Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Homs > Homs Practical > Flashcards

Homs Practical Flashcards

(68 cards)

Start Studying
1
Q

High pass

A

Allows higher frequencies and low pass is vice versa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Occluding both arteries

A

Brachial pulse

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Nernst equation

A

Ek = 58log10 ([outside]ref/[inside]test)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Membrane circuit representation

A

Resistor, capacitor and voltage source in parallel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Membrane time constant

A

T = Rm x Cm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Voltage capacitance relationship

A

V= QC

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Adding capacitor

A

Drops current to 0 then allows it to rise again as charged- reaches Vmax when fully charged

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Time constant percentage charged

A

At time t, voltage is 63% of final voltage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Frequency of UK mains

A

50Hz

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How is a partial short circuit formed

A

If tissue between two electrodes has low electric resistance- smaller potential difference than expected will be recorded

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Stimulus artefact

A

Stimulating current directly to recording electrodes through body or liquid on surface

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Earth electrode

A

Channels some unwanted stimulating current

AP unaffected

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Swapping around recording electrodes

A

Upside down APs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Intracellular recording convention

A

Ext electrode= reference

Internal is test (therefore test relative to ext = negative)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Normal electrode set up

A

Reference electrode closer to stimulating cathode

Stim anode; stim cathode, earth, recording ref (external); recording test (internal)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Anode block

A

Having stim anode after stim cathode - leads to hyperpolarisation preventing impulse passing onwards

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Recruitment

A

Adding lateral fibres- respond to stimulus- lateral fibre has higher frequency and longer latency than medial fibre

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Direction of AP in medial and lateral fibres

A

Cranial- caudal in MGF, caudal-cranial in LGF

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Temperature effect on APs

A

Affects kinetic properties of channel gating mechanisms- cooling slows rate of sodium channels opening therefore slower conduction velocity
Repolarisation slower and sodium channels inactivate slower and potassium channels open slower

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Compound AP

A

Many muscle fibres response

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Latency

A

Time between first stimulus and first sign of a response

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Short PR interval

A

Wolff Parkinson white syndrome- extra rapid path for signals to pass from atria to ventricles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Long PR value

A

First degree AV block

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Long QRS interval

A

Bundle branch block

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Long QT interval
Long QT syndrome- genetic mutation
26
Electric systole
Time between Q wave to end of T wave (rest is diastole)
27
Exercise effect on systole and diastole pressures
Systole pressures increase, diastole pressures fall
28
Heart rate increase effects
Increases slope of pacemaker potential Adrenergic stimulation B1 increases current through VGKC= more rapid repolarisation of cell after plateau = shorter cardiac AP B1 stimulation = calcium pumps in SR work harder quicker removal of Ca2+ from cytosol= rapid relaxation
29
Respiratory sins arrhythmia
Increase in HR on inspiration, decrease in HR in expiration | Normal
30
Mean arterial pressure
D + 1/3(S-D)
31
Active hyperaemia
From of metabolic auto regulation | Demand outpaces supply changing metabolic levels leading to vasodilatation
32
Increasing exercise intensity on breathing rate
Increases proportionallly then disproportional as exercise becomes anaerobic (low pH)
33
Exercise effect on Pulse rate
Increases over first minute then stabilises at steady state
34
Exercise effect on %SpO2
No change - body not reliant on negative feedback for gas levels
35
Alveolar ventilation equation
VA= (VECO2/PACO2) xK
36
Cardiac output- fick
CO= rate of CO2 production/ (venous-arterial CO2)
37
RQ
Amount of CO2 produced/ amount of O2 taken in
38
how to avoid aliasing
set sampling rate at more than twixe frequency of origimal signal
39
potential of membrane recorded as...
potential always reported as test relative to ref
40
capacitive current
flow of electrons onto left plate and off of right plate- looks like current flowing through capacitor
41
how to increase capacitance
larger surface area of plates, plates closer together (thinner insulating layer)
42
capacitance key points
stores charge capacitor takes time to charge and discharge- slows change in voltage capacitance of excitable cell membrane affects velocity of AP conduction
43
how does myelination increase conduction velocity
not through T=RC as myelination increases R but also decrease C- not much change but increased R increases length constant (lambda)
44
colours of electrodes
cathode (black) anode (red) earth (green)
45
latent period
time taken for AP to travel from stim cathode to 1st recording electrode
46
conduction velocity through absolute method and reeason why its not great
use single distance (D) and latent period (LP) v=D/LP delay with initiating AP in first place and AP peak measuring to occurs after first sign of electrical activity- gives v slighlty lower than true conduction v if use strong stim current, AP generated further from cathode therfore v too high
47
accurate conduction v
compare equivalent APs on two traces, obtained when recording at 2 diff distances -difference method v= (D2-D1)/(LP2-LP1)
48
ST segment
ventricular muscle all depolarised
49
what does a bio amp do
electrically isolated device for increasing size of v small voltage (safe)
50
aorta bp compared to pulm artery bp
5-6 x greater
51
how to increase systolic p
``` more blood pushed out arteries stiffer (less compliant) ```
52
misdiagnose hypertension using pressure cuff if...
if cuff v narrow relative to arm- gives falsely high bp (misdiagnose hypertension)- ie obese subject with larger arms
53
misdiagnose hypotension if..
cuff wide relative to arm- falsely low bp
54
recommended width of cuff
40% circumference of midpoint of arm
55
bp slighlty higher in which arm
right- use this as standard
56
cause of functional and reactive hyperaemia
hypoxia | accumulation of vasodilator metabolites (ie increase in PCO2, lactic acid, adenosine, K+ and temp, fall in pH)
57
how do pulse oximeters work
measures colour of blood to determine percentage saturation of arterial blood (more saturated = brighter red) gives peripheral oxygen saturation (%SpO2)
58
end expiratory sample
first gas similar to atmospheric air (dead space) | terminal stages=exhalation from alveoli(arterial blood)
59
resp gas analyser measures
Dried O2 and CO2 percentages
60
measurements made in douglas bag(CO) exp
``` arterial blood gas concs amount of gas exhaled in 5 mins no. of breaths in 5 mins conc of O2 nad CO2 in exhaled gas last 3 measuremtns = tidal vol, rate of CO2 and O2 consumption ```
61
why shouldnt you hyperventilate in douglas bag exp
blows off a lot of stored CO2- gives abnormally high values for CO
62
haemorrhage events
BV falls -> decrease in VR -> decrease MSP -> decrease atrial P -> decrease CO -> HR increases to try to restoore MAP -> increase in TPR -> decrease in splanchnic flow
63
normal glucose levels
4-7mmol/l
64
cephalic phase of digestion
parasympathetic stimulation of beta cells via vagal ACh = anticipatory insulin release
65
what potentiates insulin release in response to oral glucose
incretins- GIP and GLP-1
66
How is insulin release inhibited in exercise
sympathetic stimulation of alpha-2 receptors - increases blood glucose
67
most common source of error in RQ
hyperventilation- increases amount of CO2 unloaded from blood (should be aiming for an expired %O2 od 14-17%
68
how much heat does each gram of sweat take
2.45kJ

Homs (3 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions