Topic 3-Gas exchange systems and Digestions Flashcards
1
Q
What is a spirometry test?
A
A test for pulmonary function.
2
Q
What two things does a spirometry test capture?
A
Air volumes
Breathing Speed
3
Q
Define tidal volume
A
The amount of air inhaled or exhaled during normal quiet breathing.
4
Q
The health and function of a persons lungs can be measured by looking at their…
A
Forced expiratory volume
Forced vital Capacity
5
Q
Defien forced expiratory voulme
A
THe maximum volume of air that can be breathed out in 1 second
6
Q
Defien the forced vital capacity
A
The maximum volume of air it is possible to breathe out forcefully from the lungs
7
Q
What are the 3 different types of lung disease?
A
Airway Disease
Lung circulation
Lung Tissue disease
8
Q
How does an airway disease affect the body and name some
A
It affects the bodys ability to move air in and out of the lungs.
e.g. asthma and bronchitis
9
Q
What type of lung disease affects circulation of blood to and from lungs and name a few examples.
A
Lung circulation disease
Pulmonary hypertension
Pulmonary edema
10
Q
What type of lung disease comes from damaged tissue and give an example
A
Lung tissue disease
Pulmonary fibrosis
11
Q
Describe how lung disease affect rate of aerobic respiration
A
They reduce the rate of gas exhange in alveoli. Less oxygen diffuses into the bloodstream. The bodys cells receive less oxygen which reduces the rate of aerobic respiration.
12
Q
What are the two types of lung disease that affect ventilation in different ways.
A
Obstructive diseases- asthma makes it difficult to breathe out
Restrictive diseases- fibrosis makes it difficult to breathe in
13
Q
Define vital capacity
A
The total volume of air you can breathe out when relaxed, ,measure in litres
14
Q
What if FEV1
A
Forced expiratory volume.
15
Q
What is FVC?
A
Forced vital capacity
16
Q
What is VC?
A
Vital Capacity
17
Q
What is the normal volume of FEV1?
A
4 litres
18
Q
What is emphysema and how does it occur? + some symotoms
A
A lung condition caused by smpoking or long term exposure to air pollution, foreign particles become trapped in the alveoli causiong inflation. This inflation attracts phagocytes which break down elastin. Loss of elastin means alveoli cannot recoil which reduces SA of alveoli. They suffer wheezing and shortness of breath.
19
Q
What fibrosis and how does it occur and what problems arise in terms of respiration and ventilation
A
A lung disease that occurs when lung tissue becomes damaged and scarred when exposed to things like asbestos . The tissue becomes thick and stiff causing lungs to work difficulty causing shortness of breaeth. Tidal volume is reduced and so is FVC. There is also a slower rate of gas exchange due to thicker damgaged membrane
20
Q
What is tuberulosis and its how does it affect the person? + symptoms
A
An illness of the lungs caused by a type of bacteria spread through droplets in the air. When infected the person forms small hard lungs known as tubercles. Infected tissue in the tubercles dies and so gaseous exchanged is damaged.
Symotoms include a persistant cough, shortness of breath and coughing up blood
21
Q
What is asthma, its symptoms and treatment?
A
Asthma is a condition which makes your airways become inflamed and swell and may produce extra mucus. It can cause shortness of breathe due to air flow in and out of the lungs being reduced, chest tightness and coughing attacks. It is controlled using asthma pumps.
22
Q
Describe the insect exchange system
A
Insect has spiracles (openings) lined with chitin on the sides of its body. The chitin gives shapes to the openings. The spiracles can open and close by small muscles. Muscles contact and relax to open valves. This allows control of air as well as slow down of the loss of water
23
Q
What happens in the tracheal system?
A
Outside air enters the spiracles into the trachae. It then enters the tracheoles into the muscle.
24
Q
What are trachea walls in insects reinforced with and what does this help do?
A
Taenidiae which allows insects to flex and stretch without developing kinks that may restrict air flow.
25
What are the physical properties of the tracheoles?
Thin moist surface membranes surrounded by watery haemolymph
26
What is mass transport in mammals and plants
Mammals- Use of circulatory system which uses blood to carry glucose, oxygen hormones and waste
Plants- Transport of water and solutes up xylem and phloem
27
What two things do most gas exchange surfaces have in common that increase the rate of diffusion?
