Unit 4: Cardiovascular System Flashcards

1
Q

What are the main functions of the cardiovascular system? (5)

A
  • Circulates blood to all parts of the body
  • Transports water, oxygen and nutrients to cells
  • Transports wastes, including carbon dioxide, away from cells
  • Helps maintain correct body temperature
  • Helps fight disease, through white blood cells and antibodies in the blood
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2
Q

Define Myocardium

A

Myocardium is specialized muscle tissue (cardiac muscle) that forms the heart.

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3
Q

What is Pulmonary Circulation?

A

Pulmonary Circulation is the circulation of de-oxygenated blood to the lungs where it is re-oxygenated.

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4
Q

What is Systemic Circulation?

A

Systemic Circulation is the circulation of oxygenated blood from the lungs to the rest of the body.

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5
Q

Why are heart valves important?

A

Heart valves prevent back-flow of blood

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6
Q

What are the names and main functions of the 4 heart valves?

A
  • Bicuspid (mitral) valve: controls the blood flow from the atria to the ventricles
  • Tricuspid valve: controls the blood flow from the atria to the ventricles
  • Aortic semilunar valve: controls the blood flow out of the ventricles
  • Pulmonary semilunar valve: controls the blood flow out of the ventricles
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7
Q

Trace one drop of blood from the time it enters the right atrium of the heart until it enters the left atrium

A
Right atrium
Tricuspid valve
Right ventricle
Pulmonary semilunar valve
Out the pulmonary arteries to the lungs 
Blood returns from the lungs
Pulmonary vein
Left atrium
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8
Q

What are Arteries?

A

Arteries: blood vessels that carry blood away from the heart

In the systemic circulation, arteries carry blood from the left side of the heart towards the body tissues

In the pulmonary circulation, arteries carry deoxygenated blood from the right side of the heart towards the lungs

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9
Q

What are Veins?

A

Veins: blood vessels that carry blood towards the heart

In the systemic circulation, veins carry deoxygenated blood towards the right side of the heart from body tissues

In the pulmonary circulation, veins carry oxygenated blood towards the left side of the heart from the lungs

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10
Q

What is the function of the electrical conduction system of the heart?

A

Syncytium - describes the ability of these cells to transmit electrical signals. Thus allowing the myocardium to contract as a single unit, in syncytium.

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11
Q

Name the elements of the electrical conduction system, beginning with the pacemaker.

A

SA node
AV node
Bundle of His
Purkinje fibres

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12
Q

What is the SA node?

A
The SA (sinoatrial) node:
Def’n: A specialized region of tissue that is found in the wall of the right atrium where electrical signals that lead to contraction are initiated (also called the pacemaker of the heart).
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13
Q

What is the AV node?

A
The AV (atrioventricular) node:
Def’n: Specialized tissue that transmits the electrical signal from the atria into the ventricles and into another region that runs down the ventricular septum, the tissue that separates the two ventricles (the bundle of His, also known as the atrioventricular bundle)
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14
Q

What is the Bundle of His?

A

The Bundle of His

Specialized tissue within the ventricular septum that splits to form the left and right bundle branches

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15
Q

What are the Purkinje fibres?

A

The Purkinje Fibres
Pass the electrical signal to the myocardium that forms the ventricles
The ventricles then contract from the bottom up, forcing blood into the aorta and pulmonary arteries

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16
Q

What is an ECG? What information does it tell us?

A

Electrocardiogram

  • An instrument in which the electrical activity of the heart can be measured
  • It provides a graphical representation of the electrical sequence of events that occurs with each contraction of the heart
  • Each of the electrical waves generated during contraction has a specific name
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17
Q

Name the waves produced in the ECG

A

P wave: Atrial depolarization
QRS: Ventrical depolarization
T wave: Ventrical repolarization

18
Q

What are Capillaries?

A

The smallest of the blood vessels, capillaries help to enable the exchange of water, oxygen, carbon dioxide, and other nutrients and waste substances between blood and the tissues.

19
Q

What three ways is blood returned to the heart?

A

Skeletal muscle pump
Thoracic pump
Nervous system

20
Q

What is the skeletal muscle pump? How does it return blood back to the heart?

A

It describes how, with each contraction of skeletal muscle, blood is pushed or massaged back to the heart
This is because of the one-way valves within the veins, therefore the only direction the blood can travel is towards the heart

21
Q

What is the thoracic pump? How does it return blood back to the heart?

A

Related to breathing
With each breath taken by the respiratory system, pressure in the chest cavity is very low for a few seconds, while the pressure in the abdominal cavity increases
The pressure within the veins in the chest also drops, while the pressure in the veins from the abdominal cavity increase
This creates a difference in pressure between the veins in these body cavities, thus pushing blood from the veins in the abdominal cavity to the veins in the thoracic cavity
Also because of the one-way valves found in the veins

22
Q

How does the nervous system return blood back to the heart?

