Copy of `Feltham Press - Physiology Glossary`

The wordlist doesn't exist anymore, or, the website doesn't exist anymore. On this page you can find a copy of the original information. The information may have been taken offline because it is outdated.

Feltham Press - Physiology Glossary Category: Earth and Environment > Physiology Date & country: 25/11/2007, UK Words: 136

pH
A measure of acidity or alkalinity, pH 7 is neutral, increasing acidity is expressed as a number less than 7; increasing alkalinity as a number greater than 7. The normal pH of blood plasma is 7.35-7.45.

Phosphagen system
The energy system involving ATP and phosphocreatine (PC). Stores of ATP and PC are exploited first in explosive exercise in what is known as the alactic anaerobic system.

Plyometrics
Maximum concentric effort made immediately following an eccentric phase. In simpler terms bounding, hopping, and rebound jumping.

Power
The rate of doing work; the rate of transfer of energy. It is defined in watts (W). 1 watt = 1 joule per second.

Proprioceptors
Internal sensory organs found in muscles, joints and tendons, which detect movements and position of the body.

Protein
Large molecules composed of long chains of amino acids (see also amino acids). Essential for growth and repair, but also a source of energy with one gram of protein supplying four Calories when oxidised. Excess protein (amino acids) cannot be stored as such, therefore daily intake required.

Pulse rate
The rate of the pressure waves generated in the arteries as a result of the contraction (systole) of the left ventricle. In normal, healthy individuals, pulse rate and heart rate are identical.

Reliability
A measure of whether a test gives repeatable results.

Residual volume (RV)
The volume of air left in the lungs after a forced maximal expiration.

Respiratory Exchange Ratio (RER)
The ratio of carbon dioxide produced and oxygen used. Indicates the type of fuel being used in the activity, e.g. aerobic oxidation of glucose (RER = 1), fats (RER = 0.7), and protein (RER = 0.8).

Respiratory Quotient (RQ)
See Respiratory Exchange Ratio.

Sarcomere
The functional unit of a muscle myofibril, consisting of overlapping actin and myosin filaments between two Z discs (bands).

Slow-Twitch (ST) Muscle Fibres
Contract at a rate 2-3 times slower than fast-twitch (FT) fibres, but have greater endurance. Also known as red fibres as a result of the presence of myoglobin and large numbers of mitochondria.

Stationary Air
The air remaining in the lungs during quiet tidal breathing.

Strength
The force that a muscle can exert in one maximal effort.

Stroke volume (SV)
The volume of blood ejected by each contraction (systole) of the ventricle, is calculated by dividing the cardiac output by the heart rate.

Superficial
On or near the surface, visible or palpable (able to feel with hands).

Sympathetic nervous system
The part of the autonomic (involuntary) nervous system responsible for preparing the body for action (see adrenaline.) Antagonistic to the parasympathetic nervous system.

Systemic circulation
The general circulatory system of the body, as opposed to that of the lungs (pulmonary circulation). Blood passes through the heart twice, as it flows from the systemic to the pulmonary and back to the systemic circulation.

Systole
Contraction, as in ventricular systole.

Tachycardia
Resting heart rate faster than average.

Temporal summation
An increase in responsiveness of a nerve or muscle fibre, resulting from the additive effect of frequently occurring stimuli.

Tendon
Tough fibrous tissue attaching muscles to bones.

Testosterone
The male sex hormone secreted by the testes in the male, and by the adrenal cortex in both males and females. Responsible for the development of male characteristics.

Thorax
That part of the body containing the heart and the lungs, separated from the abdomen by the diaphragm.

Tidal volume
The volume of air moved during quiet breathing at rest.

Total lung capacity
Vital capacity + residual volume, difficult to measure.

Validity
A measure of whether a test actually tests what it claims to test, e.g. does the Conconi test give an accurate measure of the anaerobic threshold? (Answer = No)

Vasoconstriction
A decrease in the diameter of a blood vessel (usually an arteriole) by contraction of circular involuntary muscle fibres in the walls, resulting in a reduction of blood flow to the area supplied by the vessel.

Vasodilation
An increase in the diameter of a blood vessel (usually an arteriole) resulting in an increased blood flow to the area supplied by a vessel.

Vasomotor
Relating to the control of vasoconstriction and vasodilation.

Viscosity
'Thickness' of a fluid or 'ease of flow', e.g. plasma has a viscosity which allows it to be pumped rapidly around the body.

Vital Capacity
The total volume of air that can be expired following full inspiration, in other words the total volume of air that can be moved over the lungs in one 'breath'.

Vitamins
Complex organic substances required in the diet (NB vitamin D also produced by the action of ultra-violet light on the skin), essential for normal body functions and maintenance of health. Vitamins contribute to the regulation of metabolic processes, including a role in energy transformations.

Work
Application of a force through a distance; it is measured in joules (J, kJ, MJ).

Work rate
Work performed per unit time = power.