Cardiovascular Physiology Flashcards
1
Q
Principal components of Cardiovascular System
A
– the heart (the pump)
– the blood vessels (the pipes)
– the blood (the fluid to be moved)
2
Q
is made of “formed elements” and plasma (which is mostly water)
A
Blood
2
Q
Cardiovascular System
A
function is impacted by the endocrine system, nervous system and kidneys
3
Q
carries blood cells, proteins, nutrients, metabolic wastes, and other molecules transported around the body.
A
Plasma
4
Q
the physiological mechanisms that stop bleeding
A
Hemostasis
5
Q
3-step process of Hemostasis
A
- Vascular spasm
- Formation of platelet plug
- Blood coagulation
6
Q
- results from damage to the blood vessel
- Damaged tissue secretes factors that cause this contraction.
- Vessels constrict to minimize blood loss
- Endothelial layer becomes sticky to aid in the clotting process.
A
Vascular Spasm
7
Q
- cytoplasmic fragments derived from megakaryocytes
- no organelles, but have granules
- important in blood clotting.
A
Platelets (thrombocytes)
8
Q
The granules in Platelets contain:
A
ADP
Serotonin
Epinephrine
8
Q
- forms around site of vessel damage and is started by the sticky endothelium at the damaged site
- results in a decreased blood loss (maintains BP)
- necessary for production of a blood clot
A
Platelet Plug
9
Q
- Occurs around platelet plug
- Dominant hemostatic defense mechanism
A
Formation of a Blood Clot
Clotting = coagulation
10
Q
- produced by the liver
- secreted into blood in inactive forms
- activated during the clotting cascade
A
Clotting factors
11
Q
- given to dissolve clots obstructing flow in coronary arteries, pulmonary arteries and cerebral arteries
- used to treat stroke patients if they arrive soon enough to the hospital
A
recombinant tissue plasminogen activator (TPA)
11
Q
Plasma without clotting factors is called
A
serum
11
Q
convert plasminogen to plasmin
A
Plasminogen activators
12
Q
Decreased synthesis of clotting factors
Vitamin deficiency
A
Vitamin K deficiencies
12
Q
–Reduced levels of vWf –Decreases platelet plug formation
A
Von Willebrand’s disease
12
Q
Genetic disorder caused by deficiency of gene for specific coagulation factor
A
Hemophilia
13
Q
two proteins that circulate in the blood as a complex, and they play crucial roles in blood clotting
A protein that is essential for the blood clotting process, specifically in the intrinsic pathway.
A large glycoprotein that circulates in the plasma and is also found in the endothelium and storage granules within endothelial cells and platelets.
A
Factor VIII and von Willebrand factor (vWF)
13
Q
a large, multimeric plasma glycoprotein crucial for hemostasis, mediating platelet adhesion and aggregation at sites of vascular injury and acting as a carrier for factor VIII
A
Von Willebrand factor (VWF)
14
Q
To prevent the clot from becoming unnecessarily large, there is swift removal of clotting factors and inhibition of active clotting factors.
A
Clot Controllers
14
Q
- an anticoagulant in mast cells and basophils, and on the surface of endothelial cells
- inhibits thrombin by enhancing Antithrombin III and clotting by inhibiting the intrinsic pathway
A
Heparin
15
Q
are all used clinically to prevent clots
is an antiprostaglandin that inhibits the formation of TxA2.
A
Aspirin,
15
Q
are smooth and intact and
prevent platelets from adhering.
* secrete NO and prostacyclin, which prevent platelet aggregation
* Inappropriate clotting causes serious problems including stroke, heart attacks, tissue ischemia and death
A
Endothelial Cells
15
Unbound thrombin
is inactivated by
Antithrombin III and protein C.
15
Most of the _______ is bound to the fibrin threads to prevent systemic clotting
thrombin
16
are all used clinically to prevent clots
Warfarin is taken orally and is called
coumadin
16
are all used clinically to prevent clots
is injected clinically
heparin
17
Clotting Disorders
which result from inappropriate clot formation.
Thromboembolic disorders
18
Clotting Disorders
which are caused by the
prevention of normal clotting functions
Bleeding disorders
19
Clotting Disorders
disorders, which involve widespread clotting
and severe bleeding
Disseminated intravascular coagulation
20
is a clot that forms and persists in an unbroken blood vessel
It can block the vessel if it is large enough → leads to
ischemia and tissue death downstream from the clot
thrombus
21
Impaired liver function causes a lack of
procoagulants
21
is a clot that is free-floating in the blood stream → can wedge in a vessel
Embolus
22
is characterized by a lack of platelets, which causes spontaneous bleeding in small blood vessels.
