Reproductive System - Anatomy and Physiology LAB - Lecture Slides, Slides of Physiology

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The Reproductive System docsity.com Reproductive System • Primary sex organs (gonads) – testes in males, ovaries in females • Gonads produce sex cells called gametes and secrete sex hormones • Accessory reproductive organs – ducts, glands, and external genitalia • Sex hormones – androgens (males), and estrogens and progesterone (females) docsity.com The Scrotum • Sac of skin and superficial fascia that hangs outside the abdominopelvic cavity at the root of the penis • Contains paired testicles separated by a midline septum • Its external positioning keeps the testes 3°C lower than core body temperature (needed for sperm production) docsity.com Internal oblique muscle Aponeurosis of external oblique muscle (cut) Suspensory ligament of penis Penis (cut) Middle septum of scrotum Cremaster muscle External spermatic fascia Superficial fascia Scrotum _| containing dartos muscle Skin Superficial inguinal ring (end of inguinal canal) Spermatic cord Ductus (vas) deferens Autonomic nerve fibers Pampiniform plexus of testicular veins Testicular artery Epididymis Tunica vaginalis (from peritoneum) Tunica albuginea of testis Internal spermatic fascia Figure 27.2 docsity.com The Testes • Each testis is surrounded by two tunics: – The tunica vaginalis, derived from peritoneum – The tunica albuginea, the fibrous capsule of the testis • Septa divide the testis into 250-300 lobules, each containing 1-4 seminiferous tubules docsity.com The Testes Spermatic cord Blood vessels and nerves Seminiferous tubule Head of epididymis Efferent ductule Ductus (vas) deferens Rete testis Lobule Septum Tubulus rectus : . Tunica albuginea Body of epididymis Tunica vaginalis Cavity of tunica vaginalis Tail of epididymis Figure 27.3a docsity.com The Penis • A copulatory organ designed to deliver sperm into the female reproductive tract • Consists of an attached root and a free shaft that ends in the glans penis • Prepuce, or foreskin – cuff of skin covering the distal end of the penis – Circumcision – surgical removal of the foreskin after birth docsity.com The Penis • Internal penis – the urethra and three cylindrical bodies of erectile tissue • Erectile tissue – spongy network of connective tissue and smooth muscle riddled with vascular spaces docsity.com Accessory Glands: Seminal Vesicles • Lie on the posterior wall of the bladder and secrete 60% of the volume of semen – Semen – viscous alkaline fluid containing fructose, ascorbic acid, coagulating enzyme (vesiculase), and prostaglandins • Join the ductus deferens to form the ejaculatory duct • Sperm and seminal fluid mix in the ejaculatory duct and enter the prostatic urethra during ejaculation docsity.com Accessory Glands: Prostate Gland • Doughnut-shaped gland that encircles part of the urethra inferior to the bladder • Its milky, slightly acid fluid, which contains citrate, enzymes, and prostate-specific antigen (PSA), accounts for one-third of the semen volume • Plays a role in the activation of sperm • Enters the prostatic urethra during ejaculation docsity.com • Pea-sized glands inferior to the prostate • Produce thick, clear mucus prior to ejaculation that neutralizes traces of acidic urine in the urethra Accessory Glands: Bulbourethral Glands (Cowper’s Glands) docsity.com Comparison of Mitosis and Meiosis Mother cell ; mosome re Tetrad formed by synapsis toe eno pecaiod) Va of replicated homologous Prophase MITOSIS if x MEIOSIS f ) chromosomes Replicated hae | Chromosome replication ' t s/ Chromosome replication |, . Prophase I chromosome ——"_| 2n=d == Tetrads align at the Chromosomes align etapa pea Metaphase at the metaphase plate Metaphase | : . | Homo! us: Sister chromatids phittanceo nto separate Daughter Separate ceaini but sister chromatids cells of anaphase remain together during meiosis | anaphase —s Ay PS ( THY || Daughter cells it) No further chromosomal \ I, replication; sister SE ‘ or mmole eu iy chromatids separate Meiosis II — 2a during anaphase Il Th, n n n Daughter cells of meiosis Il (usually gametes) Event Mitosis | Meiosis _ OO | Number of divisions One; consisting of prophase, metaphase, Two; each consisting of prophase, metaphase, anaphase, and Number of daughter cells and genetic composition Importance in the body anaphase, and telophase Two; each diploid (2n) and identical to the mother cell Development of multicellular adult from zygote; to produce cells for growth and tissue repair; ensures constancy of genetic makeup of all body cells telophase; DNA replication does not occur between the two nuclear divisions; an event unique to meiosis is that during meiosis I, the homologous chromosomes synapse (join along their length), forming tetrads (groups of four chromatids) Four; each containing half as many chromosomes as the mother cell (hence haploid or n); nonidentical to mother cell To produce cells for reproduction (gametes); introduces genetic variability in the gametes and reduces chromosomal number by half so that when fertilization occurs, the normal diploid chromosomal number is restored (in humans, 2n = 46) Eéavstty7dom Hormonal Regulation of Testicular Function • Feedback inhibition on the hypothalamus and pituitary results from: – Rising levels of testosterone – Increased inhibin Figure 27.10 docsity.com Mechanism and Effects of Testosterone Activity • Testosterone is synthesized from cholesterol • It must be transformed to exert its effects on some target cells – Prostate – it is converted into dihydrotestosterone (DHT) before it can bind within the nucleus – Neurons – it is converted into estrogen to bring about stimulatory effects • Testosterone targets all accessory organs and its deficiency causes these organs to atrophy • Testosterone is the basis of libido in both males and females docsity.com The Ovaries • Paired organs on each side of the uterus held in place by several ligaments – Ovarian lig.– anchors the ovary medially to the uterus – Suspensory lig. – anchors the ovary laterally to the pelvic wall – Mesovarium lig.– suspends the ovary in between • Broad ligament – contains the suspensory ligament and the mesovarium docsity.com The Ovaries Suspensory Uterine ligament of (fallopian) ovary tube Ovarian blood Fundus vessels of uterus \ Lumen (cavity) 4 f , Ovary of uterus = Ampulla Mesosalpinx — —— i fi Isthmus Uterine ee Ee infundibulum | tube ieanent WN ‘ aa t y-Fimbriae Mesometrium Ovarian ligament — ( Round ligament of uterus ( Sz : — Endometrium oe Body of uterus a ! y Myometrium | Wall of Val Ureter ak uterus ) || SD Uterine blood vessels : fh Perimetrium (on I Isthmus Te Internal os " Uterosacral ligament Her Cervical canal } Lateral cervical External os (cardinal) ligament Lateral fornix Cervