The Skeleton
A shaping framework for internal organs which gives protection for internal organs, is the site for blood production and is a mineral store
Flat bones
Protect internal organs and act as sites for muscular attachment
Long bones
Act as levers for movement and act as sites for blood cell production
Irregular bones
Vertebrae protect the spinal cord
Short bones e.g. carpals
Carpals and tarsals bear weight
Sesamoid bones e.g. patella
Patella ease joint movement and resist compression
Two arm bones
Ulna and radius
Ulna connected to little finger
Radius connected to thumb
To lower leg bones
Tibia and fibula
Tibia is large one, fibula is small
Finger bones
Phalanges
Hand bones
Meta carpals
Wrist bone
Carpals
Ankle and Top of foot bones
Talus and Tarsals
Foot bones
Meta tarsals
Toes
Phalanges
Ligament
Makes up a synovial joint
Structure -
A tough band of slightly elastic connective tissue
Function -
Connects bone to bone and stabilises joint during movement
Synovial fluid
Makes up a synovial joint
Structure -
Lubricating liquid contained within the joint cavity
Function -
Reduces friction and nourishes articular cartilage
Articular cartilage
Makes up a synovial joint
Structure-
Smooth tissue which covers the surface of the articulating bone
Function -
Absorbs shock and allows friction-free movement
Joint capsule
Makes up a synovial joint
Structure -
A fibrous sac with an inner synovial membrane
Function -
Encloses and strengthens the joint secreting synovial fluid
Bursa
Makes up a synovial joint
Structure -
A closed, fluid fulled sac found where tendons rub over bones
Function - reduces friction between tendons and bones
Joint
An area of the body where two or more bones articulate to create human movement
Hinge joint
A cylindrical bone articulates with a trough-shaped bone held tightly by ligaments which limit sideways movement. Motion restricted to one plane
Condyloid joint
Similar to a ball and socket joint with flatter bone surfaces to allow motion in two planes
E.g. the wrist
Pivot joint
A rounded bone articulates with a ring-shaped bine which restricts motion to one plane
E.g. the radio-ulnar joint
Gliding joint
Almost flat, similar sized bones articulate with limited motion in three planes
E.g. the spine
Ball and socket joint
A ball shaped head articulates with a cup shaped socket to give a large range of motion in all three planes
The planes of movement
The sagittal plane - lies vertically. It divides the body into left and right parts from medial to lateral
The frontal plane - lies vertically. Dividing the body into front and back
The transverse plane - lies horizontally. Dividing the body into upper and lower
Transverse planes
The transverse plane - lies horizontally. Dividing the body into upper and lower
Somersault
The frontal plane
The frontal plane - lies vertically. Dividing the body into front and back
Adduction, abduction
The sagittal plane
The sagittal plane - lies vertically. It divides the body into left and right parts from medial to lateral
Flexion/extension
Flexion
Decreases the joint angle
Extension
Increases the joint angle
Dorsi-flexion
Decreases the joint angle
Bringing tors closer to the tibia
Plantar flexion
Increase the angle
Moving the toes further away from tibia
Pointing toes
Abduction
moves the articulating bones away from the midline of the body
Adduction
Moves the articulating bones closer to the midline of the body
Horizontal extension
Moves articulating bones away from midline of the body
E.g. the backswing of a discuss throw
Horizontal flexion
Moves the articulating bones closer to the midline of the body
E.g. the throw/forward swing of a discuss throw
Rotation
When articulating bones turn about it’s longitudinal axis
Rotation toward the body is medial
Rotation away from the body is lateral
Origin
The point of muscular attachment to a stationary bone which stays relatively fixed during muscular contraction e.g. the biceps brachii origin is on the scapula during an arm curl
Insertion
The point of muscular attachment to a moveable bone which gets closer to the origin during muscular contraction
Antagonistic muscle action
Agonist and antagonist and fixator work together in a coordinated movement
Agonist
A muscle responsible for creating movement at a joint. Also known as a prime mover
Antagonist
A muscle that opposes the agonist providing resistance for co-ordinated movement. Usually lengthens
Fixator
A muscle that stabilises on part of a body while another causes movement
Isotonic muscle contraction
Muscular contraction which changes length during it’s contraction
Isometric muscle contraction
Muscular contraction which stays the same length while producing tension. Posture is is maintained by isometric contraction
Concentric muscle contraction
Muscle contraction where the muscle shortens, causing tension
Eccentric
Muscle contraction in which the muscle lengthens producing tension
Motor neuron
A nerve cell which conducts a nerve impulse to group of muscle fibres
Motor unit
The motor neuron and it’s muscle fibres
Action potential
Positive electrical charge inside the nerve and muscle cells which conducts the nerve impulse down the neuron and into the muscle fibre