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Skeletal system: Difference between revisions
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=== Pivot === | === Pivot === | ||
The pivot joint allows for the most movement out of all of the joints. The most common example of this joint is the neck, which can look from side to side, up and down, and almost any way at all. | The pivot joint allows for the most movement out of all of the joints. The most common example of this joint is the neck, which can look from side to side, up and down, and almost any way at all. | ||
=== Glide === | === Glide === | ||
The glide joint is similar to the ball and socket joint in terms of the range of movement, but there is no actual ball and socket. An excellent example of this is a person's wrist, which has extreme movability but no bulky ball and socket like the shoulder. | The glide joint is similar to the ball and socket joint in terms of the range of movement, but there is no actual ball and socket. An excellent example of this is a person's wrist, which has extreme movability but no bulky ball and socket like the shoulder. Glide joints are also very delicate, and can be easily damaged. They are also very weak, and cannot apply very much force by themselves. For example, try lifting a 30 lb weight with your whole arm, and then try lifting the same weight using just your wrist. Gliding joints are useful, but lack a lot of support that allows other joints to apply more force. | ||
== Bone Types == | == Bone Types == | ||
[[Image:Compact and Spongy.jpg|thumb| | [[Image:Compact and Spongy.jpg|thumb|350px|right|Diagram of the spongy and compact layers of the bone]] | ||
There are three different types of bone in the skeletal system. These are the outer layer of the bone, the compact middle layer, and the spongy third layer. | There are three different types of bone in the skeletal system. These are the outer layer of the bone, the compact middle layer, and the spongy third layer. | ||
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=== Spongy === | === Spongy === | ||
The spongy bone is where all of the blood cells are created from the bone marrow. Spongy bone contains two different types of bone marrow: red and yellow marrow. The red bone marrow produces red and white blood cells and platelets. The yellow bone marrow, however, is used to store fats. | The spongy bone is where all of the blood cells are created from the bone marrow. Spongy bone contains two different types of bone marrow: red and yellow marrow. The red bone marrow produces red and white blood cells and platelets. The yellow bone marrow, however, is used to store fats.[http://webschoolsolutions.com/patts/systems/skeleton.htm] | ||
== Related References == | == Related References == | ||
