Human body systems Skeletal system

Axial skeleton

Bones of center/axis of the body

ex. skull, spine, chest and more

Appendicular skeleton

Bones of upper/lower extremities

ex. shoulder, arm, leg, wrist, hip and more

Cervical

(Bones of vertebral column - spine)

Neck region

Thoracic vertebrae

(Bones of vertebral column - spine)

Ribs are attached here

Lumbar vertebrae

(Bones of vertebral column - spine)

small bones in the back

Sacrum

(Bones of vertebral column - spine)

In child - 3-5 separate vertebrae, in adult - fused into 1 

• connects spine to pelvis 

Coccyx

(Bones of vertebral column - spine)

In child - 3-5 separate bones, in adult fused into 1

• tailbone, very bottom of spine

Normal curve of spine

Give strength to support the weight of the body and balance for standing/walking on 2 feet

Lordosis

(Disorder of spinal curvature)

Poor posture/disease, lumbar curve becomes extremely exaggerated 

Kyphosis

(Disorder of spinal curvature)

“Hunch back” abnormal thoracic curve

Scoliosis

(Disorder of spinal curvature)

Abnormal side to side curvature

Treatment for spinal curve disorders

• brace

• surgery

• muscle stimulation

• electrical stimulation 

• metal rods

True ribs

The first seven ribs are attached to coastal cartilage

Floating ribs

Ribs not attached to any coastal cartilage, seem to float in front

Synarthoses

(Joints)

No significant movement

ex. joints between cranial bones

Amphiarthoses

(Joints)

Slight movement

ex. joints between cranial bones

Diathroses

(Joints)

Free movement

Articular cartilage

Location - Joint ends of bones

Function - Absorbs joints, allows movement with little friction

Synovial fluid

Location - synovial membrane

Function - Allows easier movement with less movement

Total hip replacement

Most common orthopedic operation

Replacement of femur head

immediate pain relief

new tissue growth

Flexion

(joint movements)

To flex a joint

Extension

(joint movements)

To extend a joint 

Rotation

(joint movements)

To rotate a joint

Circumduction

(joint movements)

Circular movement of a joint 

Abduction

(joint movements)

Limb moves away from body

Adduction

(joint movements)

Limb moves toward the body 

Five functions of skeletal system

Support - internal framework, strong and flexible

Protection - Protects soft tissue, bones contain blood cells that can protect from disease

Movement - muscles contract and shorten, which pull on bones to move them

Storage - Bones store calcium, some fat and minerals

Hematopoiesis - “Blood forming”, blood cell formation, vital in red bone marrow

Diaphysis

Hollow tube made of hard compact bone “Shaft”

• part of long bone 

Medullary cavity

Hollow area inside the diapysis bone (inside bone)

• part of long bone 

Epiphysis

Red bone marrow fills in small spaces in the spongy bone composing the epiphysis (ends of bone)

• where growth plates are

• in long bone

Articular cartilage

A thin layer of cartilage covering each epiphysis, provides some cushion

• part of long bone

Periosteum

Strong fibrous membrane covering a long bone everywhere expect at joint surfaces (only a couple cells thick)

• part of long bone

Endosteum

A thing membrane that lines the medullary cavaity

Bone

• major type of connective tissue

Different appearances and textures - depends on location

Cartilage

Resembles and differs from bones, consists more of inter cellular substance than of cells, embedded in a firm gel, flexibility of a firm plastics

Compact bone

Outer layer of bone is hard and dense

Spongy bone

Porous bone in the end of the long bone

Haversian system

Inter cellular substance is organized into numerous structural units

• all compact bone made of many of these 

Bone formation and growth

A baby, before birth, does not consist of bones but of cartilage and fibrous structures shaped like bones. The cartilage is replaced with calcified bone matrix and hardens, the bones grow into their adult shape

Epiphyseal fracture

Epiphyseal plate can be separated from the diaphysis or epiphysis cause this type of fracture, may inhibit normal growth 

Avulsion fracture

Violent contraction or over stretching of a muscle in skeletally immature individuals

Skull growth and formation in the womb and babies

Soft spots ( fontanels ) on a newborn babies skull, show bones first formed as membranes 

• infants have many bones that are not yet completely ossified 

Oestoblasts

Form new bone

Osteoclasts

Break down bone tissue

• break down bone in order for osteoblast to build new bone

Endochrondral ossification

Bone making / bone forming

Chondrocytes

Cartilage cells

Knee injury 

Largest and most vulnerable joint, subject to strong and sudden forces, most common athletic injury 

• more common in women because wider pelvises and estrogen may cause ligaments to be more flexible and prone to over stretching 

Osteosarcoma

Malignant tumor of bone, severe pain

treatment - surgical removal and pre/post surgical chemo

Osteoporosis

Bones loose minerals and become less dense

• Genetics play a role, low estrogen and post menopausal status (elderly white women in most risk)

• excessive loss of calcified bone matrix

Osteomalacia

Metabolic skeletal disease, loss of minerals from bone related to vitamin D deficiency, severe susceptibility to fractures

Open bone fractures

Pierces the skin (Infection)

Closed bone fractures

Does not pierce the skin

• do not pose immediate danger of bone infection

Complete fracture

Bone fragments separate completely

Incomplete fractures

Bone fragments still partially joined

Comminuted fractures

Breaks that produce many fragments

Impacted fractures

Bone fragments driven into each other

Osteoarthritis

• Joint disease

Degenerative joint disease, degeneration of articular cartilage and abnormal formation of new bone 

Dislocation

• Joint disease

Articular surfaces of bones forming the joint are no longer in proper contact with each other

Rheumatoid arthritis

• Joint disease

Chronic inflammation of connective tissue 

Gout

• Joint disease

Metabolic condition in which uric acid increases in blood 

Lymes disease

• Joint disease 

Caused by a bacterium in deer ticks, inflammation in some joints (knee) accompanied by other signs/symptoms 

Arthroscopy

Imaging technique that allows a physician to examine the internal structure of a joint with out the use of extensive surgery

• a narrow tube with lenses and light source is inserted into the joint space thru a small puncture, diagnostic but can be used to perform joint surgery