They have a large surface area
They are thin
28
Describe the structure of gills
Each gill is made up of thin plates called gill filaments.
Gill filaments are covered in lots of tiny structures called lamellae which have lots of blood capillaries and a thin ;layer of cells to speed up diffusion
29
Descibe the counter current system in the gills of a fish and why it is important
It is where the blood flows through the lamaelle in one direction and water flows over them in the opposite direction.
This sysyem ensures that water with a relatively hugh oxygen conc alwyas flows next to blood with a lower conc of oxygen. THis means the steep conc gradient between water and the blood is maintained.
30
What are dicotyledonous plants?C
Category of plants that includes most green and non-woody plants
31
What is the main gas exchange surface of dicotylendonus plants?
Mesophyll cells in the leaf
32
Because the cells used for gas exchange in dicotylendonous plants are inside the leaf, how do gases move in and out?
They move through pores in the epidermis called stomata which allow exchange of gases and the opening and closing of these pores are controlled by guard cells
33
What are terrestial insects?
insects that live on land
34
Descibe the process of gas exchange in insects
Air moves through pores on the surface of the insect into the trachae. This branches off into smaller tracheoles that have thin permeable walls meaning oxygen diffuses directly into respiring cells as the insects circulatory system does not transport O2. CO2 from the cells move doen its own conc gradient towards the spiracles to be released.
35
How to insects move air in and out of the spiracles?
Using rythmic abdominal movements
36
What preventative methods/features do insects hace to reduce water loss?
They close their spiracles using muscles, they also have a waterproof waxy cuticle and tiny hairs around spiracles to reudce evaporatio
37
How do plants control water loss?
Plants keep their stomata open during the day to allow GE and water enters the guard cells making them turgid which opens stomatal pore. If plant gets dehydrated, the guard cells loose water and become more flaccid to close the pore.
38
What do you call plants specially adapted for warm, windy or dry habitats where water loss is a problem?
Xerophytes
39
Give 4 adaptations that xerophytic plants have to reduce water loss?
1)They have sunken stomata to trap water vapour and reduce evaporation from the leaf
2)They have thicker waxy, waterproof cuticles on leaves and stems to reduce evaporation
3)They have layers of hairs on the epidermis to trap water vapour round the stomata
4) They have spines and needles to reduce SA to V ratio
40
Explain where air moves through to reach the site of gas exchange in humans
As you breathe in air enter the trachea which splits into two bronchi. One bronchus leads to the lung and each bronchus then branches off into small bronchioles. The bronchioles end in small air sacs called alveoli where gases are exchanged.
41
What are the 2 layers of intercostal muscle called?
internal and external muscles
42
Describe what happens to make the volume of the thorax increase during inspiration
External intercostal muscles contract causing the ribcage to move upwards and out and the diaphram to flatten. This increases the volume of the thoracic cavity.
43
What happens to make air leave the lungs during forced expiration?
The external muscles relax and the internal muscles contract pulling the ribcage futher down and in. The two sets of intercostal mscles are antagonistic
44
Name 2 adaptations insects have to reduce water loss
-They can close their spiracles
-They have hairs around their spiracles whch reduce then water potential gradient and so decreases rate of diffusion
45
What type of digestive enzyme catalyses the breakdown of starch and describe the process?
Amalyse breaks down starch by hydrolysing starch to maltose. The membrane bound maltase hydrolyses maltose to glucucoes through hydrolysis of glycosidic bond
46
What glands produce amalyse and where do they release it?
Salivary glands- released by the mout
Pancreas- releases into small intestine
47
Where are membrane bound disaccharidases found and what do they do ?
Enzymes that are attached to the cell membrane of epithelial cells lining the ileum and they break down disaccharides into monosaccharides by catalysing hydrolysis of glycosidic bonds
48
How do lipase enzymes breakdown lipids?
Their involved in the hydrolysis of ester bonds and break them down into monoglycerides and fatty acids.
49
What is produced by the liver to emulsify lipids?
Bile salts
50
Why are bile salts important in the process of lipid digestion?
Emulsify lipids to form small droplets. This increases the surface area that is available for lipases to work on. Once the lipid has been broken down by lipases, the monoglycerides and fatty acids stick to the bile salts to form tiny structures called micells which help the products of lipid digestion to be absorbed.
51
Name the peptidases used to catalyse the conversion of proteins into amino acids?
