Cardiovascular Anatomy Flashcards
1
Q
What is the pump of the systemic circuit?
A
left ventricle
2
Q
What percent of the total blood volume is in the systemic circuit?
A
85%
3
Q
What percent of the total blood volume is contained in the ventricles?
A
7%
4
Q
How many chambers are there?
A
4 (2 atria, 2 ventricles)
5
Q
What are the veins that enter the right atrium?
A
superior vena cava, inferior vena cava, coronary sinus
6
Q
Veins carry blood…
A
to the heart
7
Q
Arteries carry blood…
A
away from the heart
8
Q
What are the muscle ridges inside the ventricles called?
A
Trabeculae Carnae
9
Q
How many veins enter the left atrium, and what are their name?
A
4 pulmonary veins
10
Q
What does the pulmonary trunk do?
A
Carry blood to the lungs through the left and right pulmonary arteries
11
Q
What do the pulmonary veins do?
A
Carry oxygenated blood from the lungs to the left atrium
12
Q
What do the coronary arteries do?
A
supply blood to the heart
13
Q
The inlet valves are closed when…
A
the pressure is higher inside the ventricle than the atrium
14
Q
The inlet valves are open when…
A
the pressure inside the atrium is higher than the ventricles
15
Q
What are the 2 inlet valves?
A
Tricuspid & mitral
16
Q
What are the 2 outlet valves?
A
Pulmonary & aortic
17
Q
The outlet valves are open when…
A
the pressure inside the ventricles is higher than the arteries
18
Q
The outlet valves are closed when
A
the pressure inside the ventricles is lower than the arteries
19
Q
Total blood volume in average person is…
A
5L
20
Q
How many litres of blood does each ventricle pump per min?
A
5L
21
Q
What are the venous veins which travel between organ capillary beds called?
A
Portal veins
22
Q
What is the vein between the gut and liver called?
A
Hepatic portal vein
23
Q
Why is heart surgery rarely done via posterior entry?
A
Damage to the spinal cord
24
Q
What is the sulcus of the heart called?
A
Interventricular Sulcus (anterior/posterior)
25
Describe the walls of the right atrium.
Inside posterior wall is smooth
Inside anterior wall is rough due to pectinate muscles
26
Describe the walls of the left atrium.
Inside walls (both posterior and anterior) are smooth as the pectinate muscles are confined to the left auricle.
27
What is the thickest chamber of the heart?
Left ventricle
28
How many ml of blood do the ventricles contain when full?
~120ml
29
How many ml of blood do the ventricles contain after contraction?
~60ml
30
What are the 2 largest veins in the body?
Superior and inferior vena cava
31
What is the fibrous skeleton made of?
Dense connective tissue
32
What valve does the fibrous skeleton not attach to?
Pulmonary valve
33
Papillary muscles are contracting when...
the mitral and tricuspid valves are closing
34
Why is it good that the atria and ventricles do not contract at the same time?
The inlet valves would be forced closed as the ventricles are stronger than the atria and blood would therefore not enter the heart.
35
What is the name of the muscle wall between the ventricles?
Interventricular septum
36
What is the name of the muscle wall between the atria?
Interatrial septum
37
Describe the pathway of electrical conduction in the heart.
Sinoatrial node -> atrial muscle -> atrioventricular node -> atrioventricular bundle (of His) -> purkinje fibres inside ventricle wall
38
What is systole?
Contraction
39
What is diastole?
Filling
40
From where do the coronary arteries arise?
Ascending aorta, downstream of the aortic valve
41
Where is the SA node located?
In the right atrial wall near the opening of the superior vena cava
42
What is the first heart sound (lupp) created by?
Closing of the atrioventricular valves
43
What is the second heart sound (dub) created by?
Closing of the semilunar valves
44
What is angina?
Chest pain
45
What is myocardial infarction?
Heart attack
46
What is atrial fibrillation?
Atrial flutter - not full contraction of the atria
47
What is the role of the papillary muscles?
Tighten the chordae tendineae during contraction
48
What is the role of the chordae tendineae?
Keep the atrioventricular valves shut/prevent eversion during ventricular ejection/systole
49
What are the layers of the heart wall in order from inner to outer?
