Skeletal System Outline

1. November 29, 2016
XI-Aristotle
SKELETAL SYSTEM
COMPOSITION: bones and tissues (i.e. tendons, ligaments and cartilage) in the body
Bone: A rigid form of connective tissue that is part of the skeletal system of vertebrates and is composed
principally of calcium.
Ligament: Connect bone to bone
Tendon: Attaches muscles to bones
Joint: Joints hold the skeleton and support movement
*Cartilage: It acts as a cushion between bones at a joint and protects the bones.
MAIN FUNCTIONS
a) Support
b) Movement - Bones provide the structure for muscles to attach so that our bodies are able to move.
*Tendons are tough inelastic bands that hold attach muscle to bone.
c) Protection- The skeleton also helps protect your internal organs and fragile body tissues.
- Cranium- brain and eyes
- Ribs- heart and lungs
- Vertebrae- spinal cord
d) Storage- Bones store minerals such as calcium and phosphorus
e) Blood Cell production - RBCs and WBCs are formed
BONE COMPOSITION
a) Compact bone – strong, dense and tough
b) Spongy bone – like a honecomb, lighter and slightly flexible
c) Bone marrow – middle; where new cells are constantly being produced for the blood.
* Calcium is an important mineral that bone cells need to stay strong (so keep drinking that low-fat milk!)
Four basic bone shapes
1. Long- arms, legs and fingers
2. Short- wrist and ankles
3. Flat- skull and sternum
4. Irregular- spine
2 DISTINCTIVE PARTS:
a) Axial Skeleton -80 bones
-Vertebral column, rib cage and skull

2. November 29, 2016
XI-Aristotle
-transmits the weight from the head, the trunk and the upper extremities down to the lower extremities at the
hip joints, which help humans maintain our upright posture
b) Appendicular Skeleton - 126 bones
- the appendages of the body which are the shoulders, arms, hips and legs
-to make walking, running and other movement possible and to protect the major organs responsible for
digestion, excretion and reproduction.
JOINTS OF THE BODY
1) Ball and Socket Joint: Round end of bone fitting snuggly within another bone.
-Ex. Shoulder and Hip
2) Hinge Joint: Movement of the joint in one direction like a door.
-Ex. Knee and Elbow
3) Pivot Joint: Bone resting atop another bone permitting free movement.
-Ex. Neck, Wrist and Ankles
4) Fixed Immovable: Joint does not move
-Ex. Skull
5) Gliding Joint: Bones slipping over other bones with a free flowing movement.
-Ex. Knuckles
PROBLEMS/DISEASES OF THE SKELETAL SYSTEM
1) Osteoporosis - results to loss of bone tissue
-bone loses calcium, becomes thinner and may disappear completely
2) Osteomalacia - softening of the bones
- often caused by a vitamin D deficiency and results from a defect in the bone-building process
3) Arthritis - group of more than 100 inflammatory diseases that damage joints and their surrounding structures
- usually affects the joints of the neck, shoulders, hands, lower back, hips, or knees
4) Scoliosis - a side-to-side curve in the back or spine, often creating a pronounced "C" or "S" shape when viewed on an
x-ray of the spine.
-typically becomes evident during adolescence
5) Leukemia
6) Spina Bifida- prevalent to infants