Cardiovascular - The Cardiovascular System Flashcards
1
Q
What is the role of the cardiovascular system?
A
The blood circulatory system is a system of organs that includes the heart, blood vessels, and blood which is circulated throughout the entire body
2
Q
What do veins, arteries and capillaries do?
A
Veins - collect deoxygenated blood and return it to heart
Arteries - take oxygenated blood from the heart and send it to the body
Capillaries - exchange nutrients
3
Q
What are the two main circulations?
A
Pulmonary - heart-lungs-heart
Systemic - heart-body-heart
4
Q
Where is the heart located?
A
Within the middle mediastinum
2/3 of mass on the LHS of the sternum
5
Q
What is anterior to the heart?
A
Sternum and costal cartilages 4-7
6
Q
What is posterior to the heart?
A
Oesophagus and descending aorta
Vertebrae T5-T8
7
Q
What is lateral to the heart?
A
Pleura and phrenic nerves
8
Q
What is inferior to the heart?
A
Central tendon of the diaphragm
9
Q
What ribs does the heart lie behind?
A
2nd rib -> 5th rib midclavicular line
10
Q
What is the pericardium?
A
The pericardium is a double walled fibrous sac that encloses the heart and great vessels.
11
Q
What are the layers of the pericardium?
A
Fibrous pericardium
Serous pericardium
12
Q
What is the fibrous pericardium made of?
A
Tough dense connective tissue
13
Q
What is the role of the fibrous pericardium?
A
Protects the heart
Prevents overfilling of the heart
Anchors heart to surrounding structures
14
Q
What are the layers of the serous pericardium?
A
Outer parietal layer that lines the internal surface of the fibrous pericardium and the Internal visceral layer that forms the outer layer of the heart (also known as the epicardium)
15
Q
What is found between the inner and outer layer of the serous pericardium an what is its role?
A
Pericardial cavity, which contains a small amount of lubricating serous fluid.
The serous fluid serves to minimize the friction generated by the heart as it contracts.
16
Q
Summarise the layers of the pericardium
A
F – Fibrous layer of the pericardium
P – Parietal layer of the serous pericardium
S – Serous fluid
V – Visceral layer of the serous pericardium
17
Q
What provides innervation to the pericardium?
A
Phrenic nerve - C3-C5
18
Q
What are the three layers of the heart wall?
A
The endocardium, myocardium, and epicardium.
19
Q
What does the endocardium line?
A
Cavities and valves of the heart
20
Q
What is the role of the endocardium?
A
Regulates contractions and aids cardiac embryological development.
Prevents clotting of blood within heart
Forms a barrier between O2 hungry myocardium and the blood (blood is supplied via coronary system)
21
Q
What is the endocardium made of?
A
Loose connective tissue and simple squamous epithelial tissue
22
Q
What lies between and joins the endocardium and the myocardium?
A
Subendocardial layer
23
Q
What is the myocardium composed of?
A
The myocardium is composed of cardiac muscle and is an involuntary striated muscle. The myocardium is responsible for contractions of the heart.
24
Q
What layer lies between and joins the myocardium and epicardium?
A
Subepicardial layer
25
What is the epicardium?
The epicardium is the outermost layer of the heart, formed by the visceral layer of the pericardium.
26
How many borders does the heart have?
Four
27
What are the four borders of the herat?
Right border – Right atrium
Inferior border – Left ventricle and right ventricle
Left border – Left ventricle (and some of the left atrium)
Superior border – Right and left atrium and the great vessels
28
How many surfaces does the heart have?
Three
29
What are the three surfaces of the heart?
Anterior (or sternocostal) – 1/3 RA, 2/3 RV +LV.
Posterior (or base) – Left atrium.
Inferior (or diaphragmatic) – Left and right ventricles.
30
What is the base of the heart?
Wholly posterior - left atrium
31
What is the apex of the heart?
5th intercostal space in the midclavicular line
Left ventricle
32
What forms the right border of the heart?