Endocardium -> myocardium -> epicardium/visceral pericardium -> pericardial space (filled with serous fluid) -> parietal pericardium -> fibrous pericadium
50
What is the myocardium made of?
Cardiac muscle
51
What initiates a heartbeat?
Sinoatrial (SA) node
52
What comprises the apex of the heart?
Tip of the left ventricle
53
What forms the right border of the heart?
Right atrium
54
What forms the inferior border of the heart?
Right ventricle
55
What forms the left border of the heart?
Left ventricle (and partly left atria & auricle)
56
What forms the superior border of the heart?
Left atrium (and part of the right atrium)
57
What is the shape of the right ventricle in cross-section?
Crescent
58
The aortic valve sits ________ to the pulmonary trunk.
Posterior
59
What valves are the largest?
The inlet valves (atrioventricular - tricuspid & mitral)
60
When do atrioventricular valves open?
When pressure in the ventricles falls below atrial pressure
61
When are all heart valves closed?
Isovolumetric ventricular contraction & relaxation (for a split second)
62
What is the left ventricle: right ventricle peak pressure ratio?
5:1
63
What is the left ventricle: right ventricle wall thickness ratio?
3:1
64
What part of the conduction system conducts the slowest?
Fibres of the AV node
65
What part of the conduction system conducts the fastest?
AV bundle -> Purkinje fibres
66
What stimulates the atria to contract?
SA node
67
Where is the SA node located?
In the right atrial wall near the opening of the superior vena cava.
68
What is the coronary sinus?
Major coronary vein which cardiac veins drain into
69
Where is the coronary sinus located?
In the coronary sulcus on the posterior surface of the heart
70
Why do the semilunar valves lack chordae tendineae?
When closed, the cusps remain stable because of their cup shape.
71
Where does blood from the pulmonary veins flow into?
Left atrium
72
What is the pericardial space normally filled with?
Serous fluid
73
Where is the mitral valve located?
Between the left atrium and the left ventricle
74
Where is the aortic valve located?
Between the left ventricle and aorta
75
Where is the pulmonary valve located?
Between the right ventricle and the pulmonary trunk
76
Where is the tricuspid valve located?
Between the right atrium and the right ventricle
77
Where does the blood from the vena cava veins flow into?
Right atrium
78
Describe the structure of coronary arteries.
Small muscular arteries, matchstick size
79
What is the innermost layer of blood vessels called?
Tunica intima
80
What is the middle layer of blood vessel walls called?
Tunica media
81
What is the outer layer of blood vessel walls called?
Tunica externa
82
What 2 types of blood vessels only have a tunica externa?
Arterioles & venules
83
What type of blood vessel has only endothelium?
Capillary
84
What are the 6 main types of blood vessels?
Elastic arteries, muscular arteries, arterioles, capillaries, venules, veins
85
Elastic artery walls comprise what percentage of their diameter?
10%
86
What is the largest type of blood vessel?
Elastic arteries
87
Where are elastic arteries found?
Near the heart
88
What do elastic arteries contain in their tunica media
Many thin sheets of elastin
89
What do muscular arteries contain in there tunica media
Many layers of smooth muscle
90
Muscular artery walls comprise what percentage of their diameter?
25%
91
What do Arterioles do?
Control the flow of blood between arteries and capillaries, prevent high pressures flowing into capillaries and direct flow to capillaries that need it.
92
What blood vessels have the largest pressure drop?
Arterioles
93
Structure of arteriole walls
1-3 layers of circular smooth muscle in tunica media
94
Arteriole walls comprise what percentage of their diameter?
50%
95
What blood vessels have the largest wall thickness: total diameter ratio?
Arterioles
96
What is the purpose of capillaries?
Allow the exchange of nutrients, gases and waste between blood and surrounding tissue
97
Is blood flow through capillaries fast or slow?
Slow
98
How wide are capillaries?
1 RBC wide
99
Describe the structure of capillaries
A single layer of endothelium
100
What is a capillary bed?
A network of capillaries belonging to a system
101
What is the function of venules?
