Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Disease, Diagnostics and Therapeutics > Hypertrophic Cardiomyopathy > Flashcards

Hypertrophic Cardiomyopathy Flashcards

(61 cards)

Start Studying
1
Q

T wave

A

Ventricular repolarisation

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

What is needed for pacemaker cells to become activated

A

hyperpolarised

-ve voltage needed at end of phase 3

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

What are the 5 steps in traditional cloning

A
  • vector preparation
  • insert preparation
  • ligation
  • transformation
  • colony screening
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the difference generally between smooth and cardiac muscle contractions

A

VSM undergoes slow, sustained, tonic contractions, whereas cardiac muscle contractions are rapid and of short duration.

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

Give an example of a technology used for recombinant DNA

A

CRISPR

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

How common is HCM

A

1 in 500

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

What type of mutation are the HCM mutations normally

A

usually point or missense, bur can be indels

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

What is the function of myosin ATPase

A

enzyme that hydrolyses ATP required for actin and myosin cross-bridge formation

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

What type of genetic dominance/recessiveness is HCM

A

autosomal dominance

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

Describe sarcomeres

A

repeating units making up myofilaments
region between two Z-lines
composed of thick and thin filaments- actin and myosin

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

What is the effective refractory period (ERP)

A

stimulation of cell cannot initiate action potential

fast Na channels close and stay inactivated after phase 1

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

Intercalated discs contain three different types of cell-cell junction. What are these?

A
  • Fascia adherens junctions
  • Expanded desmosomes
  • Gap Junctions
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is a conjugated protein

A

a protein bound to something else.

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

What is faulty in ARVC

A

Desmosomes

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

What does the calcium-calmodulin complex activate

A

myosin light chain kinase

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

bundles of what make up cardiac myocytes

A

myofibrils

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

What is an ECG

A

A trace showing the rhythm of the heartbeat, where abnormalities can be detected.

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

What do indels cause in a genetic sequence

A

frame shift

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

QT interval

A

Time taken for ventricular depolarisation and repolarisation

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

What is HCM

A

overgrowth of the septum of the heart into the left ventricle, causing outflow tract obstruction so blood cannot flow out of the aortic valve.

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

P wave

A

Atrial depolarisation

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

What gene is most commonly affected in HCM

A

42% cardiac MyBP-C

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

What are the ‘funny’ channels gated by

A

Hyperpolarisation activated cyclic nucleotide gated channels

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

What is the function of the Hyperpolarisation activated cyclic nucleotide gated channels

