Ocr As-Level Biology Unit 1, Module 2 (F211) (Miss Mcneill)

Front 1

Exchange Surface

Back 1

A specialised area that is adapted to make it easier for molecules to cross from one side of the surface to the other.

Front 2

Metabolism

Back 2

All the chemical reactions that take place in the cells of an organism.

Front 3

Gaseous exchange

Back 3

The movement of gases by diffusion between an organism and its environment across a barrier (e.g. alveolus wall)

Front 4

Plasma membrane/ Cell surface membrane

Back 4

The membrane that surrounds every cell, forming the selectively permeable boundary between the cell and its environment.

Front 5

Lumen

Back 5

The cavity in a tubular structure

Front 6

Diaphragm

Back 6

A sheet of muscular and fibrous tissue separating the chest cavity from the abdominal cavity.

Front 7

Intercostal muscles

Back 7

Muscles between the ribs, responsible for moving the rib cage during breathing.

Front 8

Transport

Back 8

The movement of substances (oxygen, nutrients, hormones, waste and heat) around the body.

Front 9

Pulmonary Circulation

Back 9

The circulation of blood through the lungs.

Front 10

Systemic circulation

Back 10

The circulation that carries blood around the body, excluding the circulation to the lungs.

Front 11

The heart

Back 11

A muscular pump that creates pressure (blood pressure) to propel blood through the arteries and around the body.

Front 12

Coronary arteries

Back 12

Arteries that carry blood to the heart muscle.

Front 13

Angina

Back 13

Intense pain, starting at the chest due to insufficient supply of blood to the heart.

Front 14

Myocardial infarction

Back 14

The medical term for a heart attack.

Front 15

Tendinous cords

Back 15

String-like tendons used to attach the atrioventricular valves to the heart to the sides of the ventricle wall. Sometimes called heart strings.

Front 16

Septum

Back 16

A wall of muscle in the heart that separates the ventricles from each other.

Front 17

Semilunar valves

Back 17

Valves between the ventricles and the main arteries leading out of the heart, which prevent backflow of blood.

Front 18

Ventricles

Back 18

The lower chambers in the heart.

Front 19

Vena cava

Back 19

Either of two large veins (superior/inferior) that carry deoxygenated blood from the body back to the heart.

Front 20

Atrium

Back 20

One of the upper chambers in the heart.

Front 21

Cardiac cycle

Back 21

The sequence of events in one heartbeat.

Front 22

Atrioventricular valves

Back 22

Valves between the atria and ventricles that prevent backflow of blood.

Front 23

Diastole

Back 23

The period when the heart muscle in the ventricles is relaxing and blood pressure is at its lowest.

Front 24

Systole

Back 24

The stage of the heart cycle in which the heart muscle contracts to pump blood.

Front 25

Myogenic

Back 25

Describes muscle tissue (heart muscle) that generates its own contractions. (without a neural stimuli).

Front 26

Sinoatrial node (SAN)

Back 26

The heart's pacemaker. It is a small patch of tissue that sends out waves of electrical excitation at regular intervals to initiate contractions.

Front 27

Purkyne tissue

Back 27

Specially adapted muscle fibres that conduct the wave of excitation from the AVN down the suptum to the ventricles.

Front 28

Fibrillation

Back 28

A state/condition in which the chambers in the heart contract out of rhythm.

Front 29

Electrocardiogram (ECG)

Back 29

A trace (graph) showing the electrical activity of the heart muscle (atria and ventricles) during a cycle.

Front 30

Peristalsis

Back 30

Muscular contractions to squeeze/push contents a canal along.

Front 31

Endothelium

Back 31

A tissue that lines the inside of a structure, such as a blood vessel.

Front 32

Smooth muscle

Back 32

A type of muscle (involuntary) found mostly in certain internal organs and involved in involuntary movements such as peristalsis.

Front 33

Tissue Fluid

Back 33

The fluid, derived from blood plasma that surrounds the cells in a tissue.

Front 34

Lymph

Back 34

A colourless fluid containing white blood cells.

Front 35

Erythrocytes

Back 35

Red Blood cells.

Front 36

Plasma proteins

Back 36

Proteins made in the liver that are found in blood plasma.

Front 37

Leucocytes/leukocytes

Back 37

White blood cells.

Front 38

Platelets

Back 38

Fragments of cells in the blood that play a part in blood clotting.

Front 39

Hydrostatic pressure

Back 39

Pressure created by a fluid pushing against the sides of a container.

Front 40

Facilitated Diffusion

Back 40

The passive movement of molecules across membranes down their concentration gradient, which is aided by transport (channel or carrier) protein molecules. No metabolic energy is required.

Front 41

Water potential

Back 41

A measure of the ability of water molecules to move freely in solution. Measures the potential for a solution to lose water - water moves from a solution with high water potential to one of a lower water potential. Water potential is decreased by the presence of solutes.

Front 42

Affinity

Back 42

An attractive force between substances or particles.

Front 43

Dissociation

Back 43

The breakdown of a molecule into two molecules, atoms or ions. For example, the release of oxygen form oxyhaemoglobin.

Front 44

Oxygen tension

Back 44

The amount of oxygen in the air expressed as the pressure created by the presence of oxygen, expressed in kilopascals (kPa).

Front 45

Partial pressure

Back 45

The proportion of total pressure provided by a particular gas as part of a mixture of gases.

Front 46

Oxyhaemoglobin dissociation curve

Back 46

The curve on a graph showing the proportion of haemoglobin that is saturated with oxygen at different oxygen tensions.

Front 47

Xylem Tissue

Back 47

Vascular tissue that transports water up the plant.

Front 48

Phloem Tissue

Back 48

Vascular tissue that transports sugars and substances up and down the plant.

Front 49

Conformational change

Back 49

The slight change of shape of a haemoglobin molecule after one oxygen molecule diffuses into it. It allows more oxygen molecules to diffuse into the haemoglobin easily.

Front 50

Vascular bundles

Back 50

-

Front 51

Endodermis

Back 51

-

Front 52

Meristem cells

Back 52

-

Front 53

Pericycle

Back 53

-

Front 54

Cambium

Back 54

-

Front 55

carbaminohaemoglobin

Back 55

The molecule resulting form the combination of carbon dioxide and haemoglobin.

Front 56

Describe three ways carbon dioxide is transported in the blood

Back 56

-About 5% is dissolved directly in the plasma as CO2.

-About 10% is combined with haemoglobin to form carbaminohaemoglobin.

-About 85% is transported as hydrogencarbonate ions (HCO3^-) in the plasma

Front 57

Chloride Shift

Back 57

The movement of chloride ions into red blood cells to balance the positive charge from the loss of negative hydrogencarbonate ions.

Front 58

Carbonic Anhydrase

Back 58

The catalyst that catalyses the reactions between carbon dioxide and water.

Front 59

Haemoglobinic acid

Back 59

The acid produced when haemoglobin takes up hydrogen ions.

Front 60

A buffer

Back 60

A chemical system that resists changes in pH/maintain a constant pH by maintaining a constant level of hydrogen ions in solution.

Front 61

The Bohr effect

Back 61

The effect of carbon dioxide concentration on the affinity of haemoglobin for oxygen.

Front 62

Tidal volume

Back 62

The volume of air moved in and out of the lungs with each breath when at rest.

Front 63

Vital capacity

Back 63

The largest volume of air that can be moved into and out of the lungs in any one breath. (varies between men and women/ people's size and age/level of fitness).

Front 64

Residual volume

Back 64

The volume of air that always remains in the lungs even after the biggest possible exhalation.

Front 65

Dead space

Back 65

The air in the bronchioles bronchi and trachea where there is no gas exchange with the blood.

Front 66

Inspiratory reserve volume

Back 66

The amount of air that can be inspired above the normal tidal volume. This reserve can be used when exercising.

Front 67

Expiratory reserve volume

Back 67

The amount of air that can be expired above the normal tidal volume.

Front 68

Cartilage

Back 68

A flexible, slightly elastic connective tissue.

Front 69

Goblet cells

Back 69

Mucus-secreting cells in epithelial tissue.

Front 70

Epithelium

Back 70

Tissue that covers the outside of a structure.

Front 71

Ciliated epithelium

Back 71

Epithelial cells that have cilia on their cell surface)

Front 72

Cilia

Back 72

Short hair-like extensions of eukaryotic cells. Usually used to move fluids or mucus over a surface.