Cardio Flashcards
(180 cards)
1
Q
What does the left atrium receive, and where from
A
Oxygenated blood from 4 pulmonary veins
2
Q
What does the right atrium receive, and where from
A
Deoxygenated blood from superior and inferior vena cava, and coronary sinus
3
Q
What does the left coronary artery branch into
A
Circumflex and anterior interventricular arteries
4
Q
What supplies the coronary sinus
A
Great and small cardiac veins
5
Q
What is the vagus nerve
A
Brake: parasympathetic nerve (rest and digest) which innervates the SA and AV nodes to decrease heart rate
6
Q
What are the sympathetic cardiac nerves
A
Accelerator: nerve from sympathetic trunk ganglion, increases heart rate by innervating nodes and increases force of contracting by telling cardiac muscle to release more calcium
7
Q
What are auricles
A
Folds of atria to create potential space for extra blood
8
Q
What is pectinate muscle
A
Ridges covering the interior walls of auricle and atrium to confer strength to the atria enabling their expansion
9
Q
What is the first major artery that branches off the aorta
A
Brachiocephalic artery
10
Q
What is the second major artery that branches off the aorta
A
Left common carotid artery
11
Q
What is the third major artery that branches off the aorta
A
Left subclavian artery
12
Q
What are the first arteries to branch off the aorta
A
Left and right coronary arteries
13
Q
What structure delineates the change between the thoracic and abdominal aorta?
A
Diaphragm
14
Q
Where is the SA node located
A
The junction of the superior vena cava and right atrium
15
Q
What is the function of the SA node
A
Pacemaker: cells spontaneously initiate each cardiac action potential, and hence heartbeat
16
Q
What is the function of the interatrial bundle
A
Conducts the action potential from the right atrium to the anterior part of the left atrium
17
Q
What is the function of the internodal bundles
A
Conduct the action potential from the SA node to the AV node
18
Q
What is the function of the AV node
A
Slows conduction of AP from atria to ventricles, ensures atria complete their contraction before ventricles are depolarised
19
Q
What is the function of the left and right branches of the AV bundle
A
Conduct the AP from the AV node to the left and right ventricles
20
Q
What is the function of the Purkinje fibres
A
Conduct AP to all parts of the ventricles
21
Q
What are serous membranes
A
Membranes which secrete fluid to lubricate internal structures
22
Q
What is the name of the loose sac covering the heart
A
Pericardium (fibrous and serous: pericardial space filled with pericardial fluid)
23
Q
What are the three layers of the heart wall
A
Epicardium, myocardium, endocardium
24
Q
Describe the epicardium
A
Visceral layer of serous pericardium**, as well as adipose, blood vessels and loose irregular fibrous connective tissue
25
Describe the myocardium
Thick, contractile muscular layer
26
Describe the endocardium
Thin inner layer of heart wall made of loose irregular fibrous connective tissue and simple squamous epithelium
27
What valve separates the right atrium and ventricle
Right AV valve: tricuspid
28
What valve separates the left atrium and ventricle
Left AV valve: bicuspid
29
What valve separates the pulmonary artery and right ventricle
Pulmonary semilunar valve (3 cusps)
30
What artery leaves the right ventricle
Pulmonary artery
31
What artery leaves the left ventricle
Aorta
32
What valve separates the aorta and left ventricle
Aortic semilunar valve (3 cusps)
33
What supplies the right atrium
Superior and inferior vena cava
34
What supplies the left atrium
The four pulmonary veins (two left, two right)
35
What is the function of chordae tendinae
Prevent AV valves from inverting when they snap shut due to ventricular pressure
36
What are papillary muscles
Finger like projections of ventricular myocardium attached to chordae tendinae
37
What is trabeculae carnae
Muscular, beam like structures on the inner surface of the myocardium forming ridges or bridges
38
What does the pulmonary trunk divide into
Right and left pulmonary arteries
39
What are the two types of connective tissue in the cardiovascular system?