A

They keep generating Aps.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
On an ECG trace, how would you work out HR using squares
HR= 1500/number of small squares in RR interval Or HR= 300/number of large squares in RR interval
26
True or false: HCM is frequently asymptomatic until sudden cardiac death
True
27
Why is depolarisation slower in pacemaker cells
no fast Na+ channels | depolarisation current carried by slow Ca2+ influx
28
What is ARVC
This is an enlargement of the right ventricle, loss of myocytes, and a fibrotic, fatty heart
29
When does VSM relaxation occur
when there is reduced phosphorylation of MLC
30
What is CRISPR cas-9
a CRISPR-associated protein containing two nuclease domains, programmed by small RNAs to cleave DNA
31
How is the resting membrane potential maintained
K+ channels open - K+ leaves cell making it more -ve Na+ and Ca2+ channels closed, cannot enter cell -90mV
32
Explain the steps of a non-pacemaker cardiac action potential
* Rapid depolarisation due to opening of fast Na+ channels (0) * Initial repolarisation caused by opening of K+ channel (1) * Inward Ca2+ movement through L-type channels (slow) which open when membrane reaches -40mV. Plateau phase due to delayed repolarisation. (2) * Repolarisation occurs when K+ channels open, and closure of Ca2+ channels (3) * True resting membrane potential (stable). Closed Na+ and Ca2+ channels, open K+ channels. (4)
33
What are gap junctions
o Provide direct contact between the cardiac cells o Facilitate electrical communication, so that waves of depolarisation spread rapidly over the entire heart, by passing from cell to cell o connexin subunits make pores
34
Q wave
Left to right interventricular septum depolarisation
35
What are fascia adherens junctions
o Actin filaments attach to thin filaments in the muscle sarcomeres to the sarcolemma o So, they all contract together in a functional syncytium
36
What does MLC phosphorylation lead too
cross-bridge formation between the myosin heads and the actin filaments, and smooth muscle contraction.
37
What are the symptoms of ARVC
palpitations, lightheadedness, and fainting. ARVC can also cause shortness of breath and abnormal swelling in the legs or abdomen.
38
What can reduce phosphorylation of MLC
1. reduced release of calcium by the SR or reduced calcium entry into the cell 2. inhibition of MLCK by increased intracellular concentration of cAMP 3. phosphatase-activated MLC dephosphorylation.
39
What is faulty in HCM
sarcomere
40
What is the purpose of the effective refractory period
protects the heart by preventing multiple APs | at a high HR, the rate would be unable to properly fill and ventricular ejection would reduce
41
What is the purpose of the intercalated discs of the heart
connect cardiomyocytes to work as a single functional organ/syncytium
42
What is the name for the invagination of the sarcolemma
Transverse (t) tubule
43
An increase in which ion stimulates VSM contraction
calcium
44
Compare the role of Calcium in depolarization of neural/skeletal APs to cardiac APs
neural/skeletal: - caused by opening of Na+ channels non-pacemaker cardiac: - caused by opening of Na channels, Ca influx prolongs duration of AP causing plateau phase pacemaker cardiac: - Ca2+ involved in initial depolarisation
45
Explain the steps of a pacemaker cardiac action potential
* Spontaneous depolarisation (pacemaker potential) caused by funny currents. T-type Ca2+ open; further depolarisation. L-type Ca2+ opens. K+ channels close (4) * Depolarisation of the AP, caused by increased Ca2+ conductance through L-Type channels. T-type channels close. (0) * Repolarisation of the AP as K+ channels open and Ca2+ close. Hyperpolarisation reached. Na+ ion channels open, initiating phase 4- also called funny currents or If. (3)
46
what happens to 'funny' and T-type Ca2+ channels near the end of phase 4 (initial depolarisation of pacemaker)
funny currents decline - Na channels close Ca2+ currents through T-type channels decline - channels close
47
S wave
Interval between ventricular depolarisation and repolarisation
48
What is the length-dependent activation of the sarcomere
stretching the sarcomere increases the affinity of Troponin-C for Ca2+
49
In VSM what does free calcium bind to initatially
Calmodulin
50
How to calculate penetrance
number of individuals displaying symptoms, divided by the number of individuals with a disease causing mutation x 100
51
Define penetrance
probability that a person carrying a disease-associated genotype will develop the disease within a given time period
52
What happens when calcium binds to troponin C
conformational change in troponin complex | myosin head exposed
53
ST segment
Interval between ventricular depolarisation and repolarisation
54
What causes phase 0 depolarisation of pacemaker cells
mainly by increased conductance of Ca2+ through L-type Ca2+ channels that open near the end of phase 4
55
Define recombinant DNA technology
the joining of DNA from two different species, that are inserted into host organisms to produce new genetic combinations
56
What is unusual about the cardiac pacemaker AP
There is no resting phase or RMP & Ca2+ (instead of Na+) is responsible for main depolarisation.
57
What are the two types of cardiac action potential
non-pacemaker A.P. - fast response | pacemaker A.P. - slow response
58
Describe smooth muscle
non-striated, single celled (mononuclear) and is found in organs such as the bladder, GI tract and blood vessels.
59
What are expanded desmosomes
o strong adhesion between cells o link to the intermediate filament of the cytoskeleton o structural integrity
60
R wave
Early ventricular depolarisation
61
What 3 proteins make up the thin filament
actin tropomyosin troponin

Disease, Diagnostics and Therapeutics (14 decks)

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