The Body at Work: A Treatise on the Principles of Physiology

=The Canal.=—The prospect presented by a widely open mouth is too familiar to need description, but a few details may be pointed out. The teeth are, or should be, thirty-two in...

Twenty-five years ago a new process was introduced for colouring the elements which by their combination make up the nervous system. With its aid anatomists discovered the inade...

From one-fourth to one-third of the whole body is fluid. If the skin be regarded as a water-tight bag, three-fourths or rather less of its contents are solid, one-fourth liquid;...

Living matter, protoplasm, is irritable. It responds to influences impressed upon it by its environment. An effective influence, termed a “stimulus,” produces a change in protop...

Life means change. We cannot imagine its continuance without liberation of energy. Arrest of molecular activity is death. There is no possibility of its revival. A watch that ha...

The blood circulates in a closed system of tubes, continuous from the heart back to the heart. The walls of these vessels separate the blood from the tissues. Nowhere, except in...

The eye is enclosed in a globe of fibrous tissue, of which the front part, or cornea, being transparent, admits light. The epithelial layer which covers the cornea, conjunctiva,...

Many things enter into the alimentary canal. If an analysis were made of a day’s food and drink, from the cup of tea on waking to the cocoa or other potion which is regarded as...

Protoplasm was defined by Huxley as “the physical basis of life.” It is the material substance which lives. There is no life in anything which does not consist of, or is not sup...

A cut carried horizontally backwards across the cartilage which projects forwards as Adam’s apple, a quarter of an inch below its notch, would show that it is =V=-shaped, the po...

The ear, like the eye, records amplitude of vibration; loudness. It also records rapidity of vibration, musical pitch, which corresponds with colour. But it seems to have a more...

=Thyroid Gland.=—On either side of the windpipe, rather below the thyroid cartilage (Adam’s apple), lies a somewhat conical mass of tissue. The two masses are connected by an is...

Immediately after its discovery in the seventeenth century, the compound microscope was applied to the study of minute plants and animals, their organs and tissues. In this conn...

In Man the chief function of these senses is to guard the entrances to the respiratory and digestive tracts. In this they are not conspicuously efficient, since various poisonou...

The senses, according to a time-honoured classification, are five in number—smell, sight, taste, hearing, and common sensation, or touch; but such a classification of our sensat...

Physiology is the science of the body at work. It is the study of life. Anatomy records how plants and animals are constructed. It maps and measures. Physiology ascertains what...