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Physiology - Hayley > Vascular > Flashcards

Vascular Flashcards

1
Q

What % of blood goes to the pulmonary circulation

A

9%

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2
Q

What % of blood goes to the artieres

A

20%

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3
Q

What % of blood is in the veins

A

64%

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4
Q

What % of blood stays in the heart

A

7%

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5
Q

What is the order of the vascular muscle wall anatomy from inside out

A

Tunica Intima
Tunica Media
Tunica Externa

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6
Q

What type of blood vessel is mostly responsible for moderating the amount of blood flow to areas of the body

A

Arterioles

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7
Q

What is arterial pressure primarily regulated by

A

Circulatory vessel changes (contriction/dilation)

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8
Q

What is the wall thickness and contents of arteries

A

Thick walls with more smooth muscle and elastin

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9
Q

What is the wall thickness and contents of veins

A

Thin walls with less smooth muscle and elastin

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10
Q

What is the purpose in the different wall structures of arteries and veins

A

Arteries are made to withstand high pressures whereas veins are able to adapt to low pressures and hold more blood

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11
Q

What is the elsatin content in ateries and veins respectively

A

Arteries - high elastin
Veins - low elastin (more stretchy)

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12
Q

What is the only artery to contain valves

A

Pulmonary Artery

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13
Q

What is the structure of the tunica intima

A

inner endothelial lining of the blood vessels

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14
Q

What is the structure of the tunica media

A

Middle smooth muscle layer (also contains elastin fibres)

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15
Q

What is the structure of the tunica externa

A

outer layer of connective tissue, holding vessels together

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16
Q

What type of valves are in veins

A

bicuspid

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17
Q

What is the glycocalyx

A

Negatively charged sugar proteins that coats all healthy vessels endothelium

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18
Q

What is the function of glycocalyx in regards to fluid dynamics

A

Provides intraluminal ‘oncotic’ pressure which limits the movement of fluid to the interstitial space, stopping edema

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19
Q

How can the glycocalyx be damaged

A

ischemia, hyperglycemia, inflammation, hypertension

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20
Q

What is the structure of large elastic arteries and some examples

A

contain substantial amounts of elastic fibres in the tunica media

e.g aorta and brachiocephalic trunk

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21
Q

What is the structure of medium muscular arteries and some examples

A

tunica media contains mostly smooth muscle fibres

e.g femoral, axillary and radial arteries

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22
Q

Where is the thoracic aorta located

A

anterior to the vertebral column, posterior to the heart, in the space at the end of the plura

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23
Q

What does the thoracic aorta branch into

A

Branches to supply the chest wall (intercostal arteries), oeasophogus and respiratory tree

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24
Q

What are paired and unpaired branches of arteries

A

Paired - arteries where two of them exist (left and right)
Unpaired - only one of its kind exist

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25
Q

What unpaired arteries branch off the abdominal aorta

A

Coeliac trunk
Superior mesenteric artery
Inferior mesenteric artery

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26
Q

What paired arteries branch off the abdominal aorta

A

Phrenic artery
Supradrenal arteries
Renal arteries
Ovarian arteries

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27
Q

Where are illiac arteries located

A

At the lower branching point of the abdominal arteries

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28
Q

What does the internal illiac artery supply blood too

A

Urinary bladder, rectum and some reproductive organs

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29
Q

What areas of the body does the external iliac artery supply blood too

A

lower extremities

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30
Q

What part of the body does the internal carotid artery supply

A

Eye and superior brain and head

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31
Q

What part of the body does the external carotid artery supply

A

Thyroid gland, neck and other structures in the head

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32
Q

What artery supplies the arm and hand

A

Subclavian artery

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33
Q

What are anastomoses and three examples of these in the body

A

these are connections between two blood vessels

e.g Circle of Willis, superficial palmer arch, mesenteric arches

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34
Q

What does the brachiocephalic trunk supply blood too

A

right arm and right side of head

(via branching into the right subclavian artery and right common carotid artery)

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35
Q

What blood vessel contains fenestrations

A

Capillaries

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36
Q

What is the structure of large veins and some examples

A

contain smooth muscle in the tunica media but the thickest layers the tunica externa

e.g superior vena cava, inferior vena cava, portal vein

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37
Q

What is the structure of small and medium veins and some examples

A

contains small amounts of smooth muscle, and the thickest layer is the tunica externa

e.g superficial veins in upper and lower limbs

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38
Q

What is the thinnest layer in veins

A

Tunica media

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39
Q

Where are deep veins usually found in the body

A

Alongside arteries

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40
Q

Where is blood coming from that is draining into the superior vena cava

A

head, neck, upper extermities and chest

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41
Q

Where is the blood coming from that is draining into the inferior vena cava

A

regions below the diaphragm

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42
Q

What are venous sinuses

A

large channel that drains deoxygenated blood

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43
Q

What makes the hepatic portal system different from all others in the body

A

Unlike in the rest of the body where all blood leading capillary beds goes straight back to the heart, blood coming out of the hepatic portal system goes through a second organ before going back to the heart

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44
Q

What is absent in terminal lymphatics that allow for the facilitation of movement of large proteins into the circulatory system

A

Doesnt contain tight junctions

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45
Q

What % of blood is plasma and RBC respectively

A

Plasma - 55%
RBC - 45%

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46
Q

What is atherosclerosis stroke

A

atherosclerosis plaque build up and artery blockage

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47
Q

What is hemorrhage stroke

A

Rupture of the vessel and haemorrhage

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48
Q

What is ischemic stroke

A

atherosclerotic plaque rupture and thrombus formation

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49
Q

What is the definition of vascular compliance

A

The total quantity of blood that can be stored in a given portion of the circulation for each mmHg pressure rise

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50
Q

What is the equation for vascular compliance

A

Compliance = volume/pressure

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51
Q

What vessels have the greatest compliance and how does this look on a pressure/volume curve

A

Veins have largest compliance, this means that their pressure/volume curve is much flatter because a change in volume doesnt affect the pressure too drastically

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52
Q

What neural activation is venous return aided by

A

Sympathetic innervation to stimulate smooth muscle contraction of venous walls

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53
Q

What are the relative pressures in the thoracic and abdominal cavities and how does this affect blood flow

A

Pressure in the thoracic cavity is lower than than of the abdominal cavity - this forces flood to move towards the heart while travelling in veins

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54
Q

What is the primary site of gas and nutrient exchange in the circulatory system

A

Capillaries

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55
Q

Role of precapillary sphincters

A

Control blood flow into the capillary bed, regulating tissue perfusion based on metabolic needs

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56
Q

What is net filtration and when this is positive what direction is fluid moving capillaries

A

Net filtration, when positive, is when blood i filtered out of the capillary bed and into the tissues

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57
Q

What are the two pressures involved in moving nutrients out of a capillary

A

Capillary pressure and Interstitial fluid colloid osmotic pressure

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58
Q

What are the two pressures involved in moving nutrients into a capillary

A

Plasma colloid osmotic pressure and interstital fluid pressure

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59
Q

What type of capillary pressures are responsible for the movement of water

A

colloid osmotic pressures

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60
Q

What type of veins have the lowest pressure

A

Large veins

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61
Q

What is the relative cross sectional area of arteries, veins and capillaries

A

Arteries have the smallest cross sectional area

Veins have a large cross sectional area

Capillaries have the largest cross sectional area

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62
Q

How does the elastic nature of arteries help maintain continuous flow

A

Elastin enable arteries to stretch and store some of the ejected blood during systole. During diastole, the elastic recoil of the artery wall helps push blood forward, smoothing out the pulsatile flow and maintaining a more continuous, stable flow.

