SKELETAL SYSTEM
Your skeletal system is all of the bones in the body and the tissues such as tendons, ligaments and cartilage that connects them. Your teeth are also considered part of your skeletal system but they are not counted as bones. Your teeth are made of enamel and dentin. Enamel is the strongest substance in your body. In your skeletal system the average adult has 206 bones in their body. Children start off with 300 bones which later combine with other bones to make bigger and stronger bones.
What
is Bone made of?
Bone is made up of layers in the body. Starting with the outside. The outer surface of bone is called the Periosteum: It's a thin, dense membrane that contains nerves and blood vessels that nourishthe bone. Then there is the Compact Bone: this is the bone that you see. It is smooth and very hard. The next layer is the Cancellous: the cancellous bone looks a bit like a sponge. Cancellous bone is not quite as hardas compact bone, but it is still very strong. In many bones, the cancellous bone protects the innermost part of the bone. The final layer to the bone is the Bone marrow: Bone marrow is sort of like a thick jelly, and its job is to make blood cells. All up this makes the bone very strong and if your were to build a replica of the human skeleton with metal it would weigh about 400 kilos! And yet bone is just as tough.
FUNCTIONS
There are 5 main functions to the human skeleton:
Movement: Bones provide the structure for muscles to attach so that our bodies are able to move.
Protection: Your skeleton also helps protect your internal organs and fragile body tissues. The brain, eyes, heart,
lungs and spinal cord are all protected by your skeleton.
Support: Without your skeleton your body would collapse into a heap. Your skeleton is strong but light. Without
bones you'd be just a puddle of skin and guts on the floor.
Storage: Our bones are a storehouse for fat and certain essential minerals.
Blood cell formation: Most of our blood components are made in the bones.
There are 5 types of bones in the body:
SHORT:
Short bones are defined as being approximately as wide as they are long and
have a primary function of providing support and stability with little movement.
Examples of short bones are the bones in your wrist and foot. (Carpals and
tarsals)
LONG:
Long bones are some of the longest bones in the body, such as the Femur, Humerus
and Tibia but are also some of the smallest including the Metacarpals,
Metatarsals and Phalanges. The classification of a long bone includes having a
body which is longer than it is wide,
FLAT:
Flat bones are as they sound, strong, flat plates of bone with the main function
of providing protection to the bodies’ vital organs and being a base for
muscular attachment. The classic example of a flat bone is the Scapula (shoulder
blade). Cranium (skull), Pelvis and Ribs are also classified as flat bones.
IRREGULAR:
These are bones in the body which do not fall into any other category, due to their non-uniform shape.
Good examples of these are the Vertebrae, Sacrum and Mandible (lower jaw). They
primarily consist of cancellous bone, with a thin outer layer of compact
bone.
SESAMOID:
Sesamoid bones are usually short or irregular bones, imbedded in a tendon.
The most obvious example of this is the Patella (knee cap) which sits within the
Patella or Quadriceps tendon
Your skeletal system is all of the bones in the body and the tissues such as tendons, ligaments and cartilage that connects them. Your teeth are also considered part of your skeletal system but they are not counted as bones. Your teeth are made of enamel and dentin. Enamel is the strongest substance in your body. In your skeletal system the average adult has 206 bones in their body. Children start off with 300 bones which later combine with other bones to make bigger and stronger bones.
What
is Bone made of?
Bone is made up of layers in the body. Starting with the outside. The outer surface of bone is called the Periosteum: It's a thin, dense membrane that contains nerves and blood vessels that nourishthe bone. Then there is the Compact Bone: this is the bone that you see. It is smooth and very hard. The next layer is the Cancellous: the cancellous bone looks a bit like a sponge. Cancellous bone is not quite as hardas compact bone, but it is still very strong. In many bones, the cancellous bone protects the innermost part of the bone. The final layer to the bone is the Bone marrow: Bone marrow is sort of like a thick jelly, and its job is to make blood cells. All up this makes the bone very strong and if your were to build a replica of the human skeleton with metal it would weigh about 400 kilos! And yet bone is just as tough.
FUNCTIONS
There are 5 main functions to the human skeleton:
Movement: Bones provide the structure for muscles to attach so that our bodies are able to move.
Protection: Your skeleton also helps protect your internal organs and fragile body tissues. The brain, eyes, heart,
lungs and spinal cord are all protected by your skeleton.
Support: Without your skeleton your body would collapse into a heap. Your skeleton is strong but light. Without
bones you'd be just a puddle of skin and guts on the floor.
Storage: Our bones are a storehouse for fat and certain essential minerals.
Blood cell formation: Most of our blood components are made in the bones.
There are 5 types of bones in the body:
SHORT:
Short bones are defined as being approximately as wide as they are long and
have a primary function of providing support and stability with little movement.
Examples of short bones are the bones in your wrist and foot. (Carpals and
tarsals)
LONG:
Long bones are some of the longest bones in the body, such as the Femur, Humerus
and Tibia but are also some of the smallest including the Metacarpals,
Metatarsals and Phalanges. The classification of a long bone includes having a
body which is longer than it is wide,
FLAT:
Flat bones are as they sound, strong, flat plates of bone with the main function
of providing protection to the bodies’ vital organs and being a base for
muscular attachment. The classic example of a flat bone is the Scapula (shoulder
blade). Cranium (skull), Pelvis and Ribs are also classified as flat bones.
IRREGULAR:
These are bones in the body which do not fall into any other category, due to their non-uniform shape.
Good examples of these are the Vertebrae, Sacrum and Mandible (lower jaw). They
primarily consist of cancellous bone, with a thin outer layer of compact
bone.
SESAMOID:
Sesamoid bones are usually short or irregular bones, imbedded in a tendon.
The most obvious example of this is the Patella (knee cap) which sits within the
Patella or Quadriceps tendon