The skeletal and muscular systems are closely integrated because they work together to enable movement. The skeletal system has 206 bones divided into the axial skeleton (bones of the head, trunk and vertebral column) and appendicular skeleton (bones of the limbs and girdles). Bones are classified by shape and composition. Joints connect bones and allow various ranges of motion. The skeletal system provides structure, protection, movement, mineral storage and blood cell formation.

1. REVIEW OF ANATOMY AND PHYSIOLOGY OF MSS
It is the second largest system in the body.
The skeletal and muscular systems considered one system
because they work together to enable the body to move.
 Their functions are highly integrated
 Therefore, disease in or injury to one adversely affects the others.
 For instance, an infection in a joint (septic arthritis)
causes degeneration of the articular surfaces

2. The skeleton is subdivided into two divisions:
• The axial skeleton, the bones that form the
longitudinal axis of the body, and
• The appendicular skeleton, the bones of the limbs
and girdles.

3. Classification of skeletal system…
Arranged in two
divisions:
• Axial skeleton ( 80
bones)
• Appendicular
skeleton (126 bones)

5. Classification of Bones
• The adult skeleton is composed of 206 bones
• there are two basic types of osseous, or bone,
tissue:
• compact bone
• spongy bone
• are classified into four groups according to shape:
• long,
• short,
• flat
• irregular.

7. Classification of skeletal system…
I. The axial skeleton
• Form the axis of the body
• Support and protect the organs of the head, neck, and trunk.
Skull:22bones
• Cranial(8)
• Facial bones(14)
Auditory ossicles: 6 ear bones
Hyoid bone =1bone

8. Classification of skeletal system…
4. Vertebral column= 26 Bones
• Cervical vertebra (7)
• Thoracic vertebra (12)
• Lumbar vertebra (5)
• Sacrum (1)
• Coccyx (1)
5. Rib Cage—25 Bones
• pairs of ribs =12
• Sternum (1)

9. Classification of skeletal system…
• Bones of the upper
• Lower extremities and
• Bony girdles that anchor the appendages
to the axial skeleton
II. The Appendicular skeleton

10. Classification of skeletal system…
Pectoral girdle/shoulder Girdle
• Paired scapulae (“shoulder blades)
• Paired clavicles (“collarbones”)
Upper extremities =60 Bones
• Each upper extremity contains
• Humerus
• Ulna and Radius,
• Carpal bones,
• Metacarpal bones, and
• Phalanges (“finger bones”) of the hand.

11. Classification of skeletal system…
3.Pelvic girdle –hipbones =3 Bones
• sacrum (1)
• Ilium, Pubis, Ischium
4. Lower extremities= 60 Bones
Each lower extremity contains
• Femur (“thighbone”) ,
• Tibia (“shinbone”) and fibula within the leg,
• Foot bones
• Tarsal bones,
• Metatarsal bones
• Phalanges (“toe bones”)
• Patella – kneecap

12. Bones
• Provide a framework to support and protect the body
• Point of attachment with muscles
• Held close together at the joint by ligaments, which
are flexible bands of fibrous tissue
• Store calcium and other minerals
• Produce blood cells within bone marrow

13. Muscle Tissue
Skeletal muscle
Striated in appearance ,multi- nucleated
Under voluntary nervous control.
Smooth or visceral muscle
Located in the walls of organs
No striations, & under involuntary control.
Cardiac muscle
Located only in the heart, striated ,1-3 central nuclei &
involuntary control.

15. Joints
Joints, also called articulations, have two
functions:
• They hold the bones together securely
• Give the rigid skeleton mobility.
Classification. Joints are classified in two
• functionally
• structurally

16. Functional classification.
• The functional classification focuses on the amount of
movement the joint allows.
Types of functional joints.
• Synarthroses or immovable joints;
• Amphiarthroses, or slightly movable joints, and
• Diarthrosis, or freely movable joints

17. Diarthroses.
• Freely movable joints predominate in the limbs, where
mobility is important.
Synarthroses and amphiarthroses.
• Immovable and slightly movable joints are restricted mainly to the
axial skeleton, where firm attachments and protection of internal
organs are priorities.

18. Structural classification.
• Fibrous,
• Cartilaginous, and
• Synovial joints;
These classifications are based on whether
they separates the bony regions at the joint.

19. In fibrous joints, the bones are united by fibrous tissue
• The best examples of this type of joint are the sutures of the skull
In cartilaginous joints, the bone ends are connected by
cartilage
• Examples of this joint type that are slightly movable are the pubic
symphysis of the pelvis and the intervertebral joints of the spinal
column
Synovial joints are joints in which the articulating bone
ends are separated by a joint cavity containing a synovial
fluid; they account for all joints of the limbs.

20.  Articular cartilage. Articular cartilage covers the ends of the bones
forming the joints.
 Fibrous articular capsule. The joint surfaces are enclosed by a sleeve or
a capsule of fibrous connective tissue, and their capsule is lined with a
smooth synovial membrane (the reason these joints are called synovial
joints).
 Joint cavity. The articular capsule encloses a cavity, called the joint
cavity, which contains lubricating synovial fluid.

21.  Reinforcing ligaments. The fibrous capsule is usually reinforced with
ligaments
 Bursae. Bursae are flattened fibrous sacs lined with synovial membrane and
containing a thin film of synovial fluid; they are common where ligaments,
muscles, skin, tendons, or bones rub together
 Tendon sheath. A tendon sheath is essentially an elongated bursa that wraps
completely around a tendon subjected to friction, like a bun around a hotdog.

22. Functions of the Skeletal System
• Support;-the bones of the legs act as pillars to support the body trunk
when we stand, and the rib cage supports the thoracic wall.
• Protection;-Bones protect soft body organs; for example, the fused
bones of the skull provide a snug enclosure for the brain, the vertebrae
surround the spinal cord, and the rib cage helps protect the vital organs
of the thorax.
• Movement. Skeletal muscles, attached to bones by tendons, use the
bones as levers to move the body and its parts.
• Storage. Fat is stored in the internal cavities of bones; bone itself serves
as a storehouse for minerals, the most important of which are calcium
and phosphorus
• Blood cell formation. Blood cell formation, or hematopoiesis, occurs
within the marrow cavities of certain bones.