Human Anatomy 205

Male & Female Reproductive System with multimedia links

Development of male & female reproductive systems

• Predetermination of sex with fertilization
  • female zygote has two "X" chromosomes
  • male zygote has one "X" and one "Y" chromosome
  • SRY gene on "Y" chromosome initiates a chain of events in 7 week old embryo that lead to development of male
• See Nova Online How is Sex Determined?
• Sex determination starts at 7 weeks
• Development of internal reproductive organs
  • Gonad forms ovary [cortex] or testis [medulla]
  • Mesonephric duct forms epididymis, ductus deferens, and ejaculatory duct.
  • Paramesonephric duct forms uterine tubes, uterus, and vagina.
• Development of external genitals
  • Labioscrotal folds forms labia or scrotum.
  • Genital tubercle forms penis or clitoris.
  • Testis descends through the processus vaginalis into scrotum before birth
• Structure of gametes before fertilization
  • Sperm head contains nucleus, midpiece mitochondria, tail is flagellum

Topics & Terms for Male Reproductive System

• See diagram of male organs in sagittal section
• Perineum - body region of external genitals and anus
• Scrotum [18] is supporting external pouch for testis
  • Forms from fetal processus vaginalis [outpouching from peritoneal cavity]
  • Interior is divided into two separate compartments by median scrotal septum
  • Regulates temperature of testis [mantains at about 34^oC.]

• Tunica vaginalis is a serous membrane that lines scrotal cavity and testes [parietal and visceral]
• Tunica albuginea is a dense fibrous capsule surrounding each testis
• Septa from tunica albuginea divide testis into lobules
• Lobule has 1 to 4 convoluted Seminiferous Tubules that produce sperm (spermatogenesis)
  • Spermatogenesis produces sperm from spermatogonia by meiosis
  • Spermatogenesis is meiosis and is stimulated by FSH
  • Spermatozoa (sperm) have acrosome (sac of enzymes for penetrating ovum) on head.
  • Sustentacular (Sertoli) cells protect and nourish sperm
• Interstitial (Leydig's) cells are endocrine and secrete testosterone
  • Located in testis between seminiferous tubules
  • Sitmultaed by LH

Ducts from testis to epididymis Rete testis is network of ducts leading to efferent ductules Efferent ductules transport spermatozoa to epididymis Ducts to urethra Epididymis [13] is single coiled tube next to testis [see interactive model] Three regions [head, body, tail] Site of sperm maturation Ductus deferens [14] transport sperm from epididymis to ejaculatory duct [emission] [see interactive lateral view] mucosa is pseudostratified columnar muscularis is 3 layers of smooth muscle Ejaculatory duct ejects sperm (in semen) into urethra Accessory sex glands produce semen [see LMC torso interactive sagittal section] Prostate [15] is inferior to urinary bladder and surrounds prostatic urethra Seminal Vesicles [16] are paired and connect to ejaculatory ducts Bulbourethral Gland (Cowper's) [17] secrets pre-ejaculatory fluid Ejaculation propels semen from urethra to exterior [sympathetic stimulation].

Interactive Sagittal Section Male Pelvis (click below to view lab model)

1. prostatic through prostate
2. membranous is about 1 cm in length
3. spongy through penis to external urethral orifice

• Prepuce covers glans in uncircumcised penis.
• Erectile tissue of penis
  • Corpus spongiosum surrounds spongy urethra and forms glans penis
  • Corpora cavernosa are paired dorsolateral masses
  • Erection results from vascular changes by parasympathetic stimulation.

• Torso male [interactive sagittal section] [Unlabeled sagittal section] [lateral view] [interactive lateral view]
• Torso 3/4 [male lateral view] [Unlabeled male Anterior view] [female sagittal view] [female frontal view]
• Torso female unlabeled [sagittal section] [lateral view]
• Torso female [sagittal section] [lateral view] [mammary gland] [mammary gland sectioned]

Click on new lab 3D reproductive models below for enlargement [* Interactive labels]
*Male,lateral view	Male,sagittal view	*Ovary,lateral view	*Vulva,lateral view	*Female,sagittal view

