ANATOMY. 



227 



the organs of sight, hearing, smell, and taste ; and 

 a portion of those organs connected with respira- 

 tion, deglutition, speech, sound, &c., and that por- 

 tion of medulla oblongata which lies upon the 

 cuneiform process of the occipital bone, the de- 

 scending portion being, till it terminates in the 

 medulla spinalis, covered by the cervical verte- 

 bra. The upper part, or commencement of the 

 larynx, or opening which terminates in the trachea, 

 or wind pipe, and of the pharynx, which ter- 

 minates in the oesophagus, or gullet, are all con- 

 tained in, or connected with, the same cavities. 



The Chest or Thorax, is divided internally into 

 five cavities, which contain the following viscera, 

 viz. the pleura, the lungs, the thyraus gland, the 

 oesophagus, thoracic duct, arch of the aorta branches 

 of the vena cava, the vena azygos, par vagum and 

 great intercostal nerves, and the cavity containing 

 these is separated from the abdomen or belly by a 

 large and powerful muscle, called the diaphragm, 

 or midriff. The Abdomen, or belly, is divided into 

 several regions, as will be seen from the plate, and 

 its internal parts and viscera are the omentum, 

 stomach, small and large intestines, liver, gall- 

 bladder, mesentery, lacteal vessels, spleen, pancreas, 

 kidneys, suprarenal glands, part of the aorta des- 

 cendens, and vena cava ascendens. The pelvis 

 contains the urinary bladder and the internal parts 

 of generation. 



The DERMOID SYSTEM consists of the skin, the 

 external envelope of the hody, which varies in its 

 thickness from about a fifth to a twentieth of an 

 inch. It is exceedingly tough, and is by far the 

 most elastic of all the softer textures. The skin 

 consists of two parts, placed one above the other. 

 The inner lamina is called the true skin, and the 

 outer cuticle, epidermis, or scarf skin. 



Although we are reminded that space forbids us 

 pursuing the interesting facts connected with the 

 structure and functions of the skin, our sketch 

 would be very defective did we omit to notice 

 another use of the tegumentary covering of the 

 human body, as without this our hints on the 

 Mucous System would be almost unintelligible. 

 The skin then is prolonged into various passages 

 of the body, the eyes, nose, ears, mouth, lungs, 

 oesophagus, stomach, intestines, urethra, bladder, 

 ureters, kidneys, vasa deferentia, and tubular struc- 

 ture in the testes of males. In females, it lines 

 the vagina, uterus, uterine, or Fallopian tubes, and 

 lactiferous tubes in the mammae or breasts. The 

 skin then, taking an internal course, changes its 

 name, and assumes that of Mucous Membrane, and 

 this membrane is attached to subjacent organs by 

 cellular tissue. That portion of it which lines the 

 digestive and respiratory organs was termed gastro- 

 pulmonary, by Bichat, and that which lines the 

 genital and urinary organs, mucous membrane. 

 The tegumentary and lining membrane of all the 

 passages of the body are continuous, and therefore 

 the diseases of the one will affect the other. 



The appendages of the skin are the nails and 

 hair. The hairs are horny filaments, which ap- 

 pear on the human body, except on the palm of 

 the hand, but very much on the scalp of the head, 

 the eye-lids, eye-lashes, face, nose, ears, axilliE, 

 pubes, &c. See Hair in Encyclopedia. 



The nails are well-known, horny productions, 

 composed of lamellae or scales, and the root of 

 each nail is received into a sulcus or groove in the 

 skin. 



We have now completed the short sketch or 



history of the structure of the human body, and seen 

 that body covered with its universal envelope, the 

 skin; 1st us now then attentively survey the won- 

 derful machine, as it appears denuded of artificial 

 covering, so as to render our short, imperfect, 

 but, we flatter ourselves, comprehensive anatomical 

 details, somewhat more complete. 



A formal description of the external appearance 

 of the human body, in its full grown state, is alto- 

 gether unnecessary, as it may be presumed to be 

 familiar to every one. For the sake of greater 

 clearness, however, in describing the situation of 

 the internal parts, we have, with the aid of figures, 

 endeavoured to fix the limits of the external 

 regions of the body, adopting the popular and 

 well marked divisions of the head, trunk, and ex- 

 tremities. 



Regions of the Head. 



A The Brow or Forehead; the space a, towards tlie middle 

 and lower part of it, being called Glabella. 



B The Occiput or H billhead ; its most prominent point 

 backwards being denominated the Occipital Protuber- 

 ance. 



C The Crown of the Head ; the most prominent point b. on 

 each side of it, being- called the Parietal Protuberance. 



D The Temple on each side of the head. 



E The Region of the Kye on each side of the head. 



F The liegion of the Nose. 



G The Region of the Mouth. 



H The Chin. 



I The Cheek on each side of the head ; c, its most prominent 

 point above and laterally being called the Malar Protu- 

 berance 



K The External Ear on each side of the head. 



The term Face is applied to all that part of the 

 head which includes the Regions of the Bro\v, 

 Eyes, Cheeks, Nose, Mouth, and Chin. 



Regions of the Trunk. 



L The Region of the Neck, bounded on each side, below and 



before, by the ridge called the collar. 

 M The Breast. 

 N The Epigastrium or Epigastric Region, at the upper and 



middle part of which there is a slight depression called 



the Pit of the Stomach or Praecordia. 

 O The Umbilical Region 

 P The Hypogastrium or Hypogastric Region. 

 Q The Pudendal Kegion, of which the upper part d, is called 