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63
Q

What percentage of blood is pumped out the the aorta during diastole

A

40%

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64
Q

What type of flow is blood when it leaves the heart and when it reaches tissues respectfully

A

When it leaves the heart it is pulsatile flow

By the time it gets to tissues it is continuous flow

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65
Q

Is MAP increases, what occurs to the signals feeding back to the brain and what is the result of this

A

These increase - activating parasympathetic nervous system which will slow heart rate and inhibit sympathetic tone of veslles (allowing vasodialtion)

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66
Q

What is orthostatic hypotension

A

Occurs when someone goes from lying down to standing up very quickly.
Gravity pulls blood down to the legs, decreasing venous return and decreasing BP

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67
Q

What is the bainbridge reflex

A

This is the response to stretch in the left atrium. When baroreceptors detect stretch in the left atrium they
1. inhibit antidiuretic hormone
2. increase ANP

(reduce BP by excreting large amounts of urine)

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68
Q

What is detecting blood flow in the kidneys

A

Juxtaglomerular Apparatus

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69
Q

What is the effect of aldosterone

A

Salt and water retention by kidneys to increase blood volume

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70
Q

What is the equation for blood flow

A

Flow = pressure/resistance

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71
Q

What is the unit of blood flow

A

ml/min

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72
Q

In what part of the blood vessel is blood flow the highest and why

A

In the middle of the vessel because there is least resistance and drag

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73
Q

What is the equation for vessel conductance

A

conductance = 1/resistance

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74
Q

What does Poiseuille’s Law describe

A

The main take away from Poiseulles law is that flow is directly proportional to the 4 th power of radius.

(if radius increase, flow increases a lot)

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75
Q

What vessels provides the most resistance to blood flow

A

Arterioles

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76
Q

What is autoregulation of blood pressure

A

Process by which blood vessels adjust their diameter to maintain a stead blood flow to tissues, regardless of changes in systemic blood pressure

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77
Q

What mediates autoregulation

A

Myogenic responses - smooth muscle in the vessel wall contracts or relaxes in response to pressure changes

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78
Q

What is the primary goal of autoregulation

A

Ensure that tissues receive a constant supply of oxygen and nutrients, especially during fluctuations in bloop pressure or changes in metabolic demand

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79
Q

What is the change in shear stress on endothelium during exercise

A

Shear stress increases due to an increase in blood flow to exercising tissues

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80
Q

What is the effect of reducing intracellular Ca2+ on vessel tone

A

Decreasing intracellular Ca2+ decreases the contraction force of smooth muscles, leading to relaxation

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81
Q

What is the effect of cGMP on Ca2+ levels in smooth muscle cells

A

cGMP lowers Ca2+ levels within smooth muscle cells

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82
Q

What is the effect of norepinephrine on vessels

A

Vasoconstriction

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83
Q

Effect of histamine on vessels

A

Vasodilation

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84
Q

What is the primary mechanism in long term blood flow regulation in tissues

A

Angiogenesis

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85
Q

What is the baseline neural activity on vasomotor tone

A

SNS is always slightly active at rest, causing continuous partial constriction of blood vessels

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86
Q

What nervous system does the vasomotor centre primarily regulate

A

Sympathetic

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87
Q

What is aneurysm

A

Abnormal bulge or ballooning in the wall of a blood vessel

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88
Q

Where is atherosclerosis mainly found

A

elastic and muscular vessels

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89
Q

What vessels does hypertension effect the most

A

Small muscular arteries and arterioles

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90
Q

What is fibromuscular dysplasia

A

Congenital

Irregular thickening of medium and large muscular arteries resulting in stenosis

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91
Q

What is anomalous coronary artery origin

A

Congenital

When both coronary arteries arise over the same coronary cusp of the aortic valve

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92
Q

What areas of a blood vessels are at highest risk of developing plaques

A

ostia, branch points and areas where the flow patterns are disturbed and non-laminar

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93
Q

How does laminar non-turbulent flow contribute decreasing to atherosclerosis

A

Increases the production of transciption factors that turn on atheroprotective genes and turn off inflammatory gene trasncription

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94
Q

How does turbulant, non-laminar flow contribute to athlerosclerosis

A

Drives gene transcription that makes those sites atheroprone

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95
Q

What are the 2 dominent lipids in atheromatous plaques

A

cholesterol and cholesterol esters

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96
Q

How does hypercholesterolemia directly impair endothelial cell function

A

Increases ROS production. Causes membrane and mitrochondiral damage and oxygen free radicals to accelerate NO decay

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97
Q

How do foam cells contribute to atherosclerosis development

A

Secrete growth factors, cytokines and chemokines that create a vicious inflammatory cycle of monocyte recruitment and activation

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98
Q

What is inflammation triggered by in vessels

A

Accumulation of cholesterol crystals and free fatty acids in macrophages

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99
Q

What is normal blood pressure for people over 80 and diabetics, respectfully

A

Over 80s - 150/90
Diabetes - 140/90

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100
Q

What is the cause of essential (primary) hypertension

A

Genetics, environment and ageing

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101
Q

What is hyaline arteriolosclerosis and what pathology is it associated with

A

Arterioles have homogonous, pink hyaline thickening and luminal narrowing.
Plasma proteins leak across the injured epithelial and increase SMC matric synthesis

Caused by hemodynamic pressure of hypertension

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102
Q

What is hyperplastic arteriolosclerosis and what pathology is it asssociated with

A

In severe hypertension, vessels exhibit concentric, laminated thickening of walls with luminal narrowing.
SMC thickened, reduplicated basement membrane

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103
Q

What is arteriosclerosis

A

hardening of the arteries

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104
Q

What is monckberg medial sclerosis

A

Calcifications on the medial walls of the muscular arteries. Don’t encroach on the lumen so not usually clinically significant

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105
Q

What is fibromuscular intimal hyperplasia

A

Arteriosclerosis occurring in muscular arteries driven by inflammation

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106
Q

Atherosclerosis is the most common cause of what pathology

A

Peripheral artery disease

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107
Q

What is the first layer of vessels to thicken in plaque formation

A

intima media

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108
Q

What are some symptoms of peripheral artery disease

A

muscle pain that occurs with activity and stops with rest. Dull achy pain, muscle spasm, cramp, numbness