• Cross words: [ male anatomy] [ female anatomy] [ Reproductive functions] [ Reproductive hormones]
• Try WebAnatomy Quizzes at the University of Minnesota.
  • Male reproductive system quizzes [ Sagittal pelvis diagram ] [Frontal view diagram ]
  • Female reproductive system quizzes [ Sagittal Pelvis diagram ] [ Frontal view diagram ]
  • Also try WebAnatomy Game [ Male anatomy] [ Female anatomy]
• Test your knowledge with the Human Reproduction Problem Set at University of Arizona

Topics & Terms for Female Reproductive System

• Anatomical Perineum is region of external genitals and anus
• Clinical perineum - Tissue between vagina and anus
• See female tract - labeled frontal section illustration

• Surface tissue = Germinal epithelium is cuboidal cells
• Beneath the germinal epithelium is the tunica albuginea [a dense connective tissue layer]
• Ovarian cortex and medulla
• Follicles are in cortex [see ovary diagram]
  • each one contains Oocyte
  • every 28 days one follicle matures [stimulated by FSH]
  • maturing follicle produces & secretes estrogen
  • Oocyte is released at ovulation about day 14 [stimulated by LH]
• Oocyte undergoes oogenesis (meiosis) in uterine tube
• corpus luteum develops from follicle after ovulation [stimulated by LH]
  • see ovary diagram
  • produces both estrogen and progesterone
  • degeneration leads to menses
  • remains for first 6 weeks of gestation
• Steroid homones from ovary [Estrogen] [ Progesterone]

Uterine Tubes (fallopian tubes or salpinx) [22] Ovarian end expands as infundibulum with margin of fimbriae. See histology slide low power view Mucosa has ciliated columnar - see high power view See functions of uterine tube Transports oocyte, sperm, and embryo Site of oogenesis (meiosis) Capacitation of sperm Site of fertilization [fertilized ovum = zygote] Site of progression of early embryo stages [cleavage, morula, blastocyst]

Female Reproductive Organs (click below to view lab torso)

• Three regions [fundus, body and cervix]
• Walls of the uterus * * [See illustration]
  • myometrium = smooth muscle
    • target for oxytocin [parturition]
  • endometrium = inner lining which becomes progressively thicker during menstral cycle
    • Two layers [stratum functionalis & stratum basalis]
    • target for estrogen and progesterone which stimulate growth
    • Embryo (blastocyst) implants about 6 days after fertilization
  • Uterus supported by Broad ligament
• Gestation site = period of embryo/fetus development in uterus

Vagina [25] Mucosa is stratified squamous [rugae are folds] Fornix is a recess at attachment to cervix vaginal orifice opens to vestibule [hymen] Functions in parturition and coitus Insemination occurs in vagina See lab female torso [sagittal section labeled] Vulva [26][covering] refers to the external genitalia [see ilustration] Clitoris [glans clitoris & prepuce] erection [corpora cavernosa are erectile bodies] functions in orgasm Vaginal vestibule contains urethral and vaginal orifice vestibular bulbs - erectile tissue in lateral walls of vestibule vestibular glands lubricate vaginal orifice labia minora enclose vestibule and form prepuce Labia majora enclose vulva [homologous to scrotum] mons pubis is elevation of adipose tissue over pubic bone

Sagittal Section Female Pelvis (click below to see lab model)

• Ovarian cycle [see animation ] [follicular phase, ovulation, and luteal phase]
• Uterine cycles [build-up and loss of endomerium]
• Menstrual phase

• Attached to Pectoralis major muscles see [LMC big torso]
• Mammary gland has 15- 20 lobes separated by adipose tissue.
• Lobes are subdivided into lobules containing sac-like clusters of milk secreting glands
• Mammary ducts lead from lobules and join to form lactiferous duct
• Lactiferous duct leads from each lobe and opens on nipple.
• Areola is circular pigmented area of skin surrounding nipple
• Mammary gland is target of hormones [estrogen, progesterone, prolactin, oxytocin]
• See diagram mammary gland and ducts
• See torso [mammary gland] [breast sectioned]

Dynamic Human at McGraw-Hill

Human Anatomy Online

Etymology of Medical Terms

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Revised April 29, 2006
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Comments to: camelet@lakemichigancollege.edu