Module 3 - Exchange & Transport Flashcards
(125 cards)
1
Q
Alveoli
A
Tiny air sacs that serve as the primary gaseous exchange surface, they consist of thin epithelial cell layer, collagen & elastic fibres
2
Q
Breathing rate
A
The no. of breaths per minute
3
Q
Bronchi
A
Division of the trachea that lead into the lungs, they are small tubes supported by incomplete rings of cartilage
4
Q
Bronchioles
A
Many small divisions of the bronchi, contain smooth muscle to restrict airflow to lungs but don’t have cartilage, they are lined with a thin layer of ciliated epithelial cells
5
Q
Cartiliage
A
Strong, flexible connective tissue that supports the walls of the trachea & bronchi, preventing collapse, is found in incomplete ring shape
6
Q
Ciliated epithelial cells
A
Specialised cells with tiny hair-like cilia found lining trachea that waft bacteria-containing mucus up to back of throat where it is swallowed
7
Q
Counter current flow
A
Adaptation for gaseous exchange in bony fish, blood in gills filaments & water moving over the gills flow in opposite directions, maintaining a steep oxygen concentration gradient
8
Q
Elastic fibres
A
Fibres of elastin that allow the alveoli to stretch as air is drawn in & recoil back to normal size, expelling air, found in trachea, bronchi & bronchioles
9
Q
Exchange surface
A
Surface over which materials are exchanged from 1 region to another. An effective exchange surface has large SA, thin layers, good blood supply & ventilation to maintain steep diffusion gradient
10
Q
Expiration
A
Diaphragm relaxes & reverts to a dome, external intercostal muscles relax, moving ribs down & in
Volume of thorax decreases & thoracic pressure exceeds air pressure, air moves out of trachea
11
Q
Gill filaments
A
The main site of gaseous exchange in fish, over which water flows, are found in large stacks, gill plates, & have gill lamellae which provide large SA for exchange
12
Q
Gill lamellae
A
Fine branches of gill filaments, are adapted for gaseous exchange by having a large SA & good blood supply
13
Q
Gill plates
A
Large stacks of gill filaments
14
Q
Gills
A
Organs of gaseous exchange in fish, are contained in a gill cavity & are made up of gill lamellae, gill filaments & gill plates
15
Q
Goblet cells
A
Specialised cells that secrete mucus onto trachea lining, mucus traps harmful substances & microorganisms, preventing their entry into lungs
16
Q
Inspiration
A
Diaphragm contracts & flattens & external intercostal muscles contract, moving ribs up & out, the volume of thorax increases & thoracic pressure falls below air pressure, air moves into trachea
17
Q
Internal intercostal muscles
A
Muscles found between ribs which are responsible for forced exhalation
18
Q
Mammalian gaseous exchange system
A
Complex system found in mammals which O2 & CO2 gases are exchanged
19
Q
Operculum
A
Flap that covers the gills on bony fish, protects the gills & helps maintain constant stream of water over them
20
Q
Smooth muscle
A
Involuntary muscle found in walls of trachea & bronchi, constricts lumen of the bronchi by contracting, reducing airflow to lungs
21
Q
Spiracles
A
Small, external openings along thorax & abdomen of most insects, through which air enters & air & water leave the gaseous exchange system, Spiracle sphincters open & close the spiracles to control gas exchange
22
Q
Spirometer
A
Device used to examine patterns of breathing & determine different aspects of lung volume
23
Q
SA:V
A
SA of object / by volume. Larger the SA:V the smaller the object
24
Q
Tidal volume
A
Volume of air breathed in or out of the lungs during a normal breath
25
Trachea (mammals)
Primary airway which carries air from nasal cavity down into chest, tube supported by incomplete rings of cartilage
26
Trachea (insects)
Large tubes that run from spiracles, into & along an insect's body, are supported by spirals of chitin, trachea divide further into smaller tracheoles
27
Tracheal fluid
Fluid found at ends of the tracheoles, amount of fluid affects surface area available for gaseous exchange & water loss
28
Tracheoles
Divisions of tracheae that runs throughout the tissue of an insect, forming a complex network, are main site of gas exchange & completely permeable for gases
29
Ventilation
Movement of fresh air into the lungs & stale air out of lungs via inspiration/expiration
30
Vital capacity
Largest volume of air that can be breathed in following the strongest possible exhalation
31
Affinity
Tendency of 1 substance to bind with another substance
32
Aorta
Artery that takes oxygenated blood away from heart to body
