What you'll learn
Applied anatomy and physiology is the study of how the body's systems (the skeleton, muscles, heart, blood vessels and lungs) work together to produce movement and to supply the energy that physical activity needs. In AQA GCSE Physical Education (8582) it is the largest topic on Paper 1: The human body and movement in physical activity and sport (1 hour 15 minutes, 78 marks, 30% of the GCSE). This guide covers the structure and functions of the musculo-skeletal system, joints and the movements they allow, the major muscles and how they work in antagonistic pairs, the cardio-respiratory system (the pathway of air, gaseous exchange, blood vessels, the heart and cardiac output, the mechanics of breathing and lung volumes), aerobic and anaerobic exercise, recovery, and the immediate, short-term and long-term effects of exercise. It sticks to what the GCSE specification requires: for example, you need to know the pathway of blood through the heart, but the names of the heart's valves are not required.
Key terms and definitions
Articulating bones — The bones that meet at a joint, such as the humerus, radius and ulna at the elbow.
Ligament — Tough tissue that joins bone to bone, keeping joints stable.
Tendon — Tough tissue that joins muscle to bone, so that muscle contraction moves the bone.
Cartilage — Smooth tissue covering the ends of bones at a joint, reducing friction and absorbing shock.
Agonist — The muscle that contracts to produce a movement (the prime mover).
Antagonist — The muscle that relaxes and lengthens to allow the movement.
Isotonic contraction — The muscle changes length as it contracts. Concentric: the muscle shortens. Eccentric: the muscle lengthens while under tension.
Isometric contraction — The muscle contracts but stays the same length, so there is no movement, as in holding a plank.
Gaseous exchange — The movement of oxygen from the alveoli into the blood and of carbon dioxide from the blood into the alveoli, by diffusion.
Stroke volume — The volume of blood pumped out of the left ventricle in each contraction.
Heart rate — The number of times the heart beats per minute (bpm).
Cardiac output — The volume of blood pumped out of the heart per minute: stroke volume × heart rate.
Tidal volume — The volume of air breathed in or out in one normal breath.
Vital capacity — The largest volume of air that can be breathed out after breathing in as much as possible.
EPOC — Excess post-exercise oxygen consumption, also called oxygen debt: the extra oxygen needed after exercise to recover.
Core concepts
Functions of the skeleton
The skeleton provides support, protection of vital organs (the cranium protects the brain, the ribs protect the heart and lungs), movement (bones act as levers moved by muscles), structural shape and points for muscle attachment, mineral storage (calcium and phosphorus) and blood cell production (red cells, white cells and platelets made in bone marrow).
The bones you should know are the cranium, vertebrae, ribs, sternum, scapula, humerus, radius, ulna, carpals, metacarpals, phalanges, pelvis, femur, patella, tibia, fibula and talus.
Joints and movements
| Joint type | Example | Articulating bones | Movements |
|---|---|---|---|
| Pivot | Neck | Atlas and axis (cervical vertebrae) | Rotation |
| Hinge | Elbow | Humerus, radius, ulna | Flexion, extension |
| Hinge | Knee | Femur, tibia | Flexion, extension |
| Hinge | Ankle | Tibia, fibula, talus | Plantar flexion, dorsiflexion |
| Ball and socket | Shoulder | Humerus, scapula | Flexion, extension, abduction, adduction, rotation, circumduction |
| Ball and socket | Hip | Pelvis, femur | Flexion, extension, abduction, adduction, rotation |
| Condyloid | Wrist | Radius, ulna, carpals | Flexion, extension, abduction, adduction, circumduction |
Flexion decreases the angle at a joint (bending the knee); extension increases it (straightening the leg). Abduction moves a limb away from the midline of the body (raising the arm sideways); adduction moves it towards the midline. Rotation turns a body part around its own axis; circumduction moves a limb in a circle, as in bowling in cricket. Plantar flexion points the toes (standing on tiptoes); dorsiflexion pulls the toes up towards the shin.