Elastin for stretch and fibrocollagen for strength
40
What is the main difference between the blood and lymph vascular systems
Blood: continuous loop, lymph: one way drainage system
41
What is the pulmonary circuit
Heart and lungs
42
What is the systemic circuit
Heart and rest of the body
43
Where do lymph projections pick up overflow
In the interstitium of capillary beds
44
Where are major arteries situated to avoid damage
Deep in the trunk or on flexor aspect of limbs
45
What are the three types of capillary
Continuous, fenestrated, sinusoidal
46
What are the three pathways for drainage
Deep veins, superficial veins and lymphatics
47
What is the only pathway for supply
Arteries
48
Why can veins exist more superficially than arteries
Operate at a much lower pressure so less dangerous
49
Where is the apex located (point of maximal impulse)
Left mid clavicular line, between ribs 5 and 6
50
Describe the position of the heart in the thorax
Rotated to the left, base tilted posteriorly
51
What separates the two ventricles
Interventricular septum
52
Describe pericardium
Outer wall: parietal serosa/pericardium, serous fluid, inner wall: visceral serosa/pericardium
53
What is diastole
Relaxation
54
What is systole
Contraction
55
Describe the four valves during diastole
AV valves open, semilunar valves closed
56
Describe the four valves during systole
AV valves closed, semilunar valves open
57
How big are capillaries
RBCs must be single file (as close as possible to walls for exchange)
58
Describe cardiac muscle cells
Striated, short, branched, 1 (occasionally 2) central, oval shaped nuclei per cell (compared to multinucleated, peripherally located skeletal muscle). Cytoplasmic organelles packed at poles. Interconnected with neighbouring cells via intercalated discs
59
Describe mitochondria in cardiac muscle cells
Make up about 20% of the cell, can never run out of ATP!
60
What are the three types of intercalated discs
Adhesion belts, desmosomes and gap junctions
61
What do adhesion belts link
Actin to actin: vertical portion
62
What do desmosomes link
Cytokeratin to cytokeratin: vertical and horizontal portion
63
What do gap junctions link
For electrochemical communication: horizontal portion
64
Conduction pathways are not nervous tissue, but are
Modified cardiac muscle
65
Describe cardiac conduction cells
Some peripheral myofibrils, central nucleus, mitochondria, glycogen, lots of gap junctions, some desmosomes, few adhesion belts (1% of all cardiac cells). Bloated compared to contractile cells.
66
List the vessels of the cardiac circulation
Aorta, coronary arteries, myocardial capillaries, cardiac veins, coronary sinus, right atrium
67
What type of nerves can alter the rate of conduction node impulse generation
Autonomic nerves
68
What artery branches into the right subclavian and common carotid arteries
Brachiocephalic
69
Where are the intercostal arteries
Along the inferior aspect of the ribs
70
What artery supplies the spleen, stomach and liver
Celiac trunk
71
What is the branching of the aorta at the pelvis called
Aortic bifurcation
72
What are the two paths of the aortic bifurcation
Left and right common iliac
73
What do the left and right common iliac arteries branch into
External and internal iliac
74
Describe a possible pathway for blood to the foot
Aorta, common iliac artery, external iliac artery, femoral artery, popliteal artery, posterior tibial artery, plantar arch
75
Describe a pathway for the return of blood from the foot
Plantar venous arch, posterior tibial vein, popliteal vein, great saphenous vein or femoral vein, external iliac vein, common iliac vein, inferior vena cava
76
What is the great saphenous vein
A superficial vein from in lower limbs
77
What are the three layers of blood vessels
Tunica intima, tunica media and tunica adventitia
78
Describe the tunica intima
A simple squamous epithelium which lines the lumen of all vessels, a sparse pad of loose FCT cushioning the endothelium, an internal elastic lamina: condensed sheet of elastic tissue (more developed in arteries)
79
Describe the tunica media
Smooth muscle, variable content of connective tissue fibres, thickness proportional to vessel diameter and blood pressure. Much thicker in arteries than veins
80
Describe the tunica adventitia
Loose FCT (high collagen, variable elastin), contains vasa vasorum (vessels of the vessel) in larger vessels. Lymphatics and autonomic nerves also found in this region. Thicker in veins (limit extent of capacitance)
81
What does IEL stand for
Internal elastic lamina
82
What wall of the blood vessel is the IEL a part of
Tunica intima
83
How is pulsatile flow dampened into vessels
Elastic walls
84
What is an approximate healthy blood pressure
120/80 mmHg
85
What are the arteriole's function
Resistance vessels of the circulation: determine blood pressure
86
What is the function of the capillaries
Exchange between blood and tissues
87
What is the function of the venules
Start of the drainage system
88
What are the main features of veins
Low pressure, large volume, unidirectional flow, capacitance vessels
89
What is a vascular bundle
Group of veins, arteries and nerves (run along similar pathways)
90
How do veins ensure unidirectional flow
Valves, tone of surrounding tissue (vein "flanked" by skeletal muscle)
91
What are the main features of capillary beds
Very thin walls, large CSA, slow and smooth blood flow, made of endothelial cells welded to themselves to form tube
92
What are precapillary sphincters
Rings of smooth muscle that constrict to stop blood running into side branches of capillary beds
93
What is shunting
The contraction of precapillary sphincters to move blood directly from arterioles to venules
94
What are continuous capillaries
Tightly welded endothelial cells, continuous basement membrane
95
What are fenestrated capillaries
Endothelial cells with fenestrations, continuous basement membrane
96
What are sinusoidal capillaries
Much wider (not primarily focussed on passive exchange) capillaries with large fenestrations and incomplete basement membrane.