33
Arteriole
Type of blood vessel that connects arteries & capillaries, walls contain large amounts of smooth muscle, some elastic fibres & some collagen
34
Artery
Type of blood vessel that carriers blood away from heart to tissues, under high pressure, walls contain collagen, smooth muscle & elastic fibres
35
Atrial fibrillation
Arrhythmia that involves rapid contraction of atria, preventing complete ventricular filling
36
Atrial systole
Stage of cardiac cycle, atria contract, pushing blood into ventricles, AV valves pushed open fully & atria are emptied of blood
37
Atrioventricular node (AVN)
Group of cells located between atria that slow down wave of excitation & pass it between ventricles, along bundle of His
38
Atrioventricular (AV) valves
Valves found between atria & ventricles, prevent backflow of blood from ventricles into atria. 2 types:
Tricuspid
Bicuspid
39
Bicuspid valves
AV valves found between left atrium & left ventricle
40
Blood
Transport medium in mammalian circulatory system, consists of plasma, RBC, WBC & platelets
41
Bohr effect
Loss of affinity of haemoglobin for O2 as partial pressure of CO2 increases
42
Bradycardia
Slow resting HR below 60bpm
43
Bundle of His
Collection of Purkyne fibres which run from AVN down to apex of ventricles
44
Capillaries
Microscopic blood vessels that form large network through tissue of body & connect the arterioles to venules, are site of exchange of substances between blood & tissues
45
Carbonic anhydrase
Enzyme that catalyses reversible reaction between H2O & CO2 to produce carbonic acid
46
Cardiac cycle
Describes sequence of events involved in 1 complete contraction & relaxation of heart, are 3 stages; atrial systole, ventricular systole & diastole
47
Cardiac output
Volume of blood pumped by heart through circulatory system in 1 min, its calculated by:
Q'=HR x SV
48
Chloride shift
Process by which chloride ions move into erythrocytes in exchange for hydrogen carbonate ions which diffuse out of them, this maintains the electrochemical equilibrium of cell
49
Circulatory system
Transport system in animals
50
Closed circulatory system
Circulatory system in which blood pumped by heart is contained within blood vessels, blood doesn't come into direct contact with cells
Found in animals e.g. vertebrates
51
Diastole
Stage of cardiac cycle, heart muscles relaxes, atria & ventricle fill with blood
52
Double circulatory system
Circulatory system in which the blood flows through the heart twice in 2 circuits, blood is pumped from the heart to the lungs before returning to heart. Then pumped around the body after which it returns to the heart again. Found in mammals
53
Ectopic heartbeat
Additional heartbeats outside of normal heart rhythm
54
Electrocardiogram (ECG)
Technique used to indirectly measure spread of electrical activity through the heart by measuring tiny changes in skin's electrical conductivity, produces trace which is used to detect abnormalities in the heart rhythm
55
Haemoglobin
Red pigment found in erythrocytes that bind reversibly with 4 O2 to form oxyhaemoglobin, it is globular protein that consists of 4 polypeptide chains, each with prosthetic haem group
56
Haemoglobinic acid
Product formed when haemoglobin accepts free H, enables haemoglobin to act as buffer, reducing changes in blood pH
57
Heart Rate
Number of times the heart beats in 1 minute
58
Hydrostatic pressure
Pressure exerted on the sides of a vessel by a fluid
59
Inferior vena cava
Vein that returns deoxygenated blood to the heart from the lower body
60
Lymph
Modified tissue fluid that drains into the lymphatic system, carries less O2 and fewer nutrients than tissue fluid, also contains fatty acids
61
Myogenic
Cardiac muscle tissue that initiates its own contraction without outside simulation from nervous system
62
Oncotic Pressure
Movement of H2O into the blood by osmosis due to tendency of plasma proteins to lower the H2O potential of the blood
63
Open circulatory system
Transport medium pumped by the heart isn't contained within vessels, but moves freely, transport fluid comes into direct contact with the cells. Found in invertevrates
64
Oxygen dissociation curve
Graph that describes relationship between partial pressure of O2 & % saturation of haemoglobin in the blood
65
Plasma
Main component of blood, carries RBC, yellow liquid that contains proteins, nutrients, mineral ions, hormones, dissolved gases & waste
66
Pulmonary arteries
Arteries that carry deoxygenated blood away from the heart to the lungs
67
Pulmonary veins
Vein that carry oxygenated blood from lungs to heart
