Home » , » Lungs Anatomy

Lungs Anatomy

We possess a pair of lungs, one in each half of the chest. But though each lung occupies an apparently similar space, they differ in size. The right lung is larger than the left, is somewhat shorter but much thicker than its neighbor to the left.

The right lung is shorter because the heavy part of the liver is situated under the diaphragm right below it and thus presses against the base of the right lung, or the big liver got there first.

The left lung is narrow and thin at its lower half because the heavy-heart snuggles right against it, and may be the sorrowing heart has had the left lung cry itself out. Well, maybe that is the punishment for being left!
anatomy lungs

However, the lung is not really red. . . . In childhood it is pink but later in life it is a bluish gray, due to the absorption of dust and soot from the dirty city air we breathe.

The lung is light in weight, will float if placed in water, and it crackles when pressed between the fingers because it is constructed like a sponge and is full of air sacs. It is really a windbag, which never gives out as witness the filibusters.

The lungs are dome-shaped, pointed at the top or apex and wide at the base conforming to the shape of the chest. The left lung is made up of 2 lobes or sections and the right has three lobes. The windpipe or trachea divides and sub-divides sending branches into each lobe.

The windpipe brings the inspired air to the lungs. The central space between the two lungs is called the mediastinum. The lungs are covered by a serous membrane called the "pleura." The pleura has two layers, one covers the lungs and the other lines the inside of the chest cavity.

The space between the two layers of the pleura is called the pleura cavity. When the pleura covering of the lung becomes inflamed (pleurisy), it gives rise to a sticking pain on breathing. The windpipe (trachea), coming down from the larynx, divides into branches called bronchi and enters each lobe of the lungs.

In the lungs the bronchi keep sub-dividing like the branches of a tree until finally they end in microscopic air sacs (alveoli). Blood vessels and nerves enter the lungs together with bronchi. The pulmonary artery brings impure blood from the right side of the heart.

Entering the lungs the artery divides and subdivides becoming capillaries which are in contact with air cells from which oxygen is taken up by the blood and carbon dioxide is given off; then the oxygenated blood is taken up by the vein capillaries and gathered up by the larger veins, to be finally emptied into the pulmonary veins which come out of the lungs.

This pure blood is carried to the left side of the heart from where it is distributed to every part of the body. The lungs breathe, inspiring and expiring, 18 times a minute during rest. The inspiration is a little shorter than the expiration, and each follows the other without a pause.

The ratio of the respiration to the pulse is 1:4 under normal conditions. During exercise and in fevers the rate of both respiration and pulse rise in the same ratio. The lungs breathe automatically, but we may increase the rate at will. The lungs can perform tricks by reflex action.

Sneezing is a deep inspiration followed by a forced expiration. Sighing is a long inspiration followed by a sudden expiration. Hiccough is similar to sighing, only it is involuntary and the expiration is caused by a reflex spasm of the diaphragm.

In speaking, the expiration is voluntary but the vocal cords are made tense and they vibrate as the air is expired, producing sounds. Laughing is a result of a series of rapid expiration. Yawning is a result of an involuntary inspiration with a stretching of the face muscles. Sobbing refuses explanation

Thanks for reading Lungs Anatomy

« Previous
« Prev Post
Next »
Next Post »

0 komentar:

Post a Comment