Movement
Structure-
The movement of the skeleton relies on tendons and ligaments connecting skeletal muscle to bone and bone to bone. There are six different types of joints; Ball and Socket joints, Hinge joints, Saddle joints, Condyloid joints, Pivot joints and Gliding Joints. Cartilage is also involved in flexible movements as it is far more flexible than bone (cartilage is found in the vertebrae) and is also surrounding some joints (knee) to help soften the impact of walking and running.
Function-
To move the brain sends an electrical signal to the spinal cord via the cerebral cortex. The signal then reaches the nerves in the muscles, which makes the skeletal muscle contract and then relax. The skeletal muscles pull bones but cannot push them in the opposite direction, this is why the skeletal muscles work in pairs of flexors and extensors. Flexors are used to bend the limbs at the joints, while extensors are used to straighten the limbs.
Also at synovial joints (knees, elbows) synovial fluid is produced in the synovial cavity between where two bones meet, which allow for smooth movement. If there was no synovial cavity and no synovial fluid inside the cavity, the bones would scrape against each other. The synovial fluid also removes waste made from the surrounding cartilage as well as supplying the bones with nutrients.
Skeletal muscles are also striated (have horizontal lines when under a microscope). The skeletal muscle is striated in part because it can stretch much more than other muscles. Skeletal muscle is mostly voluntary, meaning that we can consciously control the muscles. This is in contrast to cardiac muscle which is involuntary (cardiac muscle is only found in the heart) and is constantly being contracted and relaxed and smooth muscle which covers the organs. If cardiac muscle was voluntary than humans would have to continually make their muscle contract and relax. Smooth muscle is not striated because if it was very flexible and easily contracted, food in the digestive system would move too quickly through the organs and the nutrients absorbed through digestion wouldn’t be extracted.
The movement of the skeleton relies on tendons and ligaments connecting skeletal muscle to bone and bone to bone. There are six different types of joints; Ball and Socket joints, Hinge joints, Saddle joints, Condyloid joints, Pivot joints and Gliding Joints. Cartilage is also involved in flexible movements as it is far more flexible than bone (cartilage is found in the vertebrae) and is also surrounding some joints (knee) to help soften the impact of walking and running.
Function-
To move the brain sends an electrical signal to the spinal cord via the cerebral cortex. The signal then reaches the nerves in the muscles, which makes the skeletal muscle contract and then relax. The skeletal muscles pull bones but cannot push them in the opposite direction, this is why the skeletal muscles work in pairs of flexors and extensors. Flexors are used to bend the limbs at the joints, while extensors are used to straighten the limbs.
Also at synovial joints (knees, elbows) synovial fluid is produced in the synovial cavity between where two bones meet, which allow for smooth movement. If there was no synovial cavity and no synovial fluid inside the cavity, the bones would scrape against each other. The synovial fluid also removes waste made from the surrounding cartilage as well as supplying the bones with nutrients.
Skeletal muscles are also striated (have horizontal lines when under a microscope). The skeletal muscle is striated in part because it can stretch much more than other muscles. Skeletal muscle is mostly voluntary, meaning that we can consciously control the muscles. This is in contrast to cardiac muscle which is involuntary (cardiac muscle is only found in the heart) and is constantly being contracted and relaxed and smooth muscle which covers the organs. If cardiac muscle was voluntary than humans would have to continually make their muscle contract and relax. Smooth muscle is not striated because if it was very flexible and easily contracted, food in the digestive system would move too quickly through the organs and the nutrients absorbed through digestion wouldn’t be extracted.