anatomy and physiology

Function of the skeleton

Shape - provdes a rigid framework

Levers - lever systems alongside muscles provide movement

Attachment - skeletel framework provides essential muscle attachment joints

Protection - protects the body and organs from harm

Red blood cells - bone marrow produces red blood cells for the arculatory system

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Types of bones

Long - slightly curved to absorb stress, they act as levers

Short - cube shaped with equal length and width, there to give strength

Flat - thin and provide pretection for organs and exstensive areas of muscle attachment

Irregular - complex shape, provide a large area for muscle attachment

Sesamoid - inside a tendon, allowing it to slide over a joint

Wormain - acts as wedges or joints

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Osteoporosis

- a bone disorder that is casued by low bone density and a deterioration of bone tissue

- weaking the bone, making it more prone to fractures

- physical activity and a healthy diet help prevent osteoporosis

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Osteoarthritis

- a degenerate joint disease caused by a loss of articular cartilage at the ends of long bones

- causes pain, swelling and reduced motion

- regular activity will improve joint stability and mobility

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Joint classification

Fixed - immovable

Cartilaginous - slightly moveable

Synovial - freely moveable

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Synovial joint

Articular cartilage - smooth/glassy, is spongy and covers the ends of bones to prevent friction and absorb compression

Joint capsule - tough fibrous tissue made of 2 parts; to strengthen the joint and to secrete synovial fluid

Synovial fluid - slippery fluid like egg whites, reduces friction and gets rid of waste debris

Ligament - band of strong fibrous tissue, connecting bone to bone

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Movement patterns

Flexion - closing the angle Extension - opening the angle Horizontal flexion - moviong a joint across the body Horizontal extension - moving a joint away from the body Abduction - moving away from the centre line Adduction - moving towards the centre line Rotation - body turns about its long axis Supination - palms facing upwards Pronation - palms facing downwards Circumduction - joint stays still whilst end of limb moves Dorsi flexion - towards the tibia (ankle) Plantar flexion - away from the tibia (ankle)

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Types of joints

Ball and socket - ball shaped head of bone slots into a cuplike socket

Hinge - a cylindrical end of one bone articulates with a trough shaoed end of the adjacent bone

Pivot - one bone rotating on a longditudinal axis

Condyloid - similar to a ball and socket but with a flatter articulating surface forming a shallow joint

Gliding - bones are flat and similar size

Saddle - bones are shaped like a saddle, concave and convex

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Muscle fibre types

Type 1: - slow twitch fibres - aerobic exercise - fatigue resistance

Type2a: - fast oxidative fibres - anaerobic exercise - more resistant to fatigue than 2b but have less force

Type 2b: - fast glycolytic fibres - greatest anaerobic capacity - generate the most force

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Types of muscles

Skeletal: - to move bones, attached to the skeleton - voluntarily moved

Cardiac: - involuntary movements - held together by intercalated discs

Smooth: - internal organs and blood vessels - contraction is rhythmic and continuos

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How muscles work

Agonisitc - prime mover, the contracting muscle

Antagonistic - the relaxing muscle during movement

Synergist - a muscle contracting to reduce unnecessary movement

Fixator - a muscle contracting to stabalize the joint at the point of origin

Origin - the point that remains fixed during contraction

Insertion - the point of attachment that is responsible for movement

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Muscle contractions

Concentric: - muscle shortens under tension - occurs in the agnostic muscle

Eccentric: - muscle lengthens under tension - occurs in the antagonistic muscle

Isometric: - increase in muscle tension but not in length - no movement at origin or insertion

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Effects of a warm up

- reduction in muscle viscosity leading to greater contraction efficiency

- greater speed and force of contraction due to higher soeed of nerve transmissions

- increased flexibility and elasticity of muscles, lowering chances of injury

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Effects of a cool down

- increased speed of lactic acide removal

- decrease in the risk of DOMS

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Vascular shunt mechanism

- 80-85% of cardiac output to organs at rest

- 80-85% of cardiac output to muscles during work

Vasomotor control centre: - located in the medulla oblongata - stimulates the sympathetic nervous system to vasodilate or vasoconstrict precapillary sphyincters

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Receptors

Chemoreceptors - found in muscles, the aorta and carotid arteries, they inform the VCC of changes in PH and CO2

Baroreceptors - found in the aorta and carotid arteries, informs the VCC of change in blood pressure

Proprioreceptors - found in tendons, organs or muscle spindles, infroms the VCC of movement

