Cardiovascular System Flashcards
1
Q
What are the two components of the cardiovascular system
A
Blood vascular system
Lymphatic System
2
Q
What does the blood vascular system do, and is it closed or open?
A
It is a closed system that carries blood, starting at the heart, to the exchanges surfaces
3
Q
What does the Lymphatic system do and is it an open or closed system?
A
It is an open-ended drainage system, fluid leaving the blood is drained back into the body via lymphatics
4
Q
What is the supply side of the cardiovascular systeM?
A
Arteries are the only supply path and they are situated deep to avoid damage. They carry blood under high pressure
5
Q
What is the exchange network of the cardiovascular system?
A
Capillaries
6
Q
What are the 3 types of capillaries?
A
Continuous
Fenestrated
Sinusoidal
7
Q
What are the 3 pathways for drainage in the cardiovascular system?
A
Deep veins
Superficial Veins
Lymphatics
8
Q
What is the pointed end of the heart called?
A
Apex
9
Q
What is the broad end of the heart called?
A
Base
10
Q
Where does the base of the heart sit?
A
Along the plane of the intercostal space of the 2nd and 3rd ribs
11
Q
Where does the apex of the heart sit?
A
In the midclavicular lines between the 5th and 6th ribs
12
Q
Where does the tricuspid valve lie?
A
Between the right atruym and the right ventricle
13
Q
Where does the pulmonary (semilunar) valve lie?
A
Between the right ventricle and the left pulmonary arteries
14
Q
Where does the reoxygenated blood return to the heart?
A
Pulmonary veins into the left atrium
15
Q
What structures drain into the right atrium?
A
Superior and inferior vena cava, and the coronary sinus - all with deoxygenated blood
16
Q
What drains in the left atrium
A
Oxygenated blood via the four pulmonary veins
17
Q
Whare the 4 layers of the heart?
A
Endocardium, myocardium, epicardium, and the pericardium
18
Q
What is the function of the pericardium?
A
Lubricated sac which allows the heart to beat in a low abrasion environment
19
Q
What makes up majority of the tissue structure of the heart?
A
Myocardium, or muscle
20
Q
Which layer of tissue sits below the myocardium?
A
Endocardium
21
Q
Which layer of tissue sits above the myocardium?
A
Epicardium
22
Q
What is the purpose of FCT in the heart tissues?
A
To support the thin endothelium layer
23
Q
Which ventricle wall is larger?
A
The Left has more pumping power
24
Q
What is the epicardium mainly made up of?
A
Adipose tissue and blood vessels
25
What are the 3 layers of pericardium?
Fibrous pericardium, serous pericardium, and pericardial cavity
26
What is the function of the AV valves?
Prevent blood from returning to the atria via ventricular contraction
26
Where are the two AV valves located?
Tricuspid - right side
Bicuspid - left side
27
What is diastole?
Relaxed phase, allowing filling to occur
28
What is systole?
Contraction of the ventricles, allowing the pressure to go up in the chambers. LEaflets enter a closed position and, when there is enough pressure, the flood will spill into the outflow artery
29
What is the function of the semilunar valves?
Prevent blood from returning to the ventricles during filling (diastole)
30
What are the 2 semilunar valves and their locations?
Pulmonary (right)
Aortic (left)
31
How many cusps does a semilunar valve have?
3
32
How does a semilunar valve function?
Pushed open as the blood flows out of the heart, and closes as the blood starts to backflow back in
33
In diastole, which valves are opened and closed?
The AV valves are open and the semilunar valves re closed, allowing filling
34
IN systole, which valves are open and shut?
AV valves are closed, and semilunar valves are open, allowing blood to get ejected from the heart.
35
What is the function of the papillary muscles?
Hold the chordae tendineae
36
What is the function of the chordae tendineae?
To prevent the AV valve leafelts from folding back in the other direction
37
Why do the semilunar valves not have papillary muscles?
They are self-supporting
37
Describe the supply path of the right coronary artery?
Starts in the aorta, then runs around the right lateral margin around the heart. Supplies the right side of the heart
38
Describe the supply path of the anterior interventricular artery
Branches into the left coronary and the circumflex artery
39
Describe the supply path of the left coronary artery
Supplies the left side of the heart and branches off the anterior interventricular artery
40
Describe the supply path of the circumflex artery
Branches off of the anterior interventricular artery, supplies the rest of the body
41
What is the right side of the heart drained by?
