The Skeletal SystemAlexa Janulis, Anna Engelsman, Kyle Walton, Ariele Friedman

Ossification

The process of the formation of bones

**there are 2 types of ossification

- Endochondral

- Intramembranous

Endochondral Ossification Happens during the fetal stage, resulting in the

formation of bone tissue.

Cartilage IS present (gradual replacement of cartilage to bone)

Essential during formation/growth/length of long bones

Essential for natural healing of bone fractures.

Endochondral Ossification Osteoblasts:Bone-forming cells. Osteocytes:Mature bone tissue cells. Matrix:The intercellular substance of bone tissue

** In endochondral ossification, osteoblasts arise in regions of cartilage called ossification centers. The osteoblasts then develop into osteocytes, which are embedded in the matrix.

Intramembranous Ossification Formation of bone

tissue/formation of the skull and jaw

Cartilage is NOT present

Cells develop into connective tissues (such as bone and blood)

AXIAL SKELETON

VS.

APPENDICULAR SKELETON

Functions of the Skeleton

Support the body and maintain its shape

Movement Protection Calcium storage Blood cell

production Endocrine

regulation

Axial Skeleton

Provides protection for the inner organs of the body

Stores fat Forms new red and

white blood cells Responsible for

the upright position of the human body**Composed of the skull, the vertebral column, and the

thoracic region

AXIAL SKELETON

VERTEBRAL COLUMN Provides a pivot joint for the

skull

THE SKULL Protects sensory organs Encloses and protects the brain Makes up face structure

THORACIC REGION (rib cage)• Protects vital organs

Appendicular Skeleton

The appendicular skeleton consists of bones that are attached by girdles which bridge them to the parts of the axial skeleton.

Makes motion possible

Protects the organs of digestion, excretion, and reproduction

**Composed of the pectorals, arms, hands, pelvis, thighs, legs, and feet.

Long Bone and Joint Articulation

The Long Bone

A hard, dense bone that creates structure and allows for mobility and strength.

Structure of the Long Bone Long Bones have two tips,

called the Epiphysis and a shaft called Diaphysis

Inside the Diaphysis is the Medullary Cavity and the Nutrient Foramen.

There is two layers of membrane the Endosteum and Periosteum.

Joint Articulation

Joint: An area where two bones are attached for the purpose of movement in the body.

Structure of a Joint: Hyaline (Articular) Cartilage

covering the tips of the bones.

Synovial Membrane covers the Synovial Cavity where there is no Hyaline Cartilage.

Synovial Cavity holds the Synovial Fluid which reduces friction between the bones.

Ligaments connect the bones into a joint.

Osteoporosis

Osteoporosis - General Facts

Osteoporosis means “porous bone”

Osteoporosis results from lack of calcium being stored in the bones as well as a sex hormone deficiency (Estrogen in Women, Androgen in Men)

It makes the bones less dense and more prone to fractures.

Osteoporosis - Symptoms

Symptoms are few and include some pain and constant bone fracture.

The disease is especially dangerous in that you may not even know you have it (71% of women who have it don’t know it.)

Risk Factors and Prevention

RISK FACTORS

Smoking and Alcohol abuse

Age Being Female Poor diet Lack of exercise

PREVENTION

Exercise Healthy Diet Calcium Hormones (low

doses) Medications

(Calcitonin, raloxifene)

Two More DiseasesBowed Legs and Bone Tumors

Bowed Legs

Bowed Legs

Commonly found in toddlers When it is just a variation from

normal appearance it is called physiologic genu varum

Physiologic genu varum: term used for toddlers bowed legs that can be fixable through time and normal growth processes

Rickets - Symptoms

Bowed legs Malnutrition Vitamin D

deficiency Not enough

absorption of sunlight

All these lead to Rickets, which then leads back to bowed legs

Rickets

Studies have shown that red heads are less prone to Rickets due to their higher production of Vitamin D

Long term consequences include long bones and a curved back

Blount’s Disease

Bowed legs that don’t fix themselves with growth

Commonly found in African-American children and obese children

It can also be associated with early walking

Blount’s Disease – Before

Blount’s Disease - Treatment

Braces are used for children

Surgery is required if the brace does not work, or if the child is too old

Blount’s Disease - After

Surgeries could include cutting the shin bone to move it to the right position, or lengthen it.

Another possibility is by blocking off the growth of the outer shin bone and letting natural growth occur.

Bowed Legs - Treatments

Ilizarov Veklich Device http://www.youtube.com/watch?v=OWlppDNuIz

k (3:01)

http://www.youtube.com/watch?v=OWlppDNuIzk (2:20)

Ladisten Clinic in Ukraine uses this device to fix both Blount’s Disease and any other disorders associated with bowed legs

Bone Tumors

Bone Tumors

A bone tumor is a hyperplasia, an osteoma specifically.

Most are benign, but some can be malignant.

Bone tumors are many times found through x-rays of other problems including fractures and sprains.

Bone Tumors – Common Symptoms

Pain in the tumor area

Sometimes described as a “painless mass”

Can cause fevers and night sweats

Bone Tumors

The Different Types Multiple Myeloma Osteosarcoma Ewing’s Sarcoma

Organized by age group

Multiple Myeloma

Most common bone cancer

Affects people aged between 50 and 70, and can attack any bone

Cancer of the WBC’s which are produced in the bone marrow and transported through the lymphatic system

Multiple Myeloma - Symptoms Bone Pain

Pain usually involves the spine and ribs. The breakdown of bone leads to the release of calcium into the blood, leading to hypocalcaemia.

Kidney Failure Anemia

Results from the replacement of normal bone marrow and inhibition of normal red blood cell production

Neurological symptoms (fatigue, weakness, confusion)

Multiple Myeloma - Treatment

Focused on disease containment and suppression.

Stem-cell transplant (high dose chemotherapy) is a preferred method if treatment is necessary.

Multiple Myeloma

Summary http://www.youtube.com/watch?v=XWMtaOvwP

EY

Osterosarcoma

Second most common cancer

Affects teenagers

Affects around the knee, hip, or shoulder

Osteosarcoma - Symptoms

Depending on the size of the tumor, it can appear as swelling

Patients complain of pain that can worsen at night

Due to the tumor, the affected bone is weaker and can fracture more easily

Osteosarcoma - Treatment

Current standard treatment is to use chemotherapy followed by surgical resection (removal of the tumor)

Despite the success of chemotherapy for osteosarcoma, it has one of the lowest survival rates for pediatric cancer

Ewing’s Sarcoma

Occurs most commonly between ages 5 and 20

Affects upper and lower legs, ribs, and upper arm

Is a malignant round-cell tumor

Cancer cells are found in the bone or the soft tissue

Ewing’s Sarcoma - Causes Ewing sarcoma is

the result of a translocation between chromosomes 11 and 22.

A translocation is a “rearrangement of parts.”

Ewing’s Sarcoma - Treatment Multidrug chemothe

rapy as well as local disease control with surgery and/or radiation is indicated in the treatment of all patients.

Latest Research

In China, there are some scientists that are honing in on the use of arsenic in replacing chemotherapy

Arsenic apparently breaks down the very proteins that keep cancer cells alive

They have practiced their treatments on leukemia patients and so far have been successful

Shocking News

40-pound malignant bone tumor removed from woman

http://www.msnbc.msn.com/id/30386195/

http://www.msnbc.msn.com/id/21134540/vp/30390105#30390105