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109
Q

What are the different Fontaine stages of lower extremity arterial disease (I, IIa, IIb, III, IV)

A

I: asymptomatic
IIa: mild claudication (leg pain during exercise)
IIb: moderate to severe claudication
III: ischemic rest pain
IV: oilers and gangrene

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110
Q

What is the most common regions ofr peripheral artery disease

A

femoral popliteal segment

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111
Q

What are symptoms of superficial femoral artery disease

A

pain on exertion, pain at rest, non-healing ulcers from thigh to foot

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112
Q

What is superficial femoral artery disease mainly caused by

A

atherosclerosis in larger extermities

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113
Q

What will the blood flow sound like in someone with PAD

A

It will be audible due to the turbulant flow

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114
Q

What is the ankle brachial index

A

Measures the blood pressure in the ankle and divides it by the blood pressure in the arm

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115
Q

What ABI is indicative of PAD

A

<0.9

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116
Q

What tends to occur to the ABI during exercise

A

It decreases

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117
Q

What ABI is indicative of no artery blockage

A

1 - 1.4

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118
Q

What does a ABI >1.4 possibly indicate

A

possible calcification/vessel hardening

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119
Q

How would you calculate the right ABI

A

highest pressure in right foot/highest pressure in both arms

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120
Q

What ultrasound is used to image carotid artieres

A

B mode

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121
Q

What is Raynaud phenomenom

A

Exaggerated vasocontraction of arteries and arterioles in response to cold or emotion

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122
Q

Primary Raynaud’s
- Who does it primarily effect
- How does it effect the extremities

A

Effects young woman

Symmetrically affect extremities with no changes to arterial walls

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123
Q

Secondary Raynauds
- What causes it
- What is the effect on the extremities

A

Vascular insufficiency due to arterial disease

Asymmetric involvement of the extremities and progressively worsens

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124
Q

What are the characteristics of varicose veins

A

Abnormally dilated veins, torturous veins, vessel dilation, incompetence of valves

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125
Q

What veins are commonly involved in varicose veins

A

Superficial veins of the upper and lower leg

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126
Q

Are embolisms in superficial veins common

A

No

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127
Q

What causes portal vein hypertension and what does it lead to

A

Liver cirrhosis leading to opening of the portosystemic shunts

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128
Q

What is the consequence of the portosystemic shunts opening

A

increase in blood flow to the veins of the gastroesophageal junction, rectum and paraumbilical veins

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129
Q

What veins are mostly invovled in venous thrombosis

A

Superficial or deep veins of the lower expermities

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130
Q

What type of thrombi are usually found in veins and why

A

Red thrombi - due to the slow venous circulation, the blood tends to contain more enmeshed red cells and therefore known as red thrombi

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131
Q

What is the largest risk with DVT

A

Thrombi embolising to the lung and causing pulmonary infarctions

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132
Q

Inadequate hemostasis in blood vessels can lead to what

A

Haemorrhage

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133
Q

What is oedema

A

Accumulation of fluid in the tissues (usually feet/ankles/legs)

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134
Q

Any excess fluid in the vessels drains into what system and ends up where

A

Any excess fluid in the vessels drains into lymphatic vessels and returns into the vascular system via the thoracic duct

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135
Q

What is effusions

A

Accumulations of fluid in the body cavities

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136
Q

What does inflammation related oedema consist of

A

Protein rich exudates (mass of cells and fluid that has seeped out of blood vessels)

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137
Q

What does non-inflammatory oedema consist of

A

Protein poor transudates (thin watery liquid with little proteins and cells)

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138
Q

Transudates are common in what 4 diseases

A

Heart failure, liver failure, renal disease and malnutrition

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139
Q

What is the difference between IBS and IBD

A

IBS is a functional disorder (disease usually cant be seen in diagnostic procedures)

IBD is inflammation mediated and can be seen during diagnostics

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140
Q

What are 3 causes of oedema and effusions

A

Increased hydrostatic pressure
Reduced plasma oncotic pressure
Na+ and H20 retention

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141
Q

What is hyperaemia and its main symptom

A

High volumes of blood in the tissues due to arterial dilation

Causes erythema due to increased blood flow to that region

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142
Q

What is erythema

A

Redness of skin

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143
Q

What are congestions and what are they caused by

A

Increased blood flow to tissues caused by decreased outward flow from tissues

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144
Q

What is a major symptom of congestions

A

Cyanosis (abnormal blue/red colour due to accumulating deoxygenated blood)

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145
Q

Is congestion of blood vessels an active or passive process

A

Passive

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146
Q

What three factors cause thrombosis

A

Endothelial injury resulting in inflammation
Stasis/turbulent blood flow
Hypercoagulability

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147
Q

At what sites do arterial and cardiac thrombi usually occur at

A

Sites of turbulance or endothelial injury

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148
Q

At what sites do venous thrombi tend to occur at

A

sites of stasis

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149
Q

What direction do thrombi grow in, in both arteries and veins respectfully

A

Arterial thrombi grow in the retrograde direction of blood flow
Venous thrombi grow in the direction of blood flow

(this means that both are growing towards the heart)

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150
Q

Thrombi vs embolism

A

Thrombi is when a blood clots or forms an obstruction of the vessels

Embolism is when this clot moves through blood vessels and risks lodging somewhere else

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151
Q

What part of a thrombus is most at risk of embolism and why

A

The propagating portion of a thrombus is poorly attached and prone to fragmentation and embolism

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152
Q

What are mural thrombi

A

Thrombosis occurring in the heart chambers or in the aortic lumen

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153
Q

What 2 things underly aortic thrombi

A

Ulcerated atherosclerotic plaques and aneurysmal dilation

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154
Q

Where are the 3 most common sites of arterial thrombi

A

Coronary, cerebral and femoral arteries

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155
Q

What veins are frequency involved in venous thrombi

A

Those of the lower extremities

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156
Q

What are vegetations

A

Thrombi on heart valves

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157
Q

When does infected and sterile vegetations occur, respectfully

A

Infected thrombi occur due to bacteria, fungi, endothelial injury of the heart valves

Sterile vegetations can develop on noninfected valves in persons with hypercoagulable states

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158
Q

What is the first things that will occur to a thrombus once fully formed

A

It will begin propagation, accumulating additional platelets and fibrin

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159
Q

Once a thrombi embolises, what determines if it will undergo lysis or not

A

Recent thrombi are able to shrink and disappear

Older thrombi with extensive fibrin deposition and cross-linking are more resistant to lysis

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160
Q

When is the most useful time to administer therapeutic fibrolytic agents after a thrombotic event

A

Only effective in the first couple hours of the thrombotic event

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161
Q

If older thrombi are unable to be broken down by fibrolysis, what occurs to them

A

They become more organised (develop vasculature, smooth muscles and fibroblasts)

