Hosam Mohamed-
high to low
Blood flows from ________
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Pulmonary Circuit
-right side of the heart
-pushes blood through heart the heart, the lungs, and back to the heart
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Systemic circuit
-located on the left side of the heart
-pushes blood through heart, tissues, and back to the heart
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the purpose of gas exchange
What is the function of the pulmonary circuit?
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Pulmonary trunk
-oxygen-poor blood leaves the right ventricle via the pulmonary trunk; large artery that branches to left and right pulmonary arteries
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Pulmonary arteries
take the blood to the lung where oxygen is picked up and CO2 is left off
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Pulmonary veins
blood returns to the heart via four pulmonary veins that go to the left atrium
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Systemic
Which circulation consists of blood vessels that extend to and from the heart?
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deliver oxygen & nutrients to body tissues; picks up CO2 and waste products
What is the function of systemic circulation?
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right atrium, right ventricle, left atrium, left ventricle
What are the 4 chambers of the heart?
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tricuspid, pulmonary, mitral (bicuspid), aortic
What are the 4 valves of the heart?
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Pericardium
-provides cushioning; friction free
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Epicardium
outer visceral layer that lines the surface of the heart often infiltrated with fats
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criss-crossing, interlacing layers of cells & connective tissue
What is the orientation of cells on the myocardium?
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atria & ventricles
AV valve is between _______
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AV valves
-prevent backflow into the atria when ventricles contract
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left side
Bicuspid/mitral valve located on ______
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right side
Tricuspid valve located on ________
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Chordae Tendineae
____________ anchor AV valves to papillary muscles
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ventricles and arteries
Semilunar valves are between ___________
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Semilunar valves
-prevent backflow of blood into the ventricle
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right side
Pulmonary semilunar valve is on the ______
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left side
Aortic semilunar valve is on the _________
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Lub
- atrioventricular valves close (tricuspid & mitral valves )
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Dub
- Semilunar valves close (pulmonary and aortic)
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Intercalated discs
_________ anchor cardiac cells together.
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Desmosomes
- comprise of cell connections
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Gap junctions
- all free passage of ions for spread of depolarization
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F-channels
-have unstable resting potentials that continuously let Na+ in causing slow depolarization (drift slowly up to threshold) called pacemaker potentials
-when open, Na influxes
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Voltage-gated calcium channel
-use calcium influx (rather than sodium) for rising phase depolarization of the action potential
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Contractile Myocardium cells
cardiac muscle cell AP and CICR contraction
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F-channels
_____ close during depolarization.
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Ca2+ channels; depolarization; AP
Once membrane depolarizes to a threshold voltage, ___________ open to initiate the __________ & _________
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Ca2+; K+; repolarize
Once action potential occurs, __________ close and ________ channels open to _________ the membrane.
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Phase 0: Depolarization
- Na+ channels open
- voltage-sensitive L-type Ca2+ channels slowly open for CICR
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Phase 1: initial repolarization
-Na+ channels close
- Fast K+ channels open increasing K+ permeability for rapid repolarization
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Phase 2: Plateau
-Fast K+ channels close decreasing K+ permeability
-L-type Ca2+ channels are fully open to increase Ca2+ permeability and flatten AP
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End of Plateau
-L-type Ca2+ channels close at the end of plateau phase decreasing Ca2+ permeability
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Phase 3: Rapid Repolarization
-Slow K+ channels open increasing K+ permeability to repolarize the membrane
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Phase 4:
-resting membrane potential
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depolarize; repolarize
Cardiomyocytes _________ quickly, but take much longer to ________
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arrhythmia
What is the result of a long, uneffective refractory period?
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ACH; sodium permeability; voltaged gated calcium channels
Skeletal muscle use _______ to change _______ to open ____________. (DHP receptors)
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ACH or DHP
_______ or _________ are not used in cardiac muscle.
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Voltage-gated L-type calcium channel
open letting in a "spark of calcium"
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calcium-induced calcium release; ryanodine receptors
Calcium spark causes _________ from _______ to cause contraction.
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right atrium
The SA node or "pacemaker" is found in ______
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AV node
_________ is found in right atrium near septum
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Purkinje fibers
______ cause ventricles to contract.
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sa node, av node, av bundle, bundle branches, purkinje fibers
List the steps in heartbeat path.
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P wave
-corresponds to depolarization of SA node
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atria
after P wave begins; ________ contracts.
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QRS complex
-corresponds to ventricular depolarization and precedes ventricular contraction or systole.
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T wave
-corresponds to ventricular repolarization followed by ventricular relaxation. (diastole)
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CO= HR* SV
Formula for Cardiac output
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Preload
-load imposed on heart before contraction begins
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Afterload
-load imposed on heart after contraction
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left
What has more pressure & resistance; Left or right ventricle?
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Cardiac output
-the amount of blood the heart beats per unit time (L/min)
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Stroke Volume
-the amount of blood the heart pumps with each beat
