Cardiovascular Anatomy Flashcards
1
Q
What are the three main components of the cardiovascular system?
A
The heart, blood, and blood vessels.
2
Q
What are the 6 primary functions of the cardiovascular system?
A
- Deliver oxygen to all cells
- Return blood to the lungs for reoxygenation
- Remove waste products of cellular metabolism
- Transport nutrients, electrolytes, and hormones
- Maintain body temperature, fluid balance, and acid-base balance
- Prevent infection by invading organisms
These functions ensure adequate blood flow to all tissues.
3
Q
What is the outer layer of the heart
A
Epicardium
4
Q
What is the loose fitting bag of connective tissue which surrounds the heart
A
Pericardium
5
Q
What is the main muscle bulk of the heart
A
Myocardium
Myo = muscle. Cardium = Heart
6
Q
What is the inner layer of the heart which also forms the valves
A
Endocardium
7
Q
What percentage of the heart’s mass is made up of myocardium?
A
75%.
8
Q
What is the function of the pericardium?
A
It surrounds the heart and contains pericardial fluid to reduce friction during contractions.
9
Q
What are the names of the four chambers of the heart?
A
Right atrium, left atrium, right ventricle, and left ventricle.
10
Q
What is the role of the atrioventricular valves?
A
They ensure a one-way flow of blood from the atria to the ventricles.
11
Q
What are the names of the atrioventricular valves?
A
Tricuspid valve (right) and mitral valve (left).
12
Q
What are the semilunar valves?
A
The pulmonary valve and aortic valve.
13
Q
What is the function of the semilunar valves?
A
They permit blood flow into the arteries during ventricular contraction and prevent backflow during relaxation.
14
Q
What is happening in the heart during systole?
A
The ventricles are contracting
15
Q
During Diastole, what stops backflow into the ventricles
A
The semilunar valves close
16
Q
Why is the myocardium thicker in the left ventricle than in the right ventricle?
A
The left ventricle has to exert considerable force to eject blood into the high-pressure arterial system.
17
Q
What is the approximate pressure in the left ventricle during rest?
A
120 mmHg.
18
Q
What is the approximate pressure in the right ventricle during rest?
A
25 mmHg.
19
Q
What cells make up the bulk of the myocardium?
A
Contractile cells (myocytes).
20
Q
What structural feature do myocardial muscle cells have in common with skeletal muscle?
A
They are made up of striated fibres.
21
Q
What is unique about the contractile cells in the myocardium compared to skeletal muscle fibres?
A
They are short, branched, and interconnected, acting as a single unit.
22
Q
What are the differences in oxygen uptake between skeletal and cardiac muscle?
A
Skeletal muscle only extracts about 25% of the oxygen from the blood it recieves. They can generate ATP anerobically.
Cardiac muscle extracts 70% of oxygen from the coronary arteries when the body is at rest. It relies almost exclusively on energy released in aerobic reactions
23
Q
Describe he four main coronary arteries
A
- Left main stem
- Circumflex artery
- Left anterior desceding
- Right coronary artery
They arise from the aorta. 2 and 3 supply left side of the heart. 4 supp
24
Q
Which are the main resistance vessles with predominance of smooth muscle in media so can constrict and dilate?
A
Arterioles
25
What vessles have a predominance of elastin in media to withstand high pressure?
Arteries
26
Which vessles have valves to prevent backflow?
Veins
27
Which vessles have very thin walls to allow gas exchange
Capilaries
28
What are endothelial cells?
Endothelial cells form a single-celled layer of the inner part (trunica intima) of the whole of the cardiovascular system
29
What is the protein present i the plasma in blood that plays a key role in entangling blood cells to form a clot?
Fibrinogen
30
What is the main difference between the pumonary and systemic cirulations?
The systemic circulation is a high pressre system (BP 120 mmHg) and offers more resistance to blood flow causing a thicker ventrical wall (8-10mm). Pulmonary system is a low pressure system (25 mmHg) and has a right ventricular wall of only 2-3mm thick as a result.
31
What 3 mechanisms aid venous return to the right side of the heart?
1. Valves in veins
2. Skeletal muscle has a massaging action on the veins
3. The Respiratory Pump
| 3. Pressure difference between the thorax and the abdomen which helps to
32
What is the cardiac cycle? Name the two phases
1. Systole (contraction)
2. Diastole (relaxation)
33
Ventricles recieve about 80% of their eventual blood volume passively before atrial contraction takes place. T or F?