97
How do continuous capillaries exchange
Diffusion through membrane (lipid soluble substances), movement through intercellular clefts (water soluble substances), transport via vesicles (large substances)
98
How do fenestrated and sinusoidal capillaries exchange
Diffusion through membrane (lipid soluble substances), movement through intercellular clefts (water soluble substances), transport via vesicles (large substances), movement through fenestrations (water soluble substances)
99
What are the functions of the lymph vascular system
An open entry drainage system: drains excess tissue fluid and plasma proteins, filters foreign material, screens lymph for foreign antigens, and absorbs fat from intestine
100
Describe the structure of the lymphatic system
Lymphatic vessels: large, blind ending capillaries
101
What do lacteals (special group of lymphatic vessels from small intestine) do
Drain fat laden lymph into collecting vessel called cisterna chyli (milk jug) (swelling of thoracic duct)
102
How does exchange occur across lymph vessels
Between endothelial cells, no tight connections
103
Features of lymph vessels
Thinnest walls, no RBCs, valves
104
Lymph node structure
Many afferent lymphatics, one efferent. Bathe immune cells for immune surveillance
105
Metastasis meaning
Movement of primary tumour to form secondary tumour
106
Where are lymph vessels
Wherever there are capillary beds there will be lymphatics
107
What are some examples of lymph nodes (locations)
Cervical (neck), axillary (armpits), inguinal (inner hip)
108
What are arteries
Blood vessels with blood flowing away from the heart
109
What are veins
Blood vessels with blood flowing toward the heart
110
What are the thick and thin filaments in a myofibril
Myosin: thick, actin: thin
111
How can the force of contraction be increased?
Stimulate cells to release more calcium = more cross bridges
112
How does cardiac contraction end
Ca2+ pumped back into sarcoplasmic reticulum by SERCA
113
What are the phases of the cardiac cycle
Atrial systole, atrial diastole, ventricular systole (isovolumetric contraction, ventricular ejection), ventricular diastole (isovolumetric relaxation, late ventricular diastole)
114
Atrial and ventricular systole can be described as
Mutually exclusive
115
The heart spends the most time in
Diastole
116
What is the lubb sound
AV valves snapping shut to prevent backward movement of blood from ventricles to atria (semilunar valves closed)
117
What is the dupp sound
Semilunar valves snapping shut after ventricular ejection
118
What is the longest phase of the cardiac cycle
Passive filling of atria and ventricles
119
How does the systemic circuit blood pressure compare to the pulmonary circuit
Much higher
120
What is systolic blood pressure
Highest point on a trace (~120mmHg)
121
What is diastolic blood pressure
Lowest point on a trace (~80mmHg)
122
What is pulse pressure
The difference between the highest and lowest points on a blood pressure trace
123
What is mean pressure
The average blood pressure across the full cycle (below mid point as heart spends more time in diastole)
124
What is hypertension
High blood pressure, can be life threatening over time
125
What is hypotension
Low blood pressure, life threatening immediately
126
Why do conduction cells have actin and myosin pushed to the periphery
To make room for glycogen and mitochondria
127
Where does the SA node transmit signals to
RA, LA and AV node
128
What is the interatrial bundle
Bundle of conduction cells from SA node, along RA to LA
129
What is quiescence
Passive refilling of heart with blood
130
What is the order of de and repolarisation of parts of the heart
Atria depolarise, atria repolarise, ventricles depolarise (interventricular septum, then walls), ventricles repolarise
131
What does an ECG measure
Changes in voltage (directionality of trace irrelevant)
132
What is the P wave
Atrial depolarisation
133
What is the QRS complex
Ventricular depolarisation and atrial repolarisation (tall, skinny peak as happens fast)
134
What is the T wave
Ventricular repolarisation
135
How do depolarisation and repolarisation relate to contraction and relaxation
Electrical event (first!!) causes mechanical event
136
How does MAP relate to cardiac output and resistance
MAP = CO * TPR
137
How is CO determined
CO = SV * HR (strength * speed)
138
How is blood pressure coordinated
Within the brainstem: afferent input from CNS and periphery
139
Where are baroreceptors located
Aortic arch, carotid artery, embedded within walls
140
How do baroreceptors work
Change frequency of their signal to provide information on blood pressure
141
What are baroreceptors
Stretch receptors
142
What is the body's reaction to the tilt test
Stroke volume falls (work against gravity) hence CO falls, HR increases to combat this. TPR increases to help combat fall in blood pressure
143
How is flow related to pressure and resistance
Q = ΔP / R
You don't have control of flow unless you have a high pressure
144
How does cardiac output directed to the heart change during exercise?
