Thursday, December 16, 2010

Skeletal System

The Skeletal System
The Skeletal System serves many important functions; it provides the shape and form for our bodies in addition to supporting, protecting, allowing bodily movement, producing blood for the body, and storing minerals.
Its 206 bones form a rigid framework to which the softer tissues and organs of the body are attached.
Vital organs are protected by the skeletal system. The brain is protected by the surrounding skull as the heart and lungs are encased by the sternum and rib cage.
Bodily movement is carried out by the interaction of the muscular and skeletal systems. For this reason, they are often grouped together as the musculo-skeletal system. Muscles are connected to bones by tendons. Bones are connected to each other by ligaments. Where bones meet one another is typically called a joint. Muscles which cause movement of a joint are connected to two different bones and contract to pull them together. An example would be the contraction of the biceps and a relaxation of the triceps. This produces a bend at the elbow. The contraction of the triceps and relaxation of the biceps produces the effect of straightening the arm.
Blood cells are produced by the marrow located in some bones. An average of 2.6 million red blood cells are produced each second by the bone marrow to replace those worn out and destroyed by the liver.
Bones serve as a storage area for minerals such as calcium and phosphorus. When an excess is present in the blood, buildup will occur within the bones. When the supply of these minerals within the blood is low, it will be withdrawn from the bones to replenish the supply.
 Divisions of the Skeleton
The human skeleton is divided into two distinct parts:
The axial skeleton consists of bones that form the axis of the body and support and protect the organs of the head, neck, and trunk.

Human Anatomy Terms
The following terms are those which are used to identify the location of parts of the human body in medicine and academic study. These terms are often used to describe a specific portion of a structure or to compare the locations of two different structures. "The hand is distal to the forearm" or "the medial portion of the frontalbone contains the frontal sinus" are examples of this. We have organized this list of terms by keeping similar pairs or groups of terms together instead of by alphabetical order so that you will find them easier to learn and remember.
Superior - toward the head
Inferior - away from the head
Anterior - the front of the body or body part
Posterior - the back of the body or body part
Medial - toward the midline that divides left and right
Lateral - to the side away from the midline
Proximal - closer to the torso
{short description of image}Distal - farther away from the torso
Anatomical position - standing erect, facing the observer, arms are at the sides with palms facing forward.

Video:    Human Bones, Muscles.. Skeletal System