Even normal movement causes internal hemorrhaging (petechiae) in the skin.
Anything that affects bone marrow can cause this
Thrombocytopenia
23
Describe the role of liver and vitamin K in clotting
Vitamin K is a fat-soluble vitamin that acts as a cofactor for the liver to produce and activate certain clotting factors (II, VII, IX, and X).
The liver is the primary site for synthesizing most of the proteins (clotting factors) needed for blood coagulation. These factors are essential for forming blood clots to stop bleeding.
23
Impaired liver function treated with vitamin ____________ shots if that is deficient
vitamin K shots
24
Total impairment of liver function associated with cirrhosis and hepatitis can require .
transfusions
24
is a lack of factor IX.
Hemophilia B
25
loop carries blood from the heart to the rest of the body
systemic loop
25
a genetic X-linked disorders seen primarily in men
Hemophilia
25
or classical hemophilia is a lack of factor VIII (~77% of cases).
Hemophilia A
25
* seen in both sexes and is mild
* a lack of factor XI
* mild because IX (which is activated by XI) can also be activated by VII.
Hemophilia C
26
2 “loops” in the CVS
Systemic and pulmonary
27
loop carries oxygen poor blood to the lungs and back to the heart.
pulmonary loop
28
can be divided into arteries (muscular and conduit), arterioles, capillaries, venules and veins
Blood Vessels
29
These arteries, like the aorta and pulmonary arteries, have a high proportion of elastic tissue in their walls, allowing them to stretch and recoil with each heartbeat, absorbing pressure fluctuations.
Elastic (Conduit) Arteries
30
carry deoxygenated blood
Exception: pulmonary arteries and the pulmonary veins
veins
31
hese arteries, such as the femoral and brachial arteries, have a higher proportion of smooth muscle in their walls compared to elastic arteries.
Muscular (Distributing) Arteries
31
carry oxygenated blood
Exception: pulmonary arteries and the pulmonary veins
arteries
32
carry blood away from the heart
arteries
33
carry blood to the heart
veins
34
is the volume moved; measured in mL/min
Flow
34
is the force exerted; measured in mm Hg.
Pressure
35
Flow Basic equation
F = DP/R
36
is how difficult it is for blood to flow between two points at any given pressure difference; the measure of the friction that impedes flow.
Resistance
36
If you increase resistance you ____________ flow, if pressure stays the same
decrease
37
Factors Affecting Resistance
Blood viscosity
Total blood vessel length
Blood vessel diameter
38
relaxed vessels increase
resistance
39
vasoconstricted vessels decrease
resistance
40
Heart Layers
the most superficial (outer) layer the visceral layer of the serous pericardium
Epicardium
40
Cardiac Muscle of the Myocardium has only a limited ability to replace its muscle cells
true
40
Heart Layers
The middle layer of the heart muscle composed of cardiac muscle and forms the bulk of the heart mass. This is the layer that contracts.
Myocardium
41
Heart Layers
The inner layer, it is of endothelium which rests on a thin layer of connective tissue. It is continuous with the lining of the blood vessels entering and leaving the heart.
Endocardium
42
* initiates the heartbeat
* helps spread the impulse rapidly
throughout the heart
* in electrical contact with the cardiac muscle cells via gap junctions
Conduction System of the Heart
42
– peptide hormone secreted in the atria
– regulates the concentration of Na+ in the extracellular fluid
atrial natriuretic peptide
42
experiments suggest that only __% of heart muscle cells are replaced per year in Myocardium
~1%
42
innervates the node cells and releases acetylcholine
Parasympathetic Nervous System
43
NE receptors on cardiac muscle are mainly
beta-adrenergic
43
the heart is innervated by _____ & ______nerve fibers
sympathetic and parasympathetic
43
innervates the entire heart and release NE
Sympathetic Nervous System
44
are transmembrane proteins that respond to neurotransmitters like epinephrine (adrenaline) and norepinephrine, which are part of the sympathetic nervous system (fight-or-flight response).
beta-adrenergic
45
Acetylcholine receptors are of the
muscarinic type
46
Blood pumped chambers through the heart does not exchange nutrients and metabolic end products with the myocardial cells
true
47
Coronary Blood Supply
– branch from the aorta that supplies the myocardium
– exit from behind the aortic valve cusps in the very first part of the aorta and lead to a branching network blood vessels
coronary arteries
48
* have automaticity
* found in the Sinoatrial node (SA), the Atrioventricular node (AV), the atrioventricular bundle, and the Purkinje fibers
Node Cells
48
Coronary Blood Supply
– where most cardiac veins drain into
– empties into the right atrium
coronary sinus
49
* the pacemaker and controls the electrical impulses which cause contraction
SA node
50
SA node normal rate
60-100 impulse per minute
50
Signal has a 0.1 s delay to allow the atria to contract and totally fill the ventricles before they contract
AV node
50
Depolarization of SA node travels through the
internodal pathway
51
are the uncoordinated atrial and ventricular contractions caused by a defect in the conduction system.
