Manual of physiology for students and practitioners / by H. Willoughby Lyle.

  • Lyle, H. Willoughby.
Date:
1911
Catalogue details

Licence: In copyright

Credit: Manual of physiology for students and practitioners / by H. Willoughby Lyle. Source: Wellcome Collection.

Provider: This material has been provided by The University of Leeds Library. The original may be consulted at The University of Leeds Library.

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    of columnar ciliated epithelial cells. The glands are simple tubes, consisting of a basement membrane upon which is a layer of columnar cells continuous with those of the body of the uterus. The stroma of the mucous membrane consists of a fine reticulum of connective-tissue fibres, in which there are numerous small round and spindle-shaped cells .embedded. The cervix uteri is lined by a firmer and more fibrous mucous membrane similar in structure to that of the body, except that the epithelium is composed of shorter cells and that the glands penetrate more deeply into the underlying muscular layer. Externally the cervix is lined by a stratified epithelium which is continuous with that of the vagina. Menstruation.—The endometrium of the non-pregnant uterus undergoes a cycle of changes, which result in the periodic discharge of blood, known as menstruation. The menstrual cycle is divided into four stages :— 1. The Stage of Quiescence. 2. The Constructive Stage. 3. The Destructive Stage. 4. The Stage of Repair. The Stage of Quiescence.—This has been already described as the normal condition of the uterus. The Constructive Stage.—This stage commences as soon as the process of repair (following the preceding menstrual period) is completed, i.e. about eighteen days after the cessation of the previous menstrual flow. The mucous membrane becomes considerably increased in thickness, partly by cell division, partly by an increase in the inter- cellular stroma, and partly by an enlargement of the utricular glands and blood vessels, an enlargement which results in the production of a sero-sanguinous exudate which infiltrates the stroma. The Destructive Stage.—In this stage blood leaves the capillaries and becomes extravasated freely in the stroma, partly by diapedesis of the corpuscles, and pardy by rupture of capillaries. The blood tends to accumulate in the lacuna;, which lie beneath the superficial epithelium. These lacunre constitute the so-called sub-epithelial heematomata. The epithelium becomes lifted off its bed, and the resulting space between it and the stroma becomes filled with blood. The rupture of these sub-epithelial hrematomata allows of