Biology - Transport in Humans

Blood

Transport medium consisting of red blood cells, white blood cells and platelets suspended in plasma.

Red blood cell

Biconcave cells with no nucleus. Contains haemoglobin protein which binds to oxygen to transport it around the body.

White blood cell

Two main types: lymphocytes and phagocytes. Destroy microorganisms as a part of the body’s immune response

Plasma

Liquid part of the body, consists of mainly water that carries the blood cells, dissolved nutrients, hormones, carbon dioxide and urea around the body.

Platelets

Release chemicals to make blood clot

Haemoglobin

Protein present in red blood cells that binds with oxygen and carries it around the body.

Heart

Major organ in the human circulatory system that acts like a pump

Lungs

Site of gas exchange, where oxygen diffuses into the blood and carbon dioxide diffuses out of the blood.

Arteries

Blood vessels with a thick muscular wall and narrow lumen. Mostly carries oxygenated blood

Veins

Blood vessels with a thin muscular wall and wide lumen with valves. Mostly carries deoxygenated blood.

Capillaries

Microscopic blood vessels that carry blood through the organs and allow the exchange of substances between the blood and cells.

Aorta

Carries oxygenated blood around the body from the left ventricle.

Pulmonary artery

Carries deoxygenated blood to the lungs from the right ventricle.

Pulmonary vein

carries oxygenated blood from the lungs to the left atrium.

Vena cava

Carries deoxygenated blood from the body to the right atrium.

Heart rate

Normal resting heart rate is ~70bpm, controlled by the cardiac centre in a part of the brain.

Adrenaline

Hormone secreted from the adrenal glands that causes heart rate to increase as part of the ‘fight or flight’ response.

Coronary arteries

Blood vessels that supply the cardiac muscles (walls of the heart) with blood.

Coronary heart disease

Disease caused by blockage of the coronary arteries due to build up of fatty materials. Can cut off blood supply to the heart and cause a heart attack.

Hepatic artery

Carries oxygenated blood to the liver

Hepatic vein

Carries deoxygenated blood away from the liver

Renal artery

Carries oxygenated blood to the kidneys

Renal vein

carries deoxygenated blood away from the kidneys.

How do adaptation of a red blood cell make them suitable to transport oxygen?

Biconcave shape allows for greater surface area for oxygen to attach.

No nucleus to make more space for haemoglobin.

Lots of haemoglobin is present to bind to the oxygen so it can transport as much as possible.

Flexible to fit through small blood vessels.

Risk factors for developing CHD

Smoking, eating fatty food and doing no exercise.