(Divergent flow depending on metabolic needs)
Increases
145
How does cardiac output directed to the brain change during exercise?
(Divergent flow depending on metabolic needs)
No change
146
How does cardiac output directed to the kidneys change during exercise?
(Divergent flow depending on metabolic needs)
Decreases
147
How does cardiac output directed to the abdominal viscera change during exercise?
(Divergent flow depending on metabolic needs)
Decreases
148
How does cardiac output directed to the skin change during exercise?
(Divergent flow depending on metabolic needs)
Increases
149
How does cardiac output directed to other tissues change during exercise?
(Divergent flow depending on metabolic needs)
Decreases
150
How does cardiac output directed to skeletal muscle change during exercise?
(Divergent flow depending on metabolic needs)
Increases
151
How is peripheral resistance changed
Precapillary sphincters
152
How are resistance and radius of blood vessel related
R = 1/r^4 : Small change in radius = huge change in resistance (*16)
153
Where do we store extra blood in our body (can lose some blood and be fine)
Veins: capacitance vessels
154
What is compliance
The extent to which a vessel allows deformation in response to an applied force
155
What is the formula for compliance
ΔV / ΔP = compliance
156
What is venous pooling
Movement of blood down body to accumulate near feet due to gravity and low pressure of veins
157
What counteracts venous pooling
Valves and tone of surrounding tissue (especially skeletal muscle as it can alter its tensile state)
158
What is starling's law of the heart
(Increased venous return means increased stroke volume)
The more stretched muscle fibres are before a contraction, the stronger the contraction will be: i.e the heart will contract more strongly if there's more blood in the heart
159
Which blood vessel has the thickest tunica media
Artery
160
Which blood vessel has the thickest tunica adventitia and why
Vein, to limit capacitance capability
161
What is the R-R interval
Time between two R wave peaks (used to determine heart rate)
162
What is the Q-T interval
Time between the start of Q wave to end of T wave
163
What is the P-R interval
Time from start of P wave to start of Q wave
164
What are the three general functions of blood
Transport, immune response and coagulation
165
What does blood transport
Good stuff out, bad stuff in. Oxygen, water, nutrients, carbon dioxide, waste products, ions, heat, hormones, immune cells, coagulation factors
166
How does coagulation happen
Via platelets and coagulation factors in plasma
167
What is blood composed of
55% plasma, 45% formed elements
168
What is plasma composed of
Plasma proteins, other solutes, water
169
What are formed elements composed of
Platelets, white blood cells, red blood cells
170
What is hematopoiesis
Formation of blood cells
171
Where does hematopoiesis occur
In red bone marrow, which contains hemocytoblasts
172
Why are red blood cells biconcave
Large SA:V ratio, allow efficient diffusion of gases, flexibility for movement through narrow capillaries
173
What are the functions of RBCs
Contain large ammounts of hemoglobin for transporting oxygen (need iron to bind oxygen)
174
What is hematocrit (or packed cell volume, PCV)
The fraction of blood occupied by red cells
175
What is anemia
Low levels of hematocrit, often associated with iron deficiency
176
What is polycythemia
High levels of hematocrit resulting in very viscous blood, heart has to work very hard, vessels put under a lot of strain
177
What is erythropoiesis
Generation of red blood cells
178
What is erythropoietin (EPO)
Something which stimulates erythropoiesis
179
What hormone augments erythropoiesis
Testosterone
180
Which layer of the heart wall is vascular
Epicardium