68
Purkinje tissue
Specialised cardiac muscles fibres which make up bundle of His & conduct the wave of excitation through septum, from AVN down septum to venticles
69
Semilunar valves
Pair of valves found between ventricles and arteries, prevent backflow into the ventricles
70
Septum
Wall of muscle hwich separates left/right sides of the heart, preventing deoxygenates & oxygenated blood from mixing
71
Single circulatory system
Circulatory system where blood only travels through heart once, found in fish
72
Sinoatrial node (SAN)
Group of cells in wall of right atrium that generate electrical activity, causing atria to contract, the SAN is the heart's pacemaker
73
Stroke Volume
Volume of blood pumped by the left ventricle of the heart in a single contraction
74
Superior vena cava
Vein that returns deoxygenated blood to the heart from upper body & head
75
Tachycardia
Rapid resting HR over 100bpm
76
Tissue fluid
Fluid that surrounds the cells of animals, has same composition of plasma but doesn't contain RBC/plasma protein
77
Tricuspid valve
Atrioventricular valves found between the right atrium & right ventricle
78
Vein
Type of blood vessel that carries blood towards heart under low pressure, have wide lumen, smooth inner lining & valves
Walls of veins contain large amounts of collagen, smooth muscle & little elastic fibre
79
Ventricular systole
Stage of cardiac cycle, ventricles contracts pushing blood into arteries, semi-lunar valves pushed open fully
80
Venules
Connects capillaries & veins. The walls of venules contain small amounts of collagen & smooth muscle
81
Active loading
Process by which H+ are actively pumped out of companion cells using ATP, before diffusing down a concentration gradient, back into the cells via co-transporter proteins, whilst carrying sucrose
82
Adhesion (water movement)
Formation of H+ bonds between carbs in xylem vessel walls & H2O. This contributes to the capillarity of H2O & transpiration pull
83
Apoplast route
1/2 pathways which H2O & minerals move across the root, H2o moves through intercellular spaces between cellulose molecules in the cell wall
84
Casparian strip
Waterproof strip surrounding the endodermal cells of the root that blocks the apoplast pathway, forcing H2O through the symplast route
85
Cohesion ( H2O movement)
Formation of H+ bonds between H2O molecules, contributes to the capillarity of H2O & transpiration pull
86
Cohesion-tension theory
Model that explains the movement of H2O from the soil to the leaves, in a continuous stream
87
Companion cells
Active cells of the phloem located adjacent to the sieve tube elements, they retain their nucleus & organelles, producing ATP for metabolic processes in both themselves & the sieve tube elements
88
Dicotyledonous plants
Plants that produce seeds that contain 2 cotyledons, they have 2 primary leaves
89
Hydrophytes
Plant that are adapted to live & reproduce in very wet habitats e.g. water lilies
90
Phloem
Living plant transport vessel responsible for the transfer of assimilates to all parts of the plant, the phloem consists of sieve tube elements & companion cells
91
Plasmodesmata (phloem)
Small pores between adjacent sieve tube elements & companion cells that allow communication & exchange of materials
92
Potometer
Apparatus used to measure H2O uptake from a cut shoot
93
Root hair cell
Specialised cell responsible for the uptake of H2O & minerals from soil. Have long hair-like extensions (root hairs), are adapted as exchange surfaces
94
Sieve plates
Perforated end walls of sieve tube elements that allow plant assimilates to flow between cells unimpeded
95
Sieve tube elements
Main cells of phloem, are elongated cells laid end-to-end with sieve plates between, contain few organelles
96
Sinks (plants)
Regions of a plant that remove assimilates e.g. roots, meristems, fruits
97
Sources (plants)
Region of a plant that produce assimilates e.g. leaves, storage organs
98
Symplast route
1/2 pathways which H2O & minerals move across root, H2O enters cytoplasm through plasma membrane & moves between adjacent cells via plasmodesmata, H2O diffuses down its H2O potential gradient by osmosis
99
Translocation
Movement of organic compounds in phloem, from source to sink
100
Transpiration
H2O loss from plant leaves & stems via diffusion & evaporation, rate of transpiration is affected by light, temp, humidity, air movement, soil-H2O availability
101
Transpiration stream
Flow of H2o from the roots to the leaves in plants, where it is lost by evaporation to environment
102
Vascular bundle
