Brief Summary
This video provides an overview of the external features of the heart, including its location, shape, size, and various surfaces and borders. It also explains the anatomical position of the heart for examination purposes.
- The heart is located in the middle mediastinum, within the pericardium in the thoracic cavity.
- The heart has a conical or pyramidal shape, with an average size of 12 by 9 centimetres.
- Key external features include the apex, base, borders (right, left, inferior, superior), and surfaces (sternocostal, left, diaphragmatic).
The heart, a hollow muscular organ, resides in the middle mediastinum within the pericardium in the thoracic cavity. Known as "cardia" in Greek and "cordis" in Latin, the heart has a conical or pyramidal shape, averaging 12 by 9 centimetres in size, slightly larger than one's clenched fist. Weighing about 300 grams in males and 250 grams in females, the heart is positioned behind the sternum, with one-third lying to the right and two-thirds to the left of the median plane. It comprises four chambers: two atria and two ventricles. The atria are located upwards and backwards, while the ventricles are downward and forward. The right atrium receives the superior and inferior vena cava, and the left atrium receives four pulmonary veins.
The heart has an apex, a base, borders (right, left, inferior and superior), and surfaces (sternocostal, left and diaphragmatic). The apex, formed by the left ventricle, points downward, forward, and to the left, located in the left fifth intercostal space, nine centimetres from the midline, inside the midclavicular line. Conversely, the base faces upward, backward, and to the right. It is quadrilateral in shape, formed primarily by the left atrium (two-thirds) and partly by the right atrium (one-third).
The heart has four borders: right, left, inferior, and superior. The right border, formed by the right atrium, is rounded and convex, extending from the superior vena cava to the inferior vena cava. A shallow vertical groove, the sinus terminalis, is visible on the surface. The left border, convex and facing upward and to the left, extends from the left auricle to the apex, accompanied by the marginal branch of the left coronary artery. The inferior border is horizontal, extending from the inferior vena cava opening to the apex, mainly formed by the right ventricle and partly by the right atrium, accompanied by the right marginal branch of the right coronary artery. Near the apex, the inferior border presents the incisura cordis and separates the sternocostal surface from the diaphragmatic surface. The superior border is slightly oblique and obscured anteriorly by the aorta and pulmonary trunk, mainly formed by the left atrium and partly by the right atrium.
The heart has three surfaces: sternocostal, left, and diaphragmatic. The sternocostal surface, large and convex, faces upwards and forwards, mainly formed by the right ventricle, right atrium, and auricle, and partly by the left ventricle and left auricle. It features the anterior part of the right atrioventricular groove and the anterior interventricular groove, which houses the anterior interventricular artery. The diaphragmatic surface is flat, with its left two-thirds formed by the left ventricle and the right one-third by the right ventricle. It contains the posterior interventricular groove, lodging the posterior interventricular artery. The left surface faces upwards, backwards, and to the left, mainly formed by the left ventricle and partly by the left atrium and left auricle.
The heart features several grooves or sulci. The atrioventricular groove (coronary sulcus) separates the atria from the ventricles in a C-shape, deficient anteriorly due to the pulmonary trunk. It has anterior and posterior parts; the anterior part is divided into right and left halves. The right half contains the trunk of the right coronary artery, while the left half contains the circumflex branch of the left coronary artery, the termination of the great cardiac vein, and the commencement of the coronary sinus. The posterior atrioventricular groove contains only the coronary sinus. The interventricular sulcus separates the two ventricles, with anterior and posterior portions. The anterior interventricular groove, on the sternocostal surface, lodges the anterior interventricular artery (a branch of the left coronary artery). The posterior interventricular groove, on the diaphragmatic surface, lodges the posterior interventricular artery (mostly a branch of the right coronary artery). The interatrial groove, separating the two atria, is deficient anteriorly due to the aorta and pulmonary trunk and faint posteriorly. The meeting point of the interatrial groove, coronary sulcus, and posterior interventricular groove is known as the crux of the heart.