Right atrium
33
What forms the left border of the heart?
Left ventricle
34
What forms the anterior surface of the heart?
RA + 1/3 RV + 2/3 LV
35
How many valves does the heart have?
Four
36
What are the two categories of heart valves?
Atrioventricular valves (cuspid)
Semilunar valves
37
What valves are the atrioventricular valves?
The tricuspid valve and mitral (bicuspid) valve
38
Where are the atrioventricular valves found?
They are located between the atria and corresponding ventricle.
39
What is the function of the atrioventricular valves?
Prevent the backflow of blood into the atria during ventricular contraction
40
What supports the atrioventricular valves?
Attachment of fibrous cords (chordae tendineae) to the free edges of the valve cusps.
The chordae tendineae are attached to papillary muscles, located on the interior surface of the ventricles – these muscles contract during ventricular systole to prevent prolapse of the valve leaflets into the atria.
41
What valves are the semilunar valves?
Pulmonary and aortic valves
42
What is the difference between the atrioventricular and semilunar valves?
The mitral and tricuspid atrioventricular (AV) valves separate the atria from the ventricles, while the aortic and pulmonary semilunar (SL) valves separate the ventricles from the great arteries.
43
What is the function of the semilunar valves?
Semilunar valves prevent backflow from the great vessels to the ventricles.
44
When do atrioventricular valves close and what do they create?
They close during the start of ventricular contraction (systole), producing the first heart sound.
45
When do semilunar valves close and what do they create?
They close at the beginning of ventricular relaxation (diastole), producing the second heart sounds.
46
Where can the pulmonary valve be found?
Between RV and pulmonary trunk
47
Where can the aortic valve be found?
Between LV and aortic arch
48
What is the largest artery in the body?
The aorta
49
What is the role of the aorta?
Carry oxygenated blood (pumped by the left side of the heart) to the rest of the body.
50
Where does the aorta arise from?
Aortic orifice at the base of the left ventricle, with inflow via the aortic valve
51
What are the segments of the aorta?
Aortic root
Ascending segment
Aortic arch
Descending segment
Abdominal aorta
52
Where do the coronary arteries arise from?
Ascending aorta
There is a right and left coronary artery
53
What arises from the aortic arch?
Brachiocephalic trunk
Left common carotid artery
Left subclavian artery
54
What does the brachiocephalic branch further divide into?
Right common carotid artery
Right subclavian artery
55
What is the role of pulmonary arteries?
The pulmonary arteries receive deoxygenated blood from the right ventricle and deliver it to the lungs for gas exchange to take place.
56
What do the pulmonary arteries start off as and when do they become the pulmonary arteries?
The arteries begin as the pulmonary trunk, a thick and short vessel, which is separated from the right ventricle by the pulmonary valve.
At around the level of T5-T6, the pulmonary trunk splits into the right and left pulmonary arteries.
57
What do the left and right pulmonary arteries supply?
The left pulmonary artery - blood to the left lung, bifurcating into two branches to supply each lobe of the lung.
The right pulmonary artery - blood to the right lung. It also further divides into two branches.
58
How do the left and right pulmonary arteries differ?
The right pulmonary artery is the thicker and longer artery.
59
What is the role of the pulmonary veins?
The pulmonary veins receive oxygenated blood from the lungs, delivering it to the left side of the heart to be pumped back around the body.
60
How many pulmonary veins are there?
There are four pulmonary veins, with one superior and one inferior for each of the lungs.
61
What is the role of the superior vena cava?
Receives deoxygenated blood from the upper body (superior to the diaphragm, excluding the lungs and heart), delivering it to the right atrium.
62
What forms the superior vena cava?
Merging of the brachiocephalic veins, travelling inferiorly through the thoracic region until draining into the superior portion of the right atrium at the level of the 3rd rib.
63
What is the role of the inferior vena cava?
Receives deoxygenated blood from the lower body (all structures inferior to the diaphragm), delivering it back to the heart
64
How is the inferior vena cava formed?
