Human Cardiovascular and Respiratory System Key Terms for Exercise Science

Anticipatory rise

An increase in heart rate prior to exercise, due to the release of adrenalin.

Arterio-venous oxygen difference (A-VO2 diff)

The difference in the oxygen content of the blood between the arterial blood and the venous blood.

Blood pressure

Blood pressure is a measure of the force that your blood exerts against blood vessel walls.

Systolic blood pressure

Blood pressure while the heart is contracting.

Diastolic blood pressure

Blood pressure while the heart is relaxing.

High blood pressure

Can occur for many reasons including obesity; eating too much salt; stress; or smoking.

Bohr shift

The Bohr shift is when an oxyhaemoglobin dissociation curve moves to the right during exercise.

Bradycardia (athlete's heart)

A reduction in resting heart rate below 60 beats per minute.

Cardiac conduction system

A group of specialised cardiac muscle cells in the walls of the heart that send signals to the heart muscle, causing it to contract.

Cardiac hypertrophy

Increase in thickness of the muscular heart wall, especially around the left ventricle.

Cardiac output

The amount of blood which leaves the left ventricle per minute.

Cardiovascular drift

A reduction in stroke volume when exercising in warm conditions for longer than 10 minutes.

Cholesterol

A type of fat which is transported in the blood.

Haemoglobin

Found in red blood cells, combines with oxygen to form oxyhaemoglobin, transporting it around the body.

Heart disease

Occurs when coronary blood vessels become blocked by fatty deposits, limiting the supply of oxygenated blood to the heart.

Myoglobin

Found in muscle cells, stores and transports oxygen.

Receptors

Part of the nervous system that detects changes in the body.

Redistribution of blood

The vascular shunt mechanism directs blood flow around the body.

Starling's law of the heart

Increased venous return will result in a higher stroke volume.

Stroke

A serious life-threatening medical condition that happens when the blood supply to part of the brain is cut off.

Sympathetic nervous system

The body's 'fight or flight' system, speeding up heart rate.

Parasympathetic nervous system

Concerned with 'rest and digest', decreasing heart rate.

Venous return mechanisms

Several mechanisms to return blood to the right side of the heart via the vena cava.

Diffusion

The movement of gases from an area of high partial pressure to an area of low partial pressure.

Expiratory reserve volume

The volume of air which could be forcibly expired in addition to tidal volume.

Inspiratory reserve volume

The volume of air which could be forcibly inspired in addition to tidal volume.

Minute ventilation

Volume of air inspired or expired per minute.

Partial pressure

The pressure exerted by an individual gas in a mixture of gases.

Residual volume

The volume of air which must remain in the lungs after a maximal expiration.

Tidal volume

Volume of air breathed in or out per breath.

All or none law

Impulses arriving at the neuron must reach a threshold level.

Fast glycolytic (type IIx)

These muscle fibres produce the highest force and speed of contraction, via the anaerobic respiration. They are highly susceptible to fatigue.

Fast oxidative glycolytic (type IIa)

These muscle fibres produce a high force and speed of contraction, primarily via the anaerobic respiration. However, a limited degree of aerobic capacity allows some fatigue resistance.

Golgi tendon organ

Proprioceptors which are activated when there are high levels of tension in a muscle. They can initiate autogenic inhibition, which is a sudden relaxation of a muscle.

Motor units

A motor neuron and its muscle fibres. A motor neuron is the nerve cell which transmits electrical impulses to the muscle fibres.

Muscle spindles

Proprioceptors which detect how far or fast a muscle is stretching. They initiate the stretch reflex, where a muscle will contract, to prevent over stretching.

PNF (proprioceptive neuromuscular facilitation)

An advanced stretching technique. Considered to be one of the most effective methods for increasing range of motion at a joint.

Slow twitch (type I)

These muscle fibres produce a low force and speed of contraction, via aerobic respiration. However, they are highly fatigue resistant, allowing them to continue working for long periods of time.

Spatial summation

The addition of impulses received at the same time, but at different locations on the neuron. If, when added together, the impulses are large enough an action potential will be released.

Tetanic contraction

A smooth sustained muscle contraction. Not a muscle twitch.

Wave summation

Repeated nerve impulse which does not allow the muscle fibres time to fully relax. This results in a tetanic contraction.

Abduction

The movement of a limb away from the midline of the body.

Adduction

The movement of a limb towards the midline of the body.

Agonist

The muscle responsible for the movement which is occurring.

Antagonist

The muscle working in opposition to the agonist to help produce a smooth movement.

Articulating bones

Where two or more bones meet to allow movement at a joint.

Axis

Imaginary line through the body around which it rotates.

Dorsi flexion

Decreasing the angle at the ankle joint.

Elbow

Hinge joint, made up of the humerus, radius, and ulna.

Extension

Increasing the angle at a joint.

Flexion

Decreasing the angle at a joint.

Hip

Ball and socket joint, made up of the pelvis and femur.

Horizontal abduction

Movement of a limb away from the midline of the body while held parallel to the ground.

Horizontal adduction

Movement of a limb towards the midline of the body while held parallel to the ground.

Hyperextension

Increasing the angle at a joint beyond 180 degrees.

Isometric contraction

The muscle contracts but no movement occurs.

Isotonic concentric

A muscle contracts and shortens producing movement.

Isotonic eccentric

A muscle lengthens under tension controlling the speed of a movement caused by gravity.

Knee

A hinge joint, made up of the femur and tibia.

Plantar flexion

Increasing the angle at the ankle.

Shoulder

A ball and socket joint made up of the scapula and humerus.

Aerobic energy system

Resynthesis of ATP in the presence of oxygen.

Altitude training

Training at altitude where there is less oxygen.

Anaerobic glycolytic system

Resynthesises ATP quickly for up to 3 minutes but produces fatiguing by-products.

ATP-PC system

Fastest energy system at resynthesising ATP due to the limited number of chemical reactions required.

Energy continuum of physical activity

Refers to the changing mix of energy systems which provide the ATP required across different activities and durations.

Excess post-exercise oxygen consumption (EPOC)

Increased rate of oxygen intake following activity, intended to pay back the oxygen deficit.

High intensity interval Training (HIIT)

Alternating periods of short high intense anaerobic exercise with less intense, aerobic, recovery periods.

Indirect calorimetry

A technique that provides an estimation of energy expenditure from the amount of carbon dioxide produced and oxygen consumed during rest and steady-state exercise.

Lactate sampling

A tiny blood sample is taken to be analysed by a device. This measures how much lactate is present in the blood.

Lactate threshold

The point at which lactic acid accumulates quickly in the blood.

Onset of blood lactate accumulation (OBLA)

The point at which lactic acid exceeds 4mmols per litre in the blood.

Oxygen deficit

The difference between the oxygen required during exercise and the oxygen supplied and utilised.

Plyometrics

Anaerobic training method based on the concept that muscles contract with more force following an eccentric contraction.

Respiratory exchange ratio (RER)

The ratio of carbon dioxide produced to the oxygen consumed.

Speed agility quickness (SAQ)

This anaerobic method of training aims to improve an athlete's multi-directional movement by reprogramming their neuromuscular system.

VO2 max

The maximum amount of oxygen that can be taken in, transported, and used by the body per minute.

VO2 max test

VO2 max can be estimated using tests such as the multistage fitness test.