Small cardiac vein
42
Which vein drains the left side of the heart?
Great cardiac vein
43
Where do the the small and great cardiac veins drain into?
COronary sinus
44
What is the function of the cardiac muscle?
Beating of the heart
45
Describe the structure of the cardiac muscle
Striated
Short
1/2 nuclei
Central nucleus
Organelles at the poles
46
How do cardiac muscle cells connect to each other?
Via intercalated disks (ICDs), this is found only in cardiac muscle
47
Describe the process of ICDs (3)
Actin between cells means that a sacromere can pull on a neighbouring cell (physical cell-to-cell propagation)
A desmosome is used to keep them together
Calcium spilled through neighbouring cells to propagate contractions
48
What is the purpose of the conduction system of the heart?
Increase the efficiency of the heart
Co-ordination
48
What are the parts of the heart's conduction system?
AV node
SA node
Internodal pathways
AV bundle
R&L bundle braches
Purkinje Fibres
49
WHat is the function of a conduction cell?
Central nucleus
Mitochondria
Lots of gap junctions
Some desmosomes
50
Where is the Great saphenous vein located?
Superficial medial vein from the ankle to the groin
51
Where does the common iliac artery branch from?
Aorta
52
What does the external iliac artery branch off?
The common iliac artery
53
What are the 3 walls of blood vessels?
Tunica Intima
Tunica Media
Tunica Adventitia (Externa)
54
What are the 3 layers of the intima and their functions?
Endothelium (between free blood and the wall itself)
Sub-endothelium (Connective FCT that cushions the endothelium)
Internal elastic lamina (IEL) (Layer of elastin that acts as a rubber band for elastic recall
55
What i the structure and function of the tunica media?
Smooth muscle
Contains elastin and collagen
Thickness is proportional the blood pressure, e.g. thicker walls means more pressure
56
What is the structure and the function of the tunica adventitia (externa)?
Loose FCT forms tensile strands
VAsa Vasorum which supplies the blood vessel with its own blood supply
Lymphatics and autonomic nerves also found here
57
What is the thickest stucture in the artery?
Media
58
What is an arteriole?
Resistance vessel of the circulation which determines blood pressure
59
What is the function of a capillary?
Site of exchange between blood and tissues
60
What is a venule?
Smallest vein, start of collection drainage system
61
What are the 3 functions of a vein?
Low pressure, large volume transport
One-way (unidirectional) flow
Capacitance vessels
62
What is the shape of a vein?
Irregular, flattened, with large lumen and thin wall
63
What structure in the vein is thinner that that of the artery?
Media, because it contains muscle
64
What is the thickest layer of a vein?
Adventitia
65
What are the functional demands of a capillary?
Thin walls
Large cross sectional area of capillary bed
Slow and smooth blood flow
66
Do capillaries have a faster or slower blood flow than arterioles?
Slower (river flowing into a lake)
67
How many blood cells can flow in a capillary at a given time?
1
68
What is the purpose of the Precapillary sphincters?
Constrict and stop blood from going into the side branches, controlling the flow from the arteriole to the venule
69
Is the Precapillary Sphincter a voluntary or involuntary muscle?
Involuntary, is controlled by the CNS
70
Describe the 3 types of capillary
Continous is the most widespread
Fenestrated is leak
Sinusoidal is very leaky
71
What is on the basal surface of the capillary?
Basement membrane
72
What is the purpose of a fenestrated capillary?
Small holes that form little channels, blood cannot go through but small nutrients can
73
What is the purpose of a sinusoidal capillary
Slightly larger, gaps allow the basement membrane to have direct contact with the red blood cells
74
What is the functions of the lymph vascular system? (4)
Drain excess tissue fluid from tissues and return to blood
Filters foreign material from the lymph
Screens lymph for foreign antigens and activates immune cells
Absorbs fat from intestine and transports it to blood
75
Describe thr structure of the lymphatic vessels
Large, porous-tipped capillaries
In small intestine, larger collection vessels have valves to prevent backflow
76
What is the purpose of a lacteal?
Drain fat-laden lymph from intestine into cisterna chyli
77
What is the structural difference between the lymph vessels and veins?
Lymph vessels have much thinner walls
78
True or false: the right and left pumps contract individually
False
79
What contracts first, the atria or the ventricles?
Atria
80
What is the purpose of the aortic and pulmonary valves?
