Biology · Edexcel Paper 2
Blood, Blood Vessels and the Heart
How the structure of the blood, the blood vessels and the heart is related to their functions, how the double circulation carries blood to the lungs and to the body, and how to calculate heart rate, stroke volume and cardiac output. Matches Edexcel Topic 8.6 to 8.8 and 8.12. Every lesson is for both Combined Science and separate Biology, at Foundation and Higher.
Lessons
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1
The Structure and Functions of Blood
Blood is a tissue made of a liquid and three kinds of cell, and each part has a structure that suits its job. This lesson is for both Combined Science and…
10 terms -
2
Arteries, Veins and Capillaries
Blood travels round the body in three types of vessel, and each one is built for the job it does. This lesson is for both Combined Science and separate…
10 terms -
3
The Heart and Double Circulation
The heart is two pumps in one, and the blood passes through it twice on every trip round the body. This lesson is for both Combined Science and separate…
10 terms -
4
Heart Rate, Stroke Volume and Cardiac Output
How hard is your heart working, and how does it change when you run? This lesson is for both Combined Science and separate Biology, at Foundation and Higher…
10 terms -
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Key terms in this chapter
All 40, gathered from every lesson.
- Plasma
- The pale yellow liquid part of the blood, which carries dissolved substances, hormones, heat and blood cells.
- Red blood cell
- A blood cell with no nucleus that is full of haemoglobin and carries oxygen (an erythrocyte).
- Haemoglobin
- The red protein in red blood cells that contains iron and combines with oxygen.
- Oxyhaemoglobin
- The bright red compound formed when haemoglobin combines with oxygen in the lungs.
- Biconcave disc
- The flattened shape of a red blood cell, curved in on both sides, which gives a large surface area.
- White blood cell
- A blood cell with a nucleus that defends the body against pathogens (a leucocyte).
- Phagocyte
- A white blood cell that engulfs and digests pathogens by phagocytosis.
- Lymphocyte
- A white blood cell with a large round nucleus that makes antibodies.
- Antibody
- A protein made by a lymphocyte that sticks to a particular pathogen and helps to destroy it.
- Platelet
- A small fragment of a cell with no nucleus that helps blood to clot.
- Artery
- A blood vessel that carries blood away from the heart at high pressure.
- Vein
- A blood vessel that carries blood towards the heart at low pressure.
- Capillary
- A tiny blood vessel with a wall one cell thick, where substances are exchanged with the cells.
- Lumen
- The space inside a blood vessel through which the blood flows.
- Elastic fibres
- Fibres in the wall of an artery that stretch and recoil to smooth the flow and keep up the pressure.
- Valve
- A flap in a vein or in the heart that stops the blood flowing backwards.
- Blood pressure
- The force that the blood puts on the walls of the vessels.
- Pulse
- The stretching and recoil of an artery wall with each beat of the heart.
- Rate of blood flow
- The volume of blood that flows past a point in a given time.
- Magnification
- How many times larger an image is than the real object.
- Atrium
- An upper chamber of the heart that receives blood from the veins (plural atria).
- Ventricle
- A lower chamber of the heart with a thick muscular wall that pumps blood into the arteries.
- Septum
- The wall of muscle that separates the left and right sides of the heart.
- Vena cava
- The large vein that brings deoxygenated blood from the body to the right atrium.
- Aorta
- The largest artery, which carries oxygenated blood from the left ventricle to the body.
- Pulmonary artery
- The artery that carries deoxygenated blood from the right ventricle to the lungs.
- Pulmonary vein
- The vein that carries oxygenated blood from the lungs to the left atrium.
- Atrioventricular valve
- A valve between an atrium and a ventricle that stops the blood flowing back into the atrium.
- Semilunar valve
- A valve at the start of the aorta or pulmonary artery that stops the blood flowing back into the ventricle.
- Double circulation
- A circulation with two circuits, one to the lungs and one to the body, so blood passes through the heart twice on each trip.
- Heart rate
- The number of times the heart beats in one minute, measured in beats per minute.
- Stroke volume
- The volume of blood pumped out of a ventricle in one heartbeat.
- Cardiac output
- The volume of blood pumped out of the heart in one minute, equal to stroke volume times heart rate.
- Beats per minute
- The unit of heart rate, written bpm.
- Pulse
- The stretching and recoil of an artery wall with each heartbeat, which can be counted to find the heart rate.
- Resting heart rate
- The heart rate of a person who has been sitting quietly, usually about 60 to 80 beats per minute.
- Recovery time
- The time that it takes the heart rate to return to its resting value after exercise.
- Cardiac muscle
- The special muscle of the heart wall, which contracts without tiring.
- Adrenaline
- A hormone that makes the heart beat faster and prepares the body for action.
- Aerobic exercise
- Exercise that is fuelled by respiration with oxygen, such as running or cycling, and which trains the heart.