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What is the main function of the cardiovascular system?
It's function is to deliver oxygen and nutrients and remove carbon dioxide and other waste products
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What are examples of substances that are transported by cardiovascular system?
- transport of oxygen and nutrients to cell
- waste from cells to liver and kidney
- hormones, immune cells, clotthing proteins to specific target cells
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Where is the heart located ? what are some characteristics associated?
Heart is in thoracic cavity between lungs in the inferior mediastinum, it is the size of a fist, weighs between 250-35 grams
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What is the purpose of the vales?
Allows for unidirectional blood flow
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What do intercalated disks do? What do desmosome do?
Intracalated disks are gap junctions so that the heart conteracts as a unit and desmosomes resit stress
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What is pericardium?
A double walled membranous sac surrounding heart.
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What are functions of serous fluid?
Fills the space between the layers of pericardium and lubricats the heart decreasing friction.
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What are three layers of the heart?
Epicardium,myocardium,endocardium
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Where is epicardium located?
This is outside layer, is the visceral pericardium,connective tissue layer
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What is myocardium?
This is the middle layer and it is mostly cardiac muscle
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What is endocardium?
Endocardium is the inner layer and mostly endothelium
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How many chambers does the heart have?
what separates chambers?
Heart has four chambers and septa separates chambers
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what seperates the two ventricles?
interventricular septum
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What separates the two atria?
Interatrial septum
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What are the four chambers of the heart?
- Atria which are receiving chambers
- Ventricles which are discharging chambers
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How many valves does the heart have and where are they located?
- The heart has four valves:
- atroventricular
- Bicuspid/miteral( left) tricuspid(right)
- semilunar
- Pulmonary semilunar
- Aortic
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What do each valves of the heart do?
- AV valves are abchored in place by chordae tendineae and are open during heart relaxation
- Semilunar valves are close during heart relaxation
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What drives the blood flow?
pressure difference( high pressure to low pressure) all valves open passivel ydue to pressure gradient
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List the differences between arteries, arterioles,capilaries nenules, veins
arteries are large,branching vessels that conduct blood away from the heart. Arterioles are small branching essels with high resistance , capillaries are site of exchange between blood and tissue, veins are large converging vessles that conduct blood to the heart.
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What is pulmonary circuit?
This system takes blood from heart to lungs and lungs to heart
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What is systemic system?
This system takes blood from heart to tissue (supplied by left heart)
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Where does exchange between blood and tissue take place?
it takes place in the capillaries
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What is intrinsic conduction system?
This system is a system where heart muscles contract without nerve impulses in regular continious way
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What is the heart nourishing circulatory system?
- Coronary is a branch of aorta which supplies the heart with oxygenated blood
- cardiac vein drain the myocardium
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What is the coronary sinus?
This is a large vein on the posteriour of the heart that recives blood from cardiac veins
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What is the SA node?
This is the peacemaker of the heart which is located on the right
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What is AV bundle?
This is also called a bundel of his and is located in the interventricular septum
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What is the pathway of heart conduction system?
SA node to AV node to AV bundle to Bundle branches to Purkinje fiber
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What is the function of pacemaker cells?
Spontaneously depolarize membrane potential to generate action potential also coordinate and provide rythem to heartbeat
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What do conduction fibers do ?
they rapidly conduct action potentials initiated by pacemaker cells
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What is the cause of coordination in the heart?
This is due to presence of gap junctions and conduction systems
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What are interculated disks?
These are junctions between adjacant myocardial cells
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How does peace maker control heartbeat?
Spontaneouse depolarization caused by closing potassium channels and opening of funny channels and the calcium channels which cause further depolarization
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What are the steps of excitation-contraction coupling?
- depolarization of cardiac contractile cell to threshold via gap junction.
- opening of calcium channels in plasma
- ap travels down T
- calcium is relase from SR ( calcium induced , Action potential)
- Calcium binds to troponin causing shift in tropomyosin
- binding sites for mysin are actin are exposed
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What is tachycardia? what is bradycardia?
- Tachycardia is rapid heart beat over 100 BPM
- bradycardia is less then 60 BPM
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What is ventrical contraction called? what is venttrical relaxation called?
Ventrical contraction is systole and ventrile relaxation is diastole
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What is ECG?
This is electrical activity of the heart.
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What is p wave, what is QRS and what is T wave?
P wave corresponds to atrial depolarization, QRS ventricale depolarization and T ventricle repolarization
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What is the major structural difference in arteries and veins?
arteries are thicker , and vein lumens are larger and have valves. also arteries have less elastin and smooth muscle regulates radius.
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What are capillary exchange mechanism?
- Direct diffusion
- Endocytosis or exocytosis
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What is fenestration?
these are porses of some capillaries
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What force fluid and solutes out of cappilaries? What drives fluid into capillaries?
blood pressure force fluid out and osmotic pressure draws fluid in.
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Where is blood pressure higher then osmotic pressure?
at the atrial end of capillary
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What id relaxation caused by in arterioles ?
Metabolites
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What connects arterioles to venules?
vascular shunts
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