Low pressure vessels which drain capillary beds, allow for WBC extravasation, exchange of materials
102
What is the structure of venules?
A single layer of endothelial cells with some smooth muscle and connective tissue.
103
What is the function of veins?
Drain deoxygenated blood away from tissues and back to the heart, a giant reservoir for storing blood
104
What percentage of systemic blood is found in veins?
75%
105
What percentage of total blood is found in veins?
64%
106
Describe the structure of veins
Thin-walled, floppy, low pressure & high volume. Less smooth muscle & connective tissue than arteries, some contain bicuspid valves.
107
Are veins or arteries more numerous?
Veins
108
What are venous sinus veins?
Veins in the brain with thin endothelial walls with no smooth muscle. Surrounding dense connective tissue provides support and alters diameter.
109
What are the valves in veins made of?
Tunica interna
110
What class of blood vessels are coronary arteries?
Muscular arteries
111
Where do the coronary arteries arise from?
Downstream of the aortic valve in the ascending aorta
112
What is the size of the lumen in coronary arteries?
2-4mm
113
What is angina?
Chest pain
114
What is atheroma/arteriosclerosis?
Degradation of arteries due to build-up of fatty substance
115
What is low oxygen supply known as?
Ischemia
116
What is an anastomosis?
Junction between 2 blood vessels
117
How wide are RBC?
9µm (microns)
118
What is the size of arterioles comparable to?
A hair
119
What is the size of muscular arteries comparable to?
pencil to pin-sized
120
What is the smooth muscle in blood vessels under the influence of?
Autonomic nervous system
121
What drives plasma out of capillaries?
Hydrostatic pressure
122
What is the size of the coronary arteries comparable to?
A matchstick
123
Where does the left coronary artery run?
Down the interventricular septum
123
Where does the right coronary artery run?
To the posterior of the heart
124
What causes the 'lup' sound?
Closing of the atrioventricular valves
125
What causes the 'dup' sound?
Closing of the semilunar valves (first aortic then pulmonary)
126
Approximately how long are the isovolumetric phases in the cardiac cycle?
0.05 seconds
127
What is the longest phase in the cardiac cycle?
Filling, approximately 50% of cycle
128
What is the normal aortic peak pressure?
120mmHg
129
What is the normal aortic lowest pressure?
80mmHg
130
What is the peak pressure of the left ventricle?
120mmHg
131
What is the peak pressure of the right ventricle?
27mmHg
132
What is the peak pressure of the left atria?
8mmHg
133
What is the peak pressure of the right atria?
5mmHg
134
What percentage of the thoracic cavity should the heart never exceed?
50%
135
What is the anatomical region in which the heart lies?
Mediastinum
136
What are the layers of the heart wall in order from inside to outside?
Endocardium, myocardium, epicardium
137
What are the layers of the pericardium, from inside to outside?
Visceral pericardium, pericardial space, parietal pericardium, fibrous pericardium
138
What are the walls of the pericardium made of?
Single layer of squamous mesothelial cells
139
What is the purpose of the pericardium?
Prevent friction between the heart and surrounding organs/structures
140
What does the epicardium contain?
Blood vessels and lymphatic vessels which supply the myocardium
141
What is the function of the fibrous pericardium?
Protection, anchors the heart in the mediastinum and prevents overstretching
141
What is the fibrous pericardium made of?
Tough, inelastic, dense, irregular connective tissue.
142
What is it called when there is fluid leaking into the pericardial space?
Cardiac Tamponade
143
What class of blood vessels has the thickest wall relative to its size?
Arterioles
144
Which class of blood vessels is responsible for channelling the bulk flow of blood to different organ systems?
Muscular arteries
145
What is the fibrous skeleton made of?
Dense fibrous connective tissue
146
Describe the way in which the Apex of the heart points
Inferiorly, anteriorly and to the left
147
What percentage of total blood is in the pulmonary vessels?
9%
148
What percentage of total blood is in the systemic arteries and arterioles?
13%
148
What is the intrinsic HR of the SA node?
~100 BPM
148
What is the intrinsic HR of the AV node?
~ 50 BPM
149
How long is the delay in the AV node?
100ms
