THIS IS A STUDY GUIDE, NOT AN ALL INCLUSIVE REVIEW. THERE MIGHT BE THINGS NOT COVERED BY THIS STUDY GUIDE THAT MIGHT BE ASKED IN YOUR QUIZZES and PRACTICAL TESTS. STUDENTS ARE RESPONSIBLE FOR STUDYING THEIR MANUAL AND FOR ALL THE MATERIAL COVERED DURING THE LABORATORY PERIOD, AS PER THE COURSE SYLLABUS

Lab # 2 The Heart

The Circulatory System Heart Blood vessels -Blood It transports substances from place to place in the body. It is the liquid medium in which these substance travel. They ensure the proper routing of blood to its destination. It is the pump that keeps the blood flowing. -Cardiovascular System

Arteries Veins Capillaries They carry blood away from the heart. They carry blood back to (toward) the heart. They connect the arteries with the veins. Blood Vessels Pulmonary veins Pulmonary arteries Cardiovascular System Pulmonary Circuit Systemic Circuit It carries blood to the lungs for gas exchange and returns it to the heart. It supplies blood to every organ of the body, including the heart itself. Aorta Venae cavae

Tissue Arteriole Venule Capillary Lung CO 2 Wastes O2O2 NutrientsVenuleArteriole O 2 rich, CO 2 poor blood O 2 poor, CO 2 rich blood Gas Exchange Capillary CO 2 O2O2 Venae cavae Aorta Pulmonary arteries Pulmonary veins An Introduction to the Cardiovascular System Pulmonary Circuit Systemic Circuit

Gas exchange Systemic Circuit It supplies blood to every organ of the body, including the heart itself. O 2 rich blood through ARTERIES O 2 poor blood through VEINS O 2 poor blood through ARTERIES O 2 rich blood through VEINS Pulmonary Circuit It carries blood to the lungs for gas exchange and returns it to the heart.

RIGHT ATRIUM LEFT ATRIUM RIGHT VENTRICLE LEFT VENTRICLE Aorta To the rest of the body Poor oxygen blood Reach oxygen blood Superior vena cava Inferior vena cava Coronary sinus Pulmonary arteries Pulmonary veins (4) Internal Anatomy and Organization Gas exchange

It drains oxygen-poor blood from tissues and organs superior to the diaphragm to the right atrium. It drains oxygen-poor blood from tissues and organs inferior to the diaphragm to the right atrium. Coronary sinus (no shown) It drains oxygen-poor blood from the heart tissues to the right atrium. It carries oxygen-poor blood from the right ventricle to the lungs. Superior vena cava Pulmonary trunk They carry oxygen-rich blood from the lungs to the left atrium. Aorta It carries oxygen-rich blood from the left ventricle to the whole body. Pulmonary veins (4) Inferior vena cava

The Heart Wall Epicardium (visceral pericardium) It is a serous membrane covering heart. Also includes a thick layer of adipose tissue in some places. The coronary blood vessels travel through this layer. Myocardium It is a layer of cardiac muscle proportional to work load. Myocardium Endocardium It is the smooth inner lining of heart and blood vessels. It covers the valve surfaces and is continuous with the endothelium of blood vessels. Parietal pericardium Endocardium Pericardial cavity Pericardium Visceral pericardium or epicardium Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

(a) (b) Glycogen Striations Intercalated discs Cardiac Muscle It is limited to the heart. Cells are called myocytes or cardiocytes and they are short, branched, and notched at ends. Cardiocytes contain one centrally located nucleus surrounded by light staining glycogen. Intercalated discs join cardiocytes end to end and provide electrical and mechanical connection. They are striated, and involuntary (not under conscious control). Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

