Cardio Lec 1-3 Flashcards
Function of the valves
prevent back flow of blood
When do valves close
when arterial pressure is > than ventricle
Systole refers to
contraction
Diastole referes to
relaxation
End systolic volume
amount of blood remaining in ventricle at end of systole
End diastolic volume
amount of blood in ventricles before they contract
What blood actually gets ejected
end systolic & end diastolic
Stroke volume
amount of blood that gets ejected
Functions of the circulatory system
transportation, regulation of hormones & temp, protection
RBC’s transport __ & remove __
O2; CO2
Blood carries __ to distant sites
hormones
Cardiovascular system refers to
heart + blood vessels
4 chambered dual pump
heart
The atria ___ blood, ventricles __ blood
receive; pump blood to lungs & body
Which has a greater workload? atria or ventricles?
ventricles
Which has a greater workload? left or right ventricle?
left b/c pumps blood to systemic side
Amount of cardiac output per min?
5L/min
Arteries move blood __, veins ___
away; return blood to heart
T/F: All veins carry dO2 blood & all arteries carry O2 blood
F
Largest artery
Aorta
Arteries –>
arterioles –> capillaries
Capillaries are
site of gas exchange; THIN-walled
How does gas exchange occur in capillaries?
O2 delivered to tissues, CO2 picked up
Capillaries –>
venules –> veins
Largest veins
IVC + SVC
Components of blood
plasma + formed elements
Plasma is the ___ portion, the formed elements are the ___ portion
fluid; cellular
The Buffy coat contains
WBC’s + platelets
Plasma vol. is regulated tightly by
osmoreceptors
When blood osmolarity increases, it indicated possible
dehydration
What is the purpose of RBC’s donut shape?
increased surface area for a higher diffusion rate
Characteristics of erythrocytes
flexible (to squeeze thru small caps), donut shaped, anucleated, 120 day lifespan, no mitochondria, anaerobic resp
Why is it advantageous for erythrocytes to have no mitochondria (means they are anaerobic)
b/c they would use the O2 that they are transporting
Each RBC has ___ of Hb molecules
a lot
How many chains in each Hb?
4; 2 alpha + 2 beta
Heme
iron recycled from old RBC’s
Iron deficiency =
anemia
Characteristics of Hb
each has heme at center; contains iron which binds to O2
Heme is carried by
transferrin
Dietary needs of iron are __, but __
small; essential
Anemia causes
low Hb or low RBC count; blood loss or iron def
Symptoms of anemia
tired, pale, weak, SHORT BREATH (would be trying to get more O2), FAST HR (heart trying to deliver what blood you do have to tissues)
Pernicious anemia
lack of intrinsic factor (B12 injection)
Aplastic anemia
destruction of bone barrow (chemo could cause)
Polycythemia
elevated RBC’s
When does polycythemia lead to viscosity issues
only in severe cases
T/F: Polycythemia is usually not detrimental; it is an adaptation
T
Sickle-cell anemia is due to
a genetic mutation in Hb
Characteristics of leukocytes
contain nuclei & mitochondria; are motile
Why do leukocytes need to be motile?
to be able to move outside of bloodstream to fight pathogens
Diapedesis
ability to squeeze through capillary walls
Extravasation
exit from vascular system & enter into tissues
Types of leukocytes
granulocytes: basophils, eosinophils, neutrophils
agranulocytes: lymphocytes, monocytes
Normal hematocrit count
males: 40-54%
females: 37-47%
Normal Hb count
males: 14-17
females: 12-16
Platelets
smallest formed elements; cell fragments of megakaryocytes
Platelets form
platelet plug for CLOTTING
Characteristics of platelets
anucleated, move around, short lifespan
Platelets get destroyed by the
spleen & liver
Hematopoiesis
blood cell formation
Leukopoiesis
WBC production
Process of leukopoiesis
totipotent cells give rise to blood cell precursor
Myeloblasts –>
Lymphoblasts –>
Monoblasts –>
granulocytes
lymphocytes
monocytes
Erythropoiesis
RBC production
Erythropoiesis regulated by
erythropoietin
Erythropoietin secreted by
kidneys in response to hypoxia
T/F: People w/ asthma, w/ blood loss, at a high altitude, w/ a lung disorder, or doing strenuous exercise can all be hypoxic
T
T/F: RBC’s have a limited lifespan & require continual replacement
T
T/F: People with emphysema usually have elevated levels of Hb
T
Clinical relevance of having elevated levels of reticulocytes
it indicates recent blood loss b/c it indicated that RBC synthesis has been stimulated to a large degree
Process of EPO
hemocytoblast (stem cell) –> EPO binds receptors proerythroblasts –> erythroblast –> normoblast –> nucleus lost –> reticulocyte –> erythrocyte (then released into blood)
Antigens
molecules capable of eliciting an immune response
When we recognize antigens as cells it’s b/c we recognize those cells as ___
foreign
Antigens are important b/c they produce
antibodies
When you produce antibodies against your own cells
auto-immune disorder
A blood binds __; produces __
a-antigen; anti-b abs
B blood binds __; produces __
b-antigen; anti-a abs
AB blood binds __; produces __
a & b-antigens; neither
O blood binds __; produces __
no antigens; anti-a & anti-b abs
Why are abs produced when we have no prior exposure to them?
they are produced in response to intestinal bacteria that has antigens that look similar to blood surface antigens –> they cross react
Universal donor
O (b/c they have no antigens)
Universal recipient
AB (b/c they don’t produce A or B antibodies)
Most common type of blood
O
Least common type of blood
AB
What happens if someone w/ A receives B?
transfusion reaction –> agglutination –> clot vessels (ischemia) –> cells targeted for destruction by immune system –> donor cells lyse & free Hb released –> free Hb can block kidney tubules –> death from renal failure
Transfusion reaction
mismatched blood; donor’s blood is agglutinated by recipients abs
T/F: Plasma contains abs
T
Why does agglutination occur?
each ab molecule contains many binding sites
How is blood typing done?
drop of blood is placed in different ab solutions
Clumping =
positive reaction (antigens of that type present)
Anyone w/ d-antigens is
Rh+
Anyone w/o d-antigens is
Rh-
O+ means
type O AND Rh+ (has d-antigen)
O- means
type O AND Rh- (lacks d-antigen)
AB- means
has AB only
AB+ means
has Ab & D
T/F: Anti-d abs are not present until exposure
T
Why is it an issue for an Rh- mother to be carrying an Rh+ baby?