A

At times when the cardiac output needs to be increased, such as during exercise, the nervous system sends a signal to the veins, causing them to slightly constrict
This constriction response is known as venoconstriction
This slight constriction helps to return more blood back to the heart

23
Q

What is blood composed of?

A

55% Plasma

45% Blood cells

24
Q

What is plasma & what is it made of?

A

The fluid component of blood
water (90%)
Plasma proteins (7%)
Other (acids, salts) (3%)

25
Q

What types of blood cells make up blood?

A

Red blood cells (erythrocytes) (>99%)

White blood cells (leukocytes) and platelets (thrombocytes) (<1%)

26
Q

How to separate blood into its component parts

A

The blood is collected and put into a centrifuge unit and spun at very high speeds for a few minutes
The rapid spinning results in the heaviest components of blood (the erythrocytes) sitting at the bottom of the tube and the lightest components (the plasma) sitting at the top

27
Q

What is cardiac output?

A

Cardiac Output (Q) is the volume of blood that is pumped out of the heart in one minute, usually represented by the symbol Q and measured in litres per minute (L/min); cardiac output can be calculated as the product of stroke volume and heart rate

28
Q

What is stroke volume?

A

Stroke Volume (SV) is the amount of blood that is ejected from the left ventricle in a single beat, and is measured in millilitres (mL); it can be calculated by subtracting the left ventricular end-systolic volume (LVESV) from the left ventricular end-diastolic volume (LVEDV)

29
Q

What is LVESV?

A

Left ventricular end-systolic volume

LVESV is the amount of blood remaining in the left ventricle after the contraction of the ventricle

30
Q

What is LVEDV?

A

Left ventricular end-diastolic volume

LVEDV is the amount of blood remaining in the left ventricle after the contraction of the left atrium

31
Q

3 main factors that regulate stroke volume

A

LVEDV
Aortic blood pressure
The strength of the ventricular contraction

32
Q

What is heart rate?

A

Heart Rate (HR) is the number of times the heart contracts in a minute (beats per minute; beats/min), usually represented by the symbol HR

33
Q

What is cardiac cycle?

A

Cardiac cycle is the series of events that occurs through one heart beat. During this cycle there is both a phase of relaxation (diastole), in which the heart is filling with blood, and a phase of contraction (systole), in which the heart contracts and ejects the blood.

34
Q

What is blood pressure?

A

Blood pressure is the force exerted by the blood against the walls of the arteries and other vascular vessels; measured in millimetres of mercury (mmHg)

35
Q

Systolic blood pressure vs Diastolic blood pressure

A

Systolic blood pressure refers to the maximum pressure observed in the arteries during the contraction phase of the ventricle (e.g., 120mmHg)

Diastolic blood pressure is the minimum pressure observed in the arteries during the relaxation phase of the ventricle (e.g., 80mmHg)

36
Q

What is hypertension?

A

Hypertension is persistently elevated (high) blood pressure; a BP greater than 140/90mmHg.
It is a major risk factor for cardiovascular disease
Can be caused by obesity, smoking, aging, kidney disease, genetic factors.
Although, through changes to lifestyle (diet improvement and increases in aerobic exercise), blood pressure can be returned to near normal levels.

37
Q

What are the characteristics of an athlete’s heart?

A

Alterations in the structure of the heart
Increases in the mass and dimensions of the heart can be observed
Increases in ventricular volume; also leading to an increase in SV
Increases in thickness of ventricular walls: also leading to an increased force of contraction in the ventricle
Increased Q during exercise
** Due to the persistent increase in venous return that occurs during exercise
Increase in the number of capillaries that deliver blood to the myocardium
Increase in diameter of the coronary arteries
Increase in blood volume; leads to an increase in venous return

38
Q

Bradycardia vs Tachycardia

A

Bradycardia: HR is decreased at rest and during sub-maximal exercise
One of the most easily observed adaptations that occur with training
Characterized by a heart rate of 60 bpm or less at rest

Tachycardia:
Heart rate of more than 100 bpm at rest
** Despite the alterations in HR at rest and during sub-maximal exercise, HR is unchanged at maximal exercise; this contributes to the increase in maximal exercise capacity

39
Q

What is cardiovascular disease?

A

The term “cardiovascular disease” encompasses any disease associated with the cardiovascular system. More often people use this term to refer to coronary artery disease or coronary heart disease.

40
Q

What is coronary artery disease?

A

Coronary artery disease (aka atherosclerosis) is associated with a gradual narrowing of the coronary arteries resulting from the accumulation of hard deposits of cholesterol, called plaque, on the lining of the blood vessels. This plaque builds up over the years. Besides poor diet, other risk factors include smoking, elevated blood lipids, hypertension, family history, and physical inactivity.

41
Q

What causes a heart attack?

A

A heart attack (a myocardial infarction) can result when blood flow to a section of the heart muscle becomes blocked due to plaque build up or some other reason. If the blood flow is not restored promptly, then that section of the heart becomes damaged from a lack of oxygen.