Key words in Module 3

Question 1

Apoplast

Answer 1

The cell walls and intercellular spaces of plant cells.

Question 2

Apoplast route

Answer 2

The movement of substances through the cell walls and cell spaces by diffusion and into cytoplasm by active transport

Question 3

Arrhythmia

Answer 3

An abnormal rhythm of the heart

Question 4

Assimilates

Answer 4

The products of photosynthesis that are transported around a plant

Question 5

Atrial fibrillation

Answer 5

An abnormal rhythm of the heart when the atria beat very fast and incompletely

Question 6

Atrio-ventricular node (AVN)

Answer 6

Stimulates the ventricles to contract after imposing a slight delay to ensure atrial contraction is complete

Question 7

Bohr effect

Answer 7

the effect of carbon dioxide concentration on the uptake and release of oxygen by haemoglobin

Question 8

Bradycardia

Answer 8

A slow heart rhythm below 60bmp

Question 9

Breathing rate

Answer 9

The number of breaths (inhalation and exhalation) taken per minute

Question 10

Bundle of his

Answer 10

Conducting tissue composed of purkyne fibres that passes through the septum of the heart

Question 11

Carbaminohaemoglobin

Answer 11

A compound formed when carbon dioxide combines with haemoglobin

Question 12

Carbonic anahydrase

Answer 12

Enzyme which catalyses the reversible reaction between carbon dioxide and water to form carbonic acid

Question 13

Cardiac cycle

Answer 13

The events of a single heartbeat, composed of diastole and systole

Question 14

Catalyse

Answer 14

The enzyme that catalyses the breakdown of hydrogen peroxide

Question 15

Chloride shift

Answer 15

The movement of chloride ions into red blood cells as hydrogen ions move out to maintain electrochemical equilibrium

Question 16

Circulatory system

Answer 16

The transport system of an animal

Question 17

Closed circulatory system

Answer 17

A circulatory system where blood is enclosed in blood vessels and does not come into direct contact with the cells of the body beyond the blood vessels

Question 18

Cohesion-tension theory

Answer 18

The best current model explaining the movement of water through the xylem/plant in transpiration.

Question 19

Companion cells

Answer 19

The active cells found next to sieve elements that supply the phloem vessels with all of their metabolic needs.

Question 20

Countercurrent exchange system

Answer 20

A system for exchanging materials or heat when two different compounds flow in opposite directions past eachother

Question 21

Diastole

Answer 21

The stage of the cardiac cycle in which the atria relaxes and then the ventricles fill with blood.

Question 22

Dicotyledonous plants (dicots)

Answer 22

Plants that produce seeds containing two cotyledons, which act as food stores for the developing embryo and form the first leaves when the seeds germinate.

Question 23

Double circulatory system

Answer 23

A circulatory system where the blood travels twice through the heart for each complete circulation of the body. In the first circulation blood is pumped by the heart to the lungs. In the second circulation oxygenated blood is pumped to the brain and the body to supply the cells with oxygen.

Question 24

Ectopic heartbeat

Answer 24

Extra heartbeats that are out of the normal rhythm.

Question 25

Elastic recoil

Answer 25

The ability to return to original shape and size following stretching. Particularly of the alveoli of the lungs and of the arteries.

Question 26

Electrocardiogram (ECG)

Answer 26

To technique measuring tiny changes in the electrical conductivity of the skin that results from the electrical activity of the heart. This produces a trace that can be used to analyse the health of the heart.

Question 27

exchange surfaces

Answer 27

Surfaces over which materials are exchanged from one area to another

Question 28

Exoskeleton

Answer 28

An external skeleton of some organisms

Question 29

Expiratory reserve volume

Answer 29

The extra amount of air that can be forced out of the lungs over and above the normal exhalation volume (tidal volume)

Question 30

Gaseous exchange system

Answer 30

The complex systems in which respiratory gases and carbon dioxide are exchanged within an organism

Question 31

Gills

Answer 31

The gaseous exchange organs of fish, comprised of gill plates, gill lamellae and gill filaments

Question 32

Goblet cells

Answer 32

Differentiated cells specialised to secrete mucus

Question 33

Guard cells

Answer 33

Cells that can open and close the stomatal pores, controlling gaseous exchange and water loss in plants

Question 34

Haemoglobin

Answer 34

The red, oxygen-carrying pigment of red blood cells

Question 35

Haemoglobinic acid

Answer 35

The compound formed when haemoglobin accepts free hydrogen in its role as buffer in the blood.

Question 36

Haemolymph

Answer 36

The transport medium or 'blood' in insects

Question 37

Histamines

Answer 37

Chemicals produced by mast cells in damaged tissues that make the blood vessels dilate (causing redness and heat) and blood vessel walls leaky (causing swelling and pain)

Question 38

Hydrophytes

Answer 38

Plants with adaptations which enable them to survive in very wet habitats or submerged or at the very surface of water

Question 39

Hydrostatic pressure

Answer 39

The pressure created by water in an enclosed system