(1) Face, Lips and Mouth
Certain characteristics of man’s face have a decisive influence upon speech sounds. Comparative anatomy of the facial musculature is therefore relevant to our inquiry. The authoritative work on facial muscles of primates is by Huber (1931). He demonstrated that all of the muscles if the face were phygenetically derived from two basic muscular mantels which covered the neck and head of the prototype: the platysma (shown in Fig. 2.1 with horizontal orientation) and the sphincter colli profundus (shown with vertical orientation).
II. 體表
(1) 臉、唇、嘴巴
人臉部某些特性對於說話聲音有決定性的影響。臉部肌肉組織的比較解剖因此和我們探索主題相關。靈長類動物臉部肌肉的權威性作品出自於Huber (1931)，他應證所有臉部肌肉系統發生源自兩種覆著頸部與頭部圓形的肌肉皮質：闊頸肌（圖2.1橫面方位）、頸環束肌（縱向方位）。
In Fig. 2.2a the sphincter colli is almost entirely preserved: some differentiation over the nose and around the muzzle has, however, taken place already. However, the arrangement is much more primitive than in the simians, of whom one New-World example, spider monkey (Ateles ater), is given in Fig. 2.2(b). A number of distinct muscles that act on the peri-oral region may now be discerned. The musculature is the corner of the mouth in particular (sometimes called the mosiolus) shows a degree of complexity, absent in the more primitive forms and undergoing further and further differentiation in the higher ones. On the other hand, much of the posterior part of the sphincter colli has disappeared.
在圖表 2.2a 頸環束肌幾乎完整地保存：然而從接近鼻部和口鼻部份區域可發現不同地方。不過這些排列方式比類人猿更早期出現，一個新世紀的例子：蜘蛛猿於圖表2.2b可查看。口部周圍我們可分辨一些與其它部位不同的肌肉，位於嘴角上的肌肉組織（有時稱蝸軸）特別地展現某程度的複雜性，這組織在較早期還沒出現，在高等動物中經歷了一次又一次的變異慢慢改變而成，在另一方面，許多頸環束肌後部的部分肌肉卻沒再出現過了。
Numerous distinct schemas of modiolar anatomy have evolved. Among the apes the muscles around the mouth are more distinct than among monkeys. Three basic patterens have been described; one is peculiar to the gibbon family (Hylobatidae) and is illustrated in Fig. 2.2c. A quite different basic plan has been observed in the facial anatomy of the orangutan (Fig. 2.3a) whereas the chimpanzee and gorilla (Fig. 2.3 b, c) show an essential similarity in the schema of the modiolus. According to Lightoller (1925) and Huber (1931), the arrangement if muscles around the corner of the mouth in man is most similar to that in chimpanzee and gorilla. Huber emohasizes, however, that the muscles themselves have undergone further differentiation in man, have grown in shape and anatomical distinctiveness, and show more intricate interlacing than in the great apes (Fig. 2.4). One muscle, risorius Santorini, has no undisputed homologue in any subhuman form, and in the muscles of the lips (orbicular oris) the fibers around the oral margin (pars marginalis) assume an anatomic prominence not found elsewhere among primates (Duckworth 1910). Clearly, the complexity, size, and number of muscles originating particularly in the corner of the mouth greatly facilitate oral motility in man. The peculiar anatomy of the lips and the shape the mouth make possible rapid and air tight closure and sudden explosive opening, both being prerequisite for speech articulation.
FIG. 2.4. Lower facial muscles in man. Right: superficial layers; Left: deep layers. (From Brausm 1954.)
A most important aspect of facial anatomy is the shape and nature of our checks and their relation to the size of the mouth. The architectural peculiarities of man’s skull and jaw brought about modifications in the configuration of the cheeks. They cover most of the molars during all comfortable movements of the mouth and under no circumstances are we able to bare all our teeth. In Fig 2.4 the anatomical layers of the facial muscles are well illustrated. Once the superficial modiolar muscles are removed, the extremely sturdy muscles of the cheeks, the buccinator, may be seen, and in Fig. 2.5 the insertion of this muscle in the jaws demonstrated the enclosing nature of the soft tissues around the gap between the jaw.
Vocabulary
1. anatomy 解剖學
2. musculature 肌肉組織
3. platysma 闊頸肌
4. sphincter colli 頸環束肌
5. spider monkey 蜘蛛猿
6. mosiolus 蝸軸
