Exam II Flashcards
(104 cards)
1
Q
What does the plasma consist of?
A
Ground Substance (92%)
Dissolved Proteins and Materials (1%)
2
Q
Hematocrit
A
ratio of red blood cells in the plasma
3
Q
Normal Range in hematocrit in men
A
40%-54%
4
Q
Normal range of hematocrit in females
A
37%-47%
5
Q
Red Blood cells (erythrocytes)
A
responsible for gas transportation
6
Q
white blood cells (leukocytes)
A
fully function to immune system
7
Q
plates (thrombocytes)
A
responsible for clotting
8
Q
Hematopoiesis
A
formation of blood and it takes place in the marrow
9
Q
Colony Stimulating factor (CSF
A
causes a stem cell to commit to one specific leukocyte.
10
Q
Thrombopoietin (TPO)
A
causes the stem cell to commit to producing platelets (thrombocytes)
11
Q
Erythropoietin (EPO)
A
causes a stem cell to commit to producing a red blood cell (erythrocyte)
Example: occurs during chemotherapy
12
Q
Understand the role of erythropoietin specifically in RBC production, including what signals its release from the kidneys.
A
The committed cell becomes a large nucleated erythroblast. During maturation, the cell shrinks and loses its nucleus along with other organelles. This cell is called a reticulocyte, it enters the bone marrow blood vessels and once it matures into a biconcave RBC within 24 hours. The biconcave shape increases cell surface area which increases diffusion/exchange of respiratory gases.
13
Q
Cytokines
A
Responsible to help a stem cell commit to produce a certain cell
14
Q
Explain the initiation and role of vascular spasm in hemostasis
A
Chemical signals are released by the damaged tissue which causes the damaged blood vessels smooth muscle to vasoconstrict causing reduced blood flow.
15
Q
What are the processes of hemostasis?
A
-Vascular Spasm
-Platelet Plug
-Coagulation
16
Q
Explain the formation of a platelet plug and why it is important.
A
The damaged tissue exposes collagen, which platets around adhere to it, which results to activated platets called platelet activating factor (PAF). The aggression of platelets form a temporary platelet plug that stop bleeding temporarily.
17
Q
Understand and be able to explain the basics of the coagulation cascade leading to the formation of a clot.
A
- Proteins in the blood and released by damaged cells result in a cascade of signals that activate a circulating protein enzyme called Factor X.
- Factor X convers a circulating protein called prothrombin to thrombin, causing two effects which are converting circulating protein called fibroligin ( form clot) and another circulating enzyme Factor XIII(thickness)
18
Q
Understand the functions of the cardiovascular system
A
- Circulate and distribute nutrients (oxygen, glucose, proteins)
- Remove waste ( Co2, waste products)
- Communication (circulate hormones and other signals)
- Regulation (temperature, muscle activity)
- Protection (antibodies, platelets, immune system)
19
Q
Know the pathways of blood flow in the body (be able to trace a red blood cell as it moves through the circulatory system)
A
Inferior/Superior Vena Cava, Right atrium, tricuspid valve, right ventricle, pulmonary semilunar valve, pulmonary trunk, pulmonary arteries, lungs, pulmonary vein, left atrium, mitral/bicuspid valve, left ventricle, aortic semilunar valve, aorta, body
20
Q
Atrioventricular valves (tricuspid, mitral,bicuspid)
A
control one way movement of blood from the atria to the ventricles. Help stay In place by papillary muscles pulling on choradae tendinae. Keep from blowing out under pressure.
21
Q
Semilunar valve (aortic and pulmonary valve)-
A
Semilunar valve (aortic and pulmonary valve)- control one way flow from ventricles to body via loop. Shape helps them not prolapse.
22
Q
Fossa Ovalis
A
whole in the heart to let blood be pumped by surpassing lungs, but closes when born
23
Q
Ligamentum arteriosum
A
ligament that anchors the aorta to pulmonary trunk to make sure it stays in place, useful in fetal development but no longer has use after birth.