The apex is formed only by the left ventricle, the base by the left and right atria, the diaphragmatic surface by the right and left ventricles, and the right border by the right atrium. Two-thirds of the heart lie to the left of the midline, while one-third lies to the right. Two-thirds of the sternocostal surface are formed by the right ventricle, and one-third by the left ventricle. Conversely, two-thirds of the diaphragmatic surface are formed by the left ventricle, and one-third by the right ventricle. Two-thirds of the base are formed by the left atrium, and one-third by the right atrium. To maintain the anatomical position during examination, the apex should point downward, forward, and to the left, the inferior border should lie horizontally, and the flat diaphragmatic surface should rest on the palm of the left hand.
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Transcript
Full transcript of “Heart - external feature”. Click a timestamp to open the video at that moment. Need another video? Use the YouTube transcript generator.
0:09 hello friends welcome to the viva wars of anatomy today we discuss the heart heart is a hollow muscular organ which is situated in the middle mediastinum which is enclosed by the pericardium in the thoracic cavity now another name of the heart synonymous in the greek it is known as a cardia and in the latent it is known as a goddess so the terminology related to the heart comes from these two words cardia and the cordis now we see the shape of the heart the shape of the heart is a conical or pyramidal in the shape right its size average size is 12 by 9 centimeter right and average size of the
0:57 individual is slightly larger than the own cleanse fist right now the weight of a heart in the middle is 300 gram average and in the female 250 gram location heart lies just behind the sternum the one third of the heart lies right to the median plane and two third of it lies left to the medial plane the heart consists of the four chamber that is a right atrium two when uh two ventricle two atrium the ventricle is lies downward forward and the left atria is directed backwards upwards and toward the right
1:43 so here this is the right ventricle this is the left ventricle and from the posteriorly you can able to see the right atrium in which the superior vena cava and the inferior vena cava opens and left to it is a left atrium this one left atrium in which one two and here 3 for pulmonary veins open right now we discuss the external feature of the heart so the heart is having an apex a base the far border that is
2:28 right border left border inferior border superior border and having three surface apart from the base that is a standard coastal surface left surface and the inferior or the diaphragmatic surface we discuss all this external feature one by one the first uh apex the apex is directed downward forward and toward the left the apex is formed by the left ventricle it is a conical in the shape it is formed by the left ventricle the apex apex on the surface lies in the left fifth intercostal space nine centimeter away from the midline
3:14 just in inside the mid clavicular line so this is the apex the base is slice exact opposite to the apex that is upward backwards and toward the right the way this form see this is the base it is a quadrilateral in the shape it is formed in the left side by the left two third is formed by the left atrium and the right side it is formed by the right atrium so the more part of the base is formed by the left atrium right so this is the base now we see the border of the heart it is having
4:00 forwarder that is a right border left border inferior border and the superior border which is a obscure from the view first the right border the right border is formed by the right atrium it is rounded and the convex it extends from superior vena cava to the inferior vena cava which is open into the right atrium so here this is the right border the right border shows on the surface the shallow vertical group the shallow vertical group which is known as a sinus terminalis so this is a right order second a left border the left border is a convex and this convexity is facing upward and
4:45 the left the left border is extending from a left oracle see this is the left oracle from the left oracle to the apex up to the apex this is the left border left border is somewhat ill different okay and left border is accompanied by you can see this whistle it is a marginal branch of a left coronary artery it is accompanied by this marginal branch of a left coronary artery now the inferior water inferior water is a horizontal and it extend from the opening of a inferior vena cava up to the apex so the inferior border is manly formed by
5:32 right ventricle and partly by the right atrium inferior border is accompanied by a right marginal branch of a right coronary artery marginal branch of the right coronary artery now this inferior border near the apex present the notes this note is known as insisura kodi inferior borders separate the sternocostal surface from the diaphragmatic surface the latch is a superior border the superior border is a slightly oblique and it is obscure anteriorly by aoda and the pulmonary trunk and it is formed mainly by
