Animal breeding / by Laurence M. Winters.

  • Winter, Laurence Merriam, 1891-
Date:
1925
Catalogue details

Licence: Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0)

Credit: Animal breeding / by Laurence M. Winters. Source: Wellcome Collection.

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    THE VULVA AND CLITORIS 29 The urethra leads from the bladder to the penis and through it to the glans penis. It is an excretory passage for the urine and semen. The penis, the male organ of copula¬ tion, is of two parts, namely, penis and glans penis, or end. It contains the greater part of the urethra and it is built of erectile tissue. The erectile tissue of the penis is so con¬ structed as to allow gorging лvith blood, which causes the erection of that organ. The stimulation to erection is a nervous one, arising from the sacral portion of the brain. 23. Muscles of the Male Genital Organs.^—There are five muscles in the male genital organs: (1) The cremaster rises and assists in suspending the testicles. (2) The accel¬ erator urinae, a pair, comprise the urethra and act as an auxiliary in the discharge of the urine and semen. (3) The erector penis maintains erection by blocking the return of the blood. (4) The retractor penis Avithdraws the organ after copulation. (5) Wilson's muscle embraces the Cow- per's glands and adheres to the urethra; it comprises and aids in the discharge of the Cowper's gland and it contracts the membranous portions of the urethra. 24. Act of Ejaculation.—The impetus to ejaculation is a nervous one; it is accomplished by a contraction of the vesiculae seminales, the prostate gland, and the vas def¬ erens. The seminal fluid is thus forced into the urethra, out of which it is forced by contractions of the accelerator urinae and Wilson's muscles, which surround the urethra, and by contractions of the membranous portions of the urethra. 25. Female Genital Organs.—The genital organs of the female, beginning at the exterior, consist of the (1) vulva, (2) clitoris, (3) vagina, (4) os uteri, (5) uterus, (6) Fallopian tubes, and (7) the ovaries (Fig. 6). 26. The Vulva and Clitoris.—The vulva, the external genital organ of the female, in the mare and cow is from 6 to 10 inches long. The urethra opens into it, thus making ^ Strangeway, Veterinary Anatomy, p. 355.