Cardiovascular System 1-3 Flashcards

Question

Left anterior descending artery

Answer 1

Supplies right and left ventricles and interventricular septum •Also known as anterior interventricular artery • Widow maker!! - common place of occlusion in myocardial infarction

Answer 2

• Circumflex = curved or bent * Arise from left coronary artery * Supplies left atrium and left ventricle

Answer 3

* Also known as obtuse marginal artery * Forms obtuse angle with coronary sulcus * Supplies left ventricle

Answer 4

3 branches of right coronary artery • Sa nodal artery • Right marginal artery • Posterior descending artery 3 branches of left coronary artery • Left anterior descending • Left circumflex • Left marginal

Answer 5

• Drains the same cardiac territory supplied by the LCA

Answer 6

• Posterior surface of interventricular septum

Answer 7

• Right margin of heart

Answer 8

Artery Vein Capillary

Answer 9

-> supply oxygenated blood to body Pulmonary artery - takes deoxy blood from heart to lungs '

Answer 10

→ deoxygenated blood from tissues to heart Pulmonary vein - oxy blood from lungs to heart Capacitance vessels

Answer 11

• Exchange of nutrients • Deoxygenated and oxygenated blood – gas exchange • Reduced flow in capillaries = more efficient nutrient transfer '

Answer 12

* Tunica intimia * Tunica media * Tunica externa

Answer 13

* Innermost lining of the blood vessel * Lined by endothelium – damage to lining = clot formation * In large arteries the internal elastic membrane , looks wavy (not in veins or arterioles) marks the outer boundary of the tunica intern

Answer 14

* Middle layer * In arteries tunica media is the thickest layer - prominent * Smooth muscle cells (SMC) supported by varying amounts of connective tissue (formed from elastic fibres) * SMC contraction controlled by ANS (nervi vasorum), hormones, local chemicals * Arteries have external elastic membrane, this is absent in the veins

Answer 15

• Outermost layer • Blends into surrounding tissue and stabilises blood vessels • In thick walled vessels: blood supply→ vasa vasorum (living cells require blood) • Large arteries and veins contain vasa vasorum – provide nutrients to blood vessel -arteries it is in tunica adventitia Veins it is in tunica media

Answer 16

* Walls of arteries thicker than the veins * In cross section arteries appear rounder than veins * The endothelial lining of constricted arteries is thrown into folds and is pleated- due to elastic lamina in artery

Answer 17

* Large elastic conducting arteries * Medium Muscular (Distributing) Arteries * Arterioles

Answer 18

* Largest, closest to the heart * Aorta, pulmonary arteries – recieves large blood volume from left venticle * Tunica media contains high density of elastic fibers – allows stretch * Allows even flow of blood between systole and diastole

Answer 19

* Distribute blood to skeletal muscles and internal organs * More smooth muscle cells instead of elastic fibres * Further away from heart – lower pressure – less elastic * Muscular arteries branch * Distribute blood to arterioles

Answer 20

-> regulates total peripheral resistance tpr, by vasoconstriction) dilation * Tunica externa absent or very thin * Tunica media: SMC * Control blood flow between capillaries and arteries * Called as resistance vessels

Answer 21

One layer of endothelium and its basement membrane • Diameter of one RBC – very small • Efficient exchange of nutrients • For nutrient and gaseous exchange

Answer 22

• Three types based on the size of the gaps between the endothelial cells Continuous Fenestrated Sinusoid

Answer 23

* Most common * Endothelial cells are continous * Very small gap between cells but allows some passage using transport vesicles * Allows exchange of small moldcules between plsma membrane and interstitial fluid - in smooth , skeletal muscle and lungs

Answer 24

* Medium sized gaps * Fenestrations in endothelial cells * Allows large things to pass through but not rbc * Present in kidneys, reabsorption small intestine

Answer 25

* Large gaps btw endothelaial cells * Incomplete basememnt membrane – gaps * Very Large gaps alllow passage of large molecules – plasma proteins and even cells * Found in bone marrow, liver, spleen

Answer 26

* Collect blood from tissues return it to heart * Pressure much less than the arteries * Walls are thinner and less elastic * Capacitance vessels (70% of total blood volume) * Valves: infoldings of tunica intima = allow one directional flow of blood, prevent backflow

Answer 27

Venules Medium veins Large veins

Answer 28

Collect blood from capillaries * Resemble capillaries * Endothelium, thin middle layer with few muscle cells and elastic fibers * Very thin tunica externa made of connective tissue fibers * Venules and capillaries are the primary sites of emigration of white blood cells to enter the tissue fluid