24
Q
Know what the coronary circulation is and what its function is.
A
Circulation of blood in the arteries and veins that supply the heart muscle. It needs uninterrupted supply of oxygen and nutrients if not it will die.
25
RCA supplies the
posterior interventricular artery
Right atrium
Left Atrium (partial)
Right ventricle
Left ventricle (very little)
1/3 septum
SA/AV node
26
LCA supplies the
circumflex artery and anterior interventricular septum (including the following)
Left ventricle
Left Atrium
Right Atrium (little)
2/3 of septum
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atherosclerosis
arterial disease that begins with plaque of cholesterol followed by inflammation of arterial wall, Leads to increase systolic blood pressure
28
Myocardial infarction
the coronary vessel is blocked by either blood clot or debris of atherosclerotic plaque. Blood supply to the heart is stopped.
29
Important features of cardiomyocytes
* Smaller fibers than skeletal muscle but larger than smooth
* High branched
* Intercalated disk between adjacent cells
* SR smaller -Ca from outside and from SR
* Very oxidative
* Cannot perform anaerobic metabolism -require oxygen supply
* Capable of grades contraction
30
Be able to describe, in detail, myocardial E-C coupling
Contraction
1. Action potential enters the sacromela from adjacent cells
2. Voltage-gated Calcium (Ca2+) channels open, allowing calcium to enter cells.
3. Calcium induces calcium release through the ryanodine receptor channels (Ryr)
4. Calcium release causes the release of calcium
5. Summed calcium create a calcium signal
6. Calcium ions then binds with tropin to initiate contraction
Relaxation
1. Calcium unbinds from tropin
2. Calcium is pumped back into the sarcoplasmic reticulum for storage
3. Calcium is exchanged with Sodium (Na+) by the NCEX antiporter
4. Sodium gradient is maintained by the Na+ K+ ATP phase
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the role of calcium in myocardial contractility
Calcium helps activate signal for the heart to contract causing the pump.
32
Where do cardiomyocytes get the calcium, they need for contraction?
Myocardiocytes get their calcium for the contraction from the intercalated disk.
33
Myocardial Cell Action Potential Process
Phase 4: Resting Membrane Potential - 90 mv
Phase 0: Depolarization: Voltage Na channels open
Phase 1: Initial Repolarization: Voltage Na channels close, and Fast K channels open
Phase 2: Plateau Phase: Voltage Ca channels open, K channels slowly decrease due to Ca
Phase 3: Rapid Repolarization: Voltage Ca channels close, slow K channels open.
34
What is the role/importance of plateau phase in contractile cells
* Brings calcium into the cell for contraction and preloads AP (refractory period) to allow the heart fill with blood.
* No tetanus occurs here.
35
True or False: cardiac auto rhythmicity is the unstable pacemaker potential
True
36
10. Be able to trace electrical conduction through all parts of the heart. What are the pathways and the structures involved?
* SA node depolarizes (electrical signal moves from cell to cell via gap junctions
* Wave of Depolarization spreads through the atria – atria contract (special conductive internodal pathway is crucial)
* Electrical connection from atria to ventricle blocked except at the AV node (conduction slows down through AV node aka AV node delay; provides time for atrial contraction and ventricular filling)
* Depolarization continues down the septal conduction system ( First through AV bundle-bundle of his; Next through L and R bundle branches; Finally though small Purkinjie Fibers in walls of ventricles; Wave of depolarization spreads through ventricles (from apex to base)
* Ventricles Contract: (bottom to top, wringing twisting- spiral muscle arrangement) (artia replorize)
* Ventricles Repolarize in opposite direction ( last to polarize is first to depolarize)
37
Describe what “heart block” is and what effect it has on the coordination of contractions between the atria and ventricles.
Heart Block is known as conduction disorder. If electrical signals cant move from atria to ventricles, blood is not being pumped correctly
38
Understand what an electrocardiogram represents.
Electrocardiogram is the activity of the heart, not action. Can reflect specific part of the heart depolarizing and repolarizing.