In the pelvis by the common iliac veins joining together. It travels through the abdomen, collecting blood from the hepatic, lumbar, gonadal, renal and phrenic veins.
The inferior vena cava then passes through the diaphragm, entering the pericardium at the level of T8. It drains into the inferior portion of the right atrium.
65
How many coronary arteries are there?
Left and right coronary arteries
66
Where do the coronary arteries arise from?
Left and right aortic sinuses of the ascending aorta
67
Where does the left coronary artery run in?
Coronary sulcus
68
What does the left coronary artery divide into?
Left anterior descending (LAD), also called the anterior interventricular artery.
The LCA gives off the left marginal artery (LMA) and the left circumflex artery (Cx).
69
Where does the right coronary artery run?
Coronary (atrioventricular) sulcus
70
What does the right coronary artery branch off into?
The right marginal artery (RMA) anteriorly
71
What does the left circumflex artery supply?
Left atrium and left ventricle
72
What does the left descending artery supply?
Right ventricle, left ventricle. and intraventricular septum
73
What does the left marginal artery supply?
Left ventricle
74
What does the right marginal artery supply?
Right ventricle and apex
75
What does the right coronary artery supply?
Right atrium and right ventricle
76
What is the function of coronary arteries?
Supply heart with blood
77
What is the function of cardiac veins?
Drain deoxygenated blood from the myocardium into the cardiac chambers
78
What are the main cardiac veins?
Great cardiac vein
Small cardiac vein
Middle cardiac vein (posterior interventricular vein)
Posterior cardiac vein
79
Where can the great cardiac vein be found?
Lies alongside anterior atrioventricular artery
80
Where does the great cardiac vein drain from and to?
From: Small venules of the apex of heart
To: Coronary sinus
81
Where does the great cardiac vein arise from?
The anterior interventricular vein becomes the great cardiac vein once it has left the anterior interventricular sulcus and has entered the coronary sulcus.
82
Where does the great cardiac vein originate from and where does it go?
Apex of the heart and ascends in the anterior interventricular groove.
It then curves to the left and continues onto the posterior surface of the heart.
Here, it gradually enlarges to form the coronary sinus.
83
What is the coronary sinus?
A large venous structure located on the posterior aspect of the left atrium, coursing within the left atrioventricular groove
84
What is the function of the coronary sinus?
Drain the venous blood from the majority of the heart
85
Where does the coronary sinus drain to?
Right atrium
86
Where can the middle cardiac vein be found?
Begins at the apex of the heart and ascends in the posterior interventricular groove to empty into the coronary sinus
87
Where can the small cardiac vein be found?
Along right inferior margin
88
Where do the great, middle and small cardiac vein drain into?
Coronary sinus that lies alongside the circumflex artery
Coronary sinus drains into the right atrium
89
Where do anterior cardiac veins drain into?
Directly into right atrium
90
What does the phrenic nerve innervate?
Fibrous pericardium and parietal layer of serous pericardium - carries pain sensation
91
What does the vagus nerve innervate? (parasympathetic)
Heart and visceral layer of serous pericardium
92
What do sympathetic nerves innervate?
(T1-T4) innervate heart and visceral layer of serous pericardium (referred pain to inner surface of upper arm)
93
What are the two nodes of the heart?
Sinoatrial node
Atrioventricular node
94
Where can the SA node be found?
Upper wall of the right atrium, at the junction where the superior vena cava enters.
95
Where can the AV node be found?
In the Koch triangle, near the coronary sinus on the interatrial septum
96
What is the SA node?
A collection of specialised cells (pacemaker cells)
These pacemaker cells can spontaneously generate electrical impulses.
The wave of excitation created by the SA node spreads via gap junctions across both atria, resulting in atrial contraction (atrial systole) – with blood moving from the atria into the ventricles.
97
How can the autonomic nervous system influence the rate at which the SA node generates impulses?
Sympathetic nervous system – increases firing rate of the SA node, and thus increases heart rate.
