1. The Skeletal System

2. The Skeletal System
The skeletal system protects and supports the body.
Skeleton = Greek word meaning “a dried body”
Functions:
Provides shape
Provides support and protection
Allows movement
Stores minerals
Produces blood

3. Bones
Bones are living tissues that can grow and repair themselves, Connective tissue.
Connective tissue provides support for your body and connects all its parts.
Types of Connective Tissue:
Bone – provides support and shape.
Blood – delivers food and oxygen to the cells and carries away wastes.
Fat – keeps the body warm, cushions structures and stores energy.

4. Formation of Bone At birth humans have more than 300 bones.
As humans grow and develop, bones grow longer and fuse together.
By age 18 bones are completely ossified (hardened) and stop growing longer.
An average adult has 206 bones.

5. Bone Composition
Bones are composed of three layer of connective tissue:
Periosteum – outermost layer
contains blood vessels that bring nutrients and oxygen to the bone.
Compact bone – dense layer of bone
consists of blood vessels, nerve cells, and living bone cells.
Spongy bone – located in the ends and middle of long bones.
Porous and lightweight but strong and supportive.
Contains bone marrow.

6. Bone Composition

7. Other Components of Bone
Red
Blood Cells
White
Blood Cells
Bone Marrow
Located inside the spongy bone.
2 Types:
Red Marrow – produces red and white blood cells.
Produces 500 billion red blood cells per day!
Yellow Marrow – fat cells that store energy.
Fat
Fat

8. Cranium
Mandible
Clavicle
Scapula
Sternum
Humerus
Ribs
Vertebral Column
Pelvic Girdle
Radius
Ulna
Carpals
Metacarpals
Phalanges
Femur
Patella
Tibia
Fibula
Tarsals
Metatarsals
Phalanges

9. Total Bone Count by Category

10. Bone Classification Flat Bones Long Bones Irregular Bones
Sesamoid Bones
Short Bones

11. Bone Classification Long Bones Examples:
longer than they are wide.
have a shaft with heads at both ends.
Contain mostly compact bone.
Examples:
Humerus, Radius, Ulna, Femur, Tibia, Fibula, Clavicle, Metacarpals, Metatarsals and Phalanges

12. Bone Classification 2. Short Bones Examples: Carpals and Tarsals
Cube shaped.
Generally spongy bone.
Examples:
Carpals and Tarsals
Tarsals

13. Bones of the Hands & Feet
Carpals
Tarsals
Metacarpals
Metatarsals
Phalanges
Phalanges

14. Bone Classification
3. Flat Bones
Thin and flat.
Usually curved.

15. Male vs. Female Pelvic Girdles

16. Bone Classification 4. Irregular Bones Examples: Irregularly shaped.
Do not fit into any other bone classification.
Examples:
Vertebrae
Sacrum
Mandible

17. Bone Classification 5. Sesamoid Bones Examples:
embedded in tendons and usually related to joint surfaces.
modify pressure, to diminish friction, and occasionally to alter the direction of a muscle pull.
Examples:
Patella

18. Joints A place where two or more bones meet – Joint 2types:
A. Immovable
Immovable Joints – NO movement
Cranium
B. Movable
Ball-and- Socket = widest range of movement
Shoulder and hip
Gliding – some movement in all directions
Wrist and ankles
Hinge – only back and forth
Elbow and knee
Pivot – one bone rotates around another
Forearm, neck

19. Joint Types Immovable Pivot Ball and Socket Hinge Gliding Knee - Hinge
Hip - Ball and Socket

20. Tendons & Ligaments

21. Cartilage Located between two adjoining bones.
Cushions bones from sudden jolts
Provides a slippery surface to reduce friction.
Cartilage between Femur and Tibia
Cartilage
Cartilage