Endopeptidases
Exopeptisaes
Dipeptidases
52
What is another name for peptidases?
Proteases
53
Give some examples of endopeptidaes in the body and where they are
Pepsin- released into the stomach and the only works in acidic conditions
Trypsin & chymotrypsin- Synthesised in the pancreas and secreated in the small intestine
54
Describe the digestion of proteins by a mammal
Endopeptidases hydrolyse peptide bonds within a polypeptide so there are smaller peptides and more SA for exopeptidases. Exopeptidases hydrolyse peptide bonds at the end of polypeptide removing single amino acids. Membrane bound dipeptidases only work on dipeptides and seperate the two amino acids by hydrolysing the peptide bond.
55
Describe the absorption of amino acids and monosaccharides in mammals
Co-transport-
Sodium ions actively transported from epithelial cells lining the ileum to blood (by Na+/K+ pump) This establishes a conc gradient of NA+(higher in lumen than epithelial cell)
Sodium ions then enter epithelial cells down its conc gradient with glucose against its conc gradient via a co- transporter protein
Glucose moves down a conc gradient into blood via facillitated diffusion
56
Describe the absorption of lipids by a mammals including the role of micelles
Micelles contain bile salts,monoglycerides and fatty acids.
.They make monoglycerides and fatty acids more soluble in water
.Carry and release fatty acids and monoglycerides to lining of the ileum, this maintains high concentration of fatty acids to cell/lining
-Monoglycerides and fatty acids absorbed into the epithelial cell by diffusion
-Triglycerides reformed in epithelial cells and aggregated into globules
-Globules coated with proteins forming chylomicrons which are then packaged into vesicles
-Vesicles move to cell membrane and leave via exocytosis to enter lymphatic vessels and eventually return to blood circulation
57
How are amino acids absorbed across the ileum epithelium into the bloodstream?
Sodium ions are actively transported out of the epithelial cells into the ileum itself. They the diffuse back into the cell through sodium dependent transporter proteins in the epethelial cell membranes carrying the amino acids with them
58
Explain the features of the alveolar epithelium that make it adapted as a surface for gas exchange
1 cell thick- short diffusion distance
folded- large surface area
Permeable- allows diffusion of O2 and CO2
Moist- gases can dissolve in diffusion
Godd supply of blood from large network of capillaries mantains conc gradient
59
Descibe how gas exchange occurs in the lungs
Oxygen diffuses from alveolar air space inro the blood down its conc gradient. It then travels across alveolar epithelium then across capillary endothelium. Carbon dioxide does the opposite
60
Explain the importance of ventialtion
It bring in air containing higer conc of oxygen and removes air with lower conc this mantains conc gradients
61
Explain how humans breath in and give the name for it
External intercostal muscles contract and internal relax, the ribcage is pulled up and out and diaphgram muscles contract then flatten causing Increasing volume and decreasing pressure in thoraic cavity. Air moves down pressure gradient into the lungs from atmosphere
62
Explain how humans breath out and give the name for it
Breathing out is called expiration
The diaphragm relaxes and moves upward and the intercostal mucles may contract. The ribcages moves down and inwards. There is decreasing volume and increasing pressure in the thoraic cavity. Air moves out of the lungs down pressure gradient.
63
Suggest why expiration is normally passive at rest
Intercostal muscles do not normally need to contract
Expiration is aided by elastic recoil in the alveoli
64
Why do people with lung disease experience more fatigue?
