Blood Vessels and the Heart (Cardiovascular system)

what is the systemic circuit? which side of the heart is it located at ?

Circuit of blood that carries blood between the heart and the rest of the body. left side of the body.

why are arteries red and veins blue ?

arteries carry oxygenated blood and are deeper, veins carry deoxygenated blood and are superficial. all blood is red oxygenated blood is a bright red.

autorythmic

regular, spontaneous depolarization

components of cardiac conduction system

SA node, AV node, AV bundle, bundle branches, purkinje fibers

wha is the cardiac conduction pathway?

SA node, AV node, bundle of His, right and left bundle branches, Purkinje fibers

what is the difference between Artery vs vein walls?

Arteries are higher pressure so have thicker muscular walls

myocardial infarction

complete obstruction of arteries that causes death of cardiac cells.

endocardium

inner lining of the heart

What do the left and right coronary arteries do?

supply the heart muscle with oxygenated blood.

coronary artery bypass graft (CABG)

surgical technique to bring a new blood supply to heart muscle by detouring around blocked arteries

interatrial septum

wall between the atria of the heart

Blood flow through the heart

IVC , SVC, coronary sinus --> Rt atria --> Tricuspid valve or right atrioventricular valve --> Rt ventricle --> Pulmonary valve --> Lungs --> Lt atria --> Mitral valve --> Lt ventricle --> aortic valve --> aorta --> systemic circuit

Myogenic

Describes muscle tissue (heart muscle) that generates its own contractions.

What are varicose veins?

Dilated, tortuous superficial veins. Occur in 15% of adults. Pathology is superficial venous insufficiency and valve incompetence.

Why is the left ventricle thicker than the right?

The left ventricle must pump blood throughout the entire body and the right only has to go to the lungs.

Where is the heart located?

mediastinum, between lungs

what do the anterior and posterior interventricular sulci ?

separates left and right ventricles, and contains blood vessels of cardiac muscles.

Veins

Blood vessels that carry blood back to the heart, thin walls.

angina pectoris (chest pain)

supply of oxygen and nutrients in the blood is insufficient to meet the demands of the heart, the heart muscle "aches" The heart requires a large supply of oxygen to meet the demands placed on it

the aortic arch divides into what divisions , which are ?

brachiocephalic trunk left common carotid artery left subclavian artery,right subclavian descending aorta (thoracic aorta)

what is the Myocardium? what does it form ?

the muscular, middle layer of the heart forms the atria and ventricles

how is blood in the heart muscle returned ro the heart ?

the veins of the heart muscle all dump their deoxygenated blood into the coronary sinus which then goes into the right atria.

what is the pulmonary circuit? and which side of the heart is it located at ?

carries blood to the lungs for gas exchange and returns it to the heart right side of the heart.

Signs of a heart attack

chest pain that lasts longer than 3-5 min, often radiates down to the left arm and shoulder.

parietal pericardium and visceral pericardium

the visceral pericardium is the epicardium and it attaches straight to the heart, the parietal pericardium is the sac that covers the hear also know as pericardial sac.

what happens to the dead cardiac cells in the heart ? does the tissue that replaces the cardiac cells contract ?

they are replaced by connective tissue, so scar tissue just develops. does not contract.

Three layers of an artery

tunica interna, tunica media, tunica externa

what is the SA node (sinoatrial node)? function ? location ? causes what to contract ?

-pacemaker of the heart -sets the heartbeat rate -located in the right atrium -causes atria to contract

the role of calcium in cardiac contraction ? where and how much of calcium comes ? (Slide 6)

1. 20% of Ca+2 comes from Ca2+ entering the plasma membrane in the plateau phase 2. 80% of Ca2+ comes from calcium reserves in SR, triggered by the arrival of extracellular calcium ions. 3.as slow calcium channels close, intracellular ca2+ is absorbed by the SR or pumped out of the cell.

What is the funny current?

The unstable "resting" membrane potential in pacemaker cells that creeps up from -60 mV to -40 mV, slow leakage of Na+ into the cardiac action potentials.

atrioventricular valves

Valves located between the atrial and ventricular chambers on each side of the heart, prevent backflow into the atria when the ventricles are contracting.

coronary endarterectomy

a surgical procedure that removes plaques

what are Arterioles and Venules?

arterioles are the smallest artery in the body. venules are the smallest veins in the body.

coronary artery occlusion

blockage coronary artery (more than 50% blockage

What is the AV node and what does it do? why does it have a delay ?

electrical gateway to ventricles has a brief delay so atria can contract before ventricles?

what isRegurgitation (heart) and prolapse of the valves ? what is this condition known as ?

failure of valves to close, causes a prolapse which means the valve opens backwards, and causes back flow of the heart. this is known as a systolic heart murmur.

what are artheroselcrotic deposits ?

fatty despots in the shape of the coronary artery that is removed for a coronary endarterectomy.

AV bundle (bundle of His)

fibers in the heart that relay a nerve impulse from the AV node to the ventricles

Purkinje fibers

fibers in the ventricles that transmit impulses to the right and left ventricles, causing them to contract

coronary sulcus

groove that marks border between atria and ventricles

what are veins valves?

in larger veins one way valves that allow blood to flow only toward the heart.

how does blood flow from the veins move ?

it moves at a low speed and pressure and it happens because of muscle contraction that squeezes blood through the veins.

does the right common carotid artery come directly off the aortic arch ?

no, only the left common carotid artery. the right carotid arty branches from the brachiocephalic trunk.

what happens In the phases of cardiac action potential?

phase 4 starting phase- resting potential, slightly lower than the resting potential of neurons, at -90 mv phase 0- occurs at -40 mv, firing an action potential. stimulus allows for voltage-gated Na+ channels to open. phase 1- action potential peals at 30+, causes Na+ voltage channels to close. phase 2- Ca2+ channels open, fast k+ channels close paste 3 Ca2+ channel's close, slow K+ channels open phase 4 resting potential returns.

cardiac action potential

rapid depolarization( Brief) due to fast Na+ channels action potential reaches 30+ and Na+ gates close, plateau phase(long ) slow Ca2+ channels open and bind to fast Ca2+ channels in the SR, this release Ca2+ in the cytosol which causes a contraction to occur repolarization- the Ca2+ channels close and K+ channels open, repaid K+ outflux returns cell to resting potential. (-90mv)

cardiac cells action potentials ? how much phases ?

step 1 depolarization step 2 plateau step 3 repolarization 5 phases-0-4