Movement (11.2) Flashcards
Describe the movement systems in the body.
- The skeletal system - consists of bones that act as levers and provides a structure for the muscles to pull.- The muscular system - muscles deliver the force required to move one bone in relation to another.- The nervous system - delivers signals to the muscles which cause them to constrict and create movement.
Define a skeleton.
A rigid framework that functions to provide support and protection for body organs. They provide a surface for muscle attachment.
Describe endoskeletons.
An internal skeleton. An example is humans. Advantages of endoskeletons are that they allow for even growth/development and fast movement. Disadvantages are that they do not provide the same level of protection as exoskeletons.
Describe exoskeletons.
An external skeleton. Sometimes known as ‘shells’. An example is lobsters.Advantages of exoskeletons are that they provide protection against predators and protect the internal body. Disadvantages are that the exoskeleton cannot grow so must be shed if the organism wants to expand.
Describe hydrostatic skeletons.
Flexible skeletons that are supported by fluid pressure. An example is jellyfish. Advantages of hydrostatic skeletons is that they have a fluid shape, are well suited to their environment and have rapid healing. Disadvantages are that they have little protection.
Define joints.
The part of the body where two or more bones meet to allow movement. They function to maintain structural stability by allowing certain movements but not others.
Define synovial joints.
Capsules that surround the articulating surfaces of two bones. They allow certain movements but not others.
Give the types of synovial joints in the body.
- Ball and socket joints eg. shoulder and hip. Allows for movement in three planes.- Hinge joints eg. fingers, toes, elbows and knees. Allows for movement in one plane.- Pivot joints eg. the neck. Allows limited rotating movements.- Ellipsoidal joints eg. the wrists. Allows all types of movement apart from pivotal movements.
What makes up a joint?
Cartilage - A connective tissue covering the bones which helps to reduce the friction of movement. Also helps to absorb shock.Synovial fluid - A fluid secreted by the synovial membrane that provides oxygen and nutrition to the cartilage and also lubrication to reduce friction.Joint capsule – Seals the joint space and provides stability by restricting the range of possible movements.
What is the purpose of muscles?
Muscles connect to bones (via tendons) and contract to provide the force required to produce movement.
Give the three types of muscle tissue.
1) Cardiac muscle cells: located in the walls of the heart, appear striated and are under involuntary control.2) Smooth muscle cells: located in the walls of hollow visceral organs (except the heart), appear spindle shaped and are under involuntary control.3) Skeletal muscle fibres: located in muscles attached to the skeleton, appear striated and are under voluntary control.
What are antagonistic pairs?
Muscles that work in pairs. One muscle contracts (called the agonist) while the other relaxes (called the antagonist).
Give examples of antagonistic muscles.
Abs and lower back.Biceps and triceps.Back and chest.Quadriceps and hamstring.
Describe the elbow joint.
The elbow joint is a hinge joint. It is capable of angular movement in one direction (flexion and extension). It may also be capable of a small amount of rotation. The bicep and tricep muscles within the elbow are antagonistic.
Give the function of the following components of the elbow:Bicep (muscle)Tricep (muscle)Joint capsule (joint)Synovial fluid (joint)Cartilage (joint)Humerus (bone)Radius (bone)Ulna (bone)
Bicep: Bends the forearm (flexion).Tricep: Straightens the forearm (extension).Joint capsule: Seals joint space and limits range of movement to promote stability.Synovial fluid: Provides oxygen and nutrients to the cartilage and lubrication to reduce friction.Cartilage: Absorbs shock and reduces the friction of movement.Humerus: Anchors muscle (muscle origin).Radius: Acts as a forearm lever for the biceps.Ulna: Acts as a forearm lever for the triceps.
