Fluid And Transport Flashcards

1
Q

What are the three parts of the cardiovascular system?

A

The heart, which acts as the pump.
The blood vessels, which act as the conducting system.
The blood, which acts as the fluid medium.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the chambers of the heart?

A

The heart has four chambers, two atria and two ventricles.
There are the left and right atria, they are thin walled and separated by interatrial septum.
There are also the left and right ventricles, they have thicker walls and are separated by inteventricular septum.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the two systems that circulate blood?

A

Blood alternates between two circuits, the systemic circulation that carriers blood to and from the body and the pulmonary circulation that carriers blood to and from the lungs.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What different circulation systems do each heart chamber pump or collect from?

A

Right atrium collects blood from systemic circuit.
Right ventricle pumps blood to the pulmonary circuit.
Left atrium collects blood from pulmonary circuit.
Left ventricle pumps blood to systemic circuit.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the three parts of blood vessels?

A

Arteries that carry blood from the heart to tissues.
Veins that carry blood back to the heart.
Capillaries are networks between arteries and veins.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Where is the heart located?

A

The heart is located in the mediastinum within the thoracic cavity. It is directly behind the sternum, slightly to the left, between the two lungs, and it is in a pericardial sac which is a though fibrous tissue layer which surrounds and stabilizes the heart.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the mediastinum?

A

The mediastinum is the central part of the thoracic cavity. It is bounded by the sternum anteriorly, the thoracic vertebrae posteriorly, and the right and left lungs and pleurae on the left and right sides. It contains the heart and its vessels, esophagus, trachea, phrenic and cardiac nerves, thoracic duct, and thymus gland and mediastinal lymph nodes. It contains all the thoracic organs except the lungs.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the surface anatomy of the heart?

A

It has two parts; the base and the apex.
The base is superior end of the heart. It is connected to the great vessels.
The apex is the pointed tip. Located in the 5th intercostal space and just inside the midclaviular line.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the three layers of the heart wall?

A

The outmost layer is the pericardium.
The middle layer is the myocardium.
The inner most layer is the endocardium.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the pericardium?

A

The pericardium has two layers; the parietal pericardium (the outer layer that is attached to the pericardial sac) and the visceral pericardium/epicardium (the inner layer that is attached to the heart.)
The pericardial cavity is between the two layers and contains pericardial fluid (15-50ml)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the myocardium?

A

This is the thickest layer of the heart. It is the muscular wall with concentric layers of cardiac muscle tissues. It is composed of cardiomyocytes. It divides into two parts; the atrial myocardium and the ventricular myocardium.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the characteristics of the cardiomyocytes?

A
  • Small
  • Involuntary
  • Mononucleated
  • Striated
  • Branching interconnections between cells
  • Have short and wide T tubules
  • SR has no terminal cisternae
  • Have no triads
  • Aerobic (high in myoglobin, mitochondria)
  • Have intercalated discs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are intercalated discs?

A

Specialized contact points that join adjacent cardiomyocytes (gap junctions, desmosomes).
It has three main functions; maintain structure, conduct action potentials, and link heart cells mechanically, chemically, and electrically (the heart works like a single, fused masa of cells).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the endocardium?

A
  • Innermost layer of the heart
  • Lines the inner surface of the heart including heart valves
  • Simple squamous epithelium
  • Continuous with endothelium of the great vessels
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are diseases of the cardiac wall?

A

Carditis or inflammation of the heart (pericarditis, myocarditis, and endocarditis)

Pericardial effusion which is abnormal accumulation of fluid in the pericardial cavity.

Myocardial ischemia which is complete or partly blocked blood flow to the heart.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is on the superficial surface of the heart?

A

Coronary sulcus which divides atria and ventricles.
Anterior and posterior interventricular sulci which separates left and right ventricles.
It also contains blood vessels of cardiac muscles.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are heart valves?

A

Heart valves are one way, they permit blood flow in one direction and prevent backflow. The anatomy has valve cusps/leaflets that are fibours flaps that guard the valve openings. All heart valves are tricuspid (three cups) except mitral valves (two cups). Chordae tendineae attach free cusp edges to papillary muscles of ventricle.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are the two valve groups?

