85 of the SEHS glossary’s terms, each with the part of the syllabus where you first meet it.
The dark band of a sarcomere, equal to the length of the myosin filaments, which stays the same length during contraction.
A movement in the frontal plane that takes a body part away from the midline of the body, such as raising the arm sideways at the shoulder.
A stable, enduring and largely inherited trait, such as balance, coordination or reaction time, that underlies the performance of a range of skills.
A superficial wound in which the outer layers of skin are scraped off by friction against a rough surface, such as a graze from a fall on a road or artificial pitch.
The rate of change of velocity, ; a vector measured in m s⁻². A negative acceleration, a decrease in velocity, is called deceleration.
The physiological adaptations that develop with repeated or continuous exposure to a stressful environment such as heat, cold or altitude, reducing its strain on the body and improving performance in it.
How close a measured or calculated value is to the true or accepted value of the quantity.
A neurotransmitter released by motor neurons at the neuromuscular junction, which binds to receptors on the sarcolemma and starts a muscle action potential.
A theory proposing that people strive to feel successful and competent, and judge success either against their own previous performance (task orientation) or against other people (ego orientation).
A person’s drive to strive for success, master tasks and do well in situations where their performance can be evaluated against a standard or against other people.
A fall in muscle or blood pH caused by hydrogen ions accumulating faster than they are buffered during high-intensity exercise; it inhibits enzymes such as phosphofructokinase and calcium binding.
The thin protein filament of the sarcomere, anchored to the Z lines, which has binding sites for myosin heads and is pulled towards the centre of the sarcomere during contraction.
Low-intensity exercise performed after training or between bouts to keep blood flow high and speed the removal of metabolites such as lactate and hydrogen ions.
An illness caused by rapid ascent to high altitude, usually above about 2,500 m, with headache, nausea, fatigue, dizziness and poor sleep, which usually ease within a few days.
An immediate, short-term change in the body during or just after a single bout of exercise, which returns to resting values during recovery.
An injury caused by a single, sudden or excessive application of force, or by a force from an unexpected direction, such as a ligament torn in a tackle or a bone broken in a fall.
A movement in the frontal plane that brings a body part towards the midline of the body, such as lowering the arm from the side back to the trunk.
The molecule left when ATP loses its terminal phosphate group and releases energy; it is rebuilt into ATP with inorganic phosphate using energy from the breakdown of fuels.
A molecule made of adenosine and three phosphate groups that is the immediate source of energy for muscle contraction; energy is released when the bond to its terminal phosphate is broken.
A pair of endocrine glands on top of the kidneys; the adrenal medulla releases epinephrine and norepinephrine, and the adrenal cortex releases hormones such as cortisol and aldosterone.
Describes a process that requires oxygen, such as the resynthesis of ATP by the oxidative system in the mitochondria.
The part of the peripheral nervous system that carries nerve impulses from receptors towards the central nervous system; also called the sensory division.
An opportunity for action that the environment offers a particular performer, depending on both the environment and the performer's capabilities, for example a gap that affords a pass.
A skill-related component of fitness: the ability to change the direction of the whole body quickly and accurately while maintaining control.
The muscle that contracts to produce a particular movement at a joint; also called the prime mover.
A Big Five trait describing how well an individual relates to others and acts in ways that preserve relationships, being cooperative, trusting and considerate.
The mass of air per unit volume, about 1.2 kg per cubic metre at sea level; it falls as altitude, temperature and humidity rise, reducing drag and lift.
Drag acting on a body moving through air; it opposes the body's motion and increases as the body's speed increases.
A hormone secreted by the adrenal cortex that increases reabsorption of sodium, and excretion of potassium, by the kidneys, so that water follows by osmosis and blood volume is maintained.
The principle that when a motor neuron is stimulated above its threshold, all the muscle fibres of that motor unit contract fully, and below threshold none of them contract.
A statement that there is a real difference between conditions or a real relationship between variables, accepted when the data allow the null hypothesis to be rejected.
Training or living at altitude, usually about 1,800–3,000 m, or in simulated low-oxygen conditions, to increase red cell mass and haemoglobin and so improve endurance performance.
Tiny, thin-walled air sacs at the ends of the bronchioles, surrounded by capillaries, where oxygen diffuses into the blood and carbon dioxide diffuses out of it.
The building block of proteins; an organic molecule containing a nitrogen-containing amino group and an acid group, of which twenty kinds are found in human proteins.
The absence of motivation, which occurs when a person perceives no link between their effort and the outcome, or places no value on the activity.
A condition in which the blood's haemoglobin concentration or number of red blood cells is below normal, reducing its ability to carry oxygen; iron deficiency is the most common cause.
Describes a process that takes place without oxygen, such as the resynthesis of ATP by the phosphagen and glycolytic systems in the sarcoplasm.
The standard reference posture from which positions and movements are described: standing upright facing forward, feet slightly apart, arms by the sides and palms facing forward.
The angle between the long axis of a body, such as a discus, javelin or ski jumper, and the direction of the fluid flow relative to it; it determines how much lift and drag are produced.
The angle to the horizontal at which a projectile is released or takes off, also called the angle of projection; it decides how the speed of release is shared between horizontal and vertical motion.
The quantity of rotation possessed by a rotating body, equal to its moment of inertia multiplied by its angular velocity; measured in kg m² s⁻¹.
Movement of a body or body segment along a circular path about an axis of rotation, so that different parts travel different distances; also called rotation.
The angle turned through by a rotating body per unit of time, in a stated direction, measured in rad s⁻¹; linked to linear velocity by .