Answer 29

* Have all three layers * Thin tunica media with few SMC * Thick tunica externa

Answer 30

* Have diameters greater than 10mm * Have all three layers * Thicker tunica externa * Include superior vena cava, inferior vena cava

Answer 31

Pressure gradient maintains flow | • High pressure to low pressure – but resistance can hinder flow

Answer 32

Change in pressure = cardiac output x total peripheral resistance

Answer 33

• Cardiac output = heart rate x stroke volume

Answer 34

5L/min = normal value (amount of blood ejected by ventricles per minute)

Answer 35

amount of blood ejected from ventricles per beat (approx 70ml/beat)

Answer 36

* Flow per unit area * Increasing velocity = increasing flow * Decreasing velocity = increasing area

Answer 37

• Surface area of allll small arteries branches is larger than the surface area of just large artery • Even though diameter of small artery is smaller than large artery = surface area of all small arteries > large artery sa Velocity = inversely proportionals to area • High velocity = low area – large artery • Low velocity = high area – small artery

Answer 38

Total peripheral resistance • Total resistance felt by blood flow as it passes around body • Consider systemic circulation resistance (not pulmonary) * Resistance = Pressure difference/ CO * Resistance = Pressure difference/ Flow

Answer 39

* 𝑅 = 8𝑛𝑙 𝛱𝑟 4 | * n= viscosity, l= length of the vessel, r= radius

Answer 40

= fairly consitent for blood Viscosity: Increased in ➢ Polycythemia (Increase in RBC) ➢ Dehydration – reduce water contwent Viscosity: Decreased in ➢ Anaemia (Decrease in RBC)

Answer 41

Length: Increased with ➢ Weight ➢ Height

Answer 42

* Arterioles tend to have the ability to change radius – that is why they are called resistance vessels * Radius has profound affect on affecting reisstance Radius: Increased in ➢ Vasodilation Radius: Decreased in ➢ Vasoconstriction

Answer 43

* All blood must pass through artery, arteriole, capillary, venule, vein * All resistance adds up * Total resistance is the sum of all the vessel resistances Straight line

Answer 44

* Capillaries – low radius, but resistance is very low (not high as expected) * Capillaries branches are arranged in parallel = so resistance significantly decreases * Lower resistance in parallel * Arterioles are also parallel to eachother – but parallel to capillaries * Arterioles have high resistance due to ability to change their radius

Answer 45

Laminar | Turbulent -

Answer 46

• Smooth and parallel in straight line – Silent – Velocity highest at the centre – Low resistance Occurs in most vessel except aorta

Answer 47

• All over the place – Not silent – High resistance • Differences in properties allow blood pressure measurement – in large arteries – In diseased and narrowed arteries

Answer 48

Pressure in arteries during systole: 120 mmHg

Answer 49

pressure in arteries during diastole: 80 mmHg

Answer 50

Systolic-diastolic (difference btw systole and diastole) blood pressure: 120-80: 40 mmHg

Answer 51

'more weight to diastolic blood pressure because heart stays in diastole for longer) • 2/3 DBP+ 1/3 SBP • DBP + 1/3 PP

Answer 52

* Expansion and recoiling of arteries creates pulse * Pulse indicate heart rate * Most readily measured at the radial artery, but can be measured at any of the pulse points shown * Recorded as beats per minute * Both the rate and the strength of the pulse are important clinically. * Changes in rate and strength can indicate pathology

Answer 53

* Inflate cuff .120 mm Hg * Stops blood supply so no sound in stethoscope * Slowly decrease pressure to 120, so blood starts to flow through vessel * Hear Korotkoff sound at systolic blood pressure * Decrease bp to less than 80 bp – when last sound is heard = diastolic bp

Answer 54

Swelling and irritation of thin sac like tissue surrounding heart

Answer 55

Extra fluid build up in space around heart

Answer 56

Impact of heart against wall in systole 5 th intercostal space

Answer 57

Parasympathetic nerve suppy to nerve

Answer 58

Av node Sa node Bundle of his Purkinge fibres

Answer 59

Arise in neck c3-c5 - Sensory nerve supply of fibrous pericardium and parietal serous pericardium is - right phrenic nerve - left phrenic nerve Also supply sensation to mediastinal and diaphragmatic pleura

Answer 60

Follows superior ivc and right border of heart | Descending vertically laterally to right atrium

Answer 61

Descends obliquely across arch of aorta and the anterior surface of heart related to left ventricle