A

There are two atrioventricular (AV) valves each between an atrium and a ventricle.
There are two semilunar valves each between a ventricle and a great artery.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are atrioventricular (AV) valves?

A
  • Permit blood flow from atria to ventricles.
  • Tricuspid valve that connects right atrium to right ventricle.
  • Mitral (bicuspid) valve that connects the left atrium to the left ventricle.
  • Blood pressure closes valve cusps during ventricular contraction.
  • Papillary muscles tense chordae tendineae which prevents valves from swinging into atria.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are semilunar valves?

A
  • Permit blood flow from ventricles to great vessels.
  • Pulmonary valve which is between right ventricle and pulmonary artery.
  • Aortic valve is between the left ventricle and aorta.
  • No chordae tendineae.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are valve lesions?

A

Regurgitation (incompetence) which is backflow of blood into the opposite direction due to failure of the valves to close properly.
Stenosis which is decreased blood flow though a vavle due to narrowing of valve opening.
It can be caused by congenital or rheumatic fever.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is the pathway of blood circulation?

A

Veins of the systemic circulation  superior & inferior venae cavae  right atrium  tricuspid valve  right ventricle  pulmonary valve  pulmonary trunk  right & left pulmonary arteries  right & left lungs  right & left pulmonary veins  left atrium  mitral valve  left ventricle  aortic valve  aorta  arteries of the systemic circulation  capillaries  different body tissues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the foramen ovale?

A
  • Opening through interatrial septum.
  • Connects the two atria before birth.
  • Seals off at brith —> fossa ovalis
  • Failure to close —> ASD (atrial septal defect)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What are the differences between the right and left ventricle?

A

The right ventricle is smaller, thinner, has a pouch shaped cavity, has less power, and has less IV pressure.
The left ventricle is larger, thicker, has a round shaped cavity, has more power, and has more IV pressure.

25
Q

What are the connective tissues fibers of the heart?

A
  • Physically support cardiac muscle fibers.
  • Distribute forces of contraction.
  • Add strength and prevent overexpansion of heart
  • Elastic fibers return heart to original shape after contraction
26
Q

What is the blood supply to the heart (coronary circulation)?

A
  • Supplies blood to muscle tissues of heart.
  • Coronary arteries and veins.
27
Q

What are the coronary arteries?

A

There re the right and left coronary arteries. They originate at the aortic sinuses. They also have high blood pressure, elastic rebound forces blood though coronary arteries during diastole (in-between contractions).

28
Q

What does the coronary artery supply and where does it branch to?

A

It supplies blood to the right atrium, sinoatrial (SA) node, atroventricular (AV) node, right ventricle, and part of the left ventricle.
It branches to the marginal artery (ies) which is across the surface of the right ventricle and the posterior descending (interventricular artery) which supplies the posterior part of the interventricular septum.

29
Q

Where does the left coronary artery supply and branch to?

A

It supplies blood to the left atrium, left ventricle, and interventricular septum.
It branches to the circumflex artery and anterior descending (interventricular) artery which supplies the interventricular septum.

30
Q

Where is the coronary anastomoses and what does it do?

A

It is between the circumflex and right coronary arteries, it is anterior and posterior interventricular arteries.
It stabilizes blood supply to cardiac muscles.

31
Q

What are the four coronary (cardiac) veins?

A
  • Anterior cardiac veins that empty into the right atrium.
  • Posterior, middle, and small cardiac veins that empty into the great cardiac vein or coronary sinus.
  • Great cardiac vein drains area of anterior interventruclar artery and empties into the coronary sinus.
  • Coronary sinus that empties into the right atrium.
32
Q

What is coronary artery disease (CAD)?

A

It is the narrowing or blocking of coronary arteries that decrease coronary blood flow (ischemia) and decrease O2 supply to the heart. Atherosclerosis is the most common cause. It manifests as asymptomatic, angina pectoris (sudden onset of chest pain due to myocardial ischemia), myocardial infarction (necrosis of part of the heart muscle), and sudden death.

33
Q

What are the physiological characteristics of cardiac tissue?

