The Vesiculae Seminales
(Seminal Vesicales)
The vesiculæ seminales (Fig. 91152) are two lobulated membranous pouches, placed between the fundus of the bladder and the rectum, serving as reservoirs for the semen, and secreting a fluid to be added to the secretion of the testes. Each sac is somewhat pyramidal in form, the broad end being directed backward, upward and lateralward. It is usually about 7.5 cm. long, but varies in size, not only in different individuals, but also in the same individual on the two sides. The anterior surface is in contact with the fundus of the bladder, extending from near the termination of the ureter to the base of the prostate. The posterior surface rests upon the rectum, from which it is separated by the rectovesical fascia. The upper extremities of the two vesicles diverge from each other, and are in relation with the ductus deferentes and the terminations of the ureters, and are partly covered by peritoneum. The lower extremities are pointed, and converge toward the base of the prostate, where each joins with the corresponding ductus deferens to form the ejaculatory duct. Along the medial margin of each vesicle runs the ampulla of the ductus deferens. |
| Each vesicle consists of a single tube, coiled upon itself, and giving off several irregular cecal diverticula; the separate coils, as well as the diverticula, are connected together by fibrous tissue. When uncoiled, the tube is about the diameter of a quill, and varies in length from 10 to 15 cm.; it ends posteriorly in a cul-de-sac; its anterior extremity becomes constricted into a narrow straight duct, which joins with the corresponding ductus deferens to form the ejaculatory duct. |
| | | Structure.—The vesiculæ seminales are composed of three coats: an external or areolar coat; a middle or muscular coat thinner than in the ductus deferens and arranged in two layers, an outer longitudinal and inner circular; an internal or mucous coat, which is pale, of a whitish brown color, and presents a delicate reticular structure. The epithelium is columnar, and in the diverticula goblet cells are present, the secretion of which increases the bulk of the seminal fluid. |
| | | Vessels and Nerves.—The arteries supplying the vesiculæ seminales are derived from the middle and inferior vesical and middle hemorrhoidal. The veins and lymphatics accompany the arteries. The nerves are derived from the pelvic plexuses. |
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Gray's Anatomy 1. Embriology 2. Osteology  Vertebral Column
Skull
Exterior Skull Interior Skull Cranial Bones
Facial Bones
Extremities
Upper Extremity Bones Hand Lower Extremity Bones Foot 3. Arthrology Trunk Articulations
Vertebral Column Articulations Upper Extremity Articulations
Pelvis Articulations
Lower Extremity Articulations
4. Myology Muscles of the Head
Muscles of the Anterolateral Region of the Neck Muscles of the Trunk
Muscles of the Upper Extremity
Muscles of the Lower Extremity
Muscles and Fascia of the Thigh Muscles and Fascia of the Leg 5. Angiology Thoracic Cavity
6. The Arteries Arteries of the Head and Neck
a) Common Carotid Artery Arteries of the Upper Extremity
Axilla Arteries of the Trunk
Descending Aorta Common Iliac Arteries Arteries of the Lower Extremity
7. The Veins Systemic Veins
Veins of the Head and Neck 8. The Lymphatic System 9. Neurology Brain or Encephalon
Cranial Nerves
Spinal Nerves
Sympathetic Nerves
10. The Organs of the Senses and the Common Integument The Peripheral Organs of the Special Senses
11. Splanchnology The Respiratory Apparatus
The Digestive Apparatus
The Urogenital Apparatus
a. Development of the Urinary and Generative Organs b. The Urinary Organs c. The Male Genital Organs d. The Female Genital Organs The Ductless Glands
12. Surface Anatomy and Surface Markings Muscle Tables
Quizzes 1. Introduction
2. Head & Face
3. Neck
4. Torso
5. Shoulder & Arm
6. Forearm, Wrist & Hand
7. Hip, Thigh & Knee
8. Leg, Ankle & Foot
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