About Skeleton & Muscles

1. THE MUSCULOSKELETAL SYSTEM
Bones, Joints and Muscles Tendons
Ligaments and Cartilage
Presented by Amir Sami

2. THE HUMAN SKELETON
•Contains 206 bones
•Initially: flexible cartilage
•Ossification

3. PROCESS OF OSSIFICATION
• Approximately 20 years
• Growth plates
• Bone building:
- Osteoblasts
- Osteocytes
- Osteoclasts
•

4. STRUCTURE OF BONES
Compact bone
• Outside part of the bone
• Extremely strong and hard
• Periosteum
Spongy bone
• Mesh-like network
(trabeculae)
• Red marrow (blood cells)
• Yellow marrow (fat)

5. MICROGRAPHS

6. ANATOMICAL CLASSIFICATION OF BONES
• Bones are characterized anatomically as:
– long bones (e.g. humerus, femur)
– flat bones (Scapula)
– irregular bones (such as the vertebrae)
• All these bone types, regardless of their
anatomical form, are composed of both spongy
and compact bone.

7. FUNCTIONS OF THE SKELETON
• Bone provides the internal support of the body
and provides sites of attachment of tendons and
muscles, essential for locomotion.
• Bone provides protection for the vital organs of
the body: the skull protects the brain; the ribs
protect the heart and lungs.
• The hematopoietic bone marrow is protected by
the surrounding bony tissue.
•
• The main store of calcium and phosphate is in
bone. Bone has several metabolic functions
especially in calcium homeostasis.

8. • Meeting of two bones
• Make the skeleton flexible
• Types:
-Immovable or fibrous
-Partially movable, or cartilaginous
-Freely movable, or synovial
JOINTS

9. JOINTS
• Types of synovial joints:
-Hinge: knees and elbows
-Gliding: wrists and
ankles
- Ball and socket: hips and
shoulders
-Pivot: Head

10. JOINTS CONSIST OF THE FOLLOWING:
• Cartilage: the bones are covered with cartilage (a
connective tissue), which is made up of cells and
fibers and is wear- resistant. Cartilage helps reduce
the friction of movement.
• Synovial membrane: a tissue that lines the joint
and seals it into a joint capsule. The synovial
membrane secretes synovial fluid (a clear, sticky
fluid) around the joint to lubricate it.
• Ligaments: strong ligaments (tough, elastic
bands of connective tissue) surround the joint to give
support and limit the joint's movement.

11. JOINTS CONSIST OF THE FOLLOWING (II)
• Tendons: tendons (another type of tough
connective tissue) on each side of a joint
attach to muscles that control movement of
the joint.
•
Bursas: fluid-filled sacs, between bones,
ligaments, or other adjacent structures help
cushion the friction in a joint.
• Synovial fluid: a clear, sticky fluid secreted
by the synovial membrane.
• Meniscus: a curved part of cartilage in the knees
and other joints.

12. SYNOVIAL JOINTS

13. THE MUSCLES
• Pull on the joints, allowing us
to move.
• Help the body perform
other functions.
• More than 650 muscles
• ( half of a person's body
weight)
• Tendons: tough, cord-like
tissues
• 3 different kinds of muscle
1. Skeletal Muscle
2. Cardiac Muscle
3. Smooth Muscle

14. HOW DO MUSCLES MOVE?
• Contracting and relaxing.
• Work in pairs of flexors and extensors.
• The flexor contracts to bend a limb at a joint.
• The extensor contracts to extend or straighten the limb at
the same joint.

15. HOW DO SKELETAL MUSCLES WORK?