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162
Q

How can an MI predispose to a mural thrombi

A

An MI causes dyskinetic myocardial contraction and endocardial injury - trigger points for thrombi formation

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163
Q

What atrial abnormalities caused by rheumatic heart disease can cause atrial mural thrombi

A

Atrial dilation and fibirllation

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164
Q

What tissues are mostly effected by emoblism

A

Those with high blood supply - brain, kidney, spleen

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165
Q

What is the most common form of thromboembolism disease

A

Pulmonary embolism

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166
Q

What does pulmonary embolism usually orignate from

A

DVT

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167
Q

What is a paridoxial embolism

A

When a venous embolism passes through an interatrial and interventricular defect, into the systemic circulation

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168
Q

What is cor pulmonale

A

Right heart failure

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169
Q

What are two long term effects of pulmonary emboli

A

Pulmonary hypertension and right ventricular failure

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170
Q

Where so most systemic thromboembolisms arise from

A

Intracardiac mural thrombi which are usually associated with left ventricular wall infarcts

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171
Q

In response to what injuries are fat embolisms common

A

Skeletal injuries - injuries rupture vascular sinusoids in the marrow allowing for marrow or adipose tissue to herniate into the vascular space

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172
Q

How much air needs to be introduced into the body for it to be clinically relevant

A

100mls

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173
Q

What is the consequence of having air in the pulmonary capillaries

A

This can induce an intense inflammatory response with release of cytokines that may injure the alveoli

174
Q

What is decompression sickness

A

When air is breathed at high pressures (e.g scuba diving) more gases are dissolved into the blood and tissues.
If the diver ascends (depresurises) too quickly, the nitrogen gas will come out of solution in the blood and tissues

175
Q

What is The Bends

A

Rapid formation of gas bubbles in skeletal muscle and joints

176
Q

What is The Chokes

A

Gas bubbles in vasculature of the lungs that cause oedema or collapse of the lung

177
Q

What is treatment for decompression sickness

A

O2 chamber that forces gas bubbles back into solution

178
Q

What is the primary situation when amniotic fluid embolism would occur

A

Labour/postpartum

179
Q

What is the most common outcome of amniotic fluid embolism

A

Neurological defects

180
Q

What is amniotic fluid embolism caused by

A

Infusion of amniotic fluid or foetal tissue into the maternal circulation via a teat in the placental membrane or rupture of uterine vein

181
Q

What embolisms underly majority of infarctions

A

Arterial

182
Q

Where are infarcts due to venous embolism more common

A

Common in organs with a single efferent vein (i.e testis and ovary).

183
Q

What 2 occasions do white infarcts occur

A

With arterial occlusions in solid organs (heart, spleen, kidney)

Where tissue density limits the seepage of blood from adjoining capillary beds into the necrotic area

184
Q

Repair responses usually replace infarcts with what, with the exception of what organ

A

Scar tissue, except in the brain where a CNS infarction results in liquefactive necrosis

185
Q

When do septic infarctions occur and what do they turn into

A

Septic infarctions occur when infected cardiac valves vegetations embolise or when microbes seep into necrotic tissue

These infarcts turn into an absess

186
Q

What are the 4 variables that will influence the outcome of vascular occlusion

A

Anatomy of the vascular supply
Rate of occlusion
Tissue vulnerability to hypoxia
Hypoxemia

187
Q

What is cell shock

A

State of circulatory failure that impairs tissue perfusion and leads to cellular hypoxia

188
Q

What is cardiogenic shock

A

Low cardiac output due to myocardial pump failure

189
Q

What is hypovolemic shock

A

low cardiac output due to low blood volumes, such can occur with massive haemorrhage or fluid loss

190
Q

What is SIRS

A

septic like conditions associated with systemic inflammation. May be triggered by non-microbial insults (burns, trauma)

191
Q

What is sepsis

A

Life threatening organ dysfunction caused by a dysregulation host response to infection

192
Q

What is aneurysm

A

Localised abnormal dilation of blood vessels or the heart

193
Q

What is a true aneyrysm

A

Involves all the layers of an intact arterial wall of

194
Q

What is a false aneurysm

A

defect in the capsular wall leading to extravascular hematoma connected to the intravascular space

195
Q

What is an arterial dissection

A

tear along the inside of an artery

196
Q

What are the two most important causes of aortic aneurysm

A

Atherosclerosis and hypertension

197
Q

What are some risk factors to aneurysm

A

When the structure or function of the connective tissue within the vascular wall is compromised

Defects in synthesis or breakdown of connective tissue

Smoking, age, trauma

198
Q

What is the most common cause of abdominal aortic aneurysm

A

Atherosclerosis in the abdominal aorta and common iliac arteries

199
Q

Where are AAA’s usually located

A

Between the renal arteries and the bifurcation of the aorta

200
Q

The risk of rupture of an AAA is directly related to what

A

The size of the aneurysm

201
Q

What are thoracic aortic aneurysms common associated with

A

Hypertension and inflammation syndromes

202
Q

What is Marfan syndrome

A

congenital disorder that affects the connective tissues (including blood vessels), predisposing individuals to aortic aneurysms and dissections

203
Q

When can aortic dissections be fatal

A

Is they rupture through the adventitial and haemorrhage into the thoracic and abdominal cavities

204
Q

What patients does aortic dissections usually affect

A

men 50+ with hypertension or younger patients with disease affecting the aorta

205
Q

What does it mean if an aortic dissection is iatrogenic

A

It occurs following arterial cannulation during diagnostic catheterization or CABG

206
Q

Aortic dissections are uncommon in substantial atherosclerosis - why?

A

The fibrosis is so thick that propagation of a dissection isnt really possible

207
Q

What is a double barred aorta

A

An aortic arch subdivided into superior and inferior parallel channels, completely separated from each other by two separate adventitial layers.

208
Q

What sections of the aorta does type 1 aortic dissection involve

A

Proximal lesions involved in either both the ascending and descending aorta (DeBakey type 1) or the ascending aorta only (DeBakey type II)

209
Q

What part of the aorta does type B aortic dissections involve

A

Distal lesions involving the ascending aorta and usually beginning distal to the subclavian artery (DeBakery type III)

210
Q

What is the most common and dangerous aortic dissection type

A

Type A

211
Q

What is vasculitis and its symptoms

A

Inflammation of vessel wall

Fever, myalgia (muscle aches), arthralgias (pain in joint)

