Cardiovascular Physiology: Heart Activity and Behavior

Pulmonary valve

control the blood flow form the right ventricle into the pulmonary arteries, which carry blood to the lungs to pick up oxygen.

Septum

A wall of muscle that separates the left and right atria and the left and right ventricles

Describe action potentials and depolarization as it pertains to cardiac muscle.

Action potentials are freely conducted from one cell to another (lattice-like syncytial) across the network of cardiac fibers The depolarization of cardiac muscle consists of a spike followed by a sustained de- polarization phase of 0.2-0.3 seconds before the muscle re-polarizes (sustained contraction).

Left Coronary Artery

Branches into the left anterior descending artery and the circumflex artery. Supplies blood to the left side of the hear.

Pulmonary circulation

From the heart to the lungs

How does the heart beat?

Electrical impulses from your heart muscle (the myocardium) cause the heart to beat (contract). This electrical signal begins in the sinoatrial (SA) node, located at the top of the right atrium. The SA node is sometimes called the heart's "natural pacemaker" (the speed of polarization is faster than the AV node). When an electrical impulse is released from this natural pacemaker, it causes the atria to contract. The signal then passes through the atrioventricular (AV) node. The AV node checks the signal and sends it through the muscle fibers of the ventricles, causing them to contract.

Systemic Circulation

From the lungs to the body

Mitral Valve

Lets oxygen rich blood from the lungs pass from the left atrium into the left ventricle

Tricuspid Valve

Regulates the blood flow between the right atrium and right ventricles

Cardiac Muscle

Striated fiber containing the same arrangements of contractile filaments as skeletal muscle. Muscle has unstable resting potential - basis for intrinsic and rhythmic contraction. The force of contraction in cardiac muscle is increased by stretch (not by recruiting more muscle fibers, for instance, or summing twitches).

Right Coronary Artery

Supplies blood mainly to the right side of the heart.

The _______ (the main blood supplier to the body) branches off into ______ main coronary blood vessels (also called arteries), which branch off into smaller arteries, which supply oxygen- _______ blood to the entire heart muscle. -Vessels -Two -Aorta -Rich -Deficient -One

The *aorta* (the main blood supplier to the body) branches off into *two* main coronary blood vessels (also called arteries), which branch off into smaller arteries, which supply *oxygen- rich* blood to the entire heart muscle.

The _____ ventricle is the largest and strongest chamber in the heart.

The *left* ventricle is the largest and strongest chamber in the heart. The left ventricle's chamber walls are only about a 1/2inch thick but they have enough force to push blood through the aortic valve and into the body.

What is the largest artery?

The aorta

Pericardium

The double layered membrane that surrounds the heart like a sac. The outer layer of the pericardium surrounds the roots of the heart's major blood vessels and is attached by ligaments to the spinal column, diaphragm, and other parts of the body. The inner layer of the pericardium is attached to the heart muscle. A coating of fluid separates the two layers of membrane, letting the heart move as it beats but still be attached to the body.

Coronary Circulation

The heart muscle, like every other organ or tissue in the body, needs oxygen-rich blood to survive. Blood is supplied to the heart by its own vascular system, called coronary circulation.

The heart's pumping action is regulated by an ________ conduction system that coordinates the _________ of the various chambers of the heart.

The heart's pumping action is regulated by an *electrical conduction* system that coordinates the *contraction* of the various chambers of the heart.

Electrical Syncytium

The lateral component of the intercalated discs includes gap junctions that allows the cells to act as an *Electrical Syncytium*

The left side of the heart is larger and more muscular because it pumps blood to the ______

The left side of the heart is larger and more muscular because it pumps blood to the *rest of the body*

Lower chambers of the heart are the _____

The lower chambers are called the *left* and *right ventricles*

The right side of the heart is smaller because it pumps blood only to the ____.

The right side of the heart is smaller because it pumps blood only to the *lungs*

Myocardium

muscular tissue of the heart -Not striated or smooth -Involuntary

Aortic Valve

opens the way for oxygen-rich blood to pass from the left ventricle into the aorta, the largest artery, where it is delivered to the rest of the body

Upper chambers of the heart are the ________

the upper chambers are called the *left* and *right atria*