Intro to Circulation, Perfusion, Blood Pressure

Question 1

Venous Return

Answer 1

The rate of blood flowing back to the heart through the veins

Question 2

Preload

Answer 2

the initial stretching of the cardiac myocytes during diastole before the contraction
- this depends on venous return

Question 3

Volume overload

Answer 3

when preload becomes to large

Question 4

Factors Affecting preload (increased)

Answer 4

• increased Atrial contractility
• decreased HR
• increased Aortic pressure
• increased central venous pressure
• increased ventricular compliance

Question 5

Afterload

Answer 5

the resistance that the chambers of the heart must overcome during systole

Question 6

Features of the pulmonary circulation

Answer 6

• High capillary density
• Low vascular resistance
• Acts as a blood reservoir
• Endocrine control of BP (ACE)
• Acts as a Filter

Question 7

ACE in the lungs

Answer 7

Angiotensin Converting Enzyme, 1 into 2

- located in endothelial cells

Question 8

The affect of low O2 in a region of the lungs

Answer 8

• the arterioles constrict
• poor ventilation leads to reduced perfusion
• this minimises the amount of blood that is poorly oxygenated

Question 9

Hypertension

Answer 9

• high blood pressure (diastolic)
• lead to coranry artery disease MI
• idiopathic causes, hormones (Ang II) and Brain Medulla (NTS)

Question 10

NTS in hypertension

Answer 10

The nucleus of the solitary tract

• part of the dorsal medulla
• the first synaptic station for cardiorespiratory afferent inputs
• neurons in the NTS are essential for the processing of sympathetic and respiratory responses to hypoxia

Question 11

Chronic Hypertension can lead to

Answer 11

• Stroke
• Aneurysm
• MI
• Kidney failure
• Heart Failure
• Cardiac Hypertrophy

Question 12

Stroke

Answer 12

the rapid loss of brain function due to disturbance in blood supply to the brain

Question 13

Aneurysm

Answer 13

a localized, blood filled balloon-like enlargement in the wall of a blood vessel

• due to weakening structure
• tearing or ripping of the blood vessel
• ultimately result in internal haemorrhage

Question 14

Orthostatic Hypertension

Answer 14

low BP on standing to due to low decreased venous return

Question 15

Cardiogenic Shock

Answer 15

critically low perfusion caused by the heart

Question 16

Compensatory mechanisms of cardiogenic shock

Answer 16

• Tachycardia

- Tachypnoea

Question 17

Failure to compensate symptoms in cardiogenic shock

Answer 17

• low urine output
• hypotension
• confusion
• confusion
• syncope
• acidosis

Question 18

Perfusion

Answer 18

requires a pressure difference in order for flow to occure

Question 19

Syncope

Answer 19

• fainting, due to insufficient blood to the head, hypotension

Question 20

Shock

Answer 20

Insufficient perfusion

Question 21

Pulmonary circulation

Answer 21

• from the right heart,

- series flow system

Question 22

Systemic circulation

Answer 22

• from the left side of the heart
• parallel branching paths
• concurrent flow

Question 23

Pressure and Flow

Answer 23

BP= cardiac output x peripheral resistance

Question 24

action and role of theAorta

Answer 24

stretch and recoil, stores energy

Question 25

role of the Arteries

Answer 25

distribute, volume adjust

Question 26

role of the Arterioles

Answer 26

regulate caps, resistance set BP & TPR

Question 27

role of the Capillaries

Answer 27

Exchange, nutrients,gas,fluid

Question 28

role of the Venules

Answer 28

collect blood, some exchange

Question 29

role of the Veins

Answer 29

Reservoir for blood, muscle pump | ~64% of blood volume

Question 30

Right Ventricle

Answer 30

- thin walled - crescent x-section (anterior view) - supply only lungs - low pressure - high perfusion - low resistance

Question 31

Left ventricle

Answer 31

- Thick walled - Circular x-section from and (anterior view) - supplies many organs - high pressure - variable flow - variable resistance

Question 32

Apex Beat

Answer 32

apex of the heart moves forward and strikes the chest wall

Question 33

Mitral Valve

Answer 33

- between left atrium and ventricle - has 2 leaflets - papillary muscle and chordae tendineae prevent eversion of valve flaps

Question 34

AV Valves

Answer 34

- Mitral & tricuspid - have papillary fibres to prevent prolapse - close during systoles - S1: first heart sound (lub)

Question 35

Semilunar valves

Answer 35

- Aortic and Pulmonary valves - moon-shaped - Close during diastole - diastole is longer than systole - S2: second heart sound (dub)

Question 36

Blood volume - kidneys

Answer 36

- depends on water intake | NOT formed elements

Question 37

Formed elements

Answer 37

- red/ white blood cells | - platelets

Question 38

Peritubular capillaries

Answer 38

small blood vessels that travel alongside the nephrons | - allows reabsorption and secretion between the blood and the lumen of the nephron

Question 39

Glomerular filtration rate

Answer 39

- all the fluid entering all the bowman's capsules in the kidney

Question 40

Hypoxia, Anoxia, Hypoxemia

Answer 40

insufficient O2 supply to a region or to entire body

Question 41

Hypoxemia

Answer 41

net low amount of oxygen in arterial blood. | refers to the whole arterial system

Question 42

Ischaemia

Answer 42

insufficient blood flow to a region

Question 43

Anoxia

Answer 43

no oxygen locally

Question 44

Angina Pectoris: symptom

Answer 44

chest pain due to: | - over-exertion or damage to heart tissue

Question 45

Angina Pectoris: Treatment

Answer 45

Nitrates, opens blood vessels in the heart

Question 46

Myocardial Infarction: treatment

Answer 46

- Immediate reperfusion (within 2 hours) - PCI - removing plaque ore thrombus - MONA

Question 47

what does MONA stand for and when is it applied

Answer 47

- Morphine - Oxygen - Nitrates (vasodilation) -Aspirin treatment for MI

Question 48

what is PCI

Answer 48

Percutaneous coronary intervention: balloon angioplasty

Question 49

Syncope

Answer 49

loss of consciousness due to insufficient blood flow to the brain - Shock - Arrhythmia

Question 50

Pulse Pressure

Answer 50

= P(systolic) - P(diastolic) | the difference between the diastolic and systolic pressure

Question 51

Mean Arterial Pressure

Answer 51

= P(diastolic) + [P(systolic) - P(diastolic)]/3

Question 52

Cardiac Output

Answer 52

Stroke volume x Heart rate

Question 53

Stroke volume

Answer 53

volume of blood pumpes out of a ventricle during one beat of the heart

Question 54

Heart rate

Answer 54

reciprocal is RR interval (ECG r-waves)

Question 55

Atrial Systole cardiac cycle fact

Answer 55

adds final 20/25% of total to fill the ventricles

Question 56

End Diastolic Volume

Answer 56

120ml | - volume of blood in a ventricle at the end of diastole

Question 57

End Systolic Volume

Answer 57

50ml | - volume of blood remaining in a ventricle at the end of systole

Question 58

Ejection fraction

Answer 58

55-70%

Question 59

Exercise and Vasomotor system

Answer 59

- peripheral vasodilation (skin/muscle) | - Vasoconstriction in the splanchnic circulation

Question 60

Standing up and Vasomotor

Answer 60

- initial drop in BP followed by compensatory recovery - Peripheral vasoconstriction - arterial + venous - increase HR - BP no systolic change, diastolic increases

Question 61

Control of Systemic BP

Answer 61

Local - endothelial, NO Neurological- the autonomic system Humoral - renal/ pituitary/adrenal

Question 62

Shear force

Answer 62

the force on the endothelium in the direction of the flow of blood - increased by laminar flow - atheroprotective