2b. Organisation: circulation key words

Platelets

Fragments of cells that contain clotting factors (chemicals that can cause blood clotting)

Portal Vein

A blood vessel that runs between 2 main body organs rather than from an organ back to the heart.

Pulmonary

Relating to the lungs.

Pulmonary artery

Arteries that carry blood to the lungs from the right hand side of the heart

Pulmonary vein

Blood vessel that brings oxygenated blood to the left atrium from the lungs

Pulse

What you can feel as a result of the stretching of the artery walls when the heart contracts.

Pulse rate

The number of times the heart beats per minute.

Stent

A mesh cylinder that can be inserted into blood vessels and stretched wider (using a tiny balloon) and then left in place to open up narrowed blood vessels.

Stroke volume

The volume of blood pumped out of the heart with every beat.

Systemic

In this context, relating to the circulation to the body systems/organs.

Systole

Part of the cardiac cycle where heart muscle is contracting.

Tendons

Strong connective tissues that are not stretchy.

Tissue fluid

The liquid that bathes all body cells.It is created from blood plasma that is forced out of the

capillaries at the artery end of the capillaries and then

reabsorbed back into the capillaries at the vein end of the

capillaries.

Molecules diffuse between cells and tissue fluid and tissue fluid and the blood

Valve

Flaps of tissue that prevent the backflow of blood.

Vein

Blood vessels that carry blood back towards the heart at low pressure.

Vena Cava

The largest vein in the body that brings blood from body organs back to the heart.

Ventricle

The lower chambers of the heart. Blood is pumped from the atrium into the ventricle. Pumps blood out into the artery

Aorta

The largest artery in the body, taking oxygenated blood to the body organs.

Artery

Blood vessels that carry blood away from the heart at high pressure.

Atherosclerosis (coronary artery/ heart disease)

Narrowing of blood vessels in the heart caused by a build up of fatty deposits (cholesterol) under the lining of the artery. Arteries become less flexible.

Atrium / Atria

The top chamber of the heart where blood flows in from a vein. Pumps blood to the ventricles

Capillary

Very narrow blood vessels that run through organs. Their walls are 1 cell thick.They are the site of exchanges (e.g. O2 and CO2).

Cardiac cycle

The sequence (cycle) of events during a complete heart beat.

Cardiac muscle

The muscle that makes up most of the wall of the heart. It never gets tired. Contracts in an organised way to create blood pressure.

Cardiac output

The volume of blood pumped out by the heart every minute (cm³/min). It is the product of pulse rate and stroke volume.

Coronary artery

The blood vessel that supplies the heart with blood (and therefore supplies oxygen and glucose etc and removes waste like CO2)

Deoxygenated

Blood that has given up most of its oxygen to the respiring tissues.Likely also to have a higher CO2= concentration.

Diastole

Part of the cardiac cycle where heart muscle is relaxing.

Double circulation

Where blood flows through the heart twice on a complete circuit of the body.There are 2 circulations, 1 to the lungs (pulmonary) and 1 to the body organs (Systemic).

Haemoglobin

The red pigment found inside red blood cells. It can combine reversibly with oxygen to form oxyhaemoglobin.

Non-communicable disease

Diseases that cannot be passed from person to person/not caused by pathogens. Can be due to mutations (cancer), lifestyle, diet etc.

Oxygenated

Blood that has a high concentration of oxygen in the red blood cells (haemoglobin is oxyhaemoglobin).

Oxyhaemoglobin

Haemoglobin that has bound to oxygen (in the lungs).

Pacemaker

Part of the heart that coordinates the contraction of the heart and regulates its rate of contraction.

Plasma

The straw coloured liquid (mostly water) part of the blood that contains most of the dissolved substances that the blood carries around eg. glucose , water