212
Q

What vessels are commonly effected by vasculitis

A

Small vessels

213
Q

What histological changes are seen in vessels with non-infection vasculitis

A

Vessels develop intimal thickening, reducing the luminal diameter

214
Q

What are some examples of non-infection vasculitis

A

Giant cell arteritis, takayasu arteries, polyarteritis nodosa

215
Q

What two bacteria species are particually common in arteritis

A

Aspergillus and Mucor

216
Q

Example of infection vasulitis

A

Meningitis

217
Q

Epidural and subdural haemorrhages generally occur due to what

A

Trauma

218
Q

Subarachnoid haemorrhages almost always accompanies what

A

Parenchymal trauma

219
Q

What is a hematoma

A

A pool of mostly clotted blood that forms in an organ, tissue, or body space

220
Q

What is a epidural hematoma

A

Occurs when blood leaks into periosteum space, compressing the underlying brain

221
Q

What is a subdermal hematoma

A

This occurs when blood seeps through the two layers of the dural

222
Q

What is cerebrovascular disease

A

Injury caused by altered blood flow to the brain

223
Q

What is a stroke

A

Neurological signs and symptoms that can be explained by a vascular mechanism

224
Q

Difference between a stroke and transient ischemic event

A

A stroke must last for longer then 24 hours

225
Q

What two mechanisms is stroke mostly cause by

A

Heamorrhage and ischemia

226
Q

What sort of respiration does the brain only use

A

Aerobic

227
Q

What is focal cerebral ischemia

A

Reduction or cessation of blood flow to a localised area of brain due to partial or complete arterial obstruction

228
Q

The extent of tissue damage in cerebrovascular ischemia is dependant on what two things

A

Pressure of collateral circulation and duration of ischemia

229
Q

The precise atomic site and size of an cerebral vascular ischemic lesion is determined by what

A

The magnitude and rapidity or the reduction of blood flow

230
Q

What parts of the brain have little collateral flow

A

Deep penetrating vessels of the thalamus, basal ganglia and deep white matter

231
Q

What region of the brain is most affected by embolic infarction

A

The region of the brain supplied by the middle cerebral artery

232
Q

Where to emboli tend to lodge themselves in the brain

A

Pre-exsisting sites of luminal stenosis

233
Q

What is a shower embolism

A

Fat embolism that has occurred after fractures

234
Q

Focal cerebral ischemia caused by thrombotic occlusion is most commonly caused by what

A

Acute changes of vulnerable atherosclerosis plaques

235
Q

What vasculitis may involve inflammation cerebral vessels, and thus be a cause of ischemic cerebral disease

A

Polyarteritis nodosa and other non-infections vasculatides

236
Q

What is primary physical characteristic of brain infarcts at the beginning of their development

A

They are usually non-democratic (pale/anaemic) due to the limited collateral blood supply in the brain.

237
Q

How can secondary haemorrhage occur in the brain

A

Due to ischemia-reperfusion injury due to embolism of fragmentation of a thrombi

238
Q

What changes in appearance occurs to brain ischemic infarcts at these following time points:
6 hours
48 hours
2-10 days
10days - 3 weeks

A

6 hours - little change in appearance
48 hours - tissue becomes soft, pale and swollen
2-10 days - brain becomes gelatinous and friable
10 days - 3 weeks - tissue liquidises, leaving fluid filled cavity (oedma)

239
Q

what is the difference in timeline of development between an ischemic and non-ischemic brain infarct

A

Ischemic infarctions will have blood extraversion (leaking) and reabsorption

240
Q

Venous cerebral infarcts are usually haemorrhagic, true or false

A

True

241
Q

What is a lacunar infarct

A

Infarcts that occur in deep brain structures such as thalamus, basal ganglia and white matter

242
Q

What disease primarily causes lacunar infarcts

A

Arteriosclerosis (small vessel disease) causes small infarcts (lacunar infacts)

243
Q

What is global cerebral hypoxia caused by

A

Reduction in cerebral perfusion (cardiac arrest, shock, severe hypotension) or decreased oxygen carrying capacity (CO poisening)

244
Q

What are the two most sensitive cells to cerebral hypoxia

A

Neurons and glial cells

245
Q

Where do boarder zone (‘watershed’) infarcts occur

A

In regions of the brain or spinal cord that lie at the most distal regions of the arterial blood supply

Border zone between the anterior and the middle cerebral artery distributions is at greatest risk

246
Q

Where in the brain can intercranial haemorrhage occur

A

Either inside or outside the brain

247
Q

What is intracranial haemorrhage in the epidural and subdural space caused by

A

Trauma

248
Q

What is haemorrhage in the brains parenchymal and subarachnoid spaces mainly caused by

A

Cerebrovascular disease

249
Q

What is intraparenchymal haemorrhage

A

Rupture of a small intraparenchymal vessel can result in primary haemorrhage within the brain, often associated with sudden onset of neurological symptoms

250
Q

What accelerates atherosclerosis in larger and smaller arteries, respectfully

A

Larger arteries - hypertension
Smaller arteries - hyaline arteriolosclerosis

251
Q

Thin arterial walls are more vulnerable to rupture in cerebral space, true or false

A

False - thickened arteriolar walls are more at risk of rupture

252
Q

What risk factor is most commonly associated with lobar haemorrhages

A

Cerebral amyloid angiopathy (CAA) - peptides deposited in the walls of medium and small vessels making them very rigid

253
Q

What is the most common cause of spontaneous subarachnoid haemorrhage

A

Rupture of saccular aneurysms in a cerebral artery

254
Q

Where are majority of saccular aneurysms found

A

Near major arterial branch points in the anterior circulation

255
Q

What patients are most likley to have a ruptured saccular aneurysm

A

Woman and people 50+

256
Q

What is arteriovenous malformations

A

Tangled network of vascular channels

257
Q

What are cavernous malformations

A

Distended, loosely organised channels arranged back to back with collagenised walls

258
Q

Where does vascular malformations and cavernous malformations generally occur in the brain

A

Cerebellum, pons and subcortical regions

259
Q

What is capillary telangiectasias

A

Small areas of dilated capillaries in otherwise normal brain tissues. Commonly found in pons

260
Q

What is the most common site for arteriovenous malformations and what patients are most at risk of having one

A

Middle cerebral artery, particularly its posterior branches

Males are most at risk

261
Q

What are 4 causes of vasular dementia

A
  1. Extended periods of time with infarcts
  2. Cerebral atherosclerosis
  3. Vessel thrombosis or embolism from carotid vessels or the heart
  4. Vertebral atherosclerosis from hypertension
262
Q

What underpins the long term effects of diabetes

A

Persistent hyperglycaemia results in glucotoxicity.