True
34
During which stage of the cardiac cycle do the arteries fill?
Diastole
35
What is the function of the heart's electrical system?
It generates and conducts electrical impulses that coordinate heart contractions.
36
True or False: The electrical resistance between contractile cells in the myocardium is high.
False.
## Footnote
Electrical impulses spread quickly
37
Fill in the blank: The heart's apex points downward towards the _______.
diaphragm.
38
What separates the left and right sides of the heart?
The septum.
39
What principle applies to a single motor unit in skeletal muscle?
The all-or-none principle
40
What allows for synchronized contraction of the myocardium?
The interconnectedness of the myocardial cells acting as a single motor unit
41
Where is the impulse for heart contraction generated?
In the sinoatrial node
42
What is the location of the sinoatrial node?
In the posterior wall of the right atrium
43
What is the function of the atrioventricular node?
Conducts the impulse from the atria into the ventricles
44
Where is the atrioventricular node located?
In the right atrial wall near the centre of the heart
45
Which layer of the heart is directly nourished by the blood flowing through the heart's chambers?
The endocardium
46
How do myocardial cells receive their blood supply?
Via arteries that branch off the aorta
47
What are the four main coronory arteries called?
The right coronary artery (RCA) and the left main coronary artery (LMCA). The LMCA further branches into the left anterior descending artery (LAD) and the circumflex artery.
48
Which coronory arteries supply blood to the main part of the left ventricle?
Left Anterior descending artery and the circumflex artery
49
From where do the right and left coronary arteries arise?
From the base of the aorta, immediately above the cusps of the aortic valve
50
What valve is located between the right atrium and right ventricle?
Tricuspid valve
51
What structure prevents backflow into the ventricles during contraction?
Papillary muscles
52
What is the name of the valve located between the left atrium and left ventricle?
Bicuspid (mitral) valve
53
What is the function of the chordae tendinae?
To anchor the valves and prevent backflow
54
What separates the left and right ventricles?
Interventricular septum
55
Which artery supplies blood to the right ventricle?
The right coronary artery
## Footnote
It also supplies part of the posterior left ventricle.
56
What is the role of coronary arteries?
To deliver oxygen and nutrients to the myocardium and remove metabolic waste products
## Footnote
They form a dense network of capillaries on the surface of the heart.
57
How does deoxygenated blood leave the left ventricle?
Via a number of veins collected in the coronary sinus, which drains into the right atrium
58
The right ventricle's deoxygenated blood leaves through which vein?
The anterior cardiac vein.
## Footnote
Which drains directly into the right atrium
59
What are the components of the vascular system?
Arteries, arterioles, capillaries, venules, and veins
## Footnote
Arteries and arterioles are high-pressure distribution vessels, capillaries are exchange vessels, and venules and veins are low-pressure collection and return vessels.
60
What are the three layers of blood vessel walls?
Tunica adventitia, tunica media, and tunica intima
## Footnote
The tunica adventitia is mainly tough connective tissue, the tunica media is mainly smooth muscle, and the tunica intima consists of endothelial cells.
61
What are endothelial cells?
They are a single cell layer that makes up the inner part of the whole of the cardiovascular system
62
What is the function of endothelial cells?
They provide a lining to the heart and blood vessels, secrete agents for vasodilation and vasoconstriction, release anti-clotting molecules, and inhibit smooth muscle cell proliferation and migration
## Footnote
Endothelial cells line all structures in the cardiovascular system.
63
What happens when the endothelial lining of coronary arteries is damaged?
It inhibits the functions of endothelial cells and results in the development of atherosclerotic plaque
64
What helps the aorta and other large arteries send blood to the organs?
They contain elastin fibres and can stretch under pressure during systole, then recoil to drive blood into smaller arteries and arterioles during diastole
## Footnote
We feel it as a pulse
65
Blood passes through the pulmonary valve into which three places
Pulmonary artery, to lungs then capilaries in the lungs to absorb oxygen
66
Which arteries are less elastic and provide the greatest resistance to flow?
Smaller arteries and arterioles
## Footnote
Their narrow lumina are less affected by pressure changes during systole and diastole.
67
What is vasodilation?
The relaxation of smooth muscle, increasing the vessel lumen and flow
## Footnote
This occurs in smaller arteries and arterioles.
