Tissues of the skeletal system

why do we need both skeleton and muscle

• movement requires both msucle and incompresible skeleton bcs muscles will only produce effective movement if they pull on a structure that doesnt shorten or bend

what is a bone

the strong, calcium-rich tissue which is the main component of the vertebrae skeleton

bone structure

• Made of bone cells which are fixed firmly in a matrix of collagen and calcium salts

• Bone needs to be light to reduce weight we carry, compact bone is dense and heavy. This is the long bones of your body

• Spongy bones have a much more open structure to much lighter

what is cartilage

hard but flexible skeletal tissue that often acts as a shock absorber and prevents wear in joints

cartilage structure

• made up of cells called chondrocytes within an organic matrix which consists of varying amounts of collagen fibres

• Cartilage is elastic and able to withstand compressive forces

what are the two main types of cartilage?

• Hyaline cartilage is found at the ends of bones ( and in the nose, air passageways and parts of ear)

• White fibrous cartilage has bundles of densely packed collagen in the matrix. It has great tensile strength but is less flexible than the other forms of cartilage. It forms the discs between your vertebrae and is found between the boens in the joints

what are tendons

• strong connective tissues which connect muscles to bones

structure of tendons

• made up almost entirely of white fibrous tissue. This consists of bundles of collagen fibres,

• One end of tendon is attached to muscles and other end directly to bone or to a fibrous cover of bone

property of tendons

• They are flexible but do not stretch when a muscle is contracting and pulling on a bone

• There are a few muscles with very long tendons and also a few that are directly attached to the bone

what are ligaments

• Ligaments are also lengths of strong connective tissue but they connect bones to other bones, which keep the skeleton intact

structure of ligaments

• they form a capsule around the joint and hold the boens together inside the joint itself

• elastic so bones of joint can move

• Made of yellow elastic tissue which gives an ideal combination of strength with elasticity

what are the different types of joints

• shoulder-ball and socket joint

• elbow-pivot joint

• wrist-saddle joint

• finger joint

• knee-hinge joint

• joint between ankle bones

what is synovial fluid

• joint lined with a replaceable layer of rubbery cartilage to articulate smooth movement and to prevent ends from becoming weaker and thinner by rubbing together

• The most mobile joints also have liquid lubricant called synovial fluid

• It fills the joint cavity and ensures easy friction-free movement

how muscles mover

• Muscles are only capable of contracting or pulling, they cannot push

• As a result of this limitation muscles generally operate in pairs

• Each skeletal muscles is attached by tendons to two diferent bones,e xtending across atleast one joint

• A muscle pulls in one direction at a joint and the other muscle pulls in the opposite direction

  • This is described as antagonistic muscle action

what are extensors

muscles that extend (stretch or open) a joint

what are flexors

muscles that flex (close or bend) a joint

process of raising lower arm

• The bicep contracts and the tricep relaxes

• As the bone can't be stretched the arm flexes around the joint

• A muscle that bends a joint during contraction is known as a flexor (the bicep in this case)

• This brings the tricep into its full length so that it can contract again

process to lower the lower arm

• The tricep contracts and bicep relaxes

• As the bone can't be stretched the arm flexes around the joint

• A muscle that straightens a joint during contraction is known as an extensor (the tricep in this case)