The muscle on the opposite side of a joint to the agonist, which relaxes and lengthens to allow the agonist to produce a movement.
Two muscles on opposite sides of a joint that produce opposite movements, so that one acts as the agonist while the other acts as the antagonist, such as the biceps and triceps brachii.
A positional term meaning towards the front of the body, also called ventral, for example the patella is anterior to the knee joint.
A ligament inside the knee running from the back of the femur to the front of the tibia, which stops the tibia sliding forward on the femur and limits rotation of the knee.
A collection of standardised body measurements from a large, defined sample of people, used to describe a population's dimensions and percentiles and to design and size equipment.
The measurement of the size, shape, proportions and composition of the human body, including stature, body mass, segment lengths, breadths, girths and skinfolds.
The increase in heart rate and other sympathetic responses before exercise begins, caused by sympathetic stimulation and the release of epinephrine in response to the expectation of exercise.
A hormone made by the hypothalamus and released by the posterior pituitary when the blood is too concentrated, which increases water reabsorption by the kidneys; also called vasopressin.
A negative emotional state characterised by nervousness, worry and apprehension, associated with activation or arousal of the body.
The bones of the upper and lower limbs together with the shoulder and pelvic girdles that attach them to the axial skeleton; its main function is movement.
Behaviour in which a person seeks out and engages with achievement situations, for example choosing realistic challenges, persisting after failure and welcoming evaluation.
A principle stating that the buoyant force on a body immersed in a fluid equals the weight of the fluid the body displaces.
The level of physiological and psychological activation of a person, varying on a continuum from deep sleep to intense excitement.
A small branch of an artery leading into a capillary network, whose muscular wall narrows or widens to control how much blood flows into the capillaries it supplies.
The difference between the oxygen content of arterial and mixed venous blood, usually in mL of oxygen per 100 mL of blood, showing how much oxygen the tissues extract.
A blood vessel that carries blood away from the heart under high pressure, with a thick wall of smooth muscle and elastic tissue and a relatively narrow lumen.
The smooth layer of hyaline cartilage covering the ends of bones in a synovial joint, which reduces friction between the bones and absorbs and spreads load.
A joint: a place where two or more bones meet, classified by structure as fibrous, cartilaginous or synovial.
One of the four broad skills the course assesses: demonstrating knowledge (AO1), understanding and applying knowledge (AO2), analysing, evaluating and synthesising (AO3), and carrying out insightful, ethical investigations (AO4).
The second, practice phase of learning, in which subroutines are linked, errors become fewer and smaller, and the learner begins to use intrinsic feedback.
The build-up of fatty plaques of lipid, cholesterol, immune cells and fibrous tissue in the walls of arteries, which narrows them, reduces their elasticity and can lead to a blocking blood clot.
The enlargement of the heart, especially the left ventricle, caused by regular intense training, which increases stroke volume and maximal cardiac output as a healthy adaptation.
A group of specialised cells between the atria and ventricles that receives the impulse from the atria and delays it by about 0.1 s before passing it to the bundle of His.
One of the two thin-walled upper chambers of the heart, which receives blood from the veins and pumps it into the ventricle below.
A decrease in the size of a muscle caused by a loss of contractile proteins from its fibres, usually because of disuse, immobilisation, injury, illness, ageing or malnutrition.
The process of focusing mental resources on selected information from the environment or from within the body, while ignoring other information.
The direction (internal or external) and width (broad or narrow) of a person's attention at a particular moment, meaning what they attend to and how much information they take in.
A reduction in the width of attention as arousal increases, so that fewer cues are processed and, at high arousal, relevant cues are missed.
A stable, preferred pattern of coordination, such as walking or running, that a movement system settles into because it is efficient under the current constraints.
The reason an individual gives to explain the cause of an outcome, such as a success or a failure, for example ability, effort, task difficulty or luck.
An intervention that teaches individuals to attribute failure to unstable, controllable causes such as effort or strategy, rather than to stable, uncontrollable causes such as lack of ability.
A theory describing how individuals explain the causes of their successes and failures, and how these explanations affect their emotions, expectations, confidence and future behaviour.
A relaxation technique in which an individual repeats self-suggestions about sensations such as heaviness and warmth in the limbs and a calm heartbeat to produce deep relaxation.
The branch of the efferent division that controls involuntary functions through cardiac muscle, smooth muscle and glands; it has sympathetic and parasympathetic divisions.
Motivation in which an activity is done with a full sense of choice because it is enjoyable, interesting or personally valued, so that it is experienced as an end in itself.
The final phase of learning, in which the skill is performed automatically, consistently and efficiently with little conscious attention, and the performer corrects their own errors.
The basic psychological need to feel that one’s behaviour is self-chosen and self-endorsed, so that one is the origin of one’s own actions rather than pushed by outside pressure.
A general tendency to act out of interest in and valuing of what is happening, to seek choice and to treat events as sources of information.
Behaviour in which a person withdraws from or minimises involvement in achievement situations, for example avoiding competition, choosing very easy or very hard tasks, withdrawing effort or making excuses.
Coping strategies that try to prevent the negative impact of a stressor by physically or psychologically distancing oneself from it, such as ignoring, procrastinating, distraction or quitting.
The part of the skeleton forming the central axis of the body (skull, vertebral column, ribs and sternum), whose main functions are protecting vital organs and supporting the body.
An imaginary line about which a body or body segment rotates, passing through the joint or centre of mass and lying at right angles to the plane of movement.