بسم هللا الرحمن الرحيم

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1 Quick revision: April 19, 2012 [ANATOMY LECTURE 22 (HEART)] بسم هللا الرحمن الرحيم 1. Firstly, we took the thoracic wall, which consist bones (ribs, vertebrae) between it there is the intercostal (muscular) spaces, which consist muscles, blood vessels, and nerves. 2. After we open the thoracic wall we will find the lungs on both sides, each one is surrounded by the pleura, and between the two lungs there is a partition (space) called mediastinum. 3. If we draw a line from the sternal angle to the space between the 4 th and 5 th thoracic vertebrae this line will divide the mediastinum into superior and inferior mediastinum. 4. Because the inferior mediastinum consist a lot of structures it is divided into three parts: Medial mediastinum: consist the heart. Anterior mediastinum: located between the middle mediastinum and the sternum. Posterior mediastinum: located between the middle mediastinum and the vertebrae. After we finished the lungs in the previous lecture, we will start with the mediastinum and it is contents. o Heart: Located in the inferior mediastinum, in the middle part. It is surrounded by a membrane called pericardium (just like the lungs). Pericardium: it is a fibro-serous sac. Note: fibro-serous sac means there is two layers : 1. Outer layer :Fibrous pericardium. 2. Inner layer: Serous percardium Fibrous pericardium: The outer layer of pericardium. White in color. White tissue: which is a fibrous tissue..(مخروطي) Shape: conical Function: fixation and protection for the heart Has an apex which is located upward and a base which is located downward. Page 1

2 The apex: 1.Directed Upward. 2.it is hidden by a fat tissue called thymus gland. 3.Surrond the big vessels that enter and exit the heart. The base: 1. Directed downward. 2. It is connected with diaphragm. 3. A good factor for fixation. Relations of the fibrous pericardium: Anteriorly: Sternum and the costal cartilage attached to it Posteriorly: Posterior mediastinum and the structures located inside it: The most two important structure inside it: 1. Esophagus. 2. Aorta. On both sides: 1.Right and left lungs. 2. Phrenic vessels and nerve. Note: Phrenic Related to diaphragm. Note: Phrenic vessels and nerve pierces the diaphragm and supply it from the under surface of it. 2. Serous pericardium: (شفاف) Transparent. It is attached to the heart. (كان بلونة و لما بلش القلب يكبر بلش يزوؤ...الخ ( pleura. It is formed just like the Composed of two layers: 1. Outer layer: called Parietal layer of serous pericardium, laying the fibrous pericardium. 2. Inner layer: called visceral layer of serous pericardium. Remember that the heart is surrounded by three layers : 1. Fibrous pericardium. 2. Parietal layer of serous pericardium. 3. Visceral layer of serous pericardium. Page 2

3 (كل وا حد ياخد من األ ريب منو ويتعامل معاملته) pericardium: Blood and nerve supply of The visceral layer of serous pericardium will take the innervation and the blood supply just like the heart. The fibrous pericardium and the parietal layer will take the innervation and the blood supply just like the heart. Arterial supply: o Heart: Anteriorly: Internal mammary (internal thoracic) artery, which is located beside the sternum. Posteriorly: From the aorta. Nerve supply: From the intercostal nerves. Located in the inferior mediastinum, in the middle part. It is surrounded by a membrane called pericardium (just like the lungs). Pyramidal, hollow, four-chambered, muscular organ. Why it is hollow?? Because it have four cavities Right and left atriums and ventricles (مش زي ما نشوفوا بالصورة أل بكون نايم لقدام) forward. It is pending Has an apex, base, and four surfaces. Four surfaces: 1. Sternocostal surface. (anterior surface) 2. Diaphragmatic surface. (posterior surface) 3. Right surface. 4. Left surface. 5. How to put the heart in the anatomical position? (It is very helpful in the lab) 1. We look for coronary (atrioventricular) groove (which consist the coronary artery which is the blood supply of heart) Note: when we hold the heart from coronary groove, we divide it into two parts, upper part composed from the two atriums, lower part composed from the two ventricles. Note: The right and left atriums are separated from each other by the interatrial septum and the two ventricles by the interventricular septum. Page 3

4 2. We look for the anterior inteventricular groove (which consists of anterior interventricular artery) in the anterior aspect of the heart. Note: right to it will be the right ventricle and left to it will be the ventricle) 3. Then we look for the posterior inteventricular groove (which consists of posterior interventricular artery) in the posterior aspect of the heart. 4. We look for the aspect which is directed forward downward toward the left. Page 4

