Introduction To Musculoskeletal
System
DR. REHAN
Objectives
 Describe the musculoskeletal system
 Enlist different functions of musculoskeletal
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system
Describe the primary functions of the various
organs or structures
Explain the meaning of the basic terminology
related to musculoskeletal system
Recall three different types of muscular tissue
Describe how muscles perform in groups
Define tendon, ligament and bursa
Identify clinical application related to muscular
system
Functional Anatomy of the Musculoskeletal
System
 The skeletal system consists of the specialized supporting
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connective tissues of the bony skeleton
Associated structures are cartilage, tendon and ligaments
Cartilage is the fetal precursor tissue in the development of
many bones
Bone provides a rigid framework which protects and
supports most of the soft tissues of the body
It acts as a system of struts and levers
Action of attached skeletal muscles, permits movement of the
body
 Bones of the skeleton are connected with each other at joints
 According to their structure, allow varying degrees of
movement
 Skeletal muscles are attached to bone by strong flexible
tendons which insert into bone tissue.
 The entire assembly forms the musculoskeletal system
 All its cells are derived from mesenchymal stem cells
General Classifications of Bones
 Long Bones: "longer than they are wide"
 Clavicle, humerus, radius, ulna, femur, tibia, fibula, metatarsals,
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metacarpals
Short Bones: carpals and tarsals: consist mainly spongy bone covered
with a thin layer of compact bone
Allow movement, provide elasticity, flexibility, & shock
absorption
Flat Bones: ribs, sternum and scapula
Protect and provide attachment sites for muscles
Irregular Bones: skull, pelvis, and vertebrae
Support weight, dissipate loads, protect the spinal cord,
contribute to movement and provide sites for muscle attachment
Sesamoid Bones: a short bone embedded within a tendon or joint
capsule, i.e. patella
Parts of long bone and joints
• Diaphysis: main shaft like structure, its hollow
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cylindrical shape, its functions of providing strong
support bone
Epiphysis: both end of long bone
A joint, or articulation, is a union of two or more bones
Fibrous joints, e.g. skull bones; immovable
Cartilaginous joints, e.g. intervertebral discs slightly
movable
Synovial joints, e.g. limb joints freely movable
Synovial joints permit the greatest degree of flexibility
The ends of bones are covered with a connective tissue
(synovial membrane) filled with joint (synovial) fluid
Typical Synovial Joint
 Four main features:
 joint capsule - the joint enclosure, reinforced by
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and strengthened with ligaments
synovial membrane - a continuous sheet of
connective tissue lining the capsule
Its cells produce synovial fluid that lubricates the
joint
Synovial fluid - produced by the synovial
membrane, the fluid lubricates the joint
Hyaline (articular) cartilage - where the bones
actually "meet"
Skeletal System: Overview
 The adult skeleton is composed of 206 separate
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bones
Division of skeleton
Axial skeleton
Appendicular skeleton
Axial Skeleton: Includes the bones of: skull,
vertebral column, and rib cage
These bones are involved in protection,
support, and carrying other body parts
Appendicular skeleton
• Bones of upper & lower limbs and the girdles (shoulder
bones and hip bones) that attach them to the axial
skeleton.
• Involved in locomotion and manipulation
Axial Skeleton (80 bones)
Skull (28)
Cranial Bones
Facial Bones
 Parietal (2)
 Maxilla (2)
 Temporal (2)
 Zygomatic (2)
 Frontal (1)
 Mandible (1)
 Occipital (1)
 Ethmoid (1)
 Sphenoid (1)
 Nasal (2)
 Platine (2)
 Inferior nasal concha
(2)
 Lacrimal (2)
 Vomer (1)
 Auditory Ossicles: Malleus (2), Incus (2) and
Stapes (2)
 Hyoid (1)
 Vertebral Column: Cervical vertebrae (7),
Thoracic vertebrae (12), Lumbar vertebrae (5),
Sacrum (1), Coccyx (1)
 Thoracic Cage: Sternum (1), Ribs (24)
Appendicular skeleton
 126 bones, 64 in the shoulders and upper limbs
 62 in the pelvis and lower limbs
 Upper Extremity : The arms (humerus ) are
attached to the thorax, via synovial joints, at the
collarbone (clavicle) and shoulder bone (scapula)
(shoulder joint)
 The scapula is attached to the thoracic cage only
by muscles
 The elbow joint unites the humerus with the
two lower arm bones - the ulna and radius
 Three sets of joints connect the radius and
ulna to the bones of the palm (metacarpals),
via the eight small wrist carpals
 knuckles (metacarpophalangeal Joints)
connect the metacarpals to the proximal
phalanx of the fingers
 Each finger has 3 phalanges (proximal,
middle, distal), except the thumb which has
only two
 Lower Extremity: pelvic girdle , thigh and leg knee,
foot, ankle and toe
 The pelvis transmits the upper body weight from
the sacrum (at the sacroiliac joint) to the legs
 It begins as 3 hip bones (ilium, ischium, and
pubis)
 The hip joint unites the pelvis to the thigh bone
(femur)
 The knee joint, which includes the knee cap
(patella), links the femur to the lower leg bones the tibia and fibula
 The ankle joint links the lower leg bones to the
talus
 The body weight is then transmitted to the heel
(calcaneus) and to the balls of the feet via the
tarsal and metatarsal foot bones
 The toes have a phalangeal structure like the
fingers
Functions of Skeletal System
 Protection: protects the brain and internal organs
 Support: maintains upright posture
 Blood cell formation: hematopoiesis
 Mineral homeostasis
 Storage: stores fat and minerals.
 Leverage: A lever is a simple machine that
magnifies speed of movement or force
Clinical Application
 Osteomalacia
 Literally “soft bones”
 Includes many disorders in which osteoid is produced
but inadequately mineralized.
Causes can include insufficient dietary calcium
Insufficient vitamin D fortification or insufficient
exposure to sun light
 Rickets
 Signs include bowed legs, and deformities of the
pelvis, ribs, and skull
RADIOLOGICAL
ANATOMY
 Osteomyelitis: bone inflammation caused by the body's
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reaction to a bacterial or fungal infection
Ankylosis: abnormal stiffness of a joint or fusion of
bones at a joint
Arthralgia: pain in a joint
Acromegaly: abnormal enlargement of facial features,
hands, and feet in adults
Result of overproduction of growth hormone
Arthroplasty: Surgical repair of joint
Arthritis: is inflammation of one or more joints
Fracture Types
 Open (compound): bone ends penetrate the skin
 Closed (simple): bone ends don’t penetrate the skin
Resources
 http://webschoolsolutions.com/patts/systems/skel
eton.htm
 Clinical Anatomy by Regions: Richard. S. Snell, 9th
edition
 Last's Anatomy: Regional and Applied, 12th edition