This generates AGE (advanced glycation end products) which binds to inflammatory receptors on vascular membranes

263
Q

What is diabetic macrovascular disease and hallmark symptom of it

A

Persistent hyperglycemia and insulin resistant results in endothelial dysfunction

Associated with accelerated atherosclerosis in the aorta and large and medium sized arteries

264
Q

What is the most common cause of death in diabetics

A

MI caused by atherosclerosis of the coronary arteries

265
Q

What is one main diabetic microangiopathies

A

Consistent morphological features of diabetes is diffuse thickening of the basement membranes

266
Q

What changes occur to the permiability of capillaries in diabetic patients

A

Their capillaries are more leaky to plasma proteins

267
Q

How many years after the onset of hyperglycemia does diabetic vascular disease make clincal signficance

A

15-25 years

268
Q

What cerebral damage can occur due to diabetes

A

Glucotoxicity damages the endothelium induced chronic inflammation and promotes atherosclerosis

269
Q

Why is ABI not always a useful diagnostic tool for measuring PAD in diabetic patients

A

Diabetic patients will sometimes have heavily calcified semi-compressible and incompressible tibial arteries

270
Q

upon cessation of exercise during ABI test, what is an immediate indicator of a positive test for PAD

A

A 20% drop in ABI from baseline

271
Q

What pedal pressure in diabetic and non-diabetic patients is indicative of healing

A

Diabetic - >100mmHg
Non-diabetic - >60mmHg

272
Q

What types of tumors are primary tumours of large vessels

A

Sarcomas

273
Q

What is telangiectasia and is this a true neoplasm

A

Permanent dilation of pre-existing small vessels that forms a discrete red lesion

This is not a true neoplasm

274
Q

What is a neoplasm

A

An abnormal mass of tissue that forms when cells grow and divide more than they should or do not die when they should

275
Q

What is the most common form of ectasias

A

Nevus flammeus (birthmark) - composed of dilated vessels, mostly spontaneous.

276
Q

What are spider telangiectasias and where do they most occur

A

Non neoplastic vascular malformations commonly occur on face, neck and upper chest

277
Q

What is Hereditary hemorrhagic telangiectasia

A

Autosomal dominant disorder that are malformations composed for dilated capillaries and veins that are present in birth

278
Q

What are Haemangiomas

A

Common benign tumours in infancy and childhood

279
Q

What are Cavernous haemangiomas

A

These are tumours composed of large, dilated vascular channels. Little clinical significant

280
Q

What are the most common Haemangiomas

A

Capillary Haemangiomas - composed of thin-walled capillaries with scant stroma

281
Q

Kaposi sarcoma, haemangioendotheliomas and angiosarcomas are all what

A

Malignant tumours

282
Q

What is Kaposi sarcoma caused by

A

Herpes Virus 8 - most common in AIDS patients

283
Q

What are the most common sites for angiosarcomas

A

Skin, soft tissue, breast, liver

284
Q

What in contrast referring too in ultrasound

A

The amount of colour or greyscale differentiation that exists between different image features

285
Q

What is resolution in regards to ultrasound

A

the ability for the US probe to demonstrate differentiation between tissues having different characteristics

286
Q

What is axial resolution in US

A

The ability to display small targets along the path of the beam as separate entities (also referred too as longitudinal axis)

287
Q

What is axial resolution in US dependant on

A

The spatial pulse length (number of cycles in a given US pulse)

288
Q

How can spatial pulse length in US be enhanced

A

Increasing frequency emitted by the probe - the shorted SPL will improve the axial resolution but will no penetrate tissue

289
Q

What is lateral resolution in US

A

The ability to distinguish between two separate targets perpendicular to the beam path

290
Q

What is lateral resolution in US dependant on

A

The width of the US beam

291
Q

In order for the lateral resolution in US to be high, the near field needs to be _____

A

Low

292
Q

What is the equation for near field lenght

A

Near field legnth = diamiter^2 / 4λ

293
Q

The near field length in US increases with what changes in wavelength, frequency and aperture

A

Shorter wavelength
Higher frequency
Larger aperture

294
Q

What does focusing the US probe do to the narrowest region of the beam

A

Shortens it

295
Q

What is the focal legnth in regards to US

A

The length between the region and the tranducer

296
Q

How is high later resolution achieved on US in regards to wavelength, focal length and aperture

A

Short wavelength
Short focal length
Wide aperture

297
Q

What is temporal resolution in US

A

The time from the beginning of one frame to the next

Represents the ability for the US system to distinguish between instantaneous events of rapidly moving structures

298
Q

How can frame rate be enhanced in US

A

Reduced depth of penetration
Reduced number of focal points
Reduced scan lines

299
Q

What is temporal resolution dependant on in US

A

Frame rate

300
Q

In regards to power, what is the ideal amount of power used in US

A

We want this to be at the minimum for the required depth penetration. Too much power will result in high exposure

301
Q

What is intensity in relation to US

A

The power flowing through unit area presenting at 90 degrees to the direction of propogation

302
Q

What 4 factors contribute to attenuation of US wave

A

Reflection
Refraction
Absorption
Scattering

303
Q

What is acoustic impedance in US

A

The resistance which represents US wave penetrating the tissue

304
Q

When does reflection occur in US

A

Occurs when the interface between two mediums is large relative to the wavelength

305
Q

What is the difference between specular and diffuse reflections in US

A

Specular reflection is when a US wave hits a smooth, large surface (like bone) and the sound wave is reflected back in a singular uniform direction

Diffuse is when an US wave hits an irregular surface the reflection return to the transducer in a chaotic and disorganised pattern

306
Q

What does diffuse reflection look like on an US display

A

Various shades of grey located within scructures

307
Q

What is refraction

A

Deviation in the path of a beam when the angle of incidence to an interface is no 90 degrees

308
Q

Propogation velocities influence the direction of refraction, true or false

A

True

309
Q

What is the critical angle in regards to US and what does it cause

A

The largest possible angle of incidence which results in a refracted beam

Results in the refracted beam travelling along the boundary between two media

310
Q

What happens is the incidence angle is greater then the critical angle in US

A

The sound waves will be completely reflected by the boundary, a phenomenon known as total internal reflection

311
Q

What is absorbtion in relation to US

A

The conversion of the sound waves mechanical energy into heat energy within the tissue

312
Q

What is the primary mechanism for which attenuation of US occurs

A

Absorption

313
Q

As frequency of the US wave increases, what occurs to the amount of absorption

A

Increases

314
Q

Where does scattering occur in US

A

At the interface within the sound beam path

315
Q

What information does scattering tell us about in an US display

A

Scattering provides most of the textural information present in the images

316
Q

What 3 things is scattering in US dependant on

A

Frequency

Angle of approach

Interface being much smaller then the wavelength

317
Q

For scatter to occur in US, what must the relationship be between the interface and wavelength

A

They must be the same in order for scattering to occur

318
Q

If you have to little gain, what is the resulting issue in the image

A

The structures in the image are not well defined

319
Q

If you have too much gain what will be the resulting issue in the image

A

It will be oversaturated, creating a snowstorm effect

320
Q

What part of an US echo does gain amplify

A

Gain only amplifies the returning echos

320
Q

What is time gain compensation in US

A

The deeper the returning wave, the less energy it will have. The gain automatically increases these signals more to compensate for the additional attenuation these waves go through to get back to the surface

321
Q

What is frame rate

A

Number of images generated per second, expressed as frames per second and contributes to the ‘smoothness’ of the motion capture

322
Q

What is the result of increasing frame rate averaging

A

Can enhance subtle textural differences.

