Extra Cardio PHYS Flashcards

1
Q

What is isovolumetric contraction.

A

Ventricular contraction when all valves are closed. This increases ventricular pressure but as the valves are closed the volume remains unchanged.

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

What is the duration of systole?
Diastole?

A

0.3s
0.5s

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

What is end systolic volume?

A

The volume of blood remaining in the LV following systole

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

Define preload.

A

The initial stretching of the cardiac myocytes, or The volume of blood in the ventricles just before contraction (EDV).

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

Define afterload.

A

The pressure against which the heart must work to eject blood in systole.

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

Define contractility.

A

The inherent strength and vigour of the heart’s contraction during systole.

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

Define elasticity.

A

Myocardial ability to recover it’s original shape after systolic stress.

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

Define compliance.

A

How easily a chamber of the heart expands when it is filled with blood (C=ΔV/ΔP).

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

Define diastolic distensibility.

A

The pressure required to fill the ventricle to the same diastolic volume.

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

Give the equation for mean arterial pressure.

A

MAP = DP + 1/3(SP-DP).
(SP - systolic pressure, DP - diastolic pressure).

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

5
Give the equation for blood pressure.

A

BP=COxTPR.

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

What do arterioles respond to?

A

Blood pressure changes. Local, neural and hormonal factors.

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

Name 2 local factors that result in vasoconstriction.

A

Endothelin, internal BP.

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

Name 5 local factors that result in vasodilation.

A

Hypoxia, NO, K+ (accumulate from AP), CO2, H+, adenosine.

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

What neural factors result in vasoconstriction?

A

Sympathetic nerves that release noradrenaline.

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

What neural factors result in vasodilation?
NERUAL - Think nervous system

A

Parasympathetic innervation.

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

Name 3 hormonal factors that result in vasoconstriction.

A

Angiotenisn 2, ADH, Adrenaline (binds to alpha-adrenergic receptors in smooth muscle).

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

Name 2 hormonal factors that result in vasodilation.

A

Atrial natriuretic peptide, Adrenaline (binds to beta2 receptors).

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

Myogenic auto-regulation of blood flow: What is the response to an increase in BP?

A

Increased BP will result in vasoconstriction and so blood flow decreases.

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

Myogenic auto-regulation of blood flow: What is the response to a decrease in BP?

A

Decreased BP will result in vasodilation and so blood flow increases.

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

What is the cause of active hyperaemia?

A

When blood flow increases due to an increase in metabolic activity.
- Increased metabolic activity = decreased O2 and increased metabolites = arteriolar dilation = increased blood flow.

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

What is the cause of reactive hyperaemia?

A

When blood flow increases following occlusion to arterial flow.

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

Describe excitation-contraction coupling.

A

Pathway
1. Action potential causes wave of depolarisation across myocardium —> induces a Na+ sodium ion influx relative to the potassium
2. Plateau phase - Ca2+ coming into cells causes more calcium to be released from sarcoplasmic reticulum inside myocytes. -Ca2+ induced Ca2+ released.
3. The Ca2+ bonds to specific proteins Troponin C –> Troponin C changes shape, and sits on tropomyosin. This moves the tropomyosin away from myosin head, so actin myosin bridges can form
(after this, ATP needed to break bridges so myoisn can move along (muscle can relax))
==> ATP also needed to actively transport Ca2++ back to sarcoplasmic reticulum

After depolarisation, Ca2+ is returned to SR. K+ outflow = repolarisation.

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

What effect does myocardial contraction have on the
A) A-band of a sarcomere?
B) I band?
c) H Zone

A

a) stays the same
B and C - get shorter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is the I Band ?
What is the H band?
What is the A band?

A

I band - region containing only Thin filaments
H band (the region containing only thick filaments)
A band - just the size of the thick myosin filaments

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What is the function of troponin C?

A

Troponin C has a high affinity for Ca2+. TnC drives away TnI and so allows cross bridge formation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Where are peripheral chemoreceptors found?
What do they respond to?

What connects them to to the brain

A

Aortic arch and carotid sinus

Monitor changes in pO2 and pCO2, and conc of H+ ions for pH of blood
(but primarily changes in pO2)

Aortic arch = vagus nerve
cartoid sinus - Glossopharyngeal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What changes can the cardiac centre make in terms of vascular control?

A

has Sympathetic fibres which alter the diameter of blood vessels (vasoconstriction)

And has Cardiac accelerator centre to increase heart rate and contractility (sympathetic)
and has cardiac decelerator centres to lower heart rate (parasympathetic)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

To summarise, what is can the sympathetic autonomic nervous system change?

