Question

In Laboratory observation and dissection of a
mammalian heart,
@ Mention the external features you observed?
(6) What structures do you observe that are
protecting the heart?
@ What differences did you observe between
the upper and lower chambers?
d) Name the large blood vessel coming
out of the heart?​

Answer 1

Dissection of a mammalian heart will show the following parts:

Explanation:

• External features : Pericardium, Auricles (left and right), Ventricles (left and right), Superior Vena Cava, Inferior Vena cava, Pulmonary artery, Pulmonary vein, Aorta, Left common carotid artery, Left subclavian vein, Branchocephalic artery.
• The heart is protected by the Pericardium layer which is bilayered, comprising of fibrous pericardium and serous pericardium. The space in between the two layers is filled with pericardial fluid which protects the heart from any physical stress.
• Difference :

1. The upper chambers are smaller as compared to the lower chambers.
2. The upper and the lower chambers are connected by valves, the right auricle and ventricle are separated by the Tricuspid Valve and the left auricle and the left ventricle are separated by the Bicuspid Valve.
3. The vena cavas opens into the right auricle and the pulmonary vein opens into the left auricle.
4. The right ventricle of the heart opens itself into the pulmonary artery and the left ventricle of the heart opens itself into the aorta.
5. The auricles are separated by the inter-auricular septum.
6. The ventricles are separated by inter-ventricular septum.

• The largest blood vessel coming out is the Aorta.