1st preg = no issue b/c no prior exposure to d-abs; will be exposed during birth and mom will create d-abs
2nd preg = issue b/c mom now has d-abs that will attack baby’s blood –> baby born w/ severe anemia
How is erythroblastosis fetalis prevented?
RhoGAM prior to birth
What does RhoGam do?
antibody that effectively HIDES baby’s antigens from mom’s immune system so she wont make abs against it
Blood is
a liquid that has the ability to turn into a gel-like semi-solid substance is response to injury
T/F: People with clotting disorders bruise easily & badly
T
T/F: Inappropriate clot formation is as bad as no clot formation
T
Are platelets normally repelled from vessel walls & eachother
yes
What is the purpose of a vascular spasm when there is injury to the vessel
to slow down bleeding
Vonwillebran factor
factor that bridges the interaction between platelets & collagen strands to be able to form a platelet plug
Vonwillebran’s disease
lack factor so platelets CAN’T adhere to exposed collagen –> platelet form doesn’t form as well
What is released when platelets are ‘activated’
serotonin, thromboxane, ADP
What is the function of serotonin here
to further stimulate the vascular spasm that slows down blood loss
What is the function of ADP & thromboxane here
to recruit more platelets & make platelets sticky
The platelet plug is a ___ fix
temporary; until stable clot forms
NSAID’S act as ___ drugs
anti-platelet
How are NSAID’S anti-platelet drugs
b/c they inhibit cyclooxygenase which is required for the production of thromboxane –> if you can’t make tx, you can’t aggregate platelets as well –> can’t form platelet plug as well
What does the clotting cascade do?
convert fibrinogen –> fibrin & ensure that fibrin strands deposit on platelet plug
Serum
plasma w/o clotting factors/fibrinogen
In order to form a clot, you must form __
fibrin
Extrinsic pathway is activated by
chemicals released when tissue is damaged
Intrinsic pathway is activated by
platelet activation
Both the extrinsic & intrinsic pathways are activated as a result of
a damaged vessel
Both the intrinsic & extrinsic pathways are produced in what form?
inactive that can activate quickly
If someone can’t activate platelets, would they still be able to clot?
yes, but not so well
If someone can’t activate 1 of 2 clotting factors, can they still clot?
yes, bc they give you some redundancy in case something goes wrong
What begins the common pathway?
activation of factor x
Common pathway
activates prothrombin –> activates thrombin –> activates fibrinogen –> becomes fibrin
What activates factor x?
both the intrinsic & extrinsic pathways
Antithrombin inhibits ___
thrombin
What happens if you don’t produce thrombin & why?
you don’t clot as well bc you won’t be as good to produce fibrin
When else can the body think there is damage to a vessel?
when a vessel ruptures due to atherosclerosis
Which pathway is quicker to reach the common pathway?
extrinsic
Can long-term antibiotic therapy cause a problem with clotting?
yes bc bacteria make vit K
A defect in factor viii linked to royal families in Europe
Hemophilia A
Which factors are vit K dependent?
2, 7, 9, 10
All clot busting drugs cause activation of ___
plasmin
Anticoagulant that activates antithrombin & works quickly
Heparin
Anticoagulant that inhibits vit K & takes days to work
Coumadin
Process of vessel repair
plasminogen (inactive) –> plasmin (active) –> plasmin digests fibrin promoting clot brkdwn
Clotting cascade
damage to vessel –> vessel spasms –> exposed collagen recruits platelets to area –> platelets become activated –> serotonin release (further spasm) –> ADP & TX released (more platelets to area to stick together) –> platelet plug formed
Right side of the heart pumps blood to the
lungs
Left side of the heart pumps blood to the
body
T/F: Right heart generates greater pressure
F; left
As compared to the left heart, what percentage of blood is pumped through the right heart
100% (the same)
When should AV valves open?
atrial press > ventricular
When should AV valves shut?
when ventricles contract
When should semilunar valves open?
ventricular press > arterial pressure
When should semilunar valves shut?
arterial pressure > ventricular pressure
The cardiac cycle refers to
the repeating pattern of contraction & relaxation
First the ___ contract, THEN the ___ contract
atria; ventricles
80% of blood that ventricles receive from atria occurs
passively
20% of blood that ventricles receive from atria occurs
when atria finally contract
EDV refers to
blood in ventricles at the end of ventricular diastole/amount of blood when filled
ESV refers to
little bit of blood that remains after the ejection phase
Stroke vol
amount of blood ejected from the ventricles in one systole
SV =
EDV - ESV
If EDV = 100 mls & ESV = 20 mls, what is the SV?
80 mls
Ventricles contract once filled –>
ventricular press > atrial press –> av valves shut –> ventricular press > aortic press –> aortic semilun. valves open –> blood moves up aorta (begins ejection phase)
SV is usually about
70 mls
Which valves open during the isovolumetric contraction phase?
none
