module 3 bits Flashcards
(78 cards)
1
Q
what is tachycardia?
A
Increased heart rate
2
Q
What is brachycardia?
A
Decreased heart rate
3
Q
What is fibrillation?
A
Uncoordinated contraction of atria and ventricles
4
Q
What is an ectopic heartbeat?
A
Extra or early beat of the ventricles
5
Q
In an ECG what does the P wave mean?
A
Atria contraction
6
Q
In an ECG what does the QRS wave mean?
A
Excitation of ventricles
7
Q
In an ECG what does the T wave mean?
A
Diastole
8
Q
Calculation for cardiac output?
A
Stroke volume x heart rate
9
Q
4 bullet points of the coordination of the cardiac cycle?
A
- SAN triggers atria to contract
- Band of non-conductive fibres stops depolarisation reaching ventricles straight away
- AVN conducts impulse down septum of heart to bundle of His
4.Depolarisation spread across ventricles by purkinje fibres- ventricles contract
10
Q
What vessel does deoxygenated blood enter the right atrium?
A
Vena cava
11
Q
What vessel does oxygenated enter the left atrium in?
A
Pulmonary vein
12
Q
What chamber does oxygenated blood enter the heart in
A
left atrium
13
Q
What vessel does oxygenated blood exit the heart in?
A
Aorta
14
Q
What vessel does deoxygenated blood exit the heart in?
A
Pulmonary artery
15
Q
Does foetal Hb have a higher or lower O2 affinity?
A
Higher
16
Q
Describe how CO2 ends up being breathed out in the lungs
A
- CO2 diffuses into blood cell
- Combines with water to form carbonic acid
- Carbonic anhydrase enzyme converts this to hydrogencarbonate ion
- Hydrogencarbonate ion diffuses out of RBC and Cl- diffuses in to balance charges
- Some CO2 will bind directly to Hb creating carbaminohaemoglobin and will be carried in the blood back to the lungs
- The H+ that dissociated from the carbonic acid binds to Hb to form haemoglobonic acid
- Blood to lungs
- H+ dissociates from Haemoglobonic acid and binds with hydrogencarbonate ion (transported in tissue fluid) to form CO2 and H2O
17
Q
Describe the Bohr shift
A
At high CO2 concs…
Increased H+ from CO2 changes shape of Hb
Reduces O2 affinity to Hb
Causes more oxygen to dissociate from Hb to respiring site
18
Q
Describe how O2 conc. effects affinity to Hb
A
At low concentrations, O2 has low affinity for Hb.
This causes more O2 to dissociate from Hb
At high concentrations, O2 has high affinity for Hb. This causes more O2 to dissociate from Hb
19
Q
What wave will look funny in fibrillation?
A
The P wave
20
Q
Adaptations of nasal cavity?
A
Good blood supply which warms the air
Hairy lining which traps dirt and bacteria
Moist surfaces which increase the humidity of the incoming air, reducing evaporation from the exchange surfaces
21
Q
Adaptations of trachea? Innermost layer to outermost
A
- Cilliated epithelial cells and goblet cells
- Smooth muscle allows lumen to constrict
- Elastic fibres allow lumen to expand
- Cartilage to prevent collapse during expiration when pressure decreases
bronchus is same
22
Q
Adaptations of the bronchioles?
A
- Smooth muscle, contract and dilate
- flattened epithelium
23
Q
How does smooth muscle in the bronchioles release after contracting?
A
It can’t do it voluntarily (only contracts after allergic reaction etc) so relies on elastic fibres.
When contracting the smooth muscle deforms the elastic fibres, so, the elastic fibres will recoil back to their original shape and elongate the smooth muscle again.
24
Q
Process of inspiration?
A
Diaphragm contracts and flattens,
external intercostals contract moving ribcage upwards and outwards
thorax volume increases, internal pressure lower than outside
air flows in down pressure gradient.
25
How does spirometer work?
The air chamber in the spirometer rises and
falls as the person breathes. As the person breathes, oxygen is removed from the spirometer and the carbon dioxide breathed out is absorbed so the chamber does not rises as high after each breath
26
How does tracheal fluid in tracheoles aid the respiration of insects?
When the insect is less active, tracheoles contain fluid,
As activity increases, fluid is removed from tracheoles into muscles as muscles produce lactic acid, lowering the water potential of the cells. Gas exchange happens quicker as more SA of tracheoles exposed to air.