A
  • Automaticity: contraction without neural stimulation and is controlled by pacemaker cells.
  • Contractibility: controlled by autonomic nervous system and has extended contraction time (10X skeletal muscles).
  • Conductivity: through intercalated discs.
  • Excitability: prevention of wave summation and titanic contractions by cell membrane.
34
Q

What is a heartbeat?

A

It is a single contraction of the heart. The entire heart contracts in series, first the atria and then the ventricles.

35
Q

What are types of cardiac muscle cells?

A
  • Contractile cells that produce contractions.
  • Conducting cells that are modified cardiomyocytes and control and coordinate heartbeat.
36
Q

What is the conducting system and what are the structures within it?

A
  • A system of specialized cardiac muscle cells that initiates and distributes electrical impulses that stimulate contraction.
    It contains:
  • Sinortial (SA) node
  • Internodal pathways
  • Atrioventricular (AV) nodes
  • Bundle branches
  • Purkinje fibers
37
Q

What is impulse conduction through the heart?

A
  1. SA node activity and atrial activation begin.
  2. Stimulus spreads across the atrial surfaces and reaches the AV node.
  3. There is a 100-msec delay at the AV node. Atrial contraction begins.
  4. The impulse travels along the interventricular septum within the AV bundle and the bundle branches to the Purkinje fibers and, by the moderator band, to the papillary muscles of the right ventricle.
  5. This impulse is distributed by Purkinje fibers and relayed throughout the ventricular myocardium. Atrial contraction is completed, and ventricular contraction begins.
38
Q

What is the Sinoatrial (SA) node? (Important)

A
  • Pacemaker of the heart.
  • Depolarizes first, establishing heart rate.
  • Generates 80-100 action potentials per minute (AV node generates 40-60).
39
Q

What is heart rate?

A
  • Number of heartbeats/minute.
  • Normal range is 60-90/min and is slightly slower than the SA node rate and is modified by autonomic activity, hormones, and other factors.
40
Q

What are abnormal pacemaker functions?

A

Bradycardia: abnormally slow heart rate (under 60)
Tachycardia: abnormally slow heart rate (above 90)
Ectopic pacemaker: these are abnormal cells outside the SA node that generates a high rate of action potentials, it bypasses the conducting system, and disrupts ventricular contractions.
Sick sinus syndrome

41
Q

What is the cardiac cycle?

A

It is the period from the beginning of one heartbeat to the beginning of the next. Each cycles includes systole (contraction) with atrial systole and ventricular systole. Then diastole (relaxation) with arterial diastole and ventricular diastole.

42
Q

What does the cardiac cycle have to do with pressure?

A

Blood pressure in any chamber rises during systole and falls during diastole. Blood flows from higher to lower pressure and is controlled by timing of contractions directed by one-way valves.

43
Q

What does the cardiac cycle have to do with heart rate?

A

At 75 beats per minute the cardiac cycle lasts about 800 msec. When heart rate increases all phases of cardiac cycle shorten, particularly diastole.

44
Q

What are the four main events of the cardiac cycle?

A
  1. Atrial systole
  2. Atrial diastole
  3. Ventricular systole
  4. Ventricular diastole
45
Q

What are the seven phases of the cardiac cycle?

A
  1. Atrial contraction phase
  2. Isovolumetic contraction phase
  3. Rapid ejection phase
  4. Reduced ejection phase
  5. Isovolumetric relaxation phase
  6. Rapid filling phase
  7. Reduced filling phase
46
Q

What are the detailed phases of the cardiac cycle?

A
  1. Atrial systole: where arterial contraction begins and AV valves are still open since the end of the previous cycle.
  2. Atria eject blood into ventricles: where filling ventricles happens.
  3. Atrial systole ends: where AV nodes close and ventricles contain maximum volume = end-diastolic volume (EDV).
  4. Ventricular systole (isovolumetric contraction): where pressure in the ventricles rises and all heart valves are closed.
  5. Ventricular ejection: where semilunar valves open and stroke volume (SV) = 60% of EDV.
  6. Ventricular pressure falls: semilunar valves close and ventricles contain minimum volume = end-systolic volume (ESV), about 40% of EDV.
  7. Ventricular diastole (isovolumetric relaxation): ventricular pressure is higher than atrial pressure and all heart valves are closed.
  8. Atrial pressures becomes higher than ventricular pressure: AV valves open, passive ventricular filling, passive trial emptying, and cardiac cycle ends.
47
Q

What are the heart sounds?

