Skip to main content. Bones muscles and joints. Home Bones muscles and joints. Actions for this page Listen Print. Summary Read the full fact sheet. On this page. The skeleton The human skeleton is made up of bones, including bones of the: Skull — including the jaw bone Spine — cervical, thoracic and lumbar vertebrae, sacrum and tailbone coccyx Chest — ribs and breastbone sternum Arms — shoulder blade scapula , collar bone clavicle , humerus, radius and ulna Hands — wrist bones carpals , metacarpals and phalanges Pelvis — hip bones Legs — thigh bone femur , kneecap patella , shin bone tibia and fibula Feet — tarsals, metatarsals and phalanges.
Bone types There are four different types of bone in the human body: Long bone — has a long, thin shape. Examples include the bones of the arms and legs excluding the wrists, ankles and kneecaps. With the help of muscles, long bones work as levers to permit movement. Short bone — has a squat, cubed shape. Examples include the bones that make up the wrists and the ankles. Flat bone — has a flattened, broad surface.
Examples include ribs, shoulder blades, breast bone and skull bones. Irregular bone — has a shape that does not conform to the above three types. Examples include the bones of the spine vertebrae.
Bone tissue The different layers of bone tissue include: Periosteum — the dense, tough outer shell that contains blood vessels and nerves Compact or dense tissue — the hard, smooth layer that protects the tissue within Spongy or cancellous tissue — the porous, honeycombed material found inside most bones, which allows the bone to be strong yet lightweight Bone marrow — the jelly-like substance found inside the cavities of some bones including the pelvis that produces blood cells.
Bone marrow Bone marrow is where blood cells are made. The three different types of blood cell made by bone marrow include: Red blood cells — carry oxygen around the body. Platelets — are used for clotting. Interestingly, their placement can vary from person to person. The patella kneecap is an example of a prominent sesamoid bone in the body. Sesamoids are bones that form within a tendon and bones surrounded by tendons, which connect muscle to bone. They help to protect the tendons from wear and tear and to relieve pressure when a joint is used.
The compact bone is the outer shell of the bone. Compact bone contains a central canal that runs the length of the bone, often called a Haversian canal. Haversian canals allow blood vessels and some nerves to reach into the bone.
It contains cavities that hold the red or yellow bone marrow. Spongy bone is also important for movement. Spongy bone also helps to absorb shock and stress from movement. These are stem cells found in your bones. They can develop into a variety of different cell types, including osteoblasts. These cells originate from mesenchymal stem cells.
They work to deposit collagen and minerals that will eventually form mature bone. Osteocytes are trapped within the bone tissue and are the most prevalent cell type in mature bone tissue. They monitor things such as stress, bone mass, and nutrient content. Osteoclasts are large cells. They secrete a variety of ions and enzymes that allow bone tissue to be resorbed. The material that has been resorbed can then be used to create new bone tissue. Your bones do so much more than provide support for your body.
They facilitate movement, provide protection to internal organs, and are important for blood cell formation and nutrient storage.
Your bones are classified according to their size and function. On the inside, bones contain a variety of different tissues and cells. All of these components work together to make your bones the multifunctional tissue that they are.
It is very important to build strong and dense bones. Here are 10 natural nutrition and lifestyle tips to build and maintain healthy bones. Bone contains three types of cells:. Muscles pull on the joints, allowing us to move. They also help the body do such things as chewing food and then moving it through the digestive system.
Even when we sit perfectly still, muscles throughout the body are constantly moving. Muscles help the heart beat, the chest rise and fall during breathing, and blood vessels regulate the pressure and flow of blood.
When we smile and talk, muscles help us communicate, and when we exercise, they help us stay physically fit and healthy. The movements your muscles make are coordinated and controlled by the brain and nervous system. The involuntary muscles are controlled by structures deep within the brain and the upper part of the spinal cord called the brain stem. The voluntary muscles are regulated by the parts of the brain known as the cerebral motor cortex and the cerebellum pronounced: ser-uh-BEL-um.
When you decide to move, the motor cortex sends an electrical signal through the spinal cord and peripheral nerves to the muscles, causing them to contract. The motor cortex on the right side of the brain controls the muscles on the left side of the body and vice versa. The cerebellum coordinates the muscle movements ordered by the motor cortex. Sensors in the muscles and joints send messages back through peripheral nerves to tell the cerebellum and other parts of the brain where and how the arm or leg is moving and what position it's in.
This feedback results in smooth, coordinated motion. If you want to lift your arm, your brain sends a message to the muscles in your arm and you move it. When you run, the messages to the brain are more involved, because many muscles have to work in rhythm. Muscles move body parts by contracting and then relaxing. Muscles can pull bones, but they can't push them back to the original position.
So they work in pairs of flexors and extensors. The flexor contracts to bend a limb at a joint. Then, when the movement is completed, the flexor relaxes and the extensor contracts to extend or straighten the limb at the same joint. For example, the biceps muscle, in the front of the upper arm, is a flexor, and the triceps, at the back of the upper arm, is an extensor.
When you bend at your elbow, the biceps contracts. Then the biceps relaxes and the triceps contracts to straighten the elbow. Joints are where two bones meet. They make the skeleton flexible — without them, movement would be impossible.
Joints allow our bodies to move in many ways. Some joints open and close like a hinge such as knees and elbows , whereas others allow for more complicated movement — a shoulder or hip joint, for example, allows for backward, forward, sideways, and rotating movement.
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