The Reproductive System: Wang Weixi Department Of Human Anatomy Medical School Xian Jiaotong University

Chapter 8 The Reproductive System Wang Weixi Department of Human Anatomy Medical School Xian Jiaotong University

The general description Ⅰ. Composition and function 1.Composition (1)The male and female reproductive system. (2) The system is composed of the internal and external genital organs. 2.Function (1) producing genital cells and Breeding descendant. (2) secreting sex hormone.

Section 1 The male reproductive system The internal reproductive organs: gonad——testis ， producing sperms and secreting androgenic hormone (testosterone) conveying ducts——epididymis,ducts deferens,ejaculatory duct, male urethra.conveying the semen to the outside of the body.  accessory glands——vesicles,prostate and bulbourethral glands; secreting the spermatic fluid to maintain the nutrition and activity of the sperms.

The external reproductive organs ： The scrotum and penis.

The male genital system

1 、 Testis 

position— scrotum ， one pairs 。 

shape

— oval-shape organs 。 4 to 5 cm in length; 10 to 15 grams.

superior and inferior extremities ； Lateral and medial surfaces ； anterior(free) and posterior(mesorchial) borders 。  

structure—— tunica albuginea →testicular mediastinum→ septula testis → lobules of testis contorted seminiferous tubules （ producing sperms ）→ straight seminiferous tubules → rete testis→efferent ductules of testis (conveying sperms into the head of epididymis) 。 interstitial cells of testis: secreting male hormones(testosterone ） ,controling the development of male secondary sexual characteristics 。

tunica albuginea testicular mediastinum septula testis lobules of testis contorted seminiferous tubules straight seminiferous tubules rete testis eferent ductules of testis interstitial cells

2 、 Epididymis

position— attaches to superior extremity and posterolateral surface of testis. morphology— comma-shape ， head,body,tail. structures—— head: efferent ductules; body and tail: the ducts of epididymis function— store sperms and nourish sperms.

3 、 Ductus deferens 4 parts: testicular part —— shortest part,from tail of epididymis to superior extremity of testis. funicular part—— from the superior extremity of testis to superficial inguinal ring. To be palpated easily in the living body. Part of vasectomy.  inguinal part —— to pass through the inguinal canal. Pelvic part—— longest part,from the abdominal inguinal ring to the posterior to fundus of urinary bladder; The terminal portion is dilated and called the ampulla ductus deferentis.

spermatic cord —— the soft round ropeway.  constitution ： the ductus deferens, testicular artery, pampeniform plexus of vein, nervous plexus, lymphatic vessels and remnants of the vaginal process. Position: from the superior extremity of the testis to the inguinal abdominal ring, length: 11 〜 15cm.

4 、 Ejaculatory duct constitution: Formed by the union of the ductus deferens and the duct of the seminal vesicle. The course: passes through downward and perforate the prostate. The opening: opens to the prostatic portion of the urethra (on the both sides of the surface of

5 、 Prostate A. The portion:  Lies in the lesser pelvic cavity.  Below the urinary bladder and penetrated by urethra.  It's in front of the rectum and on the urogenital diaphragm.

B. Shape:  a chestnut-shaped organ.  the base: the broad superior extremity; the apex: slender inferior extremity; the body:  two surfaces: --- anterior surface is behind the symphysis pubis; --- posterior surface, on which there is a prostatic sulcus. *in normal, the sulcus, ampulla of the deferent duct and seminal vesicles can be palpated through the rectum in

C. Structure:  Five lobes: anterior, median, posterior and two lateral lobes  The capsule and sheath of prostate: ---the capsule is formed by connective and muscular tissues. ---the sheath is formed by pelvic fascia. ---there is venous plexus between the capsule and the sheath.

D. The function: It produces the secretion which is the important component of the semen.

6、 Seminal vesicle Shape and position: Two oval sacculated organs placed posterior to the base of the urinary bladder and lateral to the ampulla of the deferent duct. Function: The secretion of the seminal vesicles is a component of semen.

Bulbourethral gland (or Cowper’s glands)

7、

They are embedded in the urogenital diaphragm and on both sides of the membranous urethra.

8 、 Penis 

parts: a root, a body, a head (glans of penis)

 structure: ---three cavernous bodies: *two dorsal cavernous bodies of penis (crus penis) *one ventral spongy body of urethra (bulb of penis and the spongy part of the urethra) ---each cavernous body is enclosed by the albugineous coat. ---the fascia and skin cover the three cavernous bodies all together. ---the urethral orifice is on the tip of the glands. ---the prepuce is a double layer of the skin (redundant

9. scrotum  A pendulous pouch of skin and superficial fascia.  Two layers: ---skin: thin and extensible ---dartos: superficial fascia with involuntary muscle fibers has the septum of scrotum.  Two compartments: each of them houses a testis, epididymis, the lower part of the spermatic cord and their coverings.

10. male urethra  a common tube for urinary and reproductive systems

 three parts: * the prostatic part: ---2.5cm in length, the calibre is the largest ---urethral crest ---seminal calyculus (the portion of the opening of ejaculatery duct) * the membranous part: ---1-2cm in length (the shortest) and the narrowest part ---surrounded by the external sphincter of urethra * the spongy part: ---15cm in length (the longest)

 three strictures: * in internal urethra orifice * in membranous portion * in external urethra orifice

 three dilated places: * the prostatic part * bulb of urethra * navicular fossa

 two curvatures: * the subpubic curvature: concave ventrally and upwards, it is fixed and can't be changed * the prepubic curvature: concave dorsally and downwards, it can be changed

会阴 Perineum

一、会阴的概念   广义会阴：指封闭小骨盆下口的全部软组织结构。 （盆膈以下所有软组织而言，盆膈为盆腔的底，分隔上 方的盆腔和下方的会阴。） 狭义会阴：指外生殖器与肛门间的狭窄区域。 

二、会阴的界限 耻骨联合下缘——耻骨下支—— 坐骨支——坐骨结节——骶结节韧带——尾骨尖。

三、会阴区分 以坐骨结节连线为界分为前后两部：  —— 后部——肛门三角。

四、尿生殖膈的概念  由尿生殖膈上、下筋膜及其之间的会阴深横肌和尿道括约肌构成 ，男性有尿道通过，女性有尿道和阴道通过。 

五、盆膈的概念  由肛提肌、尾骨肌、肛门外括约肌及其上下筋膜构成，有直肠末 端通过。

六、坐骨直肠窝的概念 是肛管两侧的楔形腔隙。