Cardiovascular

Question 1

What is the systemic circuit?

Answer 1

Blood supply to and from all body tissues.

Question 2

What is the pulmonary circuit?

Answer 2

Blood supply to and from the lungs for oxygenation.

Question 3

Explain coronary arteries.

Answer 3

Branch off the aorta.
Lead into capillaries, supply cardiac tissue.
Left + Right main coronary artery.

Question 4

Explain coronary veins.

Answer 4

Drain into coronary sinus (posterior surface of heart) - empties into right atrium.

Question 5

Explain the sequence of excitation of the cardiac conduction system.

Answer 5

1. Sinoatrial node: pacemaker, 100/min impulses.
2. Atrioventricular node
3. Atrioventricular bundle (bundle of His)
4. Right and left bundle branches
5. Purkinje fibres
6. Parasympathetic Nervous System slows HR
7. Sympathetic Nervous System increases HR

Question 6

What is the electrical event for P wave?

Answer 6

Atrial depolarization

Question 7

What is the mechanical event for a P wave?

Answer 7

End of diastasis and starting of atrial systole

Question 8

What is the electrical event for QRS complex?

Answer 8

Result of ventricular depolarization and indicates the start of ventricular contraction.

Question 9

What is the mechanical event for QRS complex?

Answer 9

End of atrial systole and isovolumetric contraction

Question 10

What is the electrical event for T wave?

Answer 10

Results from ventricular repolarization and signals the beginning of ventricular relaxation

Question 11

What is the mechanical event for T wave?

Answer 11

End of ventricular ejection phase and isovolumetric relaxation

Question 12

What are the 2 sympathetic neurotransmitters?

Answer 12

1. Adrenaline
2. Noradrenaline

Released from adrenal medulla as hormones.

Question 13

Where is the Alpha 1 receptor located?

Answer 13

Arteries supplying skin and visceral organs.

Question 14

What effect does Alpha 1 receptor have on adrenaline/noradrenaline binding?

Answer 14

Vasocontriction

Question 15

Where is the Beta 1 receptor located?

Answer 15

Heart (muscle)

Question 16

What effect does Beta 1 receptor have on adrenaline / noradrenaline binding?

Answer 16

Increases HR; increases force of contraction

Question 17

Where are the 2 Beta 2 receptors located?

Answer 17

1. Coronary arteries

2. Respiratory bronchioles

Question 18

What effect do both the Beta 2 receptors have on adrenaline / noradrenaline binding?

Answer 18

1. Vasodilation

2. Bronchodilation

Question 19

Where in the systemic circulation does systole occur?

Answer 19

Aorta/arteries

Question 20

Where in the systemic circulation does diastole occur?

Answer 20

Arterioles

Question 21

What is peripheral resistance?

Answer 21

Opposition to blood flow due to friction

Question 22

What does peripheral resistance depend on?

Answer 22

1. Diameter of blood vessel (vasoconstriction increases resistance and BP)
2. Blood viscosity (thicker blood increases BP)

Question 23

What is arterial BP determined by?

Answer 23

1. Cardiac output

2. Peripheral resistance, by altering blood vessel diameter.

Question 24

What are 3 things that explain vasoconstriction?

Answer 24

1. Decrease in vessel diameter
2. Increases resistance
3. Increases BP

Question 25

What are 3 things that explain vasodilation?

Answer 25

1. Increases in vessel diameter 2. Decreases resistance 3. Decreases BP

Question 26

What is the equation for blood pressure?

Answer 26

BP = CO x PR Blood Pressure = Cardiac Output x Peripheral Resistance

Question 27

Explain the chemoreceptor reflex

Answer 27

In aortic arch and carotid sinus. Detects low pH and O2, stimulates cardioexcitatory centre to increase HR and vasoconstriction

Question 28

Explain the baroreceptor reflex

Answer 28

In carotid arteries and aortic arch. Detects changes in stretch e.g. when stretched less due to decrease in BP, stimulates cardioacceleratory centre to increase HR and vasoconstriction.

