BOOK OF THE HUMAN BODY
[GENERAL STRUCTURE OF THE BODY]
FRAMEWORK: [Bones, Muscles] and Cells
[THE DIGESTIVE SYSTEM AND ORGANS]
[CIRCULATION OF THE BLOOD] AND RESPIRATION: [Heart], Blood Vessels, Lymphatics, [Lungs and Bronchii]
THE EXCRETORY SYSTEM: Intestinal Tract, Kidneys, Sweat Glands, [Lungs]
[THE NERVOUS SYSTEM]: Nerves, Brain, Spinal Cord
[ORGANS OF SPECIAL SENSE]: [Eye], [Ear], [Nose], [Tongue], [Hand] and Skin
CHARTS, TABLES AND SPECIAL FEATURES
THE FRAMEWORK AND MUSCLES OF THE HUMAN BODY
[Large illustration] (385 kB)
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PRINCIPAL BONES OF THE BODY
1. Collar Bone. (Clavicle)
2. Breast Bone. (Sternum)
3. Ribs.
4. Arm Bone. (Humerus)
5. Lumbar Vertebra.
6. Haunch Bone. (Pelvis)
7. Ulna.
8. Radius.
9. Wrist. (Carpus)
10. Metacarpus.
11. Phalanges.
12. Thigh Bone. (Femur)
13. Knee Cap. (Patella)
14. Brooch Bone. (Fibula)
15. Shin Bone. (Tibia)
16. Tarsus.
17. Metatarsus.
18. Phalanges.
PRINCIPAL MUSCLES OF THE BODY
1. Sternoclidomastoid (the muscle that bends the head).
2. Trapezius.
3. Pectoralis (chest muscle).
4. Deltoid (arm lifting muscle).
5. Coraco brachialis (rudimentary arm muscle).
6. Triceps (forearm extension).
7. Pronator radii teres (turns forearm and hand).
8. Annular ligament of wrist.
9. External oblique of abdomen.
10. Muscular sheath of abdominal erectus muscle.
11. Tensor fasciæ latæ (fibrous muscle covering thigh muscles).
12. Gluteus (controls thigh and helps to keep body erect).
13. Sartorius, or tailor, muscle (enables legs to be crossed).
14. One of quadriceps extensor cruris muscles.
15. Gastroenemius (bends the knee).
16. Long extensor of toes.
17. Peroneus longus (helps to keep foot arched).
18. Annular ligament of ankle.
19. Platyama.
20. Brachialis (moves elbow joint).
21. Biceps (flexor of arm).
22. Supinator longus (turns hand).
23. Extensor carpi radialis (extensor of forearm and wrist).
24. Flexor carpi radialis (bends wrist and turns hand).
25. Rectus abdominis (retracts abdominal wall).
26 and 27. Vastus externus and internus. These, with 14 and an abductor muscle, together make up the quadriceps extensor, the largest muscle in the body. It extends the leg.
28. Tibialis (extends the ankle).
29. Extensors of the toes.
The bones which make up the framework of the body are held together by joints of different kinds which allow of widely varying ranges of motion. The skull, which contains twenty-two bones in all, includes the cranium which contains the brain, and the bones which form the framework of the face. The vertebral column, which acts as a hinged and pliable tube down the center of which runs the spinal cord, is made up of twenty-four true vertebræ and the sacrum and the coccyx. The thorax, the bony box or cage protecting the heart and lungs, is made up of the twelve dorsal vertebræ with the twelve ribs on each side and the sternum or breast bone in front. The upper extremities consist of the shoulder-blade or scapula, the collar-bone or clavicle, the humerus or upper arm bone, the two fore-arm bones (radius and ulna), and the twenty-seven bones of the hand and wrist. The pelvis is composed of the two hip bones, together with the sacrum and coccyx. The female pelvis is larger in all diameters than the male. The bones of the lower extremity, which is joined to the pelvis by the head of the thigh bone (the femur), making a ball and socket joint at the acetabulum, are the two bones of the leg, the tibia and fibula; the patella or knee-cap; and the twenty-six bones of the ankle and foot.
