THE SKELETAL SYSTEMAngie Guggino, MS, ATC, LAT

Essential Questions

What is the structure and function of the skeletal system?

What are the common diseases and injuries effecting the skeletal system?

Course Standard 6

Evaluate the anatomy, physiology, and basic pathophysiology of the muscular and skeletal systems, and perform technical skills related to the systems.

6.2 Analyze the basic structures and functions of the skeletal system, including locating and identifying the bones of the skeletal system and hemopoiesis.

6.4 Identify and explain medical terms related to the muscular and skeletal systems, and utilize when documenting in the electronic medical record.

6.5 Research common diseases, disorders, and emerging disorders of the muscular and skeletal systems including pathophysiology, prevention, diagnosis and treatment that might be utilized.

6.6 Differentiate between the axial and appendicular skeletons. 6.7 Describe the development of the skeletal system. 6.8 Locate and identify the types of joints in the skeletal system. 6.12 Demonstrate proper techniques for ambulation with assistive

devices (crutches, cane, walker); and identify limitations and abnormalities.

General Information

How many bones in the human body? 206

What is a joint? Place where two bones meet.

What is the name for the connective tissue that attaches bone to bone? ligaments

What are the two segments of the skeleton? Appendicular skeleton Axial skeleton

Functions of the Skeletal System

Support Protection Movement Storage Blood cell formation

Bone Cells

Osteocytes Mature bone cells

Osteoblasts Bone-forming cells

Osteoclasts Bone-destroying cells Break down bone matrix for remodeling and

release of calcium

Bone Tissue

COMPACT CANCELLOUS (TRABECULAR)

Dense Compact High mineral content Strong

Spongy Porous with

honeycomb structure

Shape Categories of Bone

Short bones Generally cube-shape Contain mostly spongy bone Examples: Carpals, tarsals

Long bones Typically longer than wide Have a shaft with heads at both ends Contain mostly compact bone Examples: Femur, humerus

Shape Categories of Bone

Flat bones Thin, flattened and usually curved Thin layers of compact bone around a layer of

spongy bone Examples: Skull, ribs, sternum

Irregular bones Irregular shape Do not fit into other bone classification

categories Example: Vertebrae

Anatomical Structure of Long Bones

Diaphysis Shaft Composed of

compact bone Epiphysis

Ends of the bone Composed mostly

of spongy bone

Long Bones

Periosteum Outside covering of

the diaphysis Fibrous connective

tissue membrane Sharpey’s fibers

Secure periosteum to underlying bone

Arteries Supply bone cells

with nutrients

Long Bones

Articular cartilage Covers the external

surface of the epiphyses Made of hyaline cartilage Decreases friction at joint

surfaces Medullary cavity

Cavity of the shaft Contains yellow marrow

(mostly fat) in adults Contains red marrow (for

blood cell formation) in infants

Bone Formation

Ossification In embryos, the skeleton is primarily

hyaline cartilage During development, much of this

cartilage is replaced by bone Cartilage remains in isolated areas

Bridge of the nose Parts of ribs Joints

Bone Growth

Epiphyseal plates allow for growth of long bone during childhood

New cartilage is continuously formed Older cartilage becomes ossified

Cartilage is broken down Bone replaces cartilage

Bones are remodeled and lengthened until growth stops

Adult Bone

Bone mineral peaks Women age 25-28 Men age 30-35

Remodeling Process through which adult bone can change

in density, strength, and sometimes shape When bone is subjected to high force it

tends to increase density Bone only accounts for about 15% of

body weight

Teamwork

Astronauts can experience a dramatic decrease in bone density while in a weightless environment. Explain how this happens and suggest a way to slow the loss of bone tissue.

Joints

Articulations of bones Functions of joints

Hold bones together Allow for mobility

Ways joints are classified Functionally Structurally

Functional Classifications

Synarthroses immovable joints

Amphiarthroses slightly moveable joints

Diarthroses freely moveable joints

Structural Classification

Fibrous joints Generally immovable

Cartilaginous joints Immovable or slightly moveable

Synovial joints Freely moveable

Synovial Joints

Articulating bones are separated by a joint cavity

Synovial fluid is found in the joint cavity Articular cartilage (hyaline cartilage)

covers the ends of bones Joint surfaces are enclosed by a fibrous

articular capsule Ligaments reinforce the joint

Associated Structures

Bursae – flattened fibrous sacs Lined with synovial membranes Filled with synovial fluid Not actually part of the joint

Tendon sheath Elongated bursa that wraps around a tendon

Shoulder

Types of Synovial Joints

Gliding (plane) Hinge Pivot Condyloid Saddle Ball-and- Socket

Injuries and DisordersThe Skeletal System

Common Injuries

Dislocations One of the articulating bones is displaced Shoulder, patella, fingers, elbow, jaw

Subluxation Partial dislocation

Bursitis Inflammation of the bursa

Sprains Overstretching or tearing of a ligament

Fractures Broken bone

Fractures

Extremities most common Statistics:

men up to 45 years of age women over 45 years of age Before 75 years wrist fractures most common 75 years hip fractures most common

Types of Fractures

Magnitude and direction of force Closed

– Bone fragments do not pierce skin Open/compound

– Bone fragments pierce skin Displaced or non-displaced

Transverse Fracture

Usually caused by directly applied force to fracture site

Spiral or Oblique

Caused by violence transmitted through the distal limb

twisting movement

Greenstick

Occurs in children Bones soft and

bend without fracturing completely

Avulsion Fracture

Traction Bony fragment

usually torn off by a tendon or ligament

Stress fracture

Abnormal stress on normal bone Fatigue fracture

Normal stress on abnormal bone Insufficiency

fracture

Comminuted Fracture

Two or more bone pieces

High energy trauma

Can require serious hardware to repair

Comminuted Fracture Repair

First Aid Treatment

Splinting Red Cross Videos

Physician Treatment

Reduction Open reduction (surgery)

very accurate risk of infection Usually when internal fixation is needed

Manipulation Usually with anesthesia

Traction pulling

Holding the Reduction

4-12 weeks External fixation Internal fixation Frame fixation

External fixation

Used for fractures that are too unstable for a cast.

Can shower and use the hand gently with the external fixator in place.

Frame fixation

Allows correction of deformities by moving the pins in relation to the frame.

Internal fixation

“Homedepot Method” Rods Screws Pins Plates

Fracture Healing

1. Fracture hematoma2. Fibrocartilaginous callus3. Bony callus 4. Bone Remodeling

Hematoma

blood from broken vessels forms a clot.

6-8 hours after injury

swelling and inflammation to dead bone cells at fracture site

Fibrocartilaginous

About 3 weeks New capillaries organize

fracture hematoma into granulation tissue called a procallus

Fibroblasts and osteogenic cells invade procallus.

Make collagen fibers which connect ends together

Chondroblasts begin to produce fibrocartilage

Bony Callus

After 3 weeks Lasts about 3-4

months Osteoblasts make

woven bone.

Remodeling

Osteoclasts remodel woven bone into compact bone and spongy bone

Often no trace of fracture on X-ray

Several months

ArthritisSalem Health Article

1. What is the definition of arthritis?2. Approximately how many different varieties of arthritis

have been identified?3. How do young or middle-aged adults usually experience

the disease?4. Describe the four functional classifications of arthritis.5. How are nerves affected with arthritis?6. What are the general goals of arthritis therapy?7. How does heat therapy help with arthritis?8. What are NSAIDS?9. Why should heat modalities not be used in acute cases of

arthritis?10. What is the benefit of the COX-2 inhibitor vs. the COX-1

inhibitor?

The End