Muscles and antagonistic pairs
The major muscles and their main actions are: deltoid (moves the arm at the shoulder, including abduction), latissimus dorsi (adduction and extension at the shoulder), rotator cuff (rotation at the shoulder), pectorals (adduction and flexion at the shoulder), biceps (flexion at the elbow), triceps (extension at the elbow), abdominals (flexion of the trunk), hip flexors (flexion at the hip), gluteals (extension at the hip), quadriceps (extension at the knee), hamstrings (flexion at the knee), gastrocnemius (plantar flexion at the ankle) and tibialis anterior (dorsiflexion at the ankle).
Muscles work in antagonistic pairs because they can only pull, not push. In a biceps curl, the biceps is the agonist and the triceps the antagonist during the lifting (upward) phase. Other pairs are the quadriceps and hamstrings, the hip flexors and gluteals, and the gastrocnemius and tibialis anterior.
The pathway of air and gaseous exchange
Air travels through the mouth/nose, trachea, bronchi, bronchioles and into the alveoli. Gaseous exchange happens at the alveoli, which are adapted for efficient diffusion: they have a large surface area, moist, thin walls (one cell thick), a short diffusion distance to the capillaries and a large blood supply. Oxygen diffuses from a high concentration in the alveoli to a lower concentration in the blood, where it is carried by haemoglobin in red blood cells; carbon dioxide diffuses the other way.
Blood vessels and vascular shunting
Arteries carry blood away from the heart at high pressure and have thick, muscular, elastic walls. Capillaries are one cell thick, allowing gases and nutrients to pass in and out. Veins carry blood back to the heart at low pressure and have thinner walls and valves to prevent backflow.
During exercise, vascular shunting redirects blood to the working muscles. Blood vessels supplying the muscles widen (vasodilation), while those supplying organs such as the stomach narrow (vasoconstriction). This is one reason performers should not eat a large meal shortly before exercise.
The heart and cardiac output
The heart is a double pump. The right side pumps deoxygenated blood to the lungs; the left side pumps oxygenated blood to the body. The pathway is: vena cava → right atrium → right ventricle → pulmonary artery → lungs → pulmonary vein → left atrium → left ventricle → aorta → body. Valves keep blood flowing in one direction, but you do not need to name them. In the cardiac cycle, the atria contract to fill the ventricles, then the ventricles contract to push blood out of the heart, and the heart relaxes and refills.
Cardiac output = stroke volume × heart rate. During exercise both stroke volume and heart rate rise, so cardiac output increases to deliver more oxygen to the muscles.
Breathing and lung volumes
At rest, inhalation happens when the diaphragm contracts and flattens and the external intercostal muscles lift the ribs up and out, increasing the volume of the chest so air is drawn in. Exhalation at rest is mostly passive as these muscles relax. During exercise, the pectorals and sternocleidomastoid help to lift the ribs further for deeper inhalation, and the abdominals contract to force air out more quickly.
A spirometer trace shows lung volumes. During exercise, tidal volume increases as breathing becomes deeper, using some of the inspiratory and expiratory reserve volumes. The residual volume is the air that always remains in the lungs.
Aerobic and anaerobic exercise
Aerobic exercise uses oxygen and is used for long, low- to moderate-intensity activity such as marathon running: glucose + oxygen → carbon dioxide + water + energy. Fat is also used aerobically at low intensity.
Anaerobic exercise works without oxygen and is used for short, high-intensity activity such as a 100 m sprint: glucose → lactic acid + energy. Lactic acid builds up and causes fatigue, so anaerobic work can last only a short time.
After exercise, EPOC (oxygen debt) is the extra oxygen needed to remove lactic acid and return the body to its resting state, which is why breathing stays fast and deep after a sprint.
Recovery
Recovery methods include a cool down (gentle exercise and stretching to keep breathing and heart rate elevated for a time, helping remove lactic acid and reduce stiffness), manipulation of diet (rehydrating and eating carbohydrates to restore energy stores), and ice baths and massage to reduce delayed onset of muscle soreness (DOMS).