A

SYMPATHETIC = increasing The Heart rate, heart contractility, and diameter of blood vessels

PARASYMPATHETIC = Decreasing heart rate only

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Chemorecpetors - what change would happen when chemoreceptors pick up
low pO2, high pCO2, and acidaemia?

A

Sympathetic nervous system REDUCES blood vessels diameter, leading to VASOCONSTRICTION and increase TPR

Also would limit blood flow to peripheral organs and give more to heart and brain, cause vasoconstriction in veins for increased EDV, more preload

Leads to increased BP and CO

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What does sympathetic activity leading to increased CO and BP achieve?

A

pushes more blood to the lungs so more CO2 and be breathed out and more O2 can be breathed in? (to lower hypercapernia and raise hypoxia)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Where are central chemoreceptors located? what do they measure

A

They are in the medulla oblongate

Measure the PCO2 and pH of the CSF
===> the CO2 breakdown into H+ ions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What do central chemoreceptors do?

A

Arteriolar and venous constriction , which pumps more blood to the brain so BP in brain > than CSF pressure, and more blood goes to brain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What layer of the tri-laminar disc forms the cardiovascular system?

A

The mesoderm.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What does the TRUNCUS ARTERIOSUS - gives rise to

A

AORTA, AORTIC ARTERIES moves down and to the right

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

what does BULBUS CORDIS - gives rise

A

RIGHT VENTRILE , AND OUTFLOW TRACTS, moves down and to the right

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What does PRIMITIVE VENTRICLE -give rise to

A

the left ventricle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What does PRIMITIVE ATRIUM -give rise to

A

gives rise to LEFT ATRIA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What does SINUS VENOSUS -give rise to

A

gives rise to RIGHT ATRIA, VENA CAVA AND CORONARY SINUS (pulmonary vessels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

What affect does parasympathetic stimulation have on heart rate?

A

Decreases heart rate (-ve chronotropic). Cardiac output therefore decreases with parasympathetic stimulation. (CO=HRxSV).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What affect does sympathetic stimulation have on the heart?

A

○ Increase in Heart rate (positive chronotropic effect)
○ Increase in Force of contraction (positive ionotropic effect)
More Ca2+ entering myocyte,
More action potentials triggered
More contractility and cardiac output

42
Q

What membrane channels are responsible for the plateau period in the cardiac AP?

A

Voltage gated Ca2+ ‘slow’ channels.

43
Q

Briefly describe the cardiac action potential in 5 steps.

A

potential in 5 steps.

  1. Na+ channels open; influx of Na+ into cell; depolarisation.
  2. When the Na+ channels close, a small number of K+ leave the cell resulting in partial repolarisation.
  3. Ca2+ channels open and there is Ca2+ inflow. K+ channels are also open and there is K+ outflow. This results in the plateau period.
  4. Ca2+ channels close and K+ channels remain open. K+ leaves the cell resulting in repolarisation.
  5. Maintaining the resting potential (approx -90mV). Na+ inflow, K+ outflow.
44
Q

Where is the SAN located?

A

In the RA under the crista terminalis.

45
Q

Why is there rapid conduction in the bundle of his and purkinje fibres?

A
  1. The fibres have a large diameter.
  2. There is high permeability at gap junctions.
46
Q

What is the function of the refractory period?

A
  1. It prevents excessively frequent contractions.
  2. It allows time for the atria to fill.
47
Q

What does the P wave on an ECG represent?

What is the duration of the P wave?

A

Atrial depolarisation. Duration is less than 0.12s.

48
Q

What does the QRS complex on an ECG represent?
What is its duration?

A

Ventricular depolarisation.
Duration is 0.08-0.1s. Similar to the P wave

49
Q

What does the T wave on an ECG represent?

A

Ventricular repolarisation.

50
Q

What might an elevated ST segment be associated with?

A

Myocardial infarction.

The ventricles are repolarising (relaxing) less, so less EDV and CO

51
Q

What happens in the first step of the platelet plug, after endothelin has caused local vasoconstriction?
What receptor?

A

Von Willebrand factor binds to exposed collagen that from damaged vessel - using GP1b receptor

52
Q

Platelets release alpha and electron dense granules.
What is in alpha?
What is in electron?
What do they both do?

A

Release electron granules for energy (ADP, ATP, Ca2+, Thromboxane A2)

Release alpha dense granules mediate formation of the scaffolding (Platelet dense factor, Von Willebrnad factor, Fibrinogen, Heparin antagonist)

Electron for Energy
alFA dense granules for scaFFolding

53
Q

What after platelets have binded to VWF on collagen, what happens to them?

