By the end of this section, you will be able to: Describe the structure of cardiac muscle Identify and describe the components of the conducting system that distributes electrical impulses through the heart Compare the effect of ion movement on membrane potential of cardiac conductive and contractile cells Relate characteristics of an electrocardiogram to events in the cardiac cycle Identify blocks that can interrupt the cardiac cycle Recall that cardiac muscle shares a few characteristics with both skeletal muscle and smooth muscle, but it has some unique properties of its own. Contractions of the heart heartbeats are controlled by specialized cardiac muscle cells called pacemaker cells that directly control heart rate.
The hosting site for this resource will be decommissioned December Many of the resources available here have been updated and can now be found on www. It transports oxygen, carbon dioxide, waste products, nutrients and hormones to and from various parts of the body. The cardiovascular system is made up of the heart, the blood vessels arteries and veins and capillaries and blood.
The heart has major vessels that supply it with deoxygenated blood travels back to the heart from the bodyand major vessels that carry oxygenated blood away from the heart to all the parts of the body.
The major vessels that carry blood to and from the heart are: Click here to roll over a diagram to locate the major vessels and so that you can identify the location of the heart. Activity 4 Click here to test your understanding of the location of the heart Heart The heart is a hollow organ about the size of a fist and is composed of special muscle tissue cardiac muscle.
It lies under the breast bone in the centre of the cardiothoracic cavity. In the average lifetime the heart beats million times and pumps million litres of blood. The heart is a sophisticated pump that is controlled by an electrical current that is initiated in the brain.
The heart is divided into a left and right side by a muscular wall called the septum and has four chambers. Heart chambers and valves The chambers of the heart include the: The heart wall consists of three layers - the endocardium is the inner lining, the myocardium is the muscle layer and the pericardium is the outer covering.
The chambers of the heart are separated by valves: Roll your mouse over the diagram. Blood vessels The cardiovascular system consists of arteries and veins and capillaries. Arteries carry oxygenated blood to the cells of the body, veins carry deoxygenated blood away from the cells.
Arteries Arteries are tubes that carry oxygenated blood high in oxygen away from the heart. Arteries have thick, muscular, elastic walls. They branch off forming arterioles with thinner walls that then become capillaries.
Arteries carry blood rich in oxygen and nutrients. Blood that comes from a wound to an artery is bright red and spurts. The aorta is the largest artery and as it leaves the heart it branches into smaller arteries, eventually they become capillaries.
Veins Veins are tubes that carry deoxygenated blood low in oxygen from the cells back to the heart where it is pumped to the lungs so that the blood can pick up more oxygen.
The cardiac cycle describes all the activities of the heart through one complete heartbeat—that is, through one contraction and relaxation of both the atria and ventricles. A contraction event (of either the atria or ventricles) is referred to as systole, and a relaxation event is referred to as. Cardiac physiology is a essential segment in medical studies! This course covers all important facts: frank-starling curve, membrane potential, inotrope & heart rate ranges. Learn online with high-yield video lectures & earn perfect scores/5(41). Signal-averaged electrocardiogram. It checks to see if you're at high risk of getting a condition called heart arrhythmia, which can lead to .
The veins have one-way valves that help move the blood toward the heart. Veins have thinner muscular walls. They carry blood back to the heart that is low in oxygen and high in carbon dioxide, a waste product.Lab # Cardiovascular Physiology p.1 Lab # Cardiovascular Physiology Background The heart serves as a pump to drive the flow of blood through the body.
It does so by Fig An electrocardiogram for a single cardiac cycle. Note the three distinctive waveforms: the P.
Calcium ions play two critical roles in the physiology of cardiac muscle. Their influx through slow calcium channels accounts for the prolonged plateau phase and absolute refractory period that enable cardiac muscle to function properly. Part 1: Anatomy and physiology Understanding the ECG.
Part 1: Anatomy and physiology Michael Sampson. x. Michael Sampson. Search for articles by this author, Anthony The importance of reflection in cardiac nursing practice. Myatt. Understanding the ECG.
Part 1: Anatomy and physiology. As the heart undergoes depolarization and repolarization, the electrical currents that are generated spread not only within the heart, but also throughout the alphabetnyc.com electrical activity generated by the heart can be measured by an array of electrodes placed on the body surface.
The recorded tracing is called an electrocardiogram (ECG, or EKG).
May 19, · The cardiac cycle is an important concept presented in human anatomy and physiology courses. At Kingsborough Community College, all Allied Health majors taking Anatomy & Physiology must understand the cardiac cycle to .
Electrocardiogram (ECG or EKG) What is it? An electrocardiogram — abbreviated as EKG or ECG — is a test that measures the electrical activity of the heartbeat.