Chapter 1- Prenatal Development of the Male and Female Reproductive Structureso Genetic sex is determined at fertilizationo Around 7th week of development the influence of sex chromosomes become evident Gonads become ovaries/testes – internal and external structures developo Default development is female Presence of Y chromosome causes undifferentiated gonads to develop intotesteso Male: Y chromosome induces testes, testes produce testosterone (induce internal and external development) and snit-Mullerian hormone (degenerates Mullerian ducts)o Female: gonads become ovaries, mullerian duct becomes internal and default external structures proceed- Differentiation and syndromeso First 3 months are criticalo Reproductive structures develop from homologous structureso Androgenital Syndrome: genetic female (so internal is female and fertile) but bathed in androgen on the outside causes virilizatio nof external genitalia (enlarged clitoris and fusion of labia majora)o Androgen Insensitivity Syndrome: genetic males (so gonads become testes producing MIH and testosterone) MIH degenerates mullerian but body does not respond to testosterone. Default female external structures developo Cases illustrate reproductive structures are under hormonal control and that female external tissues exposed to male hormones will prenatally develop into male-like structures- External Structures of the Maleo Penis: Male organ used for sexual intercourse Erectile tissue: corpora cavernosa penis and corpus spongiosum penis consist of dense sponge and vascular network of blood vessels and nerves- Erectile dysfunction: vascular problem Urethra: canal passage for urine and semen out of body Glans penis: sensitive structure at the end of penis Foreskin: covers the glans penis- Circumcision: removal of the foreskin for health reasons and religious beliefso Reduction of HIV, herpes, and HPV infectiono Scrotum: pouch containing the testes (internal) blood vessels and nerves that works to maintain the testicles at 5 degrees lower than core body temp. Scrotal muscles can contract and relax to control temp. - Internal Structures of the Maleo Testes: located in scrotum and produce sperm and hormones. Also contain Seminiferous tubules and leydig cells Hormones: powerful chemicals that travel through the bloodstream to affect many parts of the body produced by leydig cells Sperm: male gametes produced by seminiferous tubuleso Epididymis: comma shaped structures above the testes where the sperm mature and develop motilityo Prostate gland and cowpers gland: contribute their secretions to the male ejaculate Semen: male ejaculate consisting of sperm from testes and other secretiono Vas deferens: after maturing sperm arrive here and ravel to the ampulla and seminal vesicle Vasectomyo Seminal vesicles: pouches that provide sugar and proteins (nutrients) and vehiclesfor transporting the sperm. During ejaculation the contents are emptied into the ejaculatory duct with the contents of the vas deferens (sperm)o Ejaculatory duct: open into the urethra (at the prostate gland) which carries the sperm to the opening of the penis. Empties its contents at the time of ejaculation.- External Structures of the Femaleo Collectively known as Vulvao Labia majora: folds that form the boundarieso Labia minors: smaller folds between the labia majors, form the hood of the clitorisin the area of the clitoriso Clitoris: contains 2 cylinders of erectile tissue Corpora cavernosa clitoris: become filed with blood upon sexual excitationo Vestibule of the vagina: opening of the urethra (outlet for urine), vagina and bartholin ductso Hymen: thin membrane that covers the vaginal opening (religious and cultural significance)o Bartholin’s gland: produce sexual secretions for lubricationo Mons pubis: rounded fatty structure formed by the labia majora at the anterior of the vulva- Internal Structures of the Femaleo Ovaries: female gonads that produce eggs and the female hormones (estrogen and progesterone), decrease in size later in lifeo Fallopian tubes (oviducts): extended from the ovaries to the uterus and the site of fertilization Fimbriae: finger like portions that cover the top of the ovaries. Sweeps up eggs (cilis) released from ovaries into oviducts Tubal ligationo Uterus: muscular pear shaped organ, site of implantation and development of embryoo Vagina: tube composed of the muscle and membranes extending from vaginal orifice to the cervix, female organ of copulation and recipient of semen. During menses, product passes through the vagina, during birth child passes through vaginaChapter 2: Reproductive Physiology - Brain control of the Reproductive Systemo Endocrinology: the study of the endocrine glands and their products Ductless glands that empty products (hormones) directly into bloodstream Pituitary gland, thyroid glands, adrenal glands, pancreas, ovaries and testes Posterior pituitary gland: connected to brain by nerves Anterior pituitary gland: connected to brain by blood vessels- Produces trophic hormones, gonadotropins, which stimulate the ovaries and testes to make their own hormoneso Female: Follicle Stimulating Hormone (stimulates follicles to ripen in ovary and produce estrogen and progesterone) and Leutinizing Hormone (causes follicle to rupture releasing an egg during ovulation and the ovary to produce estrogen and progesterone)o Male: FSH (stimulates testes to produce sperm) and LH (causes testes to produce androgens)o Neuroendocrinology: the science of the relationship between the central nervous system (brain and spinal cord) and the endocrine system Pituitary gland is controlled by the brain, specifically the hypothalamus which receives info from many different brain areas Posterior pituitary control- Hypothalamus releases neurohormones that travel down the nervesto the posterior pituitary where they are stored until neurostimulation activates their release into the bloodstream Anterior pituitary control- Hypothalamus releases neurohormones into the blood vessels that lead to the anterior pituitary, in response to hormones are released into the bloodstream Control of the hypothalamus, negative feedback- Gonadal hormones control the output of the hypothalamus (also the anterior pituitary) helping the hypothalamus know when to release hormones to anterior pituitary- Example: gonadal hormone levels high, then the hypothalamus slows down and the GnRH levels lower- Male
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