A

S1: Loud sound is the closure of AV valves.
S2: Loud sound is the closure of semilunar valves.
S3: Soft sound is the blood flow into ventricles.
S4: Soft sound is the atrial contraction and is a pathological sound.

48
Q

What are heart murmurs?

A

Turbulent sounds are produced by disturbances in blood flow through valves due to regurgitation or stenosis.

49
Q

Where does the energy of heart come from?

A

It is an aerobic process that comes from mitochondrial breakdown of fatty acids and glucose. Oxygen comes from circulating hemoglobin and cardiac muscles store oxygen in myoglobin.

50
Q

What is autonomic innervation of the heart?

A
  • Sympathetic and parasympathetic nerve supply through cardiac plexuses.
  • Cardiac centres in the medulla oblongata:
    • Cardioacceleratory center controls the sympathetic nervous and raises heart rate.
    • Cardioinhibitory center controls parasympathetic neurons decrease heart rate.
    • Monitor cardiac reflexes:
      • baroreceptors (blood pressure)
      • chemoreceptors (arterial O2 and CO2)
  • Sympathetic innervation supplies both atrial and ventricles.
  • Parasympathetic innervation happens through vagus nerves and supply the atrial only.
  • Autonomic tone has dual innervation and maintains resting tone by releasing Ach and NE with fine adjustments that meet the needs of other systems.
51
Q

What are cardiodynamics?

A
  • End-diastolic volume (EDV) = +/- 120 ml
    • Blood volume in ventricles at the end of diastole
  • End-systolic volume (ESV) = +/- 50 ml
    • Blood volume in ventricles at the end of systole
  • Stoke volume (SV) = +/- 70 ml
    • Volume of blood ejected per beat
    • EDV - ESV
  • Ejection fraction (Ef) >50%
    • Percentage of blood ejected from a ventricle with each beat.
    • = SV / EDV * 100
52
Q

What is preload and after load?

A

Preload is ventricular stretching during diastole. It is determined by venous return (VR) where blood flows back to the heart.
Afterload is force produced by the ventricle to eject blood. It is determined by peripheral resistance (PR) and is the resistance of the arteries to blood flow.

53
Q

What is cardiac output (CO) and what controls it?

A
  • It is the blood volume ejected by a ventricle in one minute.
  • Heart rate affects it by adjusted by ANS or hormones.
  • Stoke volume affects this by adjusting by changing EDV or ESV?
54
Q

What are factors that control heart rate?

A

The autonomic nervous system:
- Sympathetic increases and heart rate increases
- Parasympathetic increase and heart rate decreases

Hormones
- Hormones increase heart rate
- E, NE, and thyroid hormones

Venous return (VR)
- VR increases and heart rate increases

55
Q

What are factors that control stroke volume?

A

EDV increases filling time and venous return causing the preload to increase.
ESV by preload, contractility, and after load.

56
Q

What is the bainbridge (atrial) reflex?

A

It is an increase in heart rate due to an increase in central venous pressure (CVP) and it adjusts heart rate in response to venous return (VR). The mechanisms are when VR increases, right atrial pressure increases and stretch receptors in right atrium increases and sympathetic activity increases and heart rate increases.

57
Q

What is Starling Law?

A

Within limits, the force of cardiac muscle contraction is proportional to its initial length. Mechanism are as the VR increases the EDV increases and cardiac muscles length and myocardial contractility increases and stoke volume increases.

58
Q

What is cardiac reserve?

A

The difference between resting and maximal cardiac output.
Most health people can increase cardiac output by 300-500%.

59
Q

What is heart failure?

A

The inability of the heart to pump sufficient quantities of blood to meet the requirements of hte body tissues. The lack of adequate blood flow to peripheral tissues and organs due to ventricular damage.