27
How do concentration gradients work in insects?
When cells are actively respiring, oxygen is used up and so its concentration towards the end of the tracheoles falls.
This creates a diffusion gradient for O2 towards the cells. CO2 is produced by cells creating a diffusion gradient with the atmosphere (CO2 moves out of the insect).
28
How do larger insects inspire and expire? Which process is active? Which process is passive?
Expiration: active
Muscles contract and flatten body. Volume of the tracheal system decreases. This forces air out of the body
Inspiration: passive
As muscles relax, volume of tracheal system increases again, withdrawing air through the spiracles into the tracheal system.
29
What is discontinuous gas exchange in insects?
Some insects have valves or hairs at the spiracles.
This prevents water loss or the entry of excess O2 in periods of rest
30
How are fish adapted for efficient breathing?
- Large SA:V ratio of gill lamella
- Short diffusion pathway: lamella v. thin
- Countercurrent exchange maintains a conc. gradient so that O2 outside blood always higher than inside.
31
Do fish have Hb?
Yes.
32
Describe the process of 'fish breathing'
Suction pump phase:
- water in, buccal cavity extends to suck water in, opercular valve is closed
Pressure pump phase:
- buccal cavity closed and opercular valve opens, water forced over gills.
33
What makes an efficient exchange surface?
increased surface area
thin layer
good blood supply/ventilation to maintain gradient
34
How does forced respiration in humans occur?
Contraction of abdominal wall muscles
Contraction of internal intercostals.
35
What is the point of pleura/pleural cavity?
Makes sure lungs cling to surface of thorax and don't slide around
36
Explain why all of the air cannot be removed from the lungs
- some remains in bronchus
- some remains in bronchioles
- some remains in alveoli as they cannot be completely flattened
37
What's the difference between gill filaments and lamellae?
Gill filaments are found branching off the gill arch.
Gill lamellae are found within gill filaments.
38
Journey of the blood through the heart?
1. Oxygenated blood enters through pulmonary vein into left atrium
2. Left atrium contracts (pressure higher in atrium than ventricle) so blood flows into left ventricle through AV valve.
3. Atrium relaxes and AV valve closes, Ventricle the contracts and forces blood through SL valve (pressure higher in ventricle than aorta)
4. Blood exits through aorta and travels around body.
5. Deoxygenated blood then enters through vena cava into right atrium.
6. Right atrium contracts (pressure higher in atrium than ventricle) so blood flows into right ventricle through AV valve.
7. Atrium relaxes, AV valve closes, right ventricle contracts.
8. Pressure higher in ventricle than pulmonary artery so blood forced through SL valve into pulmonary artery to lungs.
39
How is tissue fluid formed?
1. Hydrostatic pressure higher than osmotic pressure at the arteriole end of the capillary.
2. Forces plasma out of the capillaries and into the tissues
3. This forms tissue fluid
4. Large plasma proteins remain in the blood, maintaining the oncotic pressure.
5. At the venous end of the capillaries, oncotic pressure is higher than hydrostatic pressure.
6. Some of the water that initially exited the capillaries re-enters via osmosis down water potential gradient.
40
What happens to surplus tissue fluid?
it is drained by the lymph
41
Cardiac output?
heart rate x stroke volume
42
systole contraction or relaxation?
Contraction
43
How would you describe the transfer of O2 between maternal and foetal Hb?
Foetal Hb has a higher affinity to O2 (at same pO2)
There is a low pO2 in placenta so O2 dissociates from maternal Hb. Oxygen diffuses from maternal to foetal
blood.
So, there is an increased saturation of foetal Hb at lower pO2.
44
Precautions when using spirometer
- Airtight so no air leaks
- Refresh soda lime
- Sterilise mouthpiece
- Do not overfill else water will enter mouthpiece
45
Why is soda lime used in spirometer?
To absorb CO2 so that only O2 is measured
46
How does spirometer work?
Air breathed in from tank and then exhaled. Passed over soda lime and back through tank. Movement of floating chamber lid is measured.
47
What is tidal volume?
Volume of air moved in and out of lungs with each breath at rest.
48
What is residual volume?
The volume of air that remains in lungs in alveoli etc after deep exhale
49
What is vital capacity?
The maximum amount of air that can be forced out of the lungs
50
How do solvents affect cell membranes?