IMPORTANT: Does NOT show contraction, rather the mechanical events.
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P wave
atrial depolarization
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QRS complex
ventricular depolarization
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T wave
ventricular repolarization
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PR interval
total duration of P wave up to QRS complex
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PR segment
time between atrial and ventricular depolarization
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What can you determine about heart function from an EKG? This includes heart rate, cardiac rhythm, third degree AV block.
* Heart rate (bradycardia,tachycardia)
* Rhythm of the heart (fast, slow, irregular)
* Conduction blocks ( Multiple P waves per QRS)
* Cardiac hypertrophy ( enlarged QRS and T due to more conductive tissue!)
45
Basic physics of blood (fluid) flow
* Contraction of the heart results in an increased pressure of fluid inside, also known as hydrostatic pressure. (Pressure against the walls of the container).
o Pressure developed by the ventricle is known as driving pressure since it drives the flow away from the heart.
* When the driving pressure (hydrostatic) in the ventricles rise above the hydrostatic pressure of blood in the aorta, the valve will open and blood will flow out. (blood will flow from an area of high pressure to low pressure)
* Moving Fluid now exerts hydraulic pressure
* Resistance opposes blood flow
o Friction of blood against the blood vessel decreases the energy flow
o Rate of fluid flow is inversely proportional to to resistance (increase, decrease; decrease, increase)
o Vessel Diameter(increased diameters have less resistance, increased flow; decreased diameter have more resistance, decrease flow)
o Velocity of flow depends on flow rate and vessel diameter (velocity is dependent on the flow rate and the diameter. – smaller vessels have higher velocity than larger tubes if driving pressure)
46
Understand and be able to describe the cardiac cycle (Five Functional Stages)
o Late Ventricular diastole: Both chambers are relaxed and ventricles will fill with blood through AV valves.
o Artial Systole: SA node fires, atrial depolarizes. Atria contracts, primer pump for ventricles. (atrial contraction is more important in exercise)
o Early ventricular systole(no isovolumic contraction) : ventricles contract, pressure increases, no blood passes by. First heart sound is the “lub” due to the AV valves closing.
o Ventricular systole (ejection phase) : semilunar valves are forced to open, blood ejects to the arteries, aortic pressure increases dramatically, atria are repolarizing and relaxing as well as refilling.
o Isovolumic ventricular relaxation: ventricles relax, when ventricular pressure decreases below aortic pressure, semilunar valves close making the “dub sound”, ventricle pressure drops the volume will remain the same while valves are closed, pressure in ventricles are still higher than pressure in atria.
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Diastole
Cardiac muscles are relaxed, which reduce pressure inside the cardiac chambers. This allows the chamber to fill with blood.
48
Systole
cardiac contraction, increasing fluid (hydrostatic) pressure of the blood on the walls. Pressure on chambers will rise causing the fluid to fill out.
49
When do the heart sounds occur and why?
* First Heart sound “lub” occurs when the AV valves are closing
* Second heart sound “dub” occurs when the semilunar valves are closing
50
True or False: ECG comes before the mechanical events (contraction/relaxation)
True
51
ventricular pressure-volume curve process
A-B filling of ventricle
B-C isovolumic contraction (End diastolic volume)
C-D ventricular contraction (ejection)
D-A ventricular relaxation (no filling) (End systolic volume)
52
What is stroke volume and how is it determined?
Stroke volume is the volume ejected with each heartbeat
Formula: SV= EDV- EVS
Normal SV = 70ml
53
What is cardiac output and what are its components? How can you increase/decrease cardiac output?
Cardiac Output is a measure of how well the heart is functioning as a pump.
o Components are Extrinsic and Intrinsic
Formula: CO = SV x HR
Average CO = 5L/min
Can reach up to 35L/min during exercise.
54
Be able to explain the extrinsic and intrinsic control over cardiac function
The body alters cardiac output by regulating the contractility of the heart muscles and changing the heart rate
55
Describe the regulation of cardiac function extrinsically by the sympathetic branch.
