Skeletal and muscular systems Flashcards
Skeleton ?
Shaping framework for the body which gives protection for internal organs , is the site for blood cell production and is a mineral store. Crucially human movement the skeleton provides attachments for the muscular system and acts as the levers and pivot points required to create movement
What is a flat bone ?
Act as suitable sites for muscular attachment eg sternum , ribs , cranium
What is a long bone ?
Act as levers for movement and act as sites for blood cell production eg Femur , humours , radius and tibia
What is a irregular bone ?
They have a irregular shape , eg vertebrate
What is a short bone ?
They bear weight eg tarsals and carpals
Sesamoid bones ?
Ease movement and resist compression eg Patella
Define joint ?
An area of the body where two or more bones articulate to create human movement
Define ligament ?
A tough band of fibrous , slightly elastic connective tissue that attaches bone to bone
Define articular cartilage ?
Smooth tissue which covers the surface of articulating bones to absorb shock and allow friction -free movement
Ligament ? Structure and function
Structure - A tough band of slightly elastic connective tissue
Function- Connects bone to bone and stabilises joints during movement
Synovial fluid ? structure and function
Structure - Lubricating liquid contained within the joint cavity
Function- Reduces friction and nourishes articular cartilage
Articular cartilage ? structure and function
Structure -Smooth tissue which covers the surface of articulating bones
Function - Absorbs shock and allows friction - free movement
Joint capsule ? structure and friction
Structure - A fibrous sac with an inner synovial membrane
Function - Encloses and strengthens the joint secreting synovial fluid
Bursa ? structure and friction
Structure - A closed , fluid - filled sac found where tendons rub over bones
Function - Reduces friction between tendons and bones
Plane of movement ?
The description of three dimensional movements at a joint
Movements patterns ?
A description of the actions taking place at a joint
Name the three types of planes ?
Sagittal plane - divides the body into left and right parts of the medial to the lateral
Frontal plane - Divides the body into anterior and posterior
Transverse plane - It divides the body into superior and inferior
Types of joints ?
HINGE PIVOT GLIDING BALL AND SOCKET CONDYLOID
HINGE
A CYLINDRICAL BONE ARTICULATES WITH A TROUGH - SHAPED BONE HELD TIGHTLY BY LIGAMENTS WHICH LIMIT SIDEWAYS MOVEMENT
PIVOT
A rounded bone articulates with a ring shaped bone which restricts motion to one plane
GLIDING JOINT
Almost flat , similar sized bones , articulate with limited motion in three planes
BALL AND SOCKET
A ball shaped head articulates with a cup-shaped socket to give a large range of motion in all three planes
CONDLYOID JOINT
Flat bone to allow motion in two planes
Types of sagittal plane ?
Flexion and extension
Define flexion
Movement which decreases the joint angle
Define extension
Movement which increases the joint angle
Define dorsi - flexion
Movement at the ankle joint as the toes move up
Define plantar flexion
Movement at the ankle joint as the toes move down
Frontal pane ?
Abduction
Adduction
Define abduction
Movement of the limbs away from the midline of the body
Define adduction
Movement of the limbs towards the midline of the body
Transverse plane ?
Horizontal extension
Horizontal flexion
Define Horizontal extension
Joint moves the articulating bone away from the midline of the body
Define Horizontal flexion
Joint moves the articulating bone closer to the midline of the body
Define rotation
Movement whereby articulating bones turn about their longitudinal axis in screwdriver action
Define tendons
A fibrous connective tissue that attaches a muscle to bone
Origin ?
The point of muscular attachment to a stationary bone which stays relatively fixed during muscular contraction
Insertion ?
The point of muscular attachment to a moveable bone which gets closer to the origin during muscular contraction
Agonist ?
A muscle responsible for creating movement joint
Antagonist ?
A muscle that opposes the agonist providing a resistance for co-ordinated movement
Fixator ?
A muscle that stabilises one part of a body while another moves
Antagonist muscle action ?
Paired muscle action . As the agonist muscle shortens to create movement , the antagonist lengthens to co-ordinate the action
Muscle ?
Muscle uses energy to create force , It is this force that can create human movement and even be passed onto an object such as a ball
Isotonic contraction ?
Muscular contraction which changes length during its contraction
Concentric contraction ?
Muscular contraction which shortness while producing tension
Eccentric contraction ?
Muscular contraction which lengthens while producing tension
Isometric contraction ?
Muscular contraction which stays the same length while producing tension
Define motor neuron
A nerve cell which conducts a nerve impulse to a group of muscle fibres
Define motor unit
A motor neuron an the muscle fibres stimulated by its axon
Define action potential
Positive electrical change inside the nerve and muscle cells which conduct the nerve impulse down the neuron and into the muscle fibre
Define neuro transmitter
A chemical produced and secreted by a neuron which transmits the nerve impulse across the synaptic cleft to the muscle fibre
All or none law
Depending on whether the stimulus is above a threshold , all muscle fibres will give a complete contraction or no contraction
Role of motor unit
Nerve impulse initiated in the motor neuron cell body
Nerve impulse conducted down the axon of the motor neuron by a nerve action potential to the synaptic cleft
Neurotransmitter called acetylcholine is secreted into the synaptic cleft to conduct the nerve impulse across the gap
If electrical charge is above threshold , the muscle fibre will contract
Three types of muscle fibre ?
Slow oxidative
Fast oxidative
Fast glycolytic
Define slow oxidative muscle fibres
A type of muscle fibre rich in mitochondria , myglobin and capillaries which produces a small amount of force over a long period of time
Define fast glycolytic muscle fibres
A type of muscle fibre rich in phosphocreatine which produces a maximal force over a short period of time