Answer 62

sequence of alternating contraction and relaxation of the atria and ventricles with every heart beat = atria and ventricles contract and relax (mechanical), and some electrical events

Answer 63

– Heart chambers are contracted (build pressures) – Heart pumps the blood -slightly shorter than diastolic pressure Av and semilunar values closed

Answer 64

– Heart chambers are relaxed – Heart fills with the blood 2/3 of each cardiac cycle

Answer 65

Atrioventricular values separate atria and ventricle - tricuspid value separates right atrium and ventricles - mitral value separates left atrium and ventricle Values have papillary muscles connected to chorda tendinae to prevent reguirgitation

Answer 66

Separate ventricles from pulmonary and aortic circulation - aortic valve - pulmonary value

Answer 67

pacemaker of the heart • Specific cells found on base of superior vena cava form sa node – Near the opening of the superior vena cava – SA node is able to contract faster than the rest of the heart tissue – Sets the pace of cardiac contraction – Pacemaker of the heart – The impulse is spread to the rest of the heart through conductive pathways

Answer 68

Sa node to Atria then av node then common bundle, bundle branches which supply ventrcles

Answer 69

* Atrial diastole * Atria relaxes * Atrial systole (Mid to late ventricular diastole) * Early ventricular systole (Isovolumetric contraction) * Mid to late ventricular systole (ventricular ejection) * Early ventricular diastole (Isovolumetric diastole)

Answer 70

- --> atria relaxes - ---> Increase pressure * All deoxygenated blood from body fills in RA * All oxygenated blood from vein pools in LA When Atrial pressure > ventricular pressure: • AV valves open • 70-80% blood moves into ventricles (without contraction, so flow is passive) SA node fires impulse • Results in atrial depolariasation • Atria start to contract = start of atrial systole

Answer 71

--> increase atrium contraction due to sa node impulse = increase atrial pressure • Rest of the 20% of blood in atria is pushed into ventricles ---> when we are in atrial systole, ventricles are in mid to late ventricular diastole • EDV – end diastolic volume = all blood is now in ventricles • Approx 120ml

Answer 72

Patients who have problems with efficient atrial systole can still function normally. • as atrial systole only pushes out remaining 20% of blood

Answer 73

end diastolic volume = all blood is now in ventricles | • Approx 120ml

Answer 74

---> SA Node signals/ impulses reach ventricles * Ventricles begin to contract * Av valves close shut as ventricular pressure > atrial pressure = to prevent backflow of blood * AV valves closed→ S1 or lub sound or 1st heart sound

Answer 75

Closure of av valves in early ventricular systole (isovolumetric contraction)

Answer 76

blood can't go anywhere, valves are closed and no contraction

Answer 77

---> pressure in ventricle > pressure in aorta/ pressure in outflow tracts (pulmonary artery/ aorta) • Semi lunar valvues open up - av values close • All blood is ejected into outflow tract = rapid ejection phase = huge amount of blood pumped int outflow tract • Some blood remains in ventricles: End systolic volume (ESV)

Answer 78

amount of blood remaining in ventricles after ventricle systole

Answer 79

* SV = amount of blood being pumped out per beat | * Stroke volume SV = EDV – ESV

Answer 80

---> when we are in atrial systole, ventricular are in mid to late ventricular diastole At this same time atria is in systole all relaxing to fill with blood • Ventricles start to relax * Semi lunar valves close to prevent backflow * Semilunar valves closed→ Dub sound/2nd heart sound/ S2

Answer 81

n early ventricular diastole • All blood is pumped into outflow tract • Semi lunar valves close • Atrioventricular valves close = S 2 heart sound • Ventricles are slowly relax • But there is no change in blood movememnt as valves are closed in very early ventricular diastolic phase

Answer 82

2.1 b notes

Answer 83

A wave P wave

Answer 84

Atrial pressure rises due to atrial systole

Answer 85

P wave in an ecg signifies onset of atrial depolarisation

Answer 86

C wave QRs complex in ecg

Answer 87

Closing of mitral value causes c wave in atrial pressure curve

Answer 88

Signifies onset of ventricular depolarisation

Answer 89

Atrial pressure initially decreases as atrial base is pulled downward as ventricle contracts

Answer 90

T wave of ecg V wave

Answer 91

Ventricular repolarisation detected by t wave of ecg

Answer 92

Atrial pressure gradually rises due to the continued venous return from lungs

Answer 93

Dicrotic notch in aortic pressure curve caused by value closure

Answer 94

Stenosis | Regurgitation

Answer 95

valve doesn't open enough or properly, obstructs normal blood flow

Answer 96

• Valvuar regurgitation/ insufficiency / incompetence = valve doesn't close properly, causes leakage of blood, backflow

