Sexual Reproduction
Female Reproductive
- Male Reproductive system consists of organs whose functions are to produce, transfer, and introduce mature sperm into the female reproductive tract, where fertilization can occur
- Classified as essential organs for reproduction of gametes or accessory organs that support the reproductive process
- Essential organs: gonads of the male;testes
- Accessory organs of reproduction
- Genital ducts convey sperm outside the body; pair of epididymides, paired vasa deferentia, pair of ejaculatory ducts, and the urethra
- Accessory glands produce secretions that nourish, transport, and mature sperm; pair of seminal vesicles, the prostate, and pair of bulbourethral glands
- Supporting structures: scrotum, penis, and pair of spermatic cords
- Perineum: in males, roughly diamond-shaped area between thighs; extends anteriorly from pubic symphysis to coccyx posteriorly; lateral boundary is the ischial tuberosity on either side; divided into the urogenital triangle and the angle triangle
- Structure and location
- Several lobules composed of seminiferous tubules and interstitial cells (Leydig cells), separated by septa and encased in fibrous capsule called the tunica albuginea
- Seminiferous tubules in testis open into a plexus called rete testis, which is drained by a series of efferent ductules that emerge from the top of the organ and enter the head of epididymis
- Located in scrotum, one testis in each of two scrotal compartments
- Microscopic anatomy
- Interstitial (Leydig) cells: endocrine cells between the seminiferous tubules
- Seminiferous tubules
- Spermatogenic cells produce sperm
- Functions
- Spermatogenesis: formation of mature male gametes (spermatazoa) by seminiferous tubules; stimulated by follicle-stimulating hormone from the anterior pituitary (and also gonadotropin-releasing hormone from hypothalmus)
- Secretion of hormones by interstitial cells
- Testosterone
- type of androgen: maleness hormone
- functions include promoting primary and secondary male sexual characteristics and anabolism, affecting fluid and electrolyte balance
- regulated by luteinizing hormone from anterior pituitary
- Testosterone
- Inhibin: inhibits release of follicle-stimulating hormone by anterior pituitary, allowing the testis some control over spermatogenesis
- Estrogen: small amounts secreted by interstitial cells, liver, and other organs; role in males uncertain but may influence spermatogenesis and other functions
- Structure of spermatazoa: consists of a head (covered by acrosome), neck, midpiece, and tail; tail is divided into a principal piece; and an end piece
- reproductive ducts
- Epididymis
- Structure and location
- single tightly coiled tube enclosed in fibrous casing
- lies along the top and side of each testis
- Anatomical divisions include head, body, and
- Vas deferens(ductus deferens)
- Structure and Location
- tube, extension of epididymis
- Extends through inguinal canal, into the abdominal cavity, over top and down posterior surface of bladder
- Enlarge terminal portion called ampulla: joins duct of seminal vesicle
- Function
- Ejaculatory duct
- Formed by union of vas deferens with duct from seminal vesicle
- Passes through prostate gland, terminating in ur
- Accessory Reproductive Glands
- Seminal vesicles
- structure and location: convoluted pouches 5 to 7 cm long on posterior surface bladder
- function: secrete the viscous, nutrient-rich part of seminal fluid 960% of semen volume)
- Prostate gland
- Structure and location
- doughnut shaped
- encircles ure
- Bulbourethral glands
- structure and location
- Small, peas-shaped structure with approximately 2.5 cm long (1inch) ducts leading into the urethra
- Lies below prostate gland
- Function: secrete
- Supporting Structure
- Scrotum
- Skin-covered pouch suspended from perineal region into which the testes descend near the time of birth
- Divide into two compartments
- Contains testis, epididymis, and lower
- Penis
- Structure: composed of three cylindrical masses of erectile tissue, one of which contains urethra
- Function: peins contains the urethra, the terminal duct for both urinary and reproductive tracts; during sexual arousal, penis becomes erect, serving as a penetrating copulatory organ during sexual intercourse
- Consist of secetion from testes , epididymides, seminal vesicles, prostate , and bulbourethral glands
- Each millilter contains millions of sperm
- Passes from testes through epididymis,vas deferens , ejaculatory duct, and urethra
- Male Fertility
- Relates to many factors, number, size, shape, and
Female Reproductive
- function of the female reproductive system
- To produce offspring and thereby ensure continuity of the genetic code
- To produce eggs, or female gametes, each of which has potential to unite with male gametes to form the first cell of an offspring
- To provide nutrition and protection to the offspring for up to several
- Essential Organs: gonads are the paired ovaries; gametes are ova produces by the ovaries; ovaries are also internal genitals
- Accessory Organs
- Internal genitals: uterine tube, uterus, and vagina--- ducts or duct structures that extend from the ovaries to the exterior
- external genitals; the vullva
- Additional sex glands such as the mammary glands
- Perineum
- the skin- covered region between the vagina orifice and the rectum
- Ovaries
- Location
- Nodular glands located on each side of the uterus, below and behind the uterine tubs
- Ectopic pregnancy: developed of the fetus in a place other than the uterus
- Microscopic structure
- Ovum: an oocyte released from the ovaries
- Structure of the Uterus
- size and shape of the uterus
- the uterus is pear shaped and has two main parts:: the cervix and the body
- Wall of the uterus is composed of three layers: the inner endometrium ( mucous membrane), the middle myometrium (smooth muscle), and the perimetrium (outer incomplete layer of partial peritoneum)
- Cavities of the uterus are small because of the thickness of the uterine walls
- the body cavity's apex constitutes the internal os and opens into the cervix into the cervical canal, which is constricted at its lower end and form the external os that opens into the vagina
- Uterine ateries supply blood to the uterus
- Location