Parasympathetic nervous system – decreases firing rate of the SA node, and thus decreases heart rate.
98
What is the role of the AV node?
Delays electrical impulses to ensure the atria have enough time to fully eject blood into the ventricles before ventricular systole.
The wave of excitation then passes from the atrioventricular node into the atrioventricular bundle.
99
What is another name for the atrioventricular bundle?
Bundle of His
100
What is the atrioventricular bundle?
A continuation of the specialised tissue of the AV node, and transmits the electrical impulse from the AV node to the Purkinje fibres of the ventricles.
101
What is the role of the Purkinje fibres?
Allow the heart's conduction system to create synchronized contractions of its ventricles
102
What does the atrioventricular bundle descend into and what does it divide into?
Descends down interventricular septum, before dividing into:
Right bundle branch – conducts the impulse to the Purkinje fibres of the right ventricle
Left bundle branch – conducts the impulse to the Purkinje fibres of the left ventricle
103
What are the four chambers of the heart?
Right atrium
Left atrium
Right ventricle
Left ventricle
104
How does blood travel?
Blood comes into the right atrium from the body, moves into the right ventricle and is pushed into the pulmonary arteries in the lungs.
After picking up oxygen, the blood travels back to the heart through the pulmonary veins into the left atrium, to the left ventricle and out to the body's tissues through the aorta
105
What is the job of the right atrium?
Receives deoxygenated blood from the systemic circulation via the superior and inferior vena cava
106
What are the identifying features of the right atrium?
Openings for IVC, SVC, coronary sinus
Interatrial septum
Fossa ovalis in IA septum
Musculi pectinati + crista terminalis
Tricuspid valve
107
What is the role of the interatrial septum?
Separate the two atrial chambers so that there is no shunting of blood between them
108
What is the role of the fossa ovalis?
During fetal development, the foramen ovale allows blood to pass from the right atrium to the left atrium
109
What is the origin of the pectinate muscle (musculi pectinati)?
Crista terminalis aka terminal crest
110
What is the crista terminalis?
The crista terminalis (terminal crest) is a C-shaped ridge located in the endocardial aspect of the right atrium of the heart.
111
What is the role of the pectinate muscles?
112
What is the role of the right ventricle?
Pumps blood low in oxygen to the lungs
113
What are the main identifying features of the right ventricle?
Tricuspid valve
Chordae tendineae
Papillary muscles
Trabeculae carneae
Moderator band
Opening for pulmonary trunk
Interventricular septum
114
What is the role of the chordae tendinae?
Maintain the position and tension of the atrioventricular valves (tricuspid and bicuspid valves).
They maintain the one-way blood flow from the auricle to the ventricles.
115
What is the role of the trabeculae carneae?
Prevent suction that would occur with a flat surface and thus impair the heart's ability to pump blood
116
Where can the moderator band be found?
Right ventricular apex
117
What is the role of the moderator band?
Holds the anterior wall and stops it from over expanding as the right ventricular wall is thin
Convey internal conducting system impulses from the bundle of His to the right ventricle
118
What is the role of the left atrium?
Receives blood full of oxygen from the lungs and then empties the blood into the left ventricle
119
What are the main identifying features of the left atrium?
Openings for:
Left and right superior pulmonary veins
Left and right inferior pulmonary veins
Bicuspid valve
Smooth walled, small chamber, lying wholly posterio-superiorly against oesophagus
Forms base of heart
120
What is the role of the left ventricle?
Left ventricular contraction forces oxygenated blood through the aortic valve to be distributed to the entire body
The left ventricle is responsible for maintaining pulsatile blood flow against the relatively high-pressure systemic circulation.
121
What are the main identifying features of the left ventricle?
Bicuspid (mitral valve)
Chordae tendineae
Papillary muscles x3
Trabeculae carneae
Opening for aorta
Interventricular septum
Wall 3x thicker than RV
Forms apex of heart
122
How does intrinsic innervation move through the heart?