Thermoreceptors - found in the skin, informs the VCC of changes in temperature

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Blood vessels

Arteries: - transport oxygenated blood away from the heart - thick elasticated walls, thin inner tube and fast flowing

Capillaries: - bring blood into direct contact with the tissues where O2 and CO2 are exchanged - thin wall for gas exchange

Veins: - transport deoxygenated blood back to the heart

Venous return: - the transport of blood through capillaries/veins back to the heart

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Mechanisms to aid venous return

- pocket valves

- muscle pump

- respiratory pump

- smooth muscle

- gravity

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Cardiac cycle

Heart beat: - diastole, lasting 0.5 seconds, relaxation phase - systole, lasting 0.3 seconds, contraction phase

Heart rate - number of times the heart beats in a minute

Stroke volume - the volume of blood ejected each time the ventricles contract

Cardiac output - the volume of blood ejected by the heart ventricles in 1 minute

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Heart responses to exercise

- heart rate increases

- stroke volume increases

- cardiac output increases

Anticapatory rise - heart rate increases before exercise due to a release of adrenoline

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The heart

Left atrium - top chamber contains oxygenated blood Right atrium - top chamber contains deogygenated blood Left ventricle - bottom chamber contains oxygenated blood Right ventricle - bottom chamber contains deoxygenated blood Bicuspid valve - prevents backflow on the left side of the heart Tricuspid valve - prevents backflow on the right side of the heart Pulmonary vein - only vein to carry oxygenated blood to the heart Pulmonary artery - only artery to carry deoxygenated blood to the lungs Vena cava - main vein returning deoxygenated blood from the body Aorta - main artery leaving the heart carrying oxygenated blood Septum - wall of muscles seperating the ventricles

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Respiratory system

Air passage:

-naval cavity

-pharynx

-larynx

-thrachea

-bronchus

-bronchioles

-alveoli

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Respiratory mechanisms

Tidal volume - volume of air expired per breath

Frequency - number of breaths taken in 1 minute

Minute ventilation - the volume of air expired in 1 minute

ins/expiratory reserve volume - the most forcable amount of air which can be inhaled in a normal breath

Residual volume - air that is always left in the lungs

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Gaseous exchange

Diffusion - movement or gases from and area of high concentration to an area of low concentration

Partical pressure - the pressure a gas exerts within a mixture of gases

Internal respiration - exchange of O2 and CO2 between the muscles and myoglobin

External respiration - exchange of O2 and CO2 between the blood and the alveoli

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Control of breathing

Respiratory control centre: - regulates pulmonary respiration - located in the medulla oblongata

- respiratory muscles are under involuntary nerual control

- expiratory and inspiratory centres help control breathing

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Effects of smoking

What is it - the inhaling of tobacco or a drug

Effects - cancer, headaches, coughs, asthma

Performance effects: - decrease in lung performance - inadequete oxygen to the lungs - constricts blood vessels

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Respiratory adaptations

Structures: - increased alveoli and surface area - increased elasticity

Breathing volumes: - tidal volume can increase - frequency lowers at rest but increases during exercise

Breathing mechanisms: - increased efficiency of respiratory muscles, reducing fatigue

Diffusion: - increase in pulmonary diffusion during maximal activity - increase in VO2 diffusion at maximal activity

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Motion

Linear motion - when a body moves in a straight line, with all its parts moving the same distance in the same direction at the same speed

Angular motion - when a body or part of a body movesin a circle about a point called the axis of rotation

General motion - a combination of linear and angular motion

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Newtons law of inertia

- ' a body continous in a state of rest or uniform velocity unless acted upon by an external force '

- something stays still unless acted up

- eg a football on the penalty spot

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Newtons law of acceleration

- ' when a force acts on an object, the rate of change in momentum experienced by the object is proportional to the size of the force and takes place in the direction in which the force acts '

- eg the speed of the ball is prortional to the force of the kick

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Newtons third law

- ' for every action there is an equal and opposite reaction '

- eg the ball hitting the crossbar and flying back

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Centre of mass

- the point at which the body is balanced in all directions

- this point moves and can even be outside the body

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Stability

- relates to how difficult it is to disturb a body from a balanced position

- stability is determined on: - position of your centre of mass - your line of gravity - your size of support

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Force

Direct force - a force whose line of application passes through the centre of mass has a resulting linear motion

Eccentric force - a force whose line of application passes outside the centre of mass has a resulting angular motion

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