The Skeletal System
Chapter Five
Objectives:
• To identify bones that compose the skeletal
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system
To identify functions of the skeletal system
To identify subdivisions of the skeleton as axial
and appendicular
To classify types of joints according to their
movement
To identify the four types of bones
To identify various types of skeletal system
disorders
What are the functions of the
Skeletal System?
• Support
• Protection
• Movement
• Storage
• Blood Cell Formation
What are the divisions of the
Skeletal System
The Skeletal System is broken down into
two divisions:
– Axial Skeleton
– Appendicular Skeleton
Axial Skeleton
• Consists of three specific parts:
•Skull
•Vertebral Column
•Bony Thorax
Axial Skeleton
• The skull consist of:
– Cranium Bones
– Facial Bones
– Hyoid Bones
Axial Skeleton
• The vertebral column consist of :
– Vertebrae
– Sacrum
– Coccyx ( a.k.a tailbone)
Axial Skeleton
• The Bony Thorax (a.k.a the thoracic
cage)consists of:
– Sternum
– Ribs
Appendicular Skeleton
• Consists of three specific parts:
– Upper and Lower Limbs
– Pectoral Girdle
– Pelvic Girdle
Appendicular Skeleton
The Upper Limb
consists of :
The Arm
The Forearm
The Hand
The Lower Limb
consists of:
• The Thigh
• The Leg
• The Foot
Appendicular Skeleton
The Pectoral Girdle consists of :
• The Clavicle (a.k.a. the collarbone)
• The Scapula (a.k.a. the shoulder
bone)
Appendicular Skeleton
• The Pelvic Girdle consists of:
• Coxal Bones (a.k.a hip bone )
Joints
• Joints are articulations that hold
bones together securely, but allows
movement
• Joints are named based on their
movements
Joints
• Fibrous Joint
– Bones joined by fibrous tissue
– No movement
– Found in the skull
• Ex: Sutures within the brain
Joints
• Cartilaginous Joint
– Slightly moveable
– Found in the pelvic bones and spinal column
Joints
• Synovial Joints
– Found in joint cavities that contain synovial fluid
– Has the most movement
– Based on the shape of the bone
– Six different types of joints
Synovial Joints
• Plane-joint
• Hinge-joint
• Pivot-joint
• Condyloid-joint
• Saddle-joint
• Ball-n-Socket joint
Synovial Joints
• Plane-Joint
– Gliding movement
– Found in wrists
• Hinge-Joint
– Angular movement
– Found in elbow, ankle, and between figures
• Pivot-Joint
– Found in the radius and the ulna of the arm-
Synovial Joints
• Condyloid-Joint
– “knuckle-like”
• Saddle-Joint
– Found within your thumb
– “twiddling your thumbs”
• Ball-n-Socket
– Found in shoulder and pelvic areas
Bone Types
• There are 206 bones in an adult human body
• There are two bone types:
• Compact Bone- is dense and smooth
• Spongy Bone- is small and needle-like with a lot of
open space
Bone Types
•
Bones are classified based on their shape
Long
– Ex: arm, thigh, leg,
• Short
– Ex: knee-cap
• Flat
– Ex. rib
• Irregular
– spine
Bone Fractures
• A break in a bone
• Types of bone fractures
– Closed (simple) fracture – break that does not
penetrate the skin
– Open (compound) fracture – broken bone
penetrates through the skin
• Bone fractures are treated by reduction
and immobilization
– Realignment of the bone
Common Types of Fractures
Table 5.2
Repair of Bone Fractures
• Hematoma (blood-filled swelling) is
formed
• Break is splinted by fibrocartilage to form
a callus
• Fibrocartilage callus is replaced by a bony
callus
• Bony callus is remodeled to form a
permanent patch
Types of Skeletal Disorders
• Arithritis
– Rheumatoid Arithritis
– Osteroarithritis
• Gout
• Osteroporosis