6:19 superior water is formed mainly by the left atrium and partly by the right atrium here like the superior border okay so these are the borders of a heart now we discuss the surface the heart is having apart from the base only three surface that is a stone coastal surface largest the left surface and the inferior or the diaphragmatic surface sternocostal surface is a large convex surface which is directed upwards and the forward it is formed mainly by the right ventricle and the right atrium and the oracle and partly by the left ventricle and a left oracle
7:08 now this sternocostal surface it present the anterior part of a right atrioventricular group here lies the anterior part of the right atrioventricular group and also it contain the anterior interventricular group interior interventricular group which lodges the anterior interventricular artery so this is the sternocostal surface the second is a diaphragmatic surface that is the inferior surface now the diaphragmatic surface is a flat you can see this is the flat okay so the diaphragmatic surface in its left two-third it is formed by the left ventricle larger part and the right one third it is formed by the right ventricle smaller part
7:55 the diaphragmatic surface contain the posterior interventricular group which lodges the posterior interventricular artery the last is a left surface the left surface is directed upwards backwards and the left and it is formed mainly by the left ventricle and partly by the left atrium and the left oracle so this is the left surface right so these are the surface of a heart now some grooves and this are the sulcus which is present on the heart the heart is having a force inverse two atria two ventricle so between the atria and the ventricle lies the
8:41 atrioventricular groove or the atrioventricular sulcus which is also known as a coronary sulcus now this atrioventricular surface which demarcate the atria from the ventricle separate the atria from the ventricle is a c-shape like this anteriorly it is deficient because of a pulmonary trunk so it start from the here posteriorly it is continuous so this is a trio ventricular groove or the sulcus which is also known as a coronary
9:27 surface now it is having two part the anterior part and the posterior part the interior part of a trioventricular groove is again divided into the right and the left half the right half contain the trunk of a right coronary artery and the left part here it contain circumplex branch of the left coronary artery the termination of a great cardiac vein and the commencement of a coronary sinus whereas the posterior atrial ventricular growth contain only the coronary sinus right now two ventricle is separated by a interventricular sulcus or interventricular group
10:14 interventricular glue lies anteriorly as well as posteriorly anterior interventricular glue lies on the sternocostal surface it lodges the anterior interventricular artery which is a branch of a left coronary artery and the posterior interventicular glue lies on the diaphragmatic surface which lodges the posterior interventicular glue which is mostly the branch of a right coronary artery two atria is separated by the inter atrial growth on the surface the international grow is deficient anteriorly because of the presence of the iota and the pulmonary trunk and the posterior it is very much faint very much faint that separate the right
11:02 atrium from the left atrium here lies the inter atrial group now posteriorly the inter atrial groove meets with the coronary sulcus and the posterior interventricular group this point the meeting point of this three group is known as a crux of a heart so this is the sulci or a group of a heart on the surface of the heart now we see some point of the interest about the external feature of the heart the heart present the only following feature means the apex is only formed by the left ventricle the base is only formed by the left and
11:48 the right atrium the diaphragmatic surface is only formed by the right and the left ventricle and the right border is only formed by the right atrium this is the only feature now we see the two third one third feature in the heart now the two third of the entire heart lies left to the midline two third of the entire heart lies left to the midline and the one third of the remaining heart lies right to the midline second this ternary coastal surface the two third of the standard coastal surface is formed by the right ventricle and the one third of the sternocostal surface is formed by the left ventricle
12:36 opposite to each diaphragmatic surface the two third of a diaphragmatic surface is formed by the left ventricle and the one third is formed by the right ventricle last the these this is the base the two third of the base is formed by the left atrium and the one-third of the base is formed by the right atrium now when the heart is given ask in the vibra you should tell you should keep the heart in the anatomical position so we see the anatomical position it should be kept in such a way that the apex should rise downward forward and towards the left now
13:22 inferior water lies horizontally in clear water should lies horizontally and the flat surface that is a diaphragmatic surface this one is a diaphragmatic surface that should lies on your palm so you should keep the heart like this in the left hand so this is about the external feature of the heart now in the second video we discuss the interior of the heart thank you if you like our video click on the like button and share with your friends to get the regular updates on anatomy video by viva vas of anatomy subscribe to our channel and click on the bell icon