Sympathetic neurons release epinephrine onto the cells of the SA and AV node only. EPI increases heart rate and strength of contraction. Beta Receptors (heart) Alpha( smooth/organs)
56
Describe the regulation of cardiac function intrinsically by the parasympathetic branch
Parasympathetic neurons only synapse with pacemaker cells of the SA and AV node, releasing acetylcholine onto those receptors. It usually only affects the pacemaker by making it slower and less strength of contraction.
57
sympathetic constriction of blood vessels ____ resistance (which leads to increased blood pressure AND ___ volume return to the heart (causing a stretch intrinsic mechanism)
Increases; increases.
58
How does increased venous return allow for intrinsic regulation of heart activity (Frank-Starling mechanism)?
The heart can also heart contractility through self-regulation by increasing the activity of the skeletal muscles pump in the limbs, constriction of large veins, and respiratory pump.
This leads to stretching of contractile myocytes, which help improve overlap and stretchs the myocardial cells that increases the movement of Ca and Na into the cells causing rapid depolarization
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Arteries/arterioles
thicker walls, carry blood away from the heart, pressure regulators
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Veins/venules
thinner walls, carry blood to the heart, volume reservoirs.
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Capillaries
where nutrient/waste exchange occurs
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Tunica Intima
(inner layer) endothelial lining and elastic connective tissue. In arteries may include a thicker layer of elastic fibers (internal elastic membrane)
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Tunica Media
(middle layer) smooth muscle and connective tissue. Arteries may include an additional band of elastic fibers (external elastic membrane). Smooth muscle contraction causes vasoconstriction,and relaxation causes vasodilation.
64
Tunica Adventitia
(outer layer) dense, irregular connective tissue sheath containing collagen/elastin fibers, nerve endings, macrophages. Plays an important regulatory role over the function of the muscular media and the “leakiness” of the endothelium.
65
Arteries
thicker walls than veins, within thicker media(muscle) layer and may also contain internal/external elastic laters that are not found in the veins
66
Arterioles
much smaller than muscular artieries, they control blood flow to capillary beds.
67
Capillaries
the smallest blood vessels, only one RBC at a time, Permit the movement of nutrients and waste between blood and tissue.
68
Capillary beds
a network of capillaries and supporting vessels.
69
Veins/venules:
collect blood and return it to the body
70
Know the function of the large, elastic arteries in maintaining blood pressure
Stretches during ventricular systole to store the increased blood pressure
71
Know the different kinds of capillaries.
Continuous
Fenestrated
Sinusoid
72
Continuous
most common, consist of endothelial lining with cells connected by tight junctions (permits selective change of material
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Fenestrated
found where lots of exchange occur, endothelial has multiple of holes
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Sinusoid
extra-large openings to permit exchange of large substances.
75
Know the anatomy of a capillary bed
entrance of capillaries is guarded by ring of smooth muscle (precapillary sphincter) that determines whether capillart is open or closed. Capillaries that are predominantly in the menesties of the GI tract, have larger vessels called metarterioles since they bypass channels that are used to shunt blood through the capillary bed when the capillary is closed. In some areas, capillary beds are supplied by one or more artery is called a collateral channels.
76
Function of venous one-way valves
Help assist in return of blood in one direction back to the heart, they stop backwards movement of blood.
77
Know the function of the vasa vasorum.
(circulatory system) for Blood vessels to supply blood vessels themselves.
78
What are hepatic portal systems
The hepatic portal systems regulate/process nutrients and toxins from the GI tract
79
What is the importance of maintaining adequate blood pressure?
Is to ensure that nutrients and waste exchange occurs correctly in the capillaries.
80
20. What is pulse pressure and how is it calculated? Where is it most easily felt and why? What happens to pulse pressure/blood pressure as you move through the circulatory system?
Pulse pressure is the blood flow and pressure increase and decrease within the cardiac cycle. It is calculated by the systolic pressure over the diastolic pressure. The pulse is easily felt in larger arteries (carotid, femoral). As it moves through the circulatory system it disappears as it enters the capillary beds.
