Circulatory and Gas Exchange System Keywords

Human Biology key terms and words for revision. 

  • Created by: Parmz
  • Created on: 15-03-13 20:16


When the heart muscle is relaxed and the atria of the heart, and then the ventricles are filling with blood. 

1 of 26

Atria systole

The muscular wall of the atria contracts. This pushes the blood from the atria into the ventriles, so that the atria are now emptied. This pushes the atrio-ventricular valves fully open. 

2 of 26

Ventricular Systole

The muscular walls of the ventricles contract. The atrio-ventricular valves are forced shut. They can only open one way this works accordingly due to the pressure. 

3 of 26


Stimulates by itself 

4 of 26

Electrocardiogram (ECG)

Is used to monitor heart function. 

5 of 26

Ventricular Fibrillation

There is no P wave and no QRS wave, this is because the muscle in the heart wall is not contracting in a coordinated way: likely that this person has had a heart attack and is certain to be unconscious and needs urgent medical attention or he will die. 

6 of 26

Atrial Fibrillation

Small and unclear P wave, deep S wave in 3d indicates ventricular hypertrophy which is an increase in muscle thickness. 

7 of 26

Stroke Volume

The volume of blood pumped out of the left ventricle in one cardiac cycle. Normally 60-80cm3. 

8 of 26

Cardiac Output

Is the volume of blood pumped out of the left ventricle in one minute. This figure is normally 4-8dm3min-1. 

Cardiac output = stroke volume x heart rate 

9 of 26

Mass transport

Is when everything is moving in a stream in one direction. 

10 of 26

Closed system

Blood stays in vessels at all times unless injured. 

11 of 26


High blood pressure: 140/90mmHg

12 of 26


Low blood pressure 90/60mmHg

13 of 26

Normal blood pressure


14 of 26


A group of similar cells specialised to carry out the same function. 

15 of 26

Structure of lungs and breathing system

Breathe in -> trachea -> two bronchi -> bronchioles -> alveoli

16 of 26

Squamous epithelium

Is a lining tissue of flattened cells. 

17 of 26


Is a structure made up of different kinds of tissue. 

18 of 26


Liquid lining the lungs stops them from sticking together and makes it easier to inflates also has an antibacterial effect. 

19 of 26

Tidal Volume

The volume of air breathed in and out with a normal breathe, normally around 0.5dm3.

20 of 26

Vital Capacity

When you breathe out as much air as possible and the breathe out as much air as possible normally about 3.5dm3

21 of 26

Residual volume

When you breathe out as much as you can the small amount left that prevents your lungs from sticking together normally about 1.5dm3

22 of 26


An apparatus that can be used to measure lung volumes. 

23 of 26

Forced expiratory volume per second

The volume of air that can be breathed out in the first second of forced breathing out. 

24 of 26

Peak expiratory flow rate

The maximum rate at which air can be forcibly breathed out through the mouth. 

25 of 26

Respiratory arrest

When a person stops breathing but their heart still beats 

26 of 26


No comments have yet been made

Similar Human Biology resources:

See all Human Biology resources »See all Human, animal and plant physiology resources »