Cardiovascular system

Summarize how the intrinsic cardiac conduction system works.

Summarize how the intrinsic cardiac conduction system works.

Explain the importance of the valves in the heart.

The heart is important because it pumps blood around your body, delivering oxygen and nutrients to your cells and removing waste products.

Describe the location of the heart in your body, using appropriate anatomical terminology.

The heart is located in the chest between the lungs behind the sternum and above the diaphragm. It is surrounded by the pericardium.

List the overall function of the cardiovascular system and summarize how it uses the heart, blood vessels, and blood to accomplish this function.

With its complex pathways of veins, arteries, and capillaries, the cardiovascular system keeps life pumping through you. The heart, blood vessels, and blood help to transport vital nutrients throughout the body as well as remove metabolic waste. They also help to protect the body and regulate body temperature.

Explain the three factors that can cardiac resistance to blood flow, through the vessels.

Blood flow refers to the movement of blood through a vessel, tissue, or organ, and is usually expressed in terms of volume of blood per unit of time. It is initiated by the contraction of the ventricles of the heart. Ventricular contraction ejects blood into the major arteries, resulting in flow from regions of higher pressure to regions of lower pressure, as blood encounters smaller arteries and arterioles, then capillaries, then the venules and veins of the venous system. This section discusses a number of critical variables that contribute to blood flow throughout the body. It also discusses the factors that impede or slow blood flow, a phenomenon known as resistance.

Describe what makes cardiac muscle tissue unique from other muscle tissue.

Cardiac muscle tissue works to keep your heart pumping through involuntary movements. This is one feature that differentiates it from skeletal muscle tissue, which you can control. It does this through specialized cells called pacemaker cells. These control the contractions of your heart.

Summarize how the heart uses both electrical and mechanical events to circulate blood throughout the body through the cardiac cycle.

Coronary circulation intrinsic to the heart takes blood directly from the main artery (aorta) coming from the heart. For pulmonary and systemic circulation, the heart has to pump blood to the lungs or the rest of the body, respectively. In vertebrates, the lungs are relatively close to the heart in the thoracic cavity. The shorter distance to pump means that the muscle wall on the right side of the heart is not as thick as the left side which must have enough pressure to pump blood all the way to your big toe.

Summarize the pathway oxygen-poor blood will take in order to become oxygen-rich blood that can be distributed to the tissues in your body.

Oxygen-poor blood returns from the body to the heart through the superior vena cava (SVC) and inferior vena cava (IVC), the two main veins that bring blood back to the heart. The oxygen-poor blood enters the right atrium (RA), or the right upper chamber of the heart. From there, the blood flows through the tricuspid valve (TV) into the right ventricle (RV), or the right lower chamber of the heart. The right ventricle (RV) pumps oxygen-poor blood through the pulmonary valve (PV) into the main pulmonary artery (MPA). From there, the blood flows through the right and left pulmonary arteries into the lungs. In the lungs, oxygen is put into the blood and carbon dioxide is taken out of the blood during the process of breathing. After the blood gets oxygen in the lungs, it is called oxygen-rich blood. Oxygen-rich blood flows from the lungs back into the left atrium (LA), or the left upper chamber of the heart, through four pulmonary veins. Oxygen-rich blood then flows through the mitral valve (MV) into the left ventricle (LV), or the left lower chamber. The left ventricle (LV) pumps the oxygen-rich blood through the aortic valve (AoV) into the aorta (Ao), the main artery that takes oxygen-rich blood out to the rest of the body.

Describe the mechanism that causes us to hear a heartbeat through a stethoscope.

The disc and the tube of the stethoscope amplify small sounds such as the sound of a patient's lungs, heart and other sounds inside the body, making them sound louder. The amplified sounds travel up the stethoscope's tube to the earpieces that the doctor listens through.

Explain the purpose of the pericardial cavity.

The pericardial cavity is the potential space formed between the two layers of serous pericardium around the heart. Normally, it contains a small amount of serous fluid that acts to reduce surface tension and lubricate.

Differentiate between the distinct roles and structures utilized in the pulmonary, systemic, and coronary circulation.

The pulmonary circulation is the portion that brings blood to the lungs and back. The systemic circulation is the portion that brings oxygenated blood to the rest of the body. The heart gets its own supply of blood through the coronary circulation. Coronary arteries deliver oxygenated blood from the aorta to the heart.