81
Know why blood continues to flow through the circulatory system even during ventricular diastole?
* Blood is still flowing from areas of high pressure to those of lower pressure.
* In lower extremities, larger veins have one way valves to keep blood flowing upward
* Skeletal muscle and respiratory pumps are also useful in moving blood out the venous system.
82
What is mean arterial pressure? What are the major determinants of MAP and how do you calculate it
When blood pressure is maintained above zero throughout the circulatory system primarily because arterial system is elastic and maintains pressure around the blood, it is difficult to measure ventricles without procedures, so it is measured through the arteries.
83
MAP formula
a. MAP = diastolic pressure + 1/3(systolic pressure – diastolic pressure)
84
What does mean pressure result from?
Cardiac output and arteriolar resistance
85
How is blood pressure regulated and where? What are baroreceptors, where are they located and what do they do?
Blood pressure is regulated by baroreceptors that are located in the walls of carotid artery and aorta. Baroreceptors are stretch receptors that communicate with the cardiovascular control center in the medulla oblongata.
86
What are capillaries?
Capillaries are one of the major reasons that maintain blood pressure in the circulatory system. Their important feature is to facilitate the exchange of nutrients and waste in the capillary bed.
87
Capillaries features:
o Comprised of endothelial cells on basement membrane
o Contradicle pericytes and regulates leakiness
o Huge cross sectional areas (one RBC at a time)
o Have very slow rates (promotes exchange, diffusion)
o Filter and observe materials. (nutrients, waste, fluid)
o Precapillary smooth muscle (splitters)
88
Three mechanisms used in capillary exchange.
Diffusion
Transcytosis
Bulk flow
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Diffusion:
driven by the concentration differences. Occurs between cells paracellular or across cells. Is limited by tight junctions. Transcellular limited by lipid solubility and size.
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Transcytosis:
movement of large particles via vesicles (combination of endo and exocytosis)
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Bulk flow:
movement of small molecules and water though gap (or fenestrations) by combination of osmotic and hydrostatic pressure.
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capillary exchange
change chemicals between blood and interstitial fluid
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Filtration:
the direction of flow across the capillary epithelium is from the blood to the tissues
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Absorption
the direction of flow is from the tissues back into the capillary
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Hydrostatic pressure:
the blood on the wall of the arteries. Pressure is higher in capillary and lower in interstitial fluid. Favors filtration.
96
Colloid osmotic pressure
blood has high concentration of proteins but not the interstitial fluid. Have osmotic effect meaning the osmotic pressure difference between blood and tissues. Favors absorption by attracting fluid
97
Be able to explain what would happen to capillary exchange if you changed blood pressure on the arterial end (increase or decrease) or you altered the amount of proteins in the blood (oncotic pressure).
The capillary exchange would not be balanced.
98
What is the lymphatic system?
Lymphatic system is a system of blood vessels and nodules (called lymph nodes) that interact primarily with the cardiovascular system, digestive, and immune.
99
Lymphatic system functions
o Return fluid and protein to circulatory system after bulk filtration
o Filter to capture and destroy foreign pathogens.
o Transport of dietary fat from small intestine
100
How does the lymph system relate to the capillary exchange only
Lymph capillaries are found next to blood capillaries large gaps in the thin walls let fluid, proteins, and particles such as bacteria enter and become lymph fluid. Fluid moves up through contraction of smooth muscle in larger lymph vessels.
101
What is edema
Edema is a tissue swelling those results from alteration in capillary exchange with lymph vessels.
102
how can edema occur?
Can occur by
o inadequate drainage of lymph (can also cause elephantiasis)
o blood capillary filtration needs exceeds lymph drainage.
103
What is needed to transport fluid to leave the capillaries?
Net filtration
104
Understand the importance of the shape of RBCs and the general structure and role of hemoglobin
RBC shape is important since it is able to pass through vessels. Hemoglobin is a special protein. Hemoglobin is responsible for the transportation of respiratory gases, oxygen and carbon dioxide. Comprised of protein globin.