Question 29

Go through RAAS

Answer 29

1. Decreased BP detected by kidney's 2. Kidney releases renin: converts angiotensinogen to angiotensin 1 3. Angiotensin Converting Enzyme (ACE): converts angiotensin 1 to angiotensin 2 (mainly in lungs) 4. Angiotensin 2: causes aldosterone secretion from adrenal gland resulting in = reabsorption of sodium and water by kidney, increased BP + BV

Question 30

What are the 3 main dietary fats?

Answer 30

1. Triglycerides (mono/poly/trans-unsaturated fats) 2. Phospholipids (plant + animal) 3. Cholesterol (animal fats + eggs)

Question 31

What organ produces and removes cholesterol from the body?

Answer 31

Liver

Question 32

What medications are used for lowering cholesterol?

Answer 32

Lipid lowering drugs - statins

Question 33

Cholesterol is necessary for the production of what 4 hormones?

Answer 33

1. Cortisol 2. Aldosterone 3. Testosterone 4. Oestrogen

Question 34

How are lipoproteins transported?

Answer 34

Through the blood plasma

Question 35

What is dyslipidaemia?

Answer 35

Abnormal levels of lipids in the blood. Major risk factor for atherosclerosis. + triglycerids & LDL, - HDL

Question 36

What are 8 risk factors for dyslipidaemia?

Answer 36

1. High intake of saturated and trans fatty acids 2. High total energy and cholesterol intake 3. Low intake of mono & poly - unsaturated fatty acids 4. Low intake of dietary fibre including wholegrain cereals. 5. Sedentary lifestyle 6. Smoking 7. Stress 8. Genetic

Question 37

What is the target levels for lipids in the blood?

Answer 37

LDL <2.0 HDL >1.0 Triglycerides <2.0 Total Cholesterol <4.0

Question 38

What prevention and management strategies are utilized to decrease cholesterol in the blood?

Answer 38

1. Dietary (+ Fibre, - simple carbs modify fat intake) 2. Exercise 3. Lipid lowering drugs

Question 39

What is atherosclerosis?

Answer 39

Fatty deposits and hardening of the artery wall

Question 40

What 4 things progressively accumulate in atherosclerosis?

Answer 40

1. Lipids 2. Inflammatory cells 3. Smooth muscle cells 4. Connective tissue

Question 41

What are 12 risk factors for atherosclerosis?

Answer 41

MODIFIABLE: 1. Dyslipidaemia 2. Hypertension 3. Obesity / sedentary 4. DM / insulin resistance 5. Smoking 6. Inflammation 7. Stress NON-MODIFIABLE 8. Increasing age 9. Male gender; female menopause 10. Family Hx of heart disease 11. Familial hyperlipidaemia 12. Aboriginal & Torres Strait Islander

Question 42

What is the progression of atherosclerosis?

Answer 42

1. Endothelial cell injury and inflammation 2. Fatty Streak 3. Hard / fibrous plaque 4. Soft / complicated plaque

Question 43

What 3 things happen when cell injury and inflammation occur? (Atherosclerosis)

Answer 43

1. Allows LDL to enter the subendothelium 2. Macrophages enter the subendothelium, enhancing the inflammatory response 3. Unable to mediate vasodilation.

Question 44

What are some consequences of atherosclerosis?

Answer 44

Heart = chest pain, heart attack, death Brain = stroke, death Arms & Legs = peripheral artery disease, gangrene and amputation Kidneys = renal failure Genitals = erectile dysfunction, vaginal dryness

Question 45

How is an embolus formed?

Answer 45

Part of the thrombus may break off the plaque, becoming an embolus. Embolus travels downstream and lodges in a smaller diameter vessels, blocking perfusion to the organ.

Question 46

What prevention and management strategies are there for embolus formation?

Answer 46

1. Addressing risk factors, including dietary | 2. Medications (antiplatelets, anticoagulants, lipid lowering, ACE inhibitors and angiotensin 2 blockers)