Lecture I Introduction; The Cardiovascular System (CVS) Dr. Aya M. Serry 2015/2016

SUBJECTGRADE Quizzes 10 First Assessment Exam 20 Second Assessment Exam 20 Self Learning (Project) 10 Final Exam 40 TOTAL 100

Course Objectives Upon Completion of this course you should be able to: 1.Understand the relationship between the symptoms and the disease, which might be helpful in differential diagnosis 2.Understand mechanisms of different diseases 3.Discuss the etiology, pathogenesis, morphology and clinical significance of selected disorders of the cardiovascular, pulmonary, Female reproductive, renal, GIT and endocrine systems 4.Understand the causes and systemic, cellular and sub-cellular mechanisms of the development of the most significant diseases and their symptoms and syndromes.

Definition of Pathophysiology

Identifying the Components of the cardiovascular system 12 Lecture Objectives… Revising the general structure of the heart and its Basic Functions

Introduction The cardiovascular system (CVS) consists of the heart and blood vessels. It is a closed system in which blood circulates, hence the synonym ‘circulatory system’.

Components of the CVS 1.Heart: It is a pump composed of 4 chambers (2 atria & 2 ventricles) 2.Blood Vessels: The blood vessels are systems of tube including: a)Arteries and arteriols which carry the blood from the heart to all parts of the body. b) Veins and Venules which carry the blood back from the tissues to the heart. c) Blood capillaries which form a network of fine vessels connecting the arteriols with the venules, and they are the sites of exchange of gases (O2 & CO2).

THE HEART

The heart is a hollow muscular organ. Its walls are composed of a muscle called the cardiac muscle or the myocardium which is lined by a endothelial layer called the endocardium (in contact with the blood inside the heart cavity) and covered by a thin layer called the epicardium. THE HEART

The heart is the central pump of the CVS that drives blood through the blood vessels. It is a muscular structure, which is made up of four chambers.

A heart beat consists of a systole + a diastole of cardiac chambers. The heart of a normal adult male beats automatically and regularly at a rate of 75 beats/minute during rest. The normal range of heart rate is between 60 – 100 beats /minute. Heart Beats

hhjhttnjngh Tachycardia Heart rate that exceeds the normal range. A resting heart rate over 100 beats per minute is generally accepted as tachycardia. Bradycardia Heart rate that is under the normal range. the resting heart rate of under 60 beats per minute is generally accepted as bradycardia. Abnormal Heart Beats

The human HEART consists of four chambers: Two atria (right and left) which are separated from each other by the interatrial septum. Two ventricles (right and left) which are separated from each other by the interventricular septum. The wall of the left ventricle is about 3 times thicker than the wall of the right ventricle. Cardiac Chambers & their functions

The atria have 2 main functions: 1)They act as blood reservoir for the blood returning back from the body to the heart. 2)They act as pumps (primer pumps). Atrial contraction pushes about 25% of the blood filling the ventricles during ventricular diastole. Functions of The Atria

The function of the ventricles : Are the powerful cardiac pumps filling the arteries with blood. The right ventricle pushes blood into the pulmonary arteries, while the left ventricle pushes blood into the aorta during ventricular systole. Functions of The Ventricles

1) The left side of the heart (high pressure side) acts a pressure pump that pumps blood into the systemic arteries at a sufficient pressure that drives blood to the tissues 2)The right side of the heart (low pressure side) pumps blood into the pulmonary arteries at a relatively lower pressure that drives blood into the lungs only Basic Function of the Heart

Functions of the CVS 1. The heart provides the driving force for the cardiovascular system. 2. The arteries serve as distribution channels to the organs. 3. The veins serve as blood reservoirs and collect the blood to return it to the heart. 4. The microcirculation, which includes the capillaries, serve as the exchange region.

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