Vascular system in herbaceous dicotyledonous plants, consists of 2 transport vessels, xylem & phloem
103
Vascular system
Network of transport vessels in animals & plants
104
Xerophytes
Plants that are adapted to live & reproduce in dry habitats where H2O availability is low e.g. cacti 7 marram grass
105
Xylem
Non-living plant transport vessel responsible for transfer of H2O & minerals from the roots to the shoots & leaves
106
Why do multicellular organisms require specialised gas exchange surfaces
Their smaller SA:V means the distance that needs to be crossed is larger & substances cannot easily enter the cells as in a single-celled organism
107
Features of an efficient gas exchange surface
1.Large SA
2.Thin/short diffusion distance
3.Steep concentration gradient
108
Describe the trachea & its functions
-Wide tube supported by C-shaped cartilage to keep the air passage open during pressure changes
-Lined by ciliated epithelium cells which move mucus, produced by goblet cells, towards the throat to be swallowed, preventing lung infections
-Carries air to bronchi
109
Describe the bronchi & their function
-Supported by rings of cartilage & lined by ciliated epithelium cells & goblet cells
-Are narrower & are 2 of them, one for each lung
-Allow passage of air into the bronchioles
110
Describe the bronchioles & their function
-Narrower than the bronchi
-Don't need to be kept open by cartilage, mostly have only smooth muscle & elastic fibres so that they can contract & relax easily during ventilation
-Allow passage of air into the avleoli
111
Describe the alveoli & their function
-Mini air sacs, lined with epithelium cells, site of gas exchange
-Walls only 1 cell thick, covered with a network of capillaries, 300 million in each lung
-Facilitates gas diffusion
112
How a spirometer works
Person breaths into an airtight chamber which leaves a trace on a graph which shows the volume of breaths
113
Features of a fish's gas transport system
Gills=located within body, supported b arches, along which are multiple projections of gill filaments, stacked up in piles
Lamellae=right angles to gill filaments, give an increase SA, counter current exchange of blood & water
114
Process of gas exchange in fish
-Buccal cavity volume increases, enables water to flow in,
-Water is pumped over lamellae by operculum, O2 diffuses into the bloodstream
-Waste CO2 diffuses into water & flows back out of gills
115
How does counter current exchange maximise O2 absorption by fish
Maintains steep concentration gradient, water is always next to blood of lower O2 concentration
Keeps rate of diffusion constant & enables 80% of available O2 to be absorbed
116
Main feature of a insect's gas transport system
Spiracles=holes on body's surface which may open & close by valves for gas/water exchange
Tracheae=large tubes extending through all body tissues, supported by rings of cartilage
Tracheoles=Smaller branches dividing off the tracheae
117
Process of gas exchange in insects
-Gases move in & out of tracheae through spiracles
-Diffusion gradient allows O2 to diffuse into body tissue visa versa for CO2
-Contraction of muscles in tracheae allows mass movement of air in & out
118
Why do multicellular organisms require transport systems
-Large size, high metabolic rates
-Demand for O2 is high, ned specialised system to ensure strong supply to all respiring tissues
119
Structure of arteries & their function
Thick, muscular walls to handle high pressure
Elastic tissue allows recoil to prevent pressure surges
Narrow lumen to maintain pressure
120
Structure of veins & their functions
Thin walls lower pressure
Valves ensure backflow doesn't happen
Less muscular & elastic tissue as don't have to control blood flow
121
Structure of capillaries to their function
Walls only 1 cell thick, short diffusion pathway
Very narrow so can permeate tissue & RBC can lie flat against the wall
Numerous & highly branched providing large SA
122
Structure of arterioles & venules & their function
-Branch off arteries & veins to feed blood into capillaries
-Smaller than arteries & veins so that change in pressure is gradual as blood passes through increasingly small vessels
123
What types of pressure influence formation of tissue fluid
-Hydrostatic=Higher at arterial end of capillary
-Oncotic=Changing water potential of capillaries as water moves out, induced by proteins in the plasma
124
How is tissue fluid formed
As blood is pumped through increasingly small vessels, hydrostatic pressure is greater than oncotic, so fluid moves out of capillaries
125
