Human skeleton
From CreationWiki, the encyclopedia of creation science
The skeleton or skeletal system is a strong framework that supports the human body. The human skeletal system is an endoskeleton (internal) that uniquely designed for upright stance and bipedal movement. It consists of both fused and individual bones supported and supplemented by ligaments, tendons, muscles and cartilage.
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Development
Early on in the mother's womb the fetus has a cartilaginous skeleton. The cartilaginous skeleton provides the bases for the long bones to form. This process happens through out gestation and continues into the years after birth. When a baby is born it has 270 bones, but as it grows some of the small bones fuse together. So as an adult a person will have 206 bones, this can vary from person to person. [1]
Organization
The skeletal system is divided into two sections; the axial skeleton and the appendicular skeleton. The division of these bones goes along the longitudinal axis, the axial skeleton, is were the appendicular skeleton is attached.[2] The longitudinal axis is an imaginary line running down the center of the body, that is perpendicular to the transverse plane around which rotations in the transverse plane occur. [3]
Axial skeleton
The axial skeleton contains 80 bones. These bones are found in the head and trunk of a persons body. The bones are divided into five parts the skull, the ossicals(in the inner ear), the hyoid bone (in the throat), the chest (ribs and sternum), and the vertebral column. [4] The axial skeleton is responsible for the up-right position of the body. The axial skeleton transfers the weight of the head, the chest and the upper extremities down to the lower extremities at the hip joint. Most of the weight is in the spinal column. Which is why we have the erector spinae muscles and a large amount of ligaments attached to it. This is also what causes the "S" shape of the human spine. The 240 muscles of the erector spinae allow small movements in the thoracic cage(chest) for breathing and simple and complex facial movements.[5]
Appendicular skeleton
The appendicular skeleton contains 126 bones. This part of the skeleton helps with motion, protecting the digesting organs, excretion, and reproduction. The appendicular skeleton is divided into six major parts, they are the pectoral girdle, the arm, the hand, the pelvic girdle, the leg, and the foot.[6] There are 300 muscles attached to the appendicular skeleton. Together with the axial skeleton they make up the human skeleton. [7]
Function
Support
The skeleton is the frame work of the human body and helps it maintain its shape. All the muscles and tissues are able to attach to the skeleton as a base.[8]
Protection
The skeleton protects all the vital organs in the body.
- The eyes, brain, middle, and inner ear are protected by the skull.
- The lungs, heart, and major blood vessels are protected by the rib cage, sternum, and spine.
- The shoulder is protected by the clavicle and the scapula.
- The digestive system, the excretory system, reproductive system, and the hip are protects the ilium and the spine.
- The knee and elbow are protected by the patella and the ulna.
- The wrist and ankles are protected by the carpals and tarsals.
Movement
The skeleton is permitted to move by the joints between the bones. Some permit a wide range of movement others are more restricted. The movement is allowed by skeletal muscles that attach to the bone in various places. Muscles, joints, and bones are what allow the skeletal system to move.[10] There are six types of joints that help the skeleton move they are:
Ball and socket joint
The ball and socket joint allows the joint to move in all direction. It gives the widest range of motion. Examples of the ball and socket are the hip and the shoulder. [11]
Condyloid
The condyloid joint allows the joint to move in angular movements but not rotation. Examples of this joint are between the bones of the palm and the hand and between the bones of the foot and the toes. [12]
Saddle
There is only one saddle joint in the body it is the thumb. It also allows for a wide rang of motion. [13]
Pivot
The pivot joint allows rotation. An example would be the axis and and the atlas of the neck. [14]
Hinge
The hinge joint allows the joint to only flexion and extension. This occurs in the elbow joint. [15]
Gliding
The gliding joint allows the joint to slide or twist without any circular movement. This happens in the carpals in the wrist and the tarsals in the ankle. [16]
Storage
The bones in the skeletal system can store minerals like calcium and phosphorus.When the supply of these minerals runs low the body will get it from the bones. [17]
Blood Cell Production
The red bone marrow, found in the skeleton, is were haematopoiesis happens. Haematopoiesis is the making of blood cellular components. [18]
Endocrine Regulation
The bone cells release osteocalcin, a hormone that helps regulate blood sugar and fat deposition. [19]
Diseases and Disorders
There are several different disorders and diseases that can effect the skeletal system. The more common ones are fractures, arthritis, tendonitis, poliomyelitis, and scoliosis.
Fractures
There are many types of fractures that can affect the human skeleton in different ways. Some examples are:
Transverse fracture
A transverse fracture is were the bone has broken at a right angle. [20]
Greenstick fracture
A greenstick fracture is were the bone is bent. This kind of fracture is an incomplete fracture. [21]
Oblique fracture
An oblique fracture is when the bone breaks at a slope down the bone. [22]
Comminuted fracture
A comminuted fracture is when the bone has shattered into several pieces.[23]
Impacted fracture
An impacted fracture is when the bones ends have been driven into each other by force. [24]
Arthritis
Arthritis is pain, stiffness, and swelling of the joints. There are over 100 joint diseases that are referred to as arthritis. [25]
Tendinitis
Tendinitis, often called rheumatism, is pain or stiffness of the muscles and joints in the body. [26]
Poliomyelitis
Poliomyelitis is more commonly known as polio. Polio is caused by a virus that attacks the nerve cells of the brain and spinal cord, this causes paralysis. [27]
Scoliosis
Scoliosis is side-to-side curve of the spine. It is about two times more common in girls then it is in boys. It can be seen in kids over ten years of age. It is hereditary, so if someones parents have scoliosis then their children are most likely to have it.[28]
References
Function
- De Graaff, Van . "The Skeletal System". 12/24/08 [29]
- "Human Skeletal System". wikipedia. 12/24/08 [30]
- De Graaff, Van. "Joints". 12/24/08 [31]
Organization
- "Human Skeletal System". wikipedia. 12/24/08 [32]
- "longitudinal axis". Answers.com. 12-24-08 [33]
- "Axial skeleton". Wikipidea. 12/24/08 [34]
- "Appendicular skeleton". Wikipidea. 12/24/08 [35]
Diseases and Disorders
{all sites were blocked by server so i could not cite them}
Development
- "Human Skeletal System". wikipedia. 12/24/08 [39]
External links
- by Jerry Bergman. Back problems: how Darwinism misled researchers by Jerry Bergman. TJ 15(3):79–84, December 2001.
See Also
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