Effects of exercise
- Immediate effects (during exercise): hot, sweaty and red skin, increased depth and frequency of breathing, and increased heart rate.
- Short-term effects (up to about 36 hours after): tiredness or fatigue, light-headedness, nausea, aching muscles (DOMS) and cramp.
- Long-term effects (months of training): changes to body shape, improvements in specific components of fitness, muscle hypertrophy and improved muscular endurance, a bigger, stronger heart, a lower resting heart rate (bradycardia), increased stroke volume and improved cardiovascular endurance.
Worked examples
Example 1: Calculating cardiac output
At rest a performer has a stroke volume of 70 ml and a heart rate of 70 bpm. Cardiac output = 70 × 70 = 4,900 ml per minute (4.9 litres). During exercise, stroke volume rises to 120 ml and heart rate to 150 bpm, so cardiac output = 120 × 150 = 18,000 ml per minute (18 litres). The rise delivers more oxygen to the working muscles.
Example 2: Analysing a joint action
Question: Identify the joint type, movement and agonist at the knee as a footballer kicks a ball. The knee is a hinge joint. As the leg swings through to strike the ball, extension occurs, and the quadriceps are the agonist, with the hamstrings as the antagonist.
Example 3: Choosing the energy system
A netball player sprints to intercept a pass. This is anaerobic, because the effort is short and maximal and the body cannot supply oxygen quickly enough. During the rest of the match, jogging back into position is mainly aerobic.
Example 4: Explaining vascular shunting
Question: Why should a swimmer avoid a large meal just before a race? During exercise, blood is shunted away from the digestive system towards the working muscles by vasoconstriction and vasodilation. A full stomach would need blood for digestion, competing with the muscles, which could cause cramp or reduce performance.
Common mistakes and how to avoid them
Do not confuse tendons (muscle to bone) with ligaments (bone to bone).
Do not describe the pathway of blood starting in the left atrium. Deoxygenated blood returns to the right atrium through the vena cava.
Do not say arteries have valves. Veins have valves because blood is under low pressure.
Do not confuse tidal volume with vital capacity. Tidal volume is a normal breath; vital capacity is the maximum breath out after a maximum breath in.
Do not write "lactic acid + energy" for aerobic respiration. Aerobic respiration produces carbon dioxide and water.
Do not swap concentric and eccentric. The biceps contracts concentrically as the weight rises and eccentrically as it is lowered under control.
Exam technique for "Applied anatomy and physiology"
Use the specification's names exactly: pivot, hinge, ball and socket, condyloid; plantar flexion and dorsiflexion. When analysing a sporting action, give the joint type, articulating bones, movement and agonist in that order. Show every step of a cardiac output calculation with units. For "explain" questions about effects of exercise, link the change to performance, for example "a lower resting heart rate means the heart is more efficient, so the performer can work for longer". Expect data questions on heart rate graphs or spirometer traces: describe the trend first, then explain it.
Quick revision summary
- Skeleton functions: support, protection, movement, shape and muscle attachment, mineral storage, blood cell production.
- Joints: pivot (neck), hinge (elbow, knee, ankle), ball and socket (shoulder, hip), condyloid (wrist).
- Antagonistic pairs: biceps/triceps, quadriceps/hamstrings, hip flexors/gluteals, gastrocnemius/tibialis anterior.
- Contractions: isotonic (concentric, eccentric) and isometric.
- Alveoli: large surface area, thin moist walls, short diffusion distance, rich blood supply.
- Cardiac output = stroke volume × heart rate.
- Aerobic: glucose + oxygen → carbon dioxide + water + energy. Anaerobic: glucose → lactic acid + energy.
- EPOC repays the oxygen debt; recovery uses a cool down, diet, ice baths and massage.
- Long-term effects include a lower resting heart rate and increased stroke volume.