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
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
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
What is the purpose of the vales?
Allows for unidirectional blood flow
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
What is pericardium?
A double walled membranous sac surrounding heart.
What are functions of serous fluid?
Fills the space between the layers of pericardium and lubricats the heart decreasing friction.
What are three layers of the heart?
Where is epicardium located?
This is outside layer, is the visceral pericardium,connective tissue layer
What is myocardium?
This is the middle layer and it is mostly cardiac muscle
What is endocardium?
Endocardium is the inner layer and mostly endothelium
How many chambers does the heart have?
what separates chambers?
Heart has four chambers and septa separates chambers
what seperates the two ventricles?
What separates the two atria?
What are the four chambers of the heart?
- Atria which are receiving chambers
- Ventricles which are discharging chambers
How many valves does the heart have and where are they located?
- The heart has four valves:
- Bicuspid/miteral( left) tricuspid(right)
- Pulmonary semilunar
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
What drives the blood flow?
pressure difference( high pressure to low pressure) all valves open passivel ydue to pressure gradient
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.
What is pulmonary circuit?
This system takes blood from heart to lungs and lungs to heart
What is systemic system?
This system takes blood from heart to tissue (supplied by left heart)
Where does exchange between blood and tissue take place?
it takes place in the capillaries
What is intrinsic conduction system?
This system is a system where heart muscles contract without nerve impulses in regular continious way
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
What is the coronary sinus?
This is a large vein on the posteriour of the heart that recives blood from cardiac veins
What is the SA node?
This is the peacemaker of the heart which is located on the right
What is AV bundle?
This is also called a bundel of his and is located in the interventricular septum
What is the pathway of heart conduction system?
SA node to AV node to AV bundle to Bundle branches to Purkinje fiber
What is the function of pacemaker cells?
Spontaneously depolarize membrane potential to generate action potential also coordinate and provide rythem to heartbeat
What do conduction fibers do ?
they rapidly conduct action potentials initiated by pacemaker cells
What is the cause of coordination in the heart?
This is due to presence of gap junctions and conduction systems
What are interculated disks?
These are junctions between adjacant myocardial cells
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
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
What is tachycardia? what is bradycardia?
- Tachycardia is rapid heart beat over 100 BPM
- bradycardia is less then 60 BPM
What is ventrical contraction called? what is venttrical relaxation called?
Ventrical contraction is systole and ventrile relaxation is diastole
What is ECG?
This is electrical activity of the heart.
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
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.
What are capillary exchange mechanism?
- Direct diffusion
- Endocytosis or exocytosis
What is fenestration?
these are porses of some capillaries
What force fluid and solutes out of cappilaries? What drives fluid into capillaries?
blood pressure force fluid out and osmotic pressure draws fluid in.
Where is blood pressure higher then osmotic pressure?
at the atrial end of capillary
What id relaxation caused by in arterioles ?
What connects arterioles to venules?