Heart Vasculature

What are the two principal branches of the left coronary artery in a typical heart?

Circumflex artery and the anterior interventricular artery

Classic Symptoms of a heart attack

Classic Symptoms of a heart attack: the typical symptoms are chest heaviness or pressure which can be severe, lasting more than 20 minutes and often associated with sweating, the pain in the chest often radiates to the arms, left is more common than right and can be associated with nausea. The severity of ischemia and infarction depends on the rate at which the occlusion or stenosis has occurred and whether or not collateral channels have had a chance to develop.

coronary sinus

Gray's Basic Anatomy does not give us a concise beginning point for the coronary sinus. Practically, the great cardiac vein is on the anterior surface of the heart or on the left border, and the coronary sinus is in the left atrioventricular groove

Given the most common pattern of blood distribution in the coronary system, why is the definition of coronary dominance confusing?

In most right dominant hearts and most left dominant hearts, the left coronary artery supplies more blood to the heart than the right coronary supplies

What is heart block

Infarct in a major pathway of the conduction of the heart will prevent the contraction signal from propagating to the heart tissue. I the heart block is at the AV node, the atria will beat regularly but the ventricles will not be stimulated so they will beat slowly.

Conduction System and innervation of the heart.

PHYSIOANATOMY: CONDUCTION SYSTEM OF THE HEART. Describe how the conduction system of the heart forms a functional chain from the sinu-atrial node through the atrioventricular node and into Purkinje fiber system of the ventricles, and relate how this functional chain produces a well-timed signal for contraction of cardiac muscle in the atria and ventricles.

Which of the two coronary arteries branches from the aorta "right out in front?"

Right Coronary Artery

true end circulation

Segments of the kidneys have true end-arterial circulation with no collateral circulation

Parasympathetic on the heart

Stimulation of the parasympathetic system: decreases heart rate, reduces force of contraction and constricts the coronary arteries. The preganglionic parasympathetic fibers reach the heart as cardiac branches from the right and left vagus nerves. They enter the cardiac plexus and synapse in the ganglia located either within the plexus or in the walls of the atria.

Why is the pacemaker's electrode tip usually placed as close to the apex of the heart as possible?

The apex is the place to start the most effective part of the contraction cycle, squeezing blood toward the openings of the aorta and pulmonary trunk.

Why would an artificial pacemaker be appropriate for a patient with a heart block?

The beat from the atients SA node is not reaching the ventricular walls, so the artificial packemaker has located past the point that is block, clos eto the muscle that is to be stumulated. in simple terms, an artificial contraction signal can be given to the vntricles

why is this able to be used as a bypass graft

The collateral circulation that the posterior intercostal arteries provide allows the surgeon to use the internal mammary artery.

functional end arterial system

The heart's blood supply is called a functional end arterial system because if an obstruction occurs slowly enough, anastomoses can be formed to route blood around the blockage.

How is coronary dominance defined? (That is, how are right dominant heart and left dominant heart defined?) Look on pages 108 and 109 of GBA.

The only definition of coronary dominance is that in a right dominant heart, the posterior interventricular artery is a branch of the right coronary artery and in a left dominant heart, the posterior interventricular artery is a branch of the circumflex artery. So coronary dominance doesn't refer to the amount of blood that one coronary artery or the other supplies to the heart.

GBA p. 108. We find that the right coronary artery participates in the blood supply of the left ventricle. What part of the left ventricle? What name for that surface of the heart is used here in GBA?

The postero inferior 1/3rd of the interventricular septum

Sympathetic on the heart

The stimulation of the sympathetic system: increases heart rate, increases the force of contraction. The sympathetic fibers from the upper four/five segments of the thoracic spinal cord enter and move through the sympathetic trunk. They then synapse in cervical and upper thoracic sympathetic ganglia, and post ganglionic fibers proceed as bilateral branches from the sympathetic trunk to the cardiac plexus.

Visceral Afferents of the heart

Visceral afferents from the heart are also a component of the cardiac plexus. These fibers pass through the cardiac plexus and return to the CNS in the cardiac nerves from the sympathetic trunk and in the vagal cardiac vranches. The afferents associated with the vagal cardiac nerves return to the vagus nerve (X). they sense alterations in blood pressure, blood chemistry and therefore primarily concerned with cardiac reflexes.

what does the coronary sinus accept

it accepts the major cardiac vessels. greater cardiac vein, the middle cardiac vein, lesser cardiac vein.