323
Q

Decreasing or removing frame averaging in US is reccomended when

A

Scanning highly mobile tissues

324
Q

What is frame averaging in US

A

This allows the accumulation of echo over two or more frames

325
Q

What will happen is the pulse repetition frequency is too low

A

Aliasing will occur

326
Q

What will happen is the pulse repetition frequency is too high

A

It will detect slower moving blood, the scale of spectral display will not be fully utilised

327
Q

What does the pulse repetition frequency need to be in US to avoid aliasing

A

PRF needs to be twice the maximum Doppler frequency

328
Q

When working with colour box doppler, what is important when positioning the box on screen

A

The box should be at the same angle as the transducer probe

329
Q

What is the effect of variation and contrast when increasing and decreasing dynamic range in US

A

Decreasing dynamic range = limited variation, increased contrast

Increasing dynamic range = limited variation, increased contrast

330
Q

What resolution is usually used first when doing US

A

Begin with axial resolution then move to longitudinal

331
Q

What are 5 ways we can reduce artefact in US

A

Turn down gain
Alter angle of probe
Scan in two planes
Have patient use different breathing technique
Change tranducer frequency

332
Q

What are 5 ways you can optimise the image in B mode US

A
  1. Set the focal zones of interest on the scan image
  2. B mode frame rates should be high
  3. Zooming in on screen
  4. Relatively high contrast
  5. Ensure returning echo’s are uniform by adjusting the total gain and depth gain
333
Q

What are 3 ways we can optimse the image in colour doppler US

A
  1. PFR should be high
  2. Tilt colour box in direction of blood flow
  3. Colour box should be as small as possible
334
Q

What is the usual pulse repetition frequency of colour flow doppler in vascular US

A

3000-4000Hz

335
Q

What are 3 ways you can optimise imaging in spectral US

A
  1. PRF should be set high
  2. High pass filter to remove wall thump
  3. Sample volume should be placed in the centre of the vessel or at the point of maximum velocity
336
Q

What are 3 reasons to why a doppler signal may be showing above or below the baseline

A

Alising
Mirroring
Flow reversal

337
Q

What 4 criteria must quality assurance techniques always meet

A
  1. Always provide an objective and quantifiable measure of performance
  2. Should be relevant clinical application
  3. Should be reproducible over time scale of years
  4. Should be sensitive enough to detect change in performance before it comes clincally relevent
338
Q

Crystal dropout, sensitivity, uniformity and noise are all what type of quality assurance tests

A

Realtive paremeter tests

339
Q

What is crystal dropout in US

A

When a piezoelectric crystal in an US probe is faulty, this will result in a vertical line of reduced echo signal

340
Q

How can sensitivity be assessed in quality assurance

A

Examining the depth to which the reverberation pattern extends

341
Q

How is uniformilty in US quality assurence tested

A

Using a US phantom, there should be no localised bright or dark spots is the tranducer is working properly

342
Q

What are absolute performance tests used for

A

To compare with other machines that provide the same function

343
Q

What is power doppler US and what does it measure

A

New type of colour doppler US used to show much smaller vessels and slower blood flow. Cant show direction of flow.

344
Q

What type of doppler probe is used in vascular ultrasound

A

8Hz with narrow face

345
Q

What three parameters does the ABI depend on

A

Data from the ABI
Wave morphology from doppler ultrasound
Sound interpretation

346
Q

What vessel is the pressure taken from in the ankle in ABI testing

A

Dorsalis pedis

347
Q

What is the ideal waveform in doppler US of ABI testing

A

Waveforms should be multiphasic (upstroke, downstroke, upstroke)

348
Q

What changes have occurred to the structure of a vessel that would cause a reduction in waveform observed in doppler US

A

Shifts in waveform are lost due t the reduction in elasticity within the vessel

349
Q

What waveforms are associated with severe artery disease

A

High monphasic or dampened monphasic

350
Q

In which patients can ABI not be performed on

A

Patients with confirmed or suspected DVT or severe leg pain

351
Q

What are two variations to ABI testing that can be considered

A

Segmental pressure index and toe brachial index

352
Q

What value of toe brachial index is normal

A

> 0.7

353
Q

What value of toe brachial index is severe

A

<0.35

354
Q

What is carotid duplex ultrasound used for

A

Determine the presence and shape of atherosclerotic plaques in the carotid artery

355
Q

What probe is required in carotid duplex US

A

Linear probe with intensity greater then 7Hz, depth focus 30-40nm, frame rate 25Hz, dynamic range 600dB

356
Q

What are 4 symptoms of carotid artery blockage

A

Blurred vision
Confusion
Memory Loss
Weakness

357
Q

What view of the carotid arteries would you get in a longitudinal view

A

You will see the length of the artery as if you were inside it

358
Q

What view of the carotid arteries would you get in transvere US view

A

birds eye view, like you chopped someone head off and were looking down the arteries

359
Q

When doing carotid duplex US, what order do you assess the vessels

A

First find the CAA on the left in transverse plane
Once identified, move the probe until you see the bifurcation, switch to longitudinal plane and observe the ECA and ICA

360
Q

What is the main structural difference between the ICA and ECA in carotid duplex US

A

The ECA is larger and wider

361
Q

What is the normal thickness of the intima-media layer of carotid arteries

A

0.5-0.9mm

362
Q

Normal vessels should have a double laminar structure, true or false

A

True

363
Q

What will you see in a carotid duplex US in early stages of carotid artery disease

A

Thickening of the intima-media layer, uneven surface

364
Q

What should be the relative resistance, diastolic flow and velocity range be in the vertebral artery

A

Low resistance
High diastolic Flow
Velocity range 60-80ms

365
Q

What is the difference between ICA and ECA in spectral doppler

A

ICA waveform is pulsatile at slower rates and have lower diastolic flow then ECA

366
Q

If no flow is observed in spectral doppler what settings can you change

A

Altering the pulse repetition frequency or high pass filter

367
Q

What is the pulsatility index in US

A

The difference between the peack systolic velocity and the end diastolic velocity

368
Q

What is the resistance index in US

A

The pulsatile flow that results the resistance of blood flow

369
Q

In a normal spectral carotid duplex US what are the relative resistance

A

ICA - Low resistance flow
ECA - High resistance flow
CCA - in between the two

370
Q

What are characteristics of a normal carotid duplex US

A

High peaks, well defined, varience

371
Q

What will change in the velocity of a carotid duplex with stenosis

A

Increase in velocity will be observed

372
Q

In carotid duplex, in what terms is the severity of stenosis described

A

Described as a percentage, velocity is only considered when the diameter reduction is greater than 50%

373
Q

What three methods can stenosis of the ICA be treated

A
  1. Carotid endarterectomy (plaque physically removed)
  2. Carotid-carotid bypass
  3. Stenting
374
Q