A

become activated and release their alpha and electron dense granules.
Change to a branches, sudapoid shape.

54
Q

What is the point of the coagulation cascade? What does it do?

A

forms fibrin mesh to increase integrity of platelet plug formed.(extra scaffolding)
Can be activated by intrinsci or extrinsic pathway

55
Q

What is the intrinsic pathway?
What is the extrinsic pathway?

A

Intrinsic pathway - From damage to BV that happens inside the blood vessel, uncommon - 12 > 11 > 9 > 8 >10
Extrinsic pathway - from damage outside more common 3 > 7 > 10

Both lead to common pathway, 10 > 5 > 2 > 1
56
Q

What is factor 1 called- what is its inactive and active name?

A

Factor 1 is called fibrinogen activated becomes fibrin ,
Inactive form fibrinogen is soluble, fibrin is not soluble, - leads to FIBRIN MESH THAT SECURES CLOT

57
Q

What is plasmin, and what is its purpose?

A

Plasmin eats fibrin, reverts back to fibrinogen back into inactive form, so no longer scaffolded the platelet plug so platelets fall away and leave tissue

degrades fibrin meshwork in the secondary platelet plug

Plasminogen —> Plasmin

58
Q

what does having A blood type mean?

A

have A antigens, so would make/have B antibodies

59
Q

what does having AB blood type mean?

A

have A and B antigens on your blood cells, so would make no Antibodies

60
Q

What does having O blood type mean?

A

have no anitgens (think O) so have both A and B antibodies

61
Q

What is the univseral donator?
Acceptor?

A

AB+ = UNIVERSAL ACCEPTOR
O - = UNIVERSAL DONAR

62
Q

Outline +- blood types

A

Positive cannot donate to negative
Negative can donate to a positive

63
Q

Why isnt ABO blood type an issue for a mother/baby?

A

Becuse these types of antigens CAN’T cross the placenta

64
Q

What does Rhesus D postive mean ? What about Rhesus D negative?

What are its implications

A

Rhesus positive means the D antigen is present. Rhesus negative means the D antigen is not
present

IT is a peptide antigen, made by spleen, can cross the placenta

What are its implications

65
Q

Outline the conditions for haemolytic disease of the new-born

A

• Mother has Rhesus NEGATIVE blood (RhD negative) and baby has Rhesus
POSITIVE blood (RhD positive). ==> Mum dd and Baby Dd

In pregnancy, mothers immune system recognises foreign Rhesus positive
blood and begins making antibodies against babies blood

FIRST baby is unaffected since it takes time for antibodies to be produced, the mother is said to
be SENSITISED to Rhesus positive blood

However, if mothers second baby also has RhD positive blood, then when mothers
blood is exposed to babies, antibodies are produced IMMEDIATELY and begin
DESTROYING BABIES RED BLOOD CELLS - resulting in HAEMOLYSIS OF
FOETUS/NEWBORN = ANAEMIA AND JAUNDICE.

66
Q

define haematocrit

A

the ratio of the volume of red blood cells to the total volume of blood

67
Q

What is found in the Anterior mediastinum?

A

Thymus

68
Q

What is found in the Middle mediastinum?

A

Heart
Ascending aorta
Pulmonary trunk

69
Q

What is found in the Posterior mediastinum?

A

Descending aorta
Oesophagus
Azygous system of veins
Thoracic duct

70
Q

What is found in the Superior mediastinum?

A

Superior vena cava
Arch of aorta

71
Q

What is the stimulating hormone for Leuckocyte production ?

A

granulocyte colony stimulating factor GCSF

72
Q

What is the hormonal factor involved in Platelets?

A

Thrombopoietin is the hormonal factor

poetin =(stimulating factor) ?
(think Erythropoietin for Erythrocytes/RBC)

73
Q

what is the name of the precursor to all blood cells?
What about the One after this for RBC?

A

Haemomatocytoblast - percussor to all blood cells

Haemomatocytoblast - Proerythroblast –> RBC

74
Q

what are the two types of WBC?

Give examples of both

A

GRANULOCYTES - PHILS
NEUTROPHIL, EOISINOPHIL, BASOPHIL, - APPEAR GRANULATED ON HISTOLOGICAL SLIDES

AGRANULOCYTES - CYTES
MONOCYTES AND LYMPHOCYTES

75
Q

Granulocytes - what is the role of neutrophils? How do they appear?

A

key mediators of acute inflammatory response, key in bacterial infection Mulitlobed, so many different lobed regions, faint granules

76
Q

Granulocytes - what is the role of Eosinophils? How do they appear? Appearnece of Nucleus?