Heart Attack

a heart attack occurs when the perfusion to the myocardium is insufficient to meet the metabolic needs of the tissue, leading to irreversible tissue damage. The most common cause is a total occlusion of a major coronary artery

Explain the technical convenience that makes it possible or relatively easy to insert the electrode tip through major vessels etc. and then into the wall of the right ventricle rather than the wall of the left ventricle.

accessing the right side of the heart through the systemic venous system is not particularly complicated. the clinician has no venous access to the left side of the heart. the electrode wire passes through the right AV valve without much disturbance; the wire would more likely to cause problems in the smaller, higher pressure, less compliant valves.

Symptoms in men and women

although men and women can experience the typical symptoms of severe chest pain, cold sweats and pain in the left arm women are more likely than men to have subtler, less recognizable symptoms. these may include abdominal pain, achiness in the jaw, nausea, shortness of breath, and/or simply fatigue. its not understood.

Know the location of each of the arteries on the anatomy study list. What branch occupies the anterior interventricular groove?

anterior interventricular artery

anastamoses

are physical connections between blood vessels

The internal thoracic arteries are not necessary to nourish the sternum...why

because the anterior intercostal arteries anastomose with the posterior intercostal arteries to allow a collateral circulation

what artery occupies the left part of the atrioventricular groove?

circumflex artery

collateral circulation

describes how the blood flows through those anastomotic vessel to reach capillary beds by alternate routes

What other feature of similar size and roundness is nearby?

fossa ovalis

coronary artery bypass grafts

if coronary artery disease is too extensive to be treated by percutaneous intervention, surgical coronary bypass grafting may be necessary. the great caphenous vein in the lower limb is harvested and used as a graft. the internal thoracic and radial arteries can also be used.

where is the great cardiac vein

in the anterior interventricular groove

where is the coronary sinus

in the left atrioventricular groove

Where are the cardiac muscle fibers that propagate the signal through the ventricles located (near the endocardial lining of the heart, in the center of the heart muscle, or in the epicardium)?

near the endocardial lining of the heart.

Artery Disease

occlusion of a major coronary artery, usually due to artheroscleosis, leads to an inadequate oxygenation of an area of myocardium and CELL death. the severity of the problem will be related to the size and location of the artery involved whether, or not the blockage is complete and whether there are collateral vessels to provide perfusion to the territory from other vessels. depending on the severity, patient can develop pain (angina) or a myocardial infarction

What feature of the heart is normally the pacemaker that has the fastest rhythmic cycling of contractions? Notice that that structure is positioned to cause contraction of the atria first.

sinoatrial node

What structure does the signal have to pass through to get from the structure you named in question c to the ventricles?

the atrioventricular node

what are the organs that barely have anastomoses

the heart, brain and kidneys

what artery is used for a bypass graft

the internal thoracic artery.

The sternum is a good example of an organ that ordinarily gets its blood supply from the internal thoracic artery. After the bypass, how will it get its blood? (Trace the blood from the aorta.)

the other internal thoracic artery is usually left intact to nourish the sternum and other tissues.

What branch occupies the posterior interventricular groove

the posterior interventricular artery

Left is "sinistre" in Latin, and the left coronary artery is hidden in a dark place. What structure is anterior to it? What structure embraces it from a posterior direction?

the pulmonary trunk. the left auricle embraces it from a posterior direction.

Make sure you find the opening of the coronary sinus into the heart. In which chamber will that be

the right atrium

What branch occupies the anterior atrioventricular groove and part of the posterior atrioventricular groove?

the right coronary artery

Coronary Intervention

this is a technique in which a long fine tube is inserted into the femoral artery in the thigh, passed through the external and common iliac arteries and into the abdominal aorta. it continues to be moved upward through the thoracic aortic to the origin of the coronary arteries. the coronaries may also be approached via the radial or brachial arteries. a fine wire is then passed into the coronary artery and is used to cross the stenosis. a fine balloon is then passed over the wire and may be inflated at the level of the obstruction, thus widening it. this is termed angioplasty.

veins have what muscle in the wall

veins