Muscles and Movement Flashcards
Skeletal system
Consists of bones or exoskeleton which act as levers and provide a structure for the muscles to pull
Muscular system
Muscles contract and deliver the force needed to move one bone in relation to another
When do muscles exert a force?
When they contract
Antagonistic muscles
Muscles that work in pairs and cause opposite movements. When one contracts, the other relaxes
What do bones provide?
The anchorage and insertion for muscles and act as levers
How are muscles attached to bones?
By tendons at both ends of the muscle
Anchorage
A firm point of attachment that does not move when the muscle contracts
Insertion
Muscle contraction causes the bone or section of exoskeleton forming the insertion to move
How are bones connected to other bones?
Ligaments
Joint
Junctions between bones
Synovial joints
Allow certain movements but not others
What are the three parts of a synovial joint?
Cartilage
Synovial fluid
Joint capsule
Annotate the diagram of the human elbow joint
Biceps
Flexor muscle- used to bend the arm at teh elbow
Triceps
Extensor muscle- used to straighten the arm
Radius
Bone that is the insertion for the biceps and acts as forearm lever for the biceps
Ulna
Bone that is the insertion for the triceps and acts as forearm lever for the triceps
Humerus
Bone that provides a firm anchorage for the biceps and triceps
Tendon
Attaches muscle to bone
Cartilage
Layer of smooth, tough tissue that covers the surface of the bones at the joint. It helps to prevent friction where the bones could rub against each other. It also absorbs shocks
Synovial fluid
Fills the cavity between the cartilage-covered surfaces of the bones. It lubricates the joint and helps to prevent friction
Joint capsule
Tough ligamentous covering to the joint. It seals the joint, holds the synovial fluid and helps to prevent dislocation
Ligaments
Tough tissue connecting the humerus with the ulna and radius. Holds the bones in proper alignment, restrict movement and help to prevent dislocation
Describe antagonistic muscles in an insect leg
Insects leg are divided in three parts: femur, tibia and tarsus. There is a pair of antagonistic muscles inside the femur which causes the tibia to flex and extend. The tendons at the distal ends of these muscles are attached to opposite sides of the exoskeleton of the tibia, so one of them is the flexor of the joint and the other the extensor