general investment; being prolonged without interruption, below, into the superficial fascia of the chest,—above, into that of the head and face. It consists here, as elsewhere, of two layers, which have the local peculiarity of being separated by the platysnia myoides in the greater part of their extent. Its deeper layer occurs in the form of delicate, scarce, lax, fatless areolar tissue, interposed between the proper aponeurosis of the region and the platysma myoides, furnishing means for the loose gliding of this muscle, and continued, without adhesion or sensible change, into the adjoining regions. Its subcutaneous layer is of coarser materials and of less uniform thickness, is in close union with the skin, and follows its movements: it contains the variable amount of fat, which the region presents; and so, though it
Fig. 327.
Transverse horizontal section of the beck, seen from above.
- A, fourth cervical vertebra.
- B, cricoid cartilage.
- C, pharynx.
- D, Medulla spinalis.
- a, prevertebral aponeurosis.
- b, posterior pharyngeal aponeurosis.
- c, middle constrictor.
- d, thyroid body.
- e, sterno-mastoid muscle, in the space behind which is seen a section of the great vessels, and of their sheath.
- f, sterno-hyoideus.
- g, omo-hyoideus.
- h, sterno-thyroideus.
- i, crico-thyroideus.
- j, trapezius.
- k, splenius.
- l, complexus.
- m, semi-spinalis and multifidus.
- n, levator anguli scapulæ.
- o, scalenus posticus.
- p, scalenus anticus.
- q, longus colli.
- r, rectus capitis anticus major.
- s, superior thyroid vessels.
- t, ascending cervical vessels.
- u, deep cervical vessels.
- v, external jugular vein.
- w, anterior jugular vein.
- x, platysma and superficial fascia.