Arrhythmias
51
go to the apex of the ventricular septum then turn upwards
Purkinje fibers
51
* A graphic record of the heart’s
electrical activity.
* The leads must be placed
correctly to get a proper reading.
* The reading is a composite of the
electrical activity not a single
action potential.
Electrocardiogram
51
can cause clotting and inefficient filling of the ventricles.
Atrial fibrillation
51
is a rapid and irregular (usually out of phase) contraction where the SA node is no longer controlling heart rate.
Fibrillation
51
Depolarization of AV node travels through the
AV bundle of His
52
is more life threatening. The ventricles pump without filling and if the rhythm is not rapidly reestablished then circulation stops and brain death occurs.
Ventricular fibrillation
52
is the result of the depolarization wave from the SA node to the AV node. Atria contract 0.1s after P wave starts.
P wave
52
is the application of an electrical stimulus to shock the heart back into a normal SA rhythm. For chronic issues people can have “pacemakers” implanted. This is a device that delivers the electrical stimulus rather than the SA node.
Defibrillation
52
is the result of the ventricular depolarization and precedes ventricular contraction.
QRS complex
53
the events involved with the blood flow through the heart during one heart beat
Cardiac Cycle
53
is caused by ventricular repolarization.
T wave
53
The atrial repolarization is obscured by the
QRS complex
54
contraction phase
Systole
55
* SNS __________ HR
increases
55
* the amount of blood pumped out of each ventricle in one minute
* the product of heart rate (HR) and stroke volume (SV)
Cardiac Output
55
Cardiac Output formula
CO=HR x SV
55
the difference between the end diastolic volume and the end systolic volume
Stroke Volume
56
relaxation phase
Diastole
56
most important factor in causing stretch is the blood in the ventricles
amount of, which is controlled by
venous return
56
Things that decrease heartrate are
negative chronotropic factors
57
BP formula
CO * TPR
57
with every beat the heart pumps about _______ of the blood in its chambers or _____ mL.
60%
70 mL
57
If blood volume
drops or if the heart weakens, then SV __________
decreases
57
* PSNS ___________ HR
decreases
57
Things that increase heartrate are
positive chronotropic factors
57
Ejection Fraction formula
EF = SV/EDV
57
law that states the critical factor controlling stroke volume is preload
Starlings Law
57
* the degree to which the cardiac muscle cells are stretched before they contract
* optimal length/tension relationship for maximal force generation
* overextension leads to inefficient pumping
Preload
57
Stroke Volume formula
EDV-ESV
57
controls the end diastolic volume (EDV)
venous return
57
increase in EDV or increase in the force of the ventricular contraction can _________ SV
increase
57
the volume of blood pumped out of the heart's left ventricle during each systolic cardiac contraction
Stroke Volume
57
Extrinsic controls of SV include:
Sympathetic drive to ventricular muscle fibers
Hormonal control
57
describes how the heart adjusts its stroke volume (the amount of blood pumped out with each beat) in response to changes in venous return (the amount of blood returning to the heart)
Frank-Starling Mechanism
57
increase the venous return or slows heart rate ________ EDV
increases
57
Ejection Fraction Normal rates
Normally averages between 50 and 75 percent under resting conditions
57
One way to quantify contractility
ratio of stroke volume (SV) to end-diastolic volume (EDV)
Expressed as a percentage
Ejection Fraction
57
increase in contractility causes an _________ ejection fraction
increase in
58
is proportional to the amount of ventricular myocardial fiber stretch just before systole (EDV).
Preload
58
* requires the temporary threading of a thin, flexible catheter through an artery or vein into the heart
* radio-opaque contrast material is then injected through the catheter during high-speed x-ray videography
* useful for evaluating cardiac function and for identifying narrowed coronary arteries
Cardiac angiography
58
is the pressure that the ventricles must overcome to force open the aortic and pulmonary valves
Afterload
58
* a noninvasive technique that uses
ultrasonic waves
* can detect the abnormal functioning of cardiac valves or contractions of the cardiac walls
* can also be used to measure ejection fraction
Echocardiography
58
increase in systemic or pulmonary arterial pressure can ___________ afterload
increase