Their cells recieve less oxgen so the rate on aerobic respiration is reduced therefore less ATP is produced
65
Descibe the role of red blood cells and haemaglobin in o2 transport
Red blood cells contain lots of haemoglobin (hb) and hb bind and loads O2 at gas exchange surfaces where partial pressure of ocygen is high. This froms oxyhaemaglobin which transports O2. Hb unloads O2 near cells/tissue where parital pressure of oxygen (pO2) is low
66
Describe the structure of haemoglobin
-Protein with quatenary stucture
-Made of 4 polypeptide chains
-Each chain contains Haem group conatining an iron ion (Fe2+)
67
State the area in the body where there is low PO2 and descibe what that means for the transport, loading and unloading of oxygen in relation to the oxyhaemoglobin dissociation curve
Respiring tissue, Hb has low affinity for oxygen this means that O2 readily unloads/dissociates with haemaglobin so % saturation of Hb with oxygen is low
68
State the area in the body where there is high PO2 and descibe what that means for the transport, loading and unloading of oxygen in relation to the oxyhaemoglobin dissociation curve
The area is gas exchange surfaces
Here Hb has high affinity for oxygen so )2 readily loads and associates with Hb and % saturation of Hb with O2 is high
69
Explain how the cooperative nature of oxygen binding results in an S-shaped (sigmoid) oxyhaemoglobin dissociation curve
Binding of first oxygen changes tertiary/quantenary structure of haemaglobin which uncovers haem group binding sites making futher binding easier
70
Describe evidence for the cooperative nature of oxygen binding
A low pO2 as oxygen increases there is little / slow increase in % saturation of Hb with oxygen
when first oxygen is binding but at higher pO2 , as oxygen increases there is a big / rapid increase in % saturation of Hb with oxygen showing it has got easier for oxygens to bind.
71
What is the bohr effect?
The effect of CO2 conc on dissociation of oxyhaemoglobin
72
Explain the effect of CO2 conc on the dissociation of oxyhaemaglobin?
Increasing CO2 reduces blood pH making it more acidic . This reduces Hb's affinity for oxygen as shape tertiary/ quaternary structure changes slightly. So more/ faster unloading of oxygen to respiring cells at given PO2
73
Explain the advantage of the Bohr effect (eg. during exercise)
More dissociation of oxygen means faster aerobic respiration / less anaerobic respiration which means more ATP produced
74
Explain why different types of haemoglobin can have different oxygen transport properties
Different types of Haemaglobin are made of polypeptide chains with slightly different amino acid sequences resulting in different tertiary / quaternary structures / shapes which all have different affinities for oxygen
75
Describe the general pattern of blood circulation in a mammal
Double closed circulatory system in which blood passes through heart twice for every time it goes round the body
76
What is the importance of a double circulatory system
-It prevents the mixing of oxy/deoxygenated blood so blood pumped to body is fully saturated with oxygen for aerobic respiration
-SO blood can be poumped out of body at a higher pressure and substances can be taken to/removed from body cell quicker
77
Describe the process of blood flow through heart to the body
Deoxygenated blood enters the right atrium, where it is then pumped into the right ventricle. From the right ventricle, it is pumped into the lungs by the pulmonary atery, where it is oxygenated. Oxygenated blood then returns to the heart by pulmonary vein and enters the left atrium, where it is pumped into the left ventricle. The left ventricle then pumps oxygenated blood to the rest of the body through the aorta.
78
Name the blood vessels entering and leaving the kidneys and describe what they carry and where from
Renal arteries- oxygenated blood to the kidneys
Rena veins- Deoxygenated blood to vena cava from kidneys
79
Name the blood vessel that carries oxygenated blood to the heart muscle
Coronary artery
80
Why is the wall of left ventricle thicker than the right?
-Thicker muscle to contract with greater force
-Generates higher pressure to pump blood around the entire body
81
Explain and describe the pressure and volume changes associated with atrial systole phase of cardiac cycle that mantains a unidirectional flow of blood
The atria contract. The volume decreases and the pressure increases. The atrioventricular valve opens as pressure in the atria exceed pressure in the ventricles and the semilunar valve remains closed as the pressure in the arteries exceeds pressure in the ventricles. Therefore blood is pushed into the ventricles
82
Explain the pressure and volume changes and associated valve movements during the ventricular systole phase of cardiac cycle that mantains a unidirectional flow of blood
The ventricles contract and the volume decreases and pressure increases. The atrioventicular valves shut as pressure in ventricles exceeds pressure in atria. The semilunar valve opens as the pressure in ventricles exceed that in artery. Therefore the blood pushed out of the heart through the arteries
83
Describe the equation for cardiac output
Cardiac output= Stroke vol (vol blood pumped out of heart per min) x heart rate (number of beats per min)
84
How can heart rate be calculated from cardiac cycle?