A

Fight parasites. PINK GRANULES - (THINK HAEMOTXYCIN AND EOSIN)
BI LOBED
Release antihistamines, to decrease allergic response. Bind to IgE receptors, to almost competitively inhibit histamines

77
Q

Granulocytes - what is the role of Basophils? How do they appear?

A

Basophils contain histamine granules and cause local inflammatory responses through their interaction with IgE. Their role in the immune system is poorly understood but they potentially mediate type I hypersensitivity reactions alongside mast cells

DARK BLUE GRANULES, B FOR BLUE AND BASOPHIL

78
Q

Agranulocytes - what is the role of Monocytes? How do they appear?

A
  • Immature cells that can become macrophages, phagocytose. Kidney bean shaped nucleus. Also ivolved in bacterial infection

Resident macrophages in places
Mono = Macro

They also secrete cytokines, which modulate the immune response

79
Q

Agranulocytes - what is the role of Lymphocytes? How do they appear?

A

Cell mediated innate immunity, adaptive response, for specific immunity - BIG NUCLUES, SMALL CYTOPLASM

They are the smallest, and respond to virus infections

80
Q

What is chemotaxis?

A

tissues produce chemokines which recruit neutrophils allowing neutrophils to hone in to the site of infection.

The recruitment of Neutrophils through tissues producing cytokines which allow neutrophils to hone in on the site of infection

81
Q

what are the 3 main types of lymphocyte? (a type of agranulocyte, with big nucleus?)

A

Natural killer cells -
T cells
B cells

82
Q

What is the function of Natural killer cells? (Type of lymphocyte)

A

NK cells provide NON - SPECIFIC immunity against cells displaying foreign proteins such as cancer cells and virally- infected cells. They make up less than 5% of circulating leukocytes.

83
Q

What is the function of T Cells? (Type of lymphocyte)

A

T cells form in the bone marrow but mature in the thymus. They are part of the adaptive immune system and are involved in cell-mediated immunity.

Once active, CYTOTOXIC T cells can directly attack infected cells. In addition, HELPER T cells have many functions including activating B cells and forming memory T cells which respond on re-infection.

84
Q

What is the function of B Cells? (Type of lymphocyte)

A

B cells form and mature in the bone marrow. They are part of the adaptive immune system and involved in humoral immunity by secreting antibodies

85
Q

What does NO do to platelets?
What does Prostacyclin do?

A

NO inhibits platelet adhesion
Prostacyclin inhibits platelet aggregation.
===> (both are vasodilators)

86
Q

What does Ionotropic mean?
What does Chronotropic mean

A

Ionotropic = to do with FORCE of heart contraction
Chronotropic = to do with HEART RATE

87
Q

What are the progenitors for platlets called?

A

Megakaryoblasts

88
Q

Describe how antibodies are specific to one antigen.

A

Antibodies are bound to antigens via the variable region (1)
- The variable region determines the specificity of the antibody to the different
amino acids that it contains, which change the shape of the antigen binding
site (1)

89
Q

What does the RCA supply?

A

( SA node, AV Node, Posterior IV septum)

90
Q

What does the Right Marginal supply?

A

(Right Ventricle and APEX)

91
Q

What does the Posterior Descending Artery supply?

A

(Right ventricle, Left Ventricle, Posterior 1/3 of IV septum)

92
Q

what does the LCA supply?

A

(Left atrium, Left Vent. Septum and AV node and Bundles of His)

93
Q

What does the LAD supply?

A

Goes between vents, (Anterior 2/3 of Septum, Right Ventricle and Left Ventricle)

94
Q

What does the left circumflex artery supply?

A

flexes around to the posterior (Left Atria and Left Vent.)

95
Q

What does the left marginal artery supply?

A

Left Marginal Goes around margin of heart (Left ventricle)

96
Q

Where is the RCA found?

A

In the atrio-ventricular sulcus

97
Q

On what aspect of the heart would you find the left atrium?

A

The posterior aspect. It is closely related to the oesophagus.

98
Q

In 90% of hearts where does the posterior inter-ventricular artery arise from?

A

RCA

99
Q

In 30% of hearts where does the posterior inter-ventricular artery arise from?

A

The circumflex artery.

100
Q

In 20% of hearts where does the posterior inter-ventricular artery arise from?

A

The RCA and the circumflex artery

101
Q

What is the ion channels that maintain action potentials in the SA and AV nodes?

A

L type Ca2+ channels

whereas T type are used in
initiating them in the SAN and AVN.

102
Q

Which of the following is the correct order of conduction in the heart?

A

SA node > AV node > Bundle of His > Bundle branches > Purkinje fibres