To control the from the the ventricles out to the circulatory vessels
81
Describe the cellular mechanism of cardiac (MUSCLE!) contraction
Ca levels go up and released from the SR, myosin binds to actin which shortens the sarcomere to generate force.
82
How can cardiac contraction be increased?
By have more calcium.
83
What part of the cardiac cycle is the longest?
Diastole
84
Describe in 5 steps the cardiac cycle
Atrial systole
Isovolumetric Ventricular Contraction
Ventricular Ejection
Isovolumetric Ventricular Relaxation
Passive Filling
85
Describe what happens during atrial systole
Pressure being pushed into the ventricles, ready for contraction
86
Describe what happens during isovolumetric ventricular contraction
AV valves shut, volume of blood stays the same as SL valves also closed, crushing down of muscles causes the SL valves to open
87
Describe what happens during ventricular ejection
Blood ejected, after this happens, SL valves snap closed
88
Describe what happens during isometric relaxation
No path in and out, heart begins to relax, ready for filling
89
What is higher, systemic arterial pressure or pulmonary arterial pressure?
Systemic
90
What is the highest point on a blood pressure trace?
Systolic pressure
91
What is the lowest point on a blood pressure trace?
Diastolic Pressure
92
What is pulse pressure on a blood pressure trace?
Difference between the highest and lowest points
93
Will the mean of the blood pressure trace tend to be higher or lower?
Lower, because more time is spent in diastolic
94
What is hypertension?
High blood pressure
95
What kind of cell is the heart mostly comprised of?
Contractile cells
96
Describe the appearance of contractile cells
highly striated, light in actin and myosin
97
Describe the appearance of electrical cells
Pale striated, low actin and myosin
98
What is the purpose of the electrical cells?
Carry a signal as quickly as possible from one cell to another
99
Describe the propogation of APs inside of the heart
They start at the SA node, and spread quickly to neighbouring cells. They then communicate with contractile cells
100
What is the relationship between gap junctions and cardiac cells?
Connect cells with low resistance pore which allow the current to flow between the adjacent cells
101
What is a functional syncytium?
When the millions of cardiac cells behave as one
102
What is the pathway for electrical conduction in the heart (5)?
SA node, Internodal buncles, AV node, AV bundle (bundle branches), Purkinje Fibres
103
In what direction do the bundle branches flow?
From the bottom of the heart to the top, allowing the heart to be squeezed, to get the most possible blood out of it.
104
What is the pacemaker of the heart?
The SA node, it handles its own contractions, not the brain
105
Where does the SA node send the signals?
R. atrium
L. atrium
Internodal bundles
106
What does the left ventricle generate pressure for?
The systemic circuit
107
What is a critically important determinant of blood flow?
Mean arterial blood pressure (MAP)
108
Where does blood pressure fall steeply?
In arteriole, capillaries, and venules
109
What creates a driving force for blood?
The difference in pressure between the arterial and venous sides
110
What is the equation for flow?
Q=P/R
Flow = pressure difference/ resistance
111
What is the equation for mean arterial blood pressure?
MAP = Q x R
MAP = flow x resistance
112
What are arterial blood volume and pressure determined by?
Balance between blood flowing in and out
113
How can MAP be increased?
Increase cardiac output
Make the arteries more resistance to losing blood
114
What is the equation for MAP involving cardiac output?
MAP = CO x TPR
TPR is total peripheral resistance
115
What is the equation for Cardiac output based on stroke volume?
CO = SV x HR
116
What is stroke volume?
HOw much blood is being pushed out of the heart per beat
117
What is cardiac output measured in?
L/min
118
What happens during heart failure?
Contractile cells die, and are replaced with scar tissue, heart loses the ability to push blood out
119
Where is the MAP coordinated and how?
Within the brain stem, via the afferent input of the CNS and periphery, and the efferent output to the heart and vessels
120
What is the function of a baroreceptor?
They are blood pressure sensors, they are found in the aortic arch and carotid artery
121
What are the two neural controls of cardiac output?
Brake (vagus nerve)
Accelerator (sympathetic cardiac nerves)
122
What is the purpose of the vagus nerve?
To decrease heart rate
123
What is the purpose of the sympathetic trunk gangion>
Increase heart rate and the force of contraction
124
In the whole body tilt, describe the processes of SV, CO, MAP, VR, and HR
SV decreases slightly and then returns to normal
CO decreases even less and then returns to normal
HR increases
MAP must stay roughly the same
VR increases slightly
125
What is cardiac output determined by?