Heart rate (beats per min)= 60(sec) / Length of one cardiac cycle (sec)
85
Explain how the structure of arteries relates to their function
Function- Carry blood away from heart at HP
-Thick smooth muscle tiddue that can contract and control bloodflow/pressure
Thick elastic tissue- Can stretch as ventricles contract and recoil as ventricles relax to mantain HP
Thick wall- Withstand high pressure
Smooth/folded epithelium- Reduces friction/ can stretch
Narrow lumen- Mantains HP
86
Explain how the structure of arterioles relates to their function
Function- DIrect blood to diff capillaries/tissue
-Thicker smooth muscle layer than arteries allows for vasoconstriction and vasodilation (widening/narrowing of lumen) which increases blood flow to capillaries
-Thinner elastic layer as pressure surges are lower as its futher from heart/ventricle
87
Explain how the structure of veins relates to its fuction
Function- Carry blood back to heart at a low pressure
-Wider lumen than arteries as there is less resistance to blood flow
-Very little elastic and muscles tissue- Low BP
Valves- prevent backflow of blood
88
Explain how the structure of capillaries relates to its function
Function- Allow efficient exchange of substances between blood and tissue fluid (exchange surfaces)
Capillary bed is large network of branched capillaries which increases SA for diffusion
Narrow lumen/small diameter- Reduces blood flow rate so more time for diffusion
One cells thick thin walls- short diffusion distance
Pores in walls between cells- Allow larger substances through
89
Explain the formation of tissue fluid
At the ariestol end of capillaries, there is, higher hydrostatic pressure inside capillaries due to contraction of ventricles than tissue fluid so there is net outward force. This forces water and dissoleved substances out of the capillaries. Large plasma proteins remain in capillary
90
Explain the return of tissue fluid to the circulatory system
At the venule end of capillaries, hydrostatic pressure reduces as fluid leaves capillary (also due to friction) Due to water loss, an increasing conc of plasma proteins lowers water potential in capillary below than of tissue fluid. WAter enters capillaries from tissue fluid by osmosis down water potential gradient. Excess water is taken up by lymph capillaries and returned to circulatory system through the veins.
91
Suggest and explain causes of excess tissue fluid accumulation
-Low conc of protein in blood plasma could cause water potential gradient to reduce as water potential in capillary is not as low and therefore more tissue fluid formed at arterile end less absobed by venule end by osmosis.
-HBP cause by high salt conc causes high hydrostatic pressure therefore,increases outward pressure at arteriole and reduces inward pressure at venule end. More tissue fluid formed at arteriole end and less water absorbed at venule end by osmosis. Lymph system may not be able to drain excess fast enough
92
What is a risk factor and give 3 examples for cardiovasular disease
An aspect of a persons lifestyle or substances in a persons body or environment that is linked to an increased rate of disease.
Examples- Age. Smoking, Lack of exercise, Diet high in salt/ Saturated fats, genes
93
Describe how you can prepare a temporary mount of a piece of plant tissue for observation with an optical microscope
Add a drop of water to glass slide
obtain a thin section of specimen and place on the slide
Stain with iodine/ KI to view starch
Lower coverslip at an angle usin mounted needle w/o trapping air bubbles
94
Explain the pressure and volume changes and associated valve movements during the diastole phase of the cardiac cycle
Atria and venricles relax, volume increases and pressure decreases. Semilunar valves shut when pressure in arteries exceed pressure in ventricles. Atrioventricular valves open when pressure in atria exceeds pressure in ventricles. So blood fills atria via viens and flows passively to ventricles.
95
Describe some evidence to support cohesion tension
The trunks of trees reduce in diameter duting the daytime when transpiration is at its greatest. This is because ashesion of water molecules to the walls of the xylem results in tension that pulls the walls in and at nigh diameter decreases.
If trunk or stem is dammaged and xylem broken water dosent leak out
96
Name some adaptations of trachae and bronchus
Smooth muscle for contraction
Rings of cartilage for strenght
Goblet cells that secrete mucus
Cilliated epithelial cells that contract regularly to move mucus up & out
97
Name and describe 4 different cardiovascular diseases
Atheroma Formation- The endothelium layer of artery is usually smooth and unroken, if endothelium is damaged due to e.g high blood pressure, white blood cells and lipids from blood clump together under the lining to form fatty streaks WB cells, lipids and connective tissue build up and harden to form a fibrous plaque called atheroma. Blocks lumen of artery restricting blood flow increasing BP.
Aneurysm-Balloon like swelling of arterey that starts with formation of atheroma, when blood travels through a weaked artery at high pressure it pushes inner layer through outer elastic layer to form balloon
