Explanation: Pulmonary vein carries Oxygenated blood from lungs to the heart. The largest pulmonary veins are the four main pulmonary veins two from each lung that drain into the left atrium of the heart.

Explanation: Capillary is the thinnest blood vessel order of 10µm in diameter. Each capillary is lined with simple layer of flat cells called endothelium.

Explanation: Angiology is the medical specialty which studies the diseases in the circulatory system and blood vessels.

Explanation: Left ventricle is one of the four chambers of the heart. The left ventricle has a thicker wall than right ventricles because the left ventricle has to pump blood all the way around the body but right ventricle only has to pump it to the lungs.

Explanation: The arteries are the blood vessels that deliver oxygen rich blood from heart to other organs of the body. Artery is a muscular tube lined by smooth tissues and has three layers.

Explanation: Human heart is four chambered. It has two auricles and two ventricles.

Explanation: Musculi pectinatis are parallel ridges in the walls of atria of the heart. They are so called because of their resemblance to the teeth comb as in pecten.

Explanation: Esophagus is also known as food pipe. It is a muscular pipe about 8 inches long and is lined by tissue called mucosa.

Explanation: Thoracic cavity is the second largest hollow space of the body. It is also called a chest cavity. The largest hollow space is abdominal cavity.

Explanation: Accumulation of fluid in pleural cavity is called as Hydrothorax. If a fluid is bloody the condition is called hemothroax and if it contains pus it is called pythorax.

Explanation: Thoracic cavity has 3 compartments. It has mediastinum and 2 pleural cavities. Mediastinum is a home to heart trachea and vessels. Pleural cavity contains lungs and pleural linings.

Explanation: Heart is a muscular organ in humans. It pumps blood through blood vessels of circulatory system.

Explanation: Serous membrane covering heart is called pericardium. The serous membrane lining thoracic cavity and surrounding lungs are called pleura.