5 Now we are going to talk about the parts of the heart considering three things: direction, site (landmark), formed by whom??. 1. Apex: Directed: Forward, downward, toward to the left. Site (landmark, level): fifth intercostal space away from the midline 3.5 inches. Formation: Formed completely by the left ventricle. 2. Base: Above the coronary groove. Directed: Backwards (posteriorly). Site: Opposite for the middle four thoracic vertebrae. Formation: Formed by the two atriums mainly by the left one. Note: The thoracic vertebrae are divided into three groups: a. Upper four: 1-4 b. Middle four: 5 8 c. Lower four: 9 10 This is a very important especially when we do x-ray, because it help us to know which vertebrae is injured. (We know that the heart is located opposite for the middle four thoracic vertebrae) Note: The right atrium receives the superior and inferior vena cava. Note: The line connects the superior and inferior vena cava with each other represents the end of the right atrium and the beginning of the left one. 3. Four surfaces: A. The sternocostal surface: Anterior surface. Formation: Formed by the four-chambered, mainly by the ventricles, mainly by the right ventricle this represents 2/3 of it and the left ventricle represents 1/3 of it. Page 5

6 B. Diaphragmatic surface: Posterior surface. Formation: Formed by the two ventricles mainly by the left one which represents 2/3 of it and the right one represent 1/3. C. Right side (Right surface): Formation: Formed by the right atrium. D. Left side (Left surface): Formation: Formed by the left atrium. Note : as we talk before, the mediastinum surface of each lung has many impression : The mediastinum surface of the right lung has an impression from the heart by the right atrium. The mediastinum surface of the left lung has an impression from the heart by the left ventricle. Another revision: 1. The blood enters the right atrium from all the body by the superior and inferior vena cava, then it goes the right ventricle. 2. The right ventricle sends the blood by the pulmonary artery to the lungs for oxygenation, then the oxygenated blood come back from lungs to the heart ( to the left atrium ) by the pulmonary veins. 3. The blood then goes to the left ventricle, then it sends the blood to the hole body by the aorta. Pulmonary veins 4 in number 2 in the left side of the left atrium and 2 in the right side. The color of blood in the veins is dark-purple, because the carbon dioxide has a dark color so when it attach to the receptors it will give the blood a dark color. o The four-chambered of heart: 1. The right atrium: It forms the right border (surface) of heart. It is a part of the sternocostal surface. Function: Venous draining from all the body. External feature: 1. It gives a small process called the right auricle. 2. It receives the superior and inferior vena cava. 3. The line connects the superior and inferior vena cava with each other represents the end of the right atrium and the beginning of the left one. Page 6

7 Internal feature: 1. Anterior wall (part) : Rough why?! It consist muscular ridges also called musclui pectinati. Also called atrium proper. 2. Posterior wall (part): Very smooth. Also called sinus venrum. It was a vein during the development of the embryo and entered the heart and gave the smooth part. 3. Interatrial septum: Between the right and left atriums. Consist an impression: which is oval in shape so it is called fossa ovalis. المالحظتان الي تحت الدكتورة حكت انهم لمعلوماتكم Note: Fossa ovalis was an opening during the pregnancy so the blood goes from the right atrium to the left one without passes in the right ventricle and lungs because the embryo takes the blood from his mother and after birth it is closed and named fossa ovalis and the blood goes from right atrium to the left atrium and so on. Note: 10% of babies after birth the opening does not close and there color become blue because of the nonoxygenated blood which goes from the right to the left atriums directly. So we must make a surgery to heal this. The openings in the posterior wall of the right atrium: 1. Superior vena cava (superiorly). 2. Inferior vena cava (posteriorly). 3. Tricuspid opening: guarded by the tricuspid valve, and in connect the right atrium with the right ventricle. Page 7

8 4. Opening of coronary sinus: Coronary sinus lies on the posterior aspect of the heart between the base and diaphragmatic surface. Venous drainage of the heart is through this coronary sinus which opens in the right atrium. (Remember the venous drainage of the upper part of the body is through superior vena cava and the lower part is through inferior vena cave) (Remember the blood supply of heart is coronary artery) Opens just below the opening of inferior vena cava. This opening is between the tricuspid opening and inferior vena cava opening. (Land mark to locate it in the lab) ي ق ول الش اف ع ي : إ ن م ا ال ع ل م ع ل م ا ن : ع ل م الد ي ن و ع ل م الد ن ي ا ف ال ع ل م ال ذ ي ل لد ي ن ه و : ال ف ق ه و ال ع ل م ال ذ ي ل لد ن ي ا ه و : الط ب. و م ا س و ى ذ ل ك م ن الش ع ر و ن ح و ه ف ه و ع ن اء أ و ع ي ب. I hope you enjoy reading this simple sheet, and I m sorry for any mistake but really I tried my best and feel free to criticize me. Page 8