repro of m &f ch 52
A&P of male reproductive system
functions : 1.producing and storing sperm
2. Depositing sperm for fertilization
3. Developing male secondary sex characteristics
Organs: testes, ductal system, accessory glands, penis
Testes
Enclosed in scrotum (sac-like) suspended from exterior abdominal wall
3 coiled seminiferous tubules produce sperm cells
Two oval testes
Position keeps normal body temperature for viable sperm production and storage
Testosterone is responsible for development of male secondary sex characteristics
Epididymis Ductal System
Passageways: cilia sweep sperm out of the testes into the epididymis (tightly coiled tube structure that lies superior to the testes and extends posteriorly)
Contract response to sexual stimulation forces sperm to ductus deferens.
Produced in seminiferous tubules travel through a network if testicular ducts: rete testis
Ductus Deferens (vas deferens)
Enclosed in connective tissue. Sheath spermatic cord
18 in (46cm) long and rises along posterior wall of testes
Moves upward and passes through the inguinal canal into the pelvic cavity. Loops over urinary bladder, joins ejaculatory duct
Man sterilized because small slits on either side of scrotum and sever ductus. Vasectomy. Renders man sterile because sperm can no longer be expelled.
Ejaculatory duct and urethra
Urethra carries sperm and urine. Urethral sphincter @ base of bladder does not at the same time
Connects ductus deferens and seminal vesicle w/ prostatic portion of urethra
Unites w/ urethra to pass through prostate gland
Two ejaculatory ducts empties into prostatic urethra
Urethra passes through prostate gland, extends length of penis, ending at urinary meatus
Accessory Glands
Includes: seminal vesicle, prostate gland, cowper gland
Each ejaculation (2-5 ml of fluid) 200-500 million sperm are released
Prostate Gland
Passes through the posterior part. Hypertrophies with age making voiding difficult
Single doughnut shaped. Surrounds neck of bladder and urethra
Muscular and glandular tissue
Secretes alkaline fluid. Contributes motility of sperm
Cowper Gland
Peas-sized glands under male urethra
Correspond to Bartholin glands in women provide lubrication during sex
Seminal Vesicles
It Lies at the base of the bladder and produces 60% of the volume of semen.
Released in ejaculation ducts meet with sperm
Male urethra
2 purposes: conveying urine from bladder, carrying sperm to the outside
Excessive tissue is called circumcision
Circumcision prevents phimosis (tightness of prepuce of penis that prevents retraction of foreskin over the glans)
Cylindrical penis is the organ of copulation
Shaft of penis ends with enlarged tip of glans penis
3 masses of erectile tissue: corpus, two corpora cavernosa
After ejaculation penis returns to flaccid state
Sexual stimulation concludes w/ ejaculation brought by peristalsis of reproduction duct and contraction of prostate gland
Sexual stimulation sinuses fill w/ blood penis becomes erect
Contain numerous sinuses that fill shaft of penis
Sperm
Mature cells live 48 hrs sometimes up to 5 days
3 parts: 1. Head 2. Midpiece 3. Tail propels the sperm
Spermatogenesis ( developing spermatozoa) begins at puberty and continues throughout life.
Female reproductive system
Produce ovum, house fertilized egg, maintain embryo, nurture newborn infant
Includes: ovaries, uterus, fallopian tubes, vagina
Ovaries
Puberty release. Progesterone and estrogen release mature egg during menstrual cycle
Size and shape of almonds
Contain 30,000-40,000 microscope ovarian follicles
Bilateral to uterus inferior to fallopian fimbriae
Fallopian tubes (oviducts)
Pair of ducts opening @ one end into fundus (upper portion of uterus) peritoneal cavity over ovary
4in(10cm) long fimbriae distal end
Inner surface of tubes lined w/ cilia (graafian) follicle in ovary ruptures release mature ovum
Fimbriae sweep ovum into fallopian tube
Outer 3rd of tube, fertilized ovum(zygote) moved through tube by muscular peristaltic movements and sweeping action of cilia
If mature ovum is not fertilized it disintegrates
Menstrual Cycle
Starts at approx 12 years of age
Anterior pituitary gland begins to release follicle stimulating hormone (FSH) as levels increase egg matures with graafian follicle
Replaced by scar tissue corpus albicans hormone level decrease and menstruation starts again
Days 1-5 (menstrual) endometrium, sloughs off, 1-2 ounces (30-60 ml of blood)
3 phases 1) menstrual 2) preovulatory 3) postovulatory
Days 6-13 (preovulatory) estrogen causes vascularization of uterine lining
Day 14 anterior pituitary gland releases luteinizing hormone rupture of graafian follicle and releases mature ovum.
Day 15-28 (post ovulatory) corpus luteum release estrogen and progesterone to maintain uterine lining until placenta is formed, it takes over the job of hormonal release
If pregnancy does not occur usually lasts 8 days and then disintegrates
Fallopian tube (fimbriae) sweep ovum to fallopian tube transformed into granular mass: corpus luteum