As stenosis increases in the ICA, what occrs to the PSV and EDV

A

PSV decreases
EDV increases

375
Q

What disease is indicated by pulsatile swelling of the neck

A

Carotid body tumour

376
Q

What are 3 effects calcified atheroma can cause in carotid duplex

A

Shadowing artefact
Reduced quality of image
Gives false positive that flow is absent

377
Q

How does vessel tortuosity effect carotid duplex outcoems

A

The vessels may not appear in a single plane, so doppler may need to be used in multiple angles

378
Q

What is echogenicity in regards to plaque

A

The plaques ability to reflect echo (high echogenicity, more white it will be on echo)

379
Q

What types of plaque are echolucent

A

type 1 and 2

380
Q

What is transcranial doppler used to study

A

Intracranial structure and the vessels within (circle of willis)

381
Q

What are the 2 main arteries of interest in transcranial doppler

A

Middle cerebral artery and internal carotid artery (located in the circle of willis)

382
Q

What are four indications for transcranial doppler

A

Vasospasm, evaluation of left and right shunt, screening of paediatric paitents, sickle cell disease

383
Q

In the transtemporal window of transcranial doppler, what are the 4 arteries of interest

A

middle cerebral artery, anterior cerebral artery, posterior cerebral artery and terminal ICA

384
Q

In the transorbital window of transcranial doppler, what are the 2 vessels of interest

A

ophthalmic artery and carotid syphon

385
Q

What transcranial doppler window can you use in neonates to see the circle of willis

A

Transtemporal window

386
Q

What are 4 indications for AAA screening

A

Pulisile abdomen, back pain, abdominal pain, acute shock

387
Q

What is the vessel of interest in AAA screening

A

Abdominal Aorta

388
Q

In a normal ultrasound of an aorta, how wide should it be maximum

A

2.5cm

389
Q

In pulse wave doppler, what types of waveforms should the proximal aorta and distal aorta have, respectfully

A

Proximal - biphasic
Distal - triphasic

390
Q

What does an intimal flat tell us when imaged in a ultrasound of a vessel

A

Excess tissue showing there has been a tear in the vessel

391
Q

What conditions can make AAA screening difficult to visualise

A

Bowel gas or obesity

392
Q

What are 2 indications of assessment of lower limb disease

A

Pain/cramping in muscles when walking
Pain at rest

393
Q

What are the 5 arteries of interest when doing an assessment of the lower limbs

A

Aortoiliac artery, CFA, femoral artery, popliteal arteries, tibial arteries

394
Q

What waveform should we expect the lower limb arteries to have

A

Triphasic

395
Q

What are the two most commonly upper limb arteries affected with atherosclerosis

A

Subclavian artery and axillary artery

396
Q

Where are the 3 common areas of compression that are being assessed in a thoracic outlet syndrome assessment

A

Subclavian artery, artery that runs between the first rib and clavicle and subcoracoid region

397
Q

What frequency is used for DVT study

A

5-8MHz

398
Q

What are the 4 arteries of interest in the DVT study

A

Common femoral veins
Superficial veins
Popliteal Veins
Calf Veins

399
Q

Do we want the PRF high or low in DVT studies

A

Low

400
Q

What is the purpose of calf compression assessment during DVT study and what should the veins be like

A

To assess the competence of the valves, the flow in the veins towards the heart should be temporality increased or augmented

401
Q

What are the two maneuvers done in DVT study

A

Calf compression and valsava maneurver

402
Q

How do you perform calf compression manoeuvre

A

Place hand around the calf and give a firm queeze then quickly release

403
Q

What should be the result of a calf compression manourver in healthy people

A

Flow augmentation should be sufficiently strong enough to produce a transient peak flow velocity of 30cm/s in the main superficial veins.
Valve closure should be rapid upon squeeze release

404
Q

What is the Valsalva maneuver used to assess

A

The competence of the proximal deep vein and saphenofemeral

405
Q

Explain how the Valsalva manoeuvre is done

A

Patient is told to deeply inhale an then push out and expand their cheeks without breathing out, while at the same time bearing pressure done the abdomen

406
Q

What occurs to the pressure inside the body during the Valsalva manoeuvre

A

It increases the intraabdominal pressure (increasing venous blood pressure in the iliac and femoral veins)

407
Q

If the veins are healthy, what should be seen in the valsava manouver

A

There should be no reflux present in the saphenofemoeral junction or proximal superficial femoral vein

408
Q

What is varicose veins

A

Dialted tortous superficial venous channels that accompany the superficial veins of the upper and lower limbs

409
Q

What is the difference in the action of the vein valves in normal and varicose veins

A

Normal veins - only the veins upward of the blood open (so unidirectional flow)

Varicose veins - all veins flow so blood flows in both directions

410
Q

What nervous system is vascular smooth muscle regulated by

A

SNS

411
Q

What is endothelin released by, what does it do and what is the result of its action

A

Released by endothelial cells

Causes vasocontraction

Stimulates release of various hormones (ANP, aldosterone, adrenaline)

412
Q

Renin-aldosterone system activation causes the release of what 2 primary hormones

A

Renin and Aldosterone

413
Q

What is a common side effect of vasoactive drugs

A

Reflex tachycardia

414
Q

What is the direct and indirect mechanism of vasoconstrictor drugs

A

Direct - act directly onto smooth muscle
Indirect - act on endothelial cells or CNS cells

415
Q

What are some types of drugs that target the nervous system to cause vasocontriction

A

Alpha1-adrenoreceptor agonists and drugs that release noradrenline

416
Q

What are some direct vasodilators

A

L-type Ca2+ blockers and drugs that open up KATP channels

417
Q

What are some examples of indirect vasodilator drugs

A

cGMP, beta-2 antagonists, ACE inhibitors

418
Q

Why are SNS targeting vasodilator drugs not well tolerated

A

Because they target the whole SNS they have lots of side effects

419
Q

what is the main unwanted side effect of antihypertensive drugs

A

Postural Hypotention

420
Q

What drugs tend to be used to target PAD

A

Drugs that reduce the risk of ischemia and strokes - antiplatelet drugs

421
Q

What are some drugs used for pulmonary hypertension

A

Anticoagulants, diuretics

422
Q

What is the role of statins

A

Block synthesis of cholesterol within hepatocytes

423
Q

What is the rate limiting enzyme in cholesterol synthesis

A

HMG-CoA

424
Q

What is the mechanism of PCSK9 drugs

A

reduce the degradation of LDL receptors

425
Q

What is one disadvantage to mechanical treatment of thrombi

A

Any mechanical process in the vessel will result in healing = intimal thickening.

426
Q

What is interventional ultrasound

A

Using a catheter to deliver ultrasound waves to the trombi to break it up and remove the occlusion

427
Q

In what situations do synthetic grafts and autologous grafts work better

A

High flow locations are better with synthetic graft

Small vessels are best with autologous grafts

428
Q
A
429
Q
A

Physiology - Hayley (9 decks)

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