Damage cell membrane as they dissolve lipids
51
DNA purification?
Detergent and salt are added. Detergent breaks down the lipid membranes in the sample while the salt neutralises the charge in the DNA’s phosphate backbone.
The solution is heated to further break down the DNA
Cool in ice bath and filter
Protease enzymes breaks down proteins bound to the DNA
Add ethanol to precipitate
52
Define an enzyme
Biological catalysts made of protein that increases rates of intracellular and extracellular reactions by lowering the activation energy required to begin the reaction
53
How do cofactors/ prosthetic groups/ coenzymes work?
cofactors / coenzymes / prosthetic groups;
bind to, enzyme / active site / allosteric site;
temporarily;
change, shape / tertiary structure, of active site;
affect charges on active site;
bind to / interact with, substrate;
increase (likelihood of), substrate binding to active site / ESC formation;
carry (named) chemical, between / to, (named) enzymes;
54
Describe induced fit model
Complimentary substrate binds to active site
Active site changes shape to fit around substrate
ESC forms
Non-covalent forces bind substrate to enzyme active site
EPC forms
Diffent shape so pushed out of active site.
55
Q10
rate after 10degrees increase/ before
56
Can competitive inhibition be stopped by adding more substrate?
Yes
57
Can non-competitive inhibition be stopped by adding more substrate?
no
58
How do non-competitive inhibitors work?
bind irreversibly to allosteric sites
change the tertiary structure of active sites so they are no longer complementary to substrates
59
How do competitive inhibitors work?
Block active site
60
Poisons and their impact on enzymes?
Cyanide is a poisonous substance. It inhibits an enzyme called cytochrome c oxidase, which is important in aerobic respiration
Allopurinol is a common treatment for gout. It inhibits xanthine oxidase enzyme that can produce painful uric acid crystals around joints
Methotrexate is a chemotherapy drug and autoimmune disease treatment. It inhibits enzymes responsible for nucleotide synthesis needed for DNA replication during cell division
61
Properties of fibrous proteins?
Insoluble,
long and thin, metabolically inactive,
role often structural
62
Properties of globular proteins?
Spherical,
Soluble,
Metabolically active
63
Examples of fibrous proteins?
Collagen
(found in artery walls and tendons)
Keratin
(hair and nails- strong, impermeable barrier to infection)
Elastin
(bronchiole walls stretch and recoil)
64
Examples of globular proteins?
Haemoglobin
(two alpha and beta chains, 4 haem prosthetic groups- conjugated)
Insulin
Pepsin
(enzyme digests protein in stomach. V. stable in acidic environment as few basic R groups to accept H+ and denature tertiary structure)
65
magnification definition
How many times bigger an object appears than the original image
66
Calculating magnification:
A= I/M
67
Define Resolution
The highest magnification in which two objects can be seen as separate
68
How to use microscope?
1. Specimen placed on slide and clipped into place
2. Lowest power objective lens placed over specimen
3. Adjust coarse focus knob until image seen is clear
4. Adjust iris diaphragm for optimum light
5. Bring higher power objective lens into place and fine focus
6. Repeat with 40x mag etc
69
Scanning electron microscope features:
- High resolution
- Structures within specimen 3D
70
transmission electron microscope:
- Specimen stained and dehydrated first
- 2D
- Very high mag
71
Light microscope:
Limited magnification due to low resolution
non membrane-bound organelles (ribosomes) cannot be viewed under this microscope too small
72
What is an eyepiece graticule?
Ruler placed in the eyepiece to measure a specimin
73
What is a stage graticule?
Placed on microscope stage used to calibrate eyepiece graticule
74
What organelles are non membrane-bound?
Ribosome and cytoskeleton
75
Features of fish circulatory system?
- Single
- Closed
- Arteries, veins, and capillaries
- Heart only 1 atrium and 1 ventricle
- Lower metabolic demand
76
In a spherical bilayer, how do hydrophilic/hydrophobic interactions work?
Hydrophilic on outside, hydrophobic on inside.
77
Why is phospholipid bilayer described as fluid mosaic?
- phospholipids and proteins can move around via diffusion
- scattered pattern produced by the proteins within the phospholipid bilayer looks somewhat like a mosaic when viewed from above
78
Why do aerobically fit people have lower heart rate
- Larger stroke volume
- Increased volume of ventricles
- Increased strength of cardiac muscle
