeleton.
- Axial Skeleton: Includes the skull, vertebral column, and thoracic cage.
- Skull: Composed of cranial and facial bones, it protects the brain and supports facial structures.
- Cranium: Houses and protects the brain.
- Facial Bones: Form the structure of the face and support sensory organs.
- Hyoid Bone: Supports the tongue and aids in swallowing.
- Fetal Skull: Features soft spots (fontanelles) that allow flexibility during childbirth.
- Vertebral Column: Consists of cervical, thoracic, lumbar vertebrae, sacrum, and coccyx. It protects the spinal cord and supports the head and trunk.
- Thoracic Cage: Includes the sternum and ribs, protecting the heart and lungs.
- Appendicular Skeleton: Includes the bones of the limbs and their girdles.
- Shoulder Girdle: Consists of the clavicle and scapula, connecting the upper limbs to the axial skeleton.
- Upper Limb: Includes the arm (humerus), forearm (radius and ulna), and hand (carpals, metacarpals, and phalanges).
- Pelvic Girdle: Supports the lower limbs and protects reproductive and digestive organs.
- Lower Limb: Includes the thigh (femur), leg (tibia and fibula), and foot (tarsals, metatarsals, and phalanges).
Classification of Bones
Bones are classified based on their shape and structure:
- Long Bones: Longer than they are wide, such as the femur and humerus. They function in movement and support.
- Short Bones: Cube-shaped, such as the carpals and tarsals. They provide stability and some movement.
- Flat Bones: Thin and flat, such as the skull and scapula. They protect internal organs and provide surface area for muscle attachment.
- Irregular Bones: Have complex shapes, such as the vertebrae and pelvic bones.
Gross and Microscopic Anatomy
Gross anatomy refers to the visible structures of bones, while microscopic anatomy focuses on their internal composition:
- Gross Anatomy: Includes features like the diaphysis (shaft), epiphysis (ends), and articular cartilage of long bones.
- Microscopic Anatomy: Reveals the compact bone (dense outer layer) and spongy bone (porous inner layer). Osteons are the structural units of compact bone, while trabeculae form the lattice-like structure of spongy bone.
Joints
Joints are the points where bones meet and allow movement. They are classified based on their structure and function:
- Fibrous Joints: Immovable joints connected by dense connective tissue, such as sutures in the skull.
- Cartilaginous Joints: Slightly movable joints connected by cartilage, such as the intervertebral discs.
- Synovial Joints: Freely movable joints with a synovial cavity, such as the knee and shoulder. They are further classified into hinge, ball-and-socket, pivot, saddle, and gliding joints.
In conclusion, the skeletal system is essential for maintaining the body's structure, enabling movement, and protecting vital organs. Understanding its anatomy and physiology provides valuable insights into human health and functionality.
Info!
If you are the copyright owner of this document and want to report it, please visit the copyright infringement notice page to submit a report.
