Changes

The heart is located in the thoracic cavity in between the [[Lungs - Anatomy & Physiology|lungs]], 60% of it lying to the left of the median plane. The heart’s lateral projection extends from [[Ribs and Sternum - Anatomy & Physiology|rib]] 3 to 6. Most of the heart’s surface is covered by the [[Lungs - Anatomy & Physiology|lungs]] and in juveniles it is bordered cranially by the [[Thymus - Anatomy & Physiology|thymus]]. Caudally the heart extends as far as the [[Diaphragm - Anatomy & Physiology|diaphragm]]. Variations in position and size exist among individuals depending on species, breed, age, fitness and pathology. Roughly speaking, the heart is responsible for about 0.75% of the bodyweight.

The heart is located in the thoracic cavity in between the [[Lungs - Anatomy & Physiology|lungs]], 60% of it lying to the left of the median plane. The heart’s lateral projection extends from [[Ribs and Sternum - Anatomy & Physiology|rib]] 3 to 6. Most of the heart’s surface is covered by the [[Lungs - Anatomy & Physiology|lungs]] and in juveniles it is bordered cranially by the [[Thymus - Anatomy & Physiology|thymus]]. Caudally the heart extends as far as the [[Diaphragm - Anatomy & Physiology|diaphragm]]. Variations in position and size exist among individuals depending on species, breed, age, fitness and pathology. Roughly speaking, the heart is responsible for about 0.75% of the bodyweight.

The heart is cone-shaped, with a broad base at the top from which the large blood vessels enter and exit. The tip, known as the apex, points downwards and lies close to the sternum. The longitudinal axis of the heart is tilted to varying degrees depending on the species resulting in the base facing craniodorsally and the apex caudoventrally.

The heart is cone-shaped, with a broad base at the top from which the large blood vessels enter and exit. The tip, known as the apex, points downwards and lies close to the [[Ribs and Sternum - Anatomy & Physiology|sternum]]. The longitudinal axis of the heart is tilted to varying degrees depending on the species resulting in the base facing craniodorsally and the apex caudoventrally.

The heart has a right and left lateral surface, which meet cranially at the right ventricular border and caudally at the left ventricular border. The auricles of the atria are visible on the left side, surrounding the root of the aorta and the pulmonary trunk, whilst the large veins and the main parts of the atria are situated on the right.

The heart has a right and left lateral surface, which meet cranially at the right ventricular border and caudally at the left ventricular border. The auricles of the atria are visible on the left side, surrounding the root of the aorta and the pulmonary trunk, whilst the large veins and the main parts of the atria are situated on the right.