BOOK OF THE HUMAN BODY
The study of the Human Body involves numerous other branches of science, and, as a whole, is the most complex and intricate of all the sciences. To explain its structure and workings we apply the principles of Biology, Physiology, Chemistry, Physics, Psychology, and Metaphysics.
The individual man, as a whole, is frequently forgotten both in physiology and in medicine, owing to the extraordinary minuteness and exactness with which each part and organ is examined and described. At the outset, then, it should be remembered that the human body is an organic whole, and what makes it one is not the similarity or unity of the machines and processes, for they are unlike and many; but it is the unity of the one governing force, the mind, and especially the unconscious mind, which presides over the body.
Nothing in the body is merely mechanical, although there is much mechanism; all is vital, all is united in one great aim—the health and well-being of the individual.
All organs and systems are held together and formed into one body by means of a framework, partly fixed and partly movable, partly rigid and partly flexible, partly hard and partly soft.
The skeleton part of the framework is made of bone; flexibility is given to certain parts by means of joints, which are simply smoothed and rounded ends of bone covered with gristle to avoid friction, and joined together by fiber and ligament for strength. This forms the rigid and hard parts of the framework.
The flexible and soft part, which everywhere covers organs and muscles, is composed of a layer of fat to preserve the warmth, as fat is a non-conductor, and an outer covering of skin.
This framework is exquisitely adapted to give strong protection to the vital parts so that they cannot readily be injured; and the whole of the organs are so arranged and stowed away that a perfect human body is a beautiful object full of symmetry and graceful curves and lines.
Divisions of the Body.—If we divide the body into six parts—four limbs, trunk, and head and neck—we find each part contains about thirty bones (counting the ribs in pairs) there being about two hundred in the entire body.
The height of the body depends mainly on the length of the bones of the lower limbs.
Everything in Pairs.—In the body almost everything is paired, right and left, giving it symmetry. There are but five central bones: two in the head, one in the throat, and the breastbone and backbone (or spine); and there are but five single muscles, all the rest—out of many hundreds—being in pairs. In the interior, where economy rather than symmetry is required, it is not so; there being as many single organs as there are double.
The Body Viewed as a Machine.—A favorite way of looking at the body as a whole is to regard it as an anatomical machine. In this view the body has an internal skeleton, of which the chief feature is the central axis or backbone.
Considering the skull and backbone as one, the body may be said to be built up of two tubes. The smaller posterior or neural tube includes the cavity of the skull and the vertebral canal. Within this tube is lodged the nervous center, or engine, of the body. The anterior, or body, tube is much larger, consisting of the face above, and the neck and trunk below, and it contains the four nutritive systems of life, so that the whole body in section is like an eight with the lower circle immensely exaggerated. The limbs, of course, are not tubular, and merely form part of the machinery.
Adopting the simile of the human engine and boiler and machinery, we see that the limbs, etc., are the machinery; the posterior tube the engines and force that move them; and the anterior tube the human boiler that generates the force. This boiler, like one in a steam engine, has an upper and lower part. The upper part is where the steam is generated (in lungs) and sent to the engine (the brain) by the heart. The lower part is where the fuel is burned (the stomach) and the ashes and refuse drop through (the intestines). So that the analogy between the two is close and striking.
Centers of Control.—There are two distinct seats of government in the human body: the one in the upper brain, or cortex, the other principally in the very center of the human body. That in the upper brain, or cortex, is the human will and the conscious mind. It has absolute control given to it over the animal part of the human life—that is, over the part that consists in the using of force, which includes the nervous and locomotor systems, and the special senses.
Nutritive Systems.—The other government, situated in the lower part of the brain and spinal cord and in the center of the body—in front of the spine and behind the stomach—is of an entirely different order. To put this more plainly: The four systems that lie in the body—digestive, circulatory, respiratory, and excretory—may be termed the nutritive systems, being designed for the maintenance and storage of life-forces. They are almost entirely under the control of the involuntary nerve centers, and have full and undisputed sway over life itself—that is, over the generating and storing of vital force, rather than over its usage.