Signals arise in SA node simulate atria to contract and travel to the AV node
After a delay, stimulus is conducted through the bundle of His to L&R bundle branches and purkinje fibres to the endocardium at the apex of the heart.
Then to the ventricles and finally the ventricular epicardium
123
Where can the aortic valve be auscultated?
Right 2nd intercostal space next to the sternum
124
Where can the pulmonary valve be auscultated?
Left 2nd intercostal space next to the sternum
125
Where can the tricuspid valve be auscultated?
Left 5th intercostal space next to the sternum
126
Where can the mitral valve be auscultated?
Left 5th intercostal space in the midclavicular line
127
What are the main vessels of the anterior chest wall?
Internal thoracic artery - gives off anterior intercostal arteries
Internal thoracic vein - receives anterior thoracic veins
Anterior intercostal artery
128
What are the main arteries of the upper limb?
Subclavian
Axillary
Brachial
Radial
Ulnar
129
How are the main arteries of the upper limb formed?
Subclavian arises from the brachiocephalic trunk of the aorta
Subclavian becomes axillary at the lateral border of 1st rib
Axillary becomes brachial once it leaves the axilla and enters the brachium
Brachial divides into radial and ulnar in the cubital fossa
130
What are the superficial veins of the upper limb?
Cephalic vein
Basilic vein
Medial cubital vein
131
How are the superficial veins of the upper limb formed?
Superficial veins arise from the dorsal venous arch on the back of the hand
Cephalic vein travels up the limb on the lateral side
Basilic vein travels up limb on medial side
Median cubital vein connects cephalic and basilic across cubital fossa
132
What are the main arteries of the lower limb?
Common femoral
Superficial femoral
Deep femoral
Popliteal
Anterior tibial
Posterior tibial
Fibular
Dorsalis pedis
133
How are the main arteries of the lower limb formed?
External iliac becomes common femoral in anterior thigh
Common femoral gives off superficial and deep femoral
Superficial becomes popliteal
Popliteal gives of anterior and post tibial in leg
Posterior tibial gives off fibular
Anterior tibial continues down to dorsum of foot where it becomes the dorsalis pedis between the 1st and 2nd toes
134
How are the main arteries of the lower limb formed?
External iliac becomes common femoral in anterior thigh
Common femoral gives off superifical and deep demoral
Superifical becomes popliteal
Popliteal gives oof anterior and post tibial in leg
Posterior ribial gives off fibular
135
What are the superficial veins of the lower limb?
Long (aka great) saphenous vein
Short saphenous vein
136
How are superficial veins of the lower limb formed?
Superficial veins arise from the dorsal arch of the foot
Long saphenous vein travels up the limb medially to drain the femoral
Short saphenous vein travels up the limb posteriorly to train into the popliteal
137
What are the main arterial pulse points of the body?
Temporal
Facial
Carotid
Brachial
Radial
Femoral
Popliteal
Posterior tibial
Dorsalis pedis
138
Where do temporal and facial pulses originate from?
Branches of external carotid
139
Where does the common carotid pulse originate from?
Branch of the aortic arch
140
Where does the brachial pulse originate from?
Continuation of the axillary
141
Where does the radial pulse originate from?
Lateral branch of brachial
142
Where does the femoral pulse originate from?
Continuation of external illiac
143
Where does the popliteal pulse originate from?
Continuation of femoral
144
Where does the posterior tibial pulse originate from?
Branch off popliteal
145
Summarise heart innervation
Phrenic nerve (somatic) - Fibrous layer & parietal layer of serous layer
Parasympathetic innervation of visceral layer and myocyte: Vagus nerve
Sympathetic innervation of visceral layer and myocyte: T1-T4
146
What does sympahetic innervation do?
Increase HR and contraction force
147
What does parasympathetic innervation do?
Decrease HR and contraction force
148
What does the coronary sinus drain originate from?
It is the direct continuation of the Great Cardiac Vein.