Answer 97

Aortic valve stenosis | Mitral valve stenosis

Answer 98

Mitral valve regurgitation (left atrioventricular valve) | Aortic valve regurgitation

Answer 99

* Less blood passes through valve * Increases left ventricle pressure * = left ventricle hypertrophy (push harder to pass blood through narrow valve opening, increased ventricle muscle mass)

Answer 100

* (degenerative) Age = calcified ends of valves over time/ fibrosis * Congenitial causes (born with) = some may have a bicuspid valve formation rather than the tricuspid structure * Chronic rheumatic fever = where antibodies released to deal with strep infection have an autoimmune effect --> inflammation and commissural fusion of leaflets

Answer 101

Left sided heart failure • Lead to syncope • Angina = lack of sufficient blood supply to the heart • Microangiopathic hemolytic anaemia = force blood through narrow valve at hight pressure can damage rbcs

Answer 102

mumur between s1 and s2 heart sound due to increased ressistance to flow • Crescendo-decrescendo murmur

Answer 103

Blood flows back into left ventricle during diastole | • Valve leaflets don't close properly

Answer 104

* Aortic root dilation (dilation of valve leaflets) | * Valvular damage (endocarditis – infammation of endocardium, rheumatic fever)

Answer 105

* Increased blood backflow = increases blood volume in left ventricle = increase stroke volume on next cardiac cycle * Diastolic pressure decreases * = higher pressure difference between systole and diastole – causes bounding pulse (head bobbing, Quinke's sign = flushing red to pale white in nail bed) * Left ventricular hypertrophy = increased LV pressure

Answer 106

* Early decrescendo diastolic murmur | * Bouncring red line after s2 phase, due to movement and backflow of blood

Answer 107

Blood flows back into left atrium Myxomatous degeneration can weaken tissue leading to prolapse ---> papillary muscle and chordae tendineae - normally pull leaflets of mitral valve taught to keep valve closed in systole = when these prolapse - regurgitation

Answer 108

* Damage to papillary muscle after heart attack * Left sided heart failure, leads to left ventricle dilation which can stretch valve * Rheumatic fever can lead to leaflet fibrosis which disrupts seal formation

Answer 109

---> some blood leaks back onto left atria after systole • Increases preload as more blood enters • More blood then enters ventricle in next heart cycle • Can cause left ventricule hypertrophy

Answer 110

--> holosystolic murmur – due to flow of blood through partilally open mitral valve, lasts the duration of systole

Answer 111

Mitral value is narrowed, does not open properly so it blocks blood flow

Answer 112

• Rheumatic fever • Commissural fusion of valve leaflets • Harder for blood to flow from left atria to ventricle Increase in left atria blood pressure as it can't properly expel its blood volume

Answer 113

• LA dilation ○ Atrial fibrilation --> increase rsik of thrombus formation and stroke ○ Oessophagus compression--> problems swallowing, dyshpagia • Pulmoary odeoma • Dyspnea • Pulmonary hyertension Rv hypertrophy =

Answer 114

Snap and diastolic rumble

Answer 115

* Bedside indicator of right heart function * No structures impede observed pressure ways * Observable fluctuations over sternacleidomastoid muscle SCM = distinct ways – for right heart

Answer 116

Graph on 2.1 c A- back pressure on IVC due to atrial contraction (largest) • Pressure wave that reverberates back up to jugular vein C- tricuspid valve closure (valve between ra and rv) x – ventricular contraction V – atrial filling Y – tricuspid valve opening anf venticular filling

