The human body is made up of the head (caput), neck (collum), trunk (truncus), and two pairs of limbs, or extremities, the upper (membra s. ex-tremitates [BNA] superiores) and lower (membra s. extremitates [BNA] in-feriores). The following parts are distinguished in the head: the forehead (frons); the highest point of the skull (vertex); the back of the head (occiput); the temples (tempora) and the face (facies). The trunk consists of the chest (thorax), the abdomen (abdomen) and the back (dorsum). The following linest are drawn for orientation on the chest surface: 1) midline (linea mediana anterior); (2) sternal line (linea sternalis) stretching along the sternal bor­der; (3) mamillary line (linea mamillaris s. medioclavicularis) passing through the nipple or the middle of the clavicle; (4) parasternal line (linea paraster­nal) passing midway between the sternal and mamillary lines; (5) ante­rior, (6) middle, and (7) posterior axillary lines (lineae axillarea anterior, media and posterior), the first and last passing through the anterior and pos­terior folds of the axilla, respectively, and the middle line passing through the point midway between these folds; (8) scapular line (linea scapularis) passing through the inferior angle of the scapula. The abdomen is divided by two horizontal lines, one drawn between the ends of the 10th ribs and the other between both the anterior superior iliac spines, into three parts, one located above another: the upper part of the abdomen (epigastrium), the middle part (mesogastrium) and the lower part (hypogastrium) (Fig. 7). Each of these three parts of the abdomen is subdivided by two vertical lines into three secondary regions: the epigas­trium is divided into a middle epigastric region (regio epigastrica) and two lateral regions, the right and left hypochondrium (regiones hypochondriacae dextra and sinistra). The middle abdomen is divided in the same manner into a medial umbilical region (regio umbilicalis) and two lateral, right and left lumbar regions (regiones abdominales laterales, dextra and sinistra). Finally, the hypogastrium is divided into the pubic region (regio pubica) and two lateral, right and left inguinal regions (regiones inguinales, dex­tra and sinistra). The upper limb is divided into the arm (brachium), the forearm (antebrachium) and the hand (manus); the palm (palma manus), the back (dorsum manus) and the fingers (digiti manus) are distinguished in the hand. The lower limb, in turn, is divided into the following parts: the thigh (femur), the leg (crus), and the foot (pes), in which the sole (planta), the dorsum of foot (dorsum pedis), and the toes (digiti pedis) are distinguished. The sex characters distinguishing a male from a female are divided into primary and secondary. The reproductive organs, the sex glands in the first instance, which determine the sex are the primary characters. All the other characters are secondary. Females are smaller in height (by 12 cm on the average) and weigh less (a female weighs 55 kg on the average). In relation to the body height, the trunk is shorter in a female than in a male, but the low­er limbs of a female are longer. The shoulders are narrower in females, but the lower part of the trunk is wider because a female pelvis is wider than the pelvis of males. The chest of a female is shorter and narrower than that of a male as a result of which, as well as because the female pelvis is inclined more to the front, the abdomen of a female is longer. The average total bulk of muscles makes up 40 per cent of total body weight in males but only 32 per cent in females, as a consequence the physical strength of females is in gene­ral less than that of males. The adipose tissue is developed more copiously in females. Developed mammary glands are a typical secondary sex character of females; in males these glands are rudimentary. The skin of males is thick­er and coarser and, moreover, is more hairy (especially on the face).