Circulatory System

These flashcards cover key concepts from the lecture on the circulatory system, including heart anatomy, blood flow, circulation types, and related physiological concepts.

What is the location, size, and position of the heart?

The heart is a triangular organ located in the mediastinum, with two-thirds of its mass to the left of the body midline and one-third to the right.

What is cardiopulmonary resuscitation (CPR)?

CPR involves rhythmic compression of the heart between the sternum and thoracic vertebrae to maintain blood flow during cardiac arrest.

What are the two upper chambers of the heart called?

The two upper chambers are called atria (right atrium and left atrium).

What are the two lower chambers of the heart?

The two lower chambers are called ventricles (right ventricle and left ventricle).

What type of muscle tissue makes up the heart wall?

The wall of each heart chamber is composed of cardiac muscle tissue called myocardium.

What is endocarditis?

Endocarditis is the inflammation of the endocardium, the smooth lining of heart chambers.

What is the function of heart valves?

Heart valves keep blood flowing through the heart and prevent backflow.

What are the two atrioventricular valves in the heart?

The two atrioventricular valves are the tricuspid valve (right side) and the bicuspid (mitral) valve (left side).

What does the term systole refer to?

Systole refers to the contraction phase of the heart.

What does the term diastole refer to?

Diastole refers to the relaxation phase of the heart.

What are the normal heart sounds during a heartbeat?

The two distinct heart sounds are 'lub' (closure of AV valves) and 'dub' (closure of semilunar valves).

What is the sequence of blood flow through the heart?

Venous blood enters the right atrium, passes through the tricuspid valve to the right ventricle, then through the pulmonary semilunar valve to the pulmonary artery to the lungs, and then from the lungs to the left atrium, passing through the bicuspid valve to the left ventricle.

What is the purpose of coronary circulation?

Coronary circulation supplies oxygen and nutrients to the myocardium of the heart.

What condition is referred to as a heart attack?

Myocardial infarction is referred to as a heart attack.

What is angina pectoris?

Angina pectoris is chest pain caused by inadequate oxygen supply to the heart.

What does cardiac output refer to?

Cardiac output is the amount of blood that one ventricle can pump each minute, usually about 5 liters at rest.

What are the specialized structures that generate electrical impulses in the heart?

The SA node (pacemaker), AV node, AV bundle (bundle of His), and Purkinje fibers.

What does ECG stand for?

ECG stands for electrocardiogram, which represents the electrical activity of the heart.

What does systemic circulation involve?

Systemic circulation carries blood throughout the body from the left ventricle to the right atrium.

What does pulmonary circulation refer to?

Pulmonary circulation carries blood to and from the lungs for gas exchange.

What is the hepatic portal circulation?

Hepatic portal circulation is a unique route that carries blood through the liver and connects two capillary beds.

What factors influence blood pressure?

Blood volume, strength of contractions, blood viscosity, and resistance to blood flow influence blood pressure.

What mechanisms facilitate venous return to the heart?

Venous return is facilitated by a strongly beating heart, adequate arterial blood pressure, valves in the veins, skeletal muscle contraction, and pressure changes in the chest cavity.

What are the nine major pulse points?

The major pulse points are found in arteries such as the superficial temporal, facial, carotid, axillary, brachial, radial, femoral, popliteal, and dorsalis pedis.

What is the function of the pulmonary semilunar valve?

The pulmonary semilunar valve prevents backflow of blood from the pulmonary artery into the right ventricle.

What is the function of the aortic semilunar valve?

The aortic semilunar valve prevents backflow of blood from the aorta into the left ventricle.

Which specialized structure is known as the heart's primary pacemaker?

The SA (sinoatrial) node is the heart's primary pacemaker.

What is the function of the AV (atrioventricular) node in the heart's electrical conduction?

The AV node delays electrical impulses from the atria before transmitting them to the ventricles.

What is the role of the Purkinje fibers in the heart's electrical conduction system?

Purkinje fibers rapidly distribute electrical impulses throughout the ventricular myocardium, causing ventricular contraction.

What is the approximate cardiac output of one ventricle at rest?

The approximate cardiac output of one ventricle at rest is about 5 liters per minute.

How is the heart's mass distributed in relation to the body midline?

Two-thirds of the heart's mass is located to the left of the body midline, and one-third is to the right.

What is the primary function of the right atrium?

The right atrium receives deoxygenated blood from the body via the superior and inferior vena cava.

What is the primary function of the left atrium?

The left atrium receives oxygenated blood from the lungs via the pulmonary veins.

What is the primary function of the right ventricle?

The right ventricle pumps deoxygenated blood to the lungs through the pulmonary artery.

What is the primary function of the left ventricle?

The left ventricle pumps oxygenated blood to the rest of the body through the aorta.

What are the two major veins that deliver deoxygenated blood to the right atrium?

The superior vena cava and the inferior vena cava.

What is the mediastinum?

The mediastinum is the space in the thoracic cavity between the lungs that contains the heart, great vessels, trachea, and esophagus.