Answer 117

``` 1 = closure of mitral and tricuspid values 2= closure of aortic and pulmonary valves 3= sometimes present from filling of left ventricle ```

Answer 118

• Maintain blood pressure ○ Blood pressure = cardiac output x TPR (total peripheral resisstance) ○ Increase bp bring down cardiac output • Supply should meet demand

Answer 119

anything that effects heart rate

Answer 120

High heart rate > 100

Answer 121

Heart rate below 60 bpm

Answer 122

• Average heart rate in healthy adult is 60-80bpm

Answer 123

* sympathetic nervous system (Epinephrine/norepinephrine) * Hormones (T3, T4) = increase metabolism * Body temperature (increase) * Increased Ca2+ levels (more action potentials) * Hypoxia and hypercapnia * Age

Answer 124

○ heart --> baroreceptors --> medulla ---> sympathetic nervous system --> epinephrine/norepinephrine --> stimulate SA and AV nodes

Answer 125

○ Hypoxia = low oxygen in tissues ○ Hyercapnia = high co2 ○ Both are due to problems in lungs, detected by chemoreceptors --> brain --> increase respiratory rate --> increase heart rate

Answer 126

• Parasympathetic nervous system (Acetylcholine) • Hyperkalaemia (Increased K+ levels) Impact action potentials . • Decreased Ca2+ levels

Answer 127

○ heart --> baroreceptors --> medulla ---> sympathetic nervous system --> acetylcholine --> stimulate SA and AV nodes

Answer 128

• Preload ○ Stretch of the ventricles • Contractility • Afterload

Answer 129

--> • Amount of stretch of the ventricles in diastole (before pumping out blood) = end-diastolic volume (EDV)

Answer 130

* Venous return * Skeletal muscle pump * Respiratory pump * Venous tone * Gravity

Answer 131

○ Blood being brought back into atria (oxygenated or deoxygenated) ○ Increase venous return = increase preload

Answer 132

○ Used to pump blood back to heart, ○ More skeletal muscle pump = more contraction Increase venous return, edv and stroke volume

Answer 133

○ Inspiration = increase thorax volume = decrease thorax pressure ○ Push diaphragm down in inspiration = increase abdominal pressure = increased venous return - due to suction like effect pulling blood from venous system to heart

Answer 134

○ Veins have sympathetic supply, that may tell them to constrict, when veins constrict all blood is pushed up = increased venous return

Answer 135

○ When person stands up blood turns to pool into legs = decrease venous return slightly

Answer 136

* Increasing venous return leads to increased left ventricular end diastolic pressure (LVEDP) and volume (‘increased preload’). * This causes an increase in stroke volume, so that the extra blood is pumped out of the ventricle * Shows more end diastolic volume = more stroke volume or less end diastolic volume = less stroke volume → stroke volume of heart increases in response to an increase in volume of blood in vessels

Answer 137

anything that affects contractility

Answer 138

• Sympathetic nervous system (Epinephrine/norepinephrine) ○ Impact myocardium, muscle contraction ○ Bind to beta adrengeric receptors in myocardium * Hormones (T3/T4), glucagon * Drugs - - increase calcium ion influx during action potential

Answer 139

• Beta blockers ○ Blocking the beta adrenergic receptors • Ca2+ channel blockers ○ Blocking calcium entering cells that is needed by troponin for muscle contraction (refer to FBS) • Increase in K+, Na+, H+

Answer 140

---> Afterload: The amount of resistance that needs to be overcome by the ventricles to pump blood to aorta • Resistance ventricles feel when pushing blood into aorta Increase in afterload decreases stroke volume (negative relationship)

Answer 141

• Semilunar valve damage '' ○ Any problem with valves = resistance = increased afterload • Increased vascular resistance ○ Heart has to push further = increase afterload

Answer 142

• Decreased vascular resistance | ○ Decrease afterload

Answer 143

Where deoxygenated blood from heart drains

Answer 144

Ridges in the ventricles

Answer 145

Hold back blood as ventricles pump Remnants of fetal atria Relieve high pressure by increasing atrial capacity at times of stress

Answer 146

``` Blastulation (week 1) Gastrulation (week 2) Neurulation (week3) Development of heart (week 3) Heart tube Looping of the heart ( 22nd - 23rd day) Septation of the heart (27 th day) Formation of av valves (week 4) Formation of interatrial septum Formation of intravenericular septum Formation of inflow tracts to right atrium Formation of outflow tracts ```

Answer 147

Oocyte → zygote =cleavage) → morulla → blastocyst

Answer 148

``` Inner cell mass (embryoblast) Outer cell mass (trophoblast) - cytrotrophoblast - Syncytiotrophoblast = placenta ```

Answer 149

1. Inner cell mass differentiates – into 2 discs • Epiblast • Hypoblast 2. Pre chordal plate forms --> where epiblast and hypoblast fuse together 3. Formation of primitive groove (made from epiblast cells proliferation) 4. formation of 3 germ layers • Cells near primitive groove start to migrate into the groove down into the hypoblast layers - endoderm, mesoderm, ectoderm

Answer 150

1. Formation of notochord ---> near primitaive groove more cells migrate down and form the tube = notochord 2. Notochord pushed into mesoderm layer 3. Formation of neural groove • Neural fold closes and is pushed down into mesoderm