68
What is vasoconstriction?
The contraction of smooth muscle, reducing the vessel lumen and flow
## Footnote
This process is crucial for regulating blood distribution in the body.
69
True or False: The distribution of blood around the body is determined by arteriolar smooth muscle activity.
True
## Footnote
The extent of smooth muscle activity in organs and tissues influences blood flow.
70
What are capillaries not capable of?
Vasoconstriction or vasodilation
## Footnote
Capillaries depend on arteriolar activity for blood flow regulation.
71
What do arteriolar vasodilation and vasoconstriction affect?
Capillary flow
## Footnote
Vasodilation increases flow, while vasoconstriction decreases flow.
72
What is the composition of capillary walls?
A single layer of endothelial cells
## Footnote
This structure allows for rapid transport of oxygen and nutrients.
73
What do capillaries lack that other vessles have?
Smooth muscle and connective tissue
## Footnote
this means oxygen can flow rapidly between capillaries
74
What type of blood do capillaries feed into venules?
Deoxygenated blood
## Footnote
Blood is deoxygenated because oxygen has been taken up by active tissues.
75
How do veins and venules compare to arteries and arterioles?
They are relatively flaccid and more compliant
76
Most of the blood in the body is contained within the arteries.True or False?
False
## Footnote
Most of the blood in the body is contained within the veins.
77
What role do smooth muscles play in the venous system?
They alter the volume and pressure within veins using vasoconstriction
78
What function do valves in peripheral veins serve?
They allow blood to flow towards the heart and prevent backflow
## Footnote
Valves ensure unidirectional blood flow.
79
Fill in the blank: Capillaries end in a network of tiny vessels called _______.
Venules
## Footnote
Deoxygenated blood flows from capillaries into the tiny veins called venules
80
What are metarterioles?
Less muscular vessels that branch from arterioles
## Footnote
They lead to capillary networks.
81
True or False: Capillaries have smooth muscle and connective tissue in their walls.
False
## Footnote
The absence of these tissues allows for rapid transport.
82
What percentage of blood volume is plasma?
55 - 60%
## Footnote
Plasma consists of approximately 90% water, 7% plasma proteins, and 3% other substances.
83
Plasma contains 3% of what six substances?
1. Nutrients
2. Electrolytes
3. Enzymes
4. Hormones
5. Antibodies
6. Metabolic by-products
84
What are the main components of formed elements in blood?
>99% red blood cells, <1% white blood cells and platelets
85
Red blood cells are called...?
Erythrocytes
86
What are Leucocytes?
White blood cells
87
What is another name for platelets?
Thrombocytes
## Footnote
A blood clot is called a Thrombus
88
Red blood cells are comprised of which two elements?
Haem (pigment) and Globin (protein)
89
What does haemoglobin need to bind with oxygen?
Iron
90
What is haemotocrit?
The percentage of total blood volume that is erythrocytes
91
What is a normal haematocrit level for a woman?
42%
## Footnote
For a man, it's 45%
92
Is it true that increased fibrinogen levels decrease the propensity for blood to clot?
No
93
What are the three potential dangers of high propensity for forming blood clots?
1. Stroke
2. Heart Attack
3. Perepheral Arterial Disease (PAD)
94
What is the primary fluid contained within cells?
Intracellular fluid
## Footnote
Approximately two-thirds of total body water is intracellular fluid.
95
Where is extracellular fluid distributed?
Between tissues (interstitial fluid) and blood plasma
## Footnote
Extracellular fluid constitutes one-third of total body water.
96
What two conditions drives the exchange of fluid between blood plasma and interstitial fluid?
Differences in pressure of the blood in the capillaries and the concentration of substances like glucose contained in the plasma
## Footnote
Fluid moves out of or into the capillary based on these differences.
97
What is oedema?
Excessive accumulation of interstitial fluid
## Footnote
Oedema is often evident as swelling, such as swollen ankles. Can be caused by high blood pressure
98
What are the primary functions of the cardiovascular system?
* Deliver oxygen to all cells
* Return blood to the lungs for reoxygenation
* Remove waste products of cellular metabolism
* Transport nutrients, electrolytes, and hormones
* Maintain body temperature, fluid balance, and acid-base balance
* Prevent infection by invading organisms
## Footnote
These functions ensure adequate blood flow to all tissues.