Stroke volume and heart rate
126
Is cardiac output increased or decreased during exercise?
Increased
127
Why does blood pressure need to be high?
So that it is easier to determine where blood is going to go
128
True or false, the flow in the pulmonary circuit is greater than the flow in the systemic circuit?
False, they are equal
129
What does the parallel design of the systemic circuit mean?
That there is a continual branching of the arterial network. There are many circuits working in parallel with each other
130
What organs require more blood as exercise increases?
Skin, skeletal muscles, heart
131
Which organs require less blood during heavy exercise?
Kidney, abdominal viscera (stomach), other tissues
132
Where is there always constant blood flow (no increase or decrease)?
Brain
133
How is MAP controlled during exercise?
Increased cardiac output
Decreased
MAP = CO x TPR
134
What are the resistance vessels?
Arterioles
135
What is the relationship between blood flow and vessel radius?
Halving the diameter will increase the resistance by 16, rule of 16
136
How is blood flow to an organ controlled?
Adjusting arteriolar tone and radius, i.e. contraction of the smooth muscle around the arterioles, making the space smaller
137
Where is most blood in the body found?
In the systemic veins
138
Why is most blood found in the systemic veins?
Because they have stretchable and bendable walls
139
How are veins able to store blood at a lower pressure?
Compliance, they have a thin muscular and stretchy wall, which can change to accommodate the extra blood
140
Are arteries high or low compliance vessels?
Low
141
What is venoconstriction?
When the smooth muscle in the wall of the vein constricts to help push the blood back up to the heart for circulation when blood is lost to increase arterial blood pressure
142
What causes blood to pool in veins?
When the body is in an upright position, the venous blood volume below the heart increases due to the low pressure of the veins
143
How does tissue tone reduce pooling?
Veins run through rigid skeletal muscle, this allows the vein to hold its shape and less prone to pools
144
What is sarcopenia?
Low muscle tone
145
How does the tensing of muscles effect veins?
The tensing of muscle allows blood to be pushed through veins at a greater rate due to the muscle tone
146
What is Starling's Law of the Heart?
The more stretched the muscle fibres are before a contraction, the stronger the contraction will be
147
How can be increase the length of the muscle fibres in the heart?
By putting a large volume of blood, allowing the fibres to 'stretch'
148
How does venous return affect the performance of the heart?
Less volume of blood in the heart means that the contractile fibres are much shorter, stopping the potential for a larger stroke volume
149
What are the 3 general functions of blood?
Circulate nutrients, products, etc
Dissipate heat
Immune factors and coagulation factors
150
What are the 5 things pumped around the body via blood?
Oxygen, water, waste products, hormones, ions
151
What is the purpose of white blood cells?
Fighting infection and production of immune response
152
What is coagulation?
Prevention of bleeding via platelets and coagulation factors in plasma
153
What are the 2 main constituents of blood?
Plasma, and formed elements
154
What is the major constituent of blood plasma?
Water
155
What are the 3 major types of formed elements?
Platelets, white blood cells, and red blood cells (erythrocytes)
156
What is hematopoiesis?
Formation of blood cells
157
Where is hematopoiesis initiated?
In the red bone marrow, via hemocytoblasts
158
What is the purpose of a hemocytoblast?
Multipotent and can differentiate into many other cells
159
What is the purpose of EPO?
Signals the hemocytoblasts to differentiate
160
What is the shape and purpose of the shape of a red blood cell?
Biconcave disc shape, this allows it to have a large SA:V, and subsequent efficient diffusion of gases. It is very flexible so that it can fit through narrow capillaries
161
Why do red blood cells need to have efficient diffusion?
Because gases diffuse slowly through aqueous material, so you need to be as close to the membrane as possible
162
What are the 3 characteristics of a red blood cell?
Contain haemoglobin
Uses iron to bind oxygen
4 haem units
163
What is a haematocrit?
Packed cell volume, fraction of blood occupied by the red cells
164
What is it called when you have too many red blood cells?
Polycythemic
165
What is red blood cell production stimulated by?
EPO
166
What is the process for RBC production stimulated by?
Testosterone
167
Why do athletes train at high altitudes?
Because the air at high atitudes has less oxygen. When exposed to this for long periods of time, the kidneys will release more EPO to stimulate RBC production, resulting in more hematocrit