The Chambers of the Heart Right atrium It receives poor O 2 blood returning to the heart through the superior and inferior vena cava and the coronary sinus Right ventricle It pumps blood to the lungs through the pulmonary arteries Superior vena cava Inferior vena cava Left atrium It receives rich O 2 blood returning from the lungs through the pulmonary veins Pulmonary veins Left ventricle It pumps blood through the aorta artery to every organ of the body Pulmonary trunk Aorta Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Anatomy of the Heart Right atrium Right ventricle Left atrium Left ventricle Anterior view Posterior view Left auricle Coronary or atrioventricular sulcus Anterior interventricular sulcus Posterior interventricular sulcus Interventricular septum Interatrial septum Trabeculae carneae Pectinate muscles Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

The Valves The valves ensure a one-way flow, by preventing back flow of the blood Right AV (tricuspid) valve Left AV (bicuspid) valve Left AV (bicuspid or mitral) valve Right AV (tricuspid) valve It prevents back flow of blood from the RV to the RA It prevents back flow of blood from the LV to the LA

The Valves Left AV (bicuspid or mitral) valve Right AV (tricuspid) valve Pulmonary semilunar valve Aortic semilunar valve It prevents back flow of blood from the aorta to the LV Aortic semilunar valve Chordae tendineae Papillary muscles The valves ensure a one-way flow, by preventing back flow of the blood Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

The Valves Left AV (bicuspid or mitral) valve Right AV (tricuspid) valve Pulmonary semilunar valve It prevents back flow of blood from the pulmonary trunk to the RV Pulmonary semilunar valve Aortic semilunar valve Chordae tendineae Papillary muscles The valves ensure a one-way flow, by preventing back flow of the blood Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Conduction System It is composed of an internal pacemaker and nervelike conduction pathways through myocardium that generate and conduct rhythmic electrical signals. It depolarizes spontaneously around 60 times per minute and determines heart rate. Sinoatrial (SA) node (pacemaker) Atrioventricular (AV) node It delays the conduction of the impulses to the ventricles, which allows the ventricles to contract after the atria. Atrioventricular (AV) bundle It is a group of fibers that transmits impulses from the AV node to the ventricles. Left bundle branch Right bundle branch Purkinje fibers Purkinje fibers They distribute the electrical excitation to the cardiocytes of the ventricles. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Cardiac Conduction System

Extra heart beats produced in any region of spontaneous firing other than the SA node. It is the failure of any part of the of the cardiac conducting system to transmit signals. The Cardiac Rhythm It is the normal heartbeat triggered by the SA node.Sinus rhythm: At rest, the sinus rhythm is about 70 to 80 times per minute (rates from 60 to 100 bpm). Arrhythmia:It is any abnormal cardiac rhythm. Heart block: Extra-systoles: Tachycardia:It is a persistent, resting adult heart rate above 100 bpm. Bradycardia:It is a persistent, resting adult heart rate below 60 bpm.

Right auricle Left auricle Right ventricle Superior vena cava Aortic arch Pulmonary trunk S A node (pace maker) Anterior interventricular artery Left coronary artery Right coronary artery Marginal artery (to the right atrium) (from the left ventricle) (from the right ventricle) Ascending aorta Left ventricle Circumflex artery Anterior view The Heart

(to the left atrium) Inferior vena cava Great cardiac vein Middle cardiac vein Small cardiac vein Posterior cardiac vein (to the right atrium) Posterior interventricular artery (branch of the right coronary artery) Coronary sinus Posterior view Right pulmonary veins (to the left atrium) Left pulmonary veins Right auricle Left auricle Right ventricle Left ventricle The Heart

Left AV valve or bicuspid valve Ascending aorta Aortic arch Left bundle branch Right bundle branch Pulmonary trunk Orifices of coronary arteries Aortic semilunar valve Atrioventricular bundle (of His) Purkinje fibers AV node Superior vena cava S A node (pace maker) Right AV valve or tricuspid valve Chordae tendineae Papillary muscles Trabeculae carneae Conducting system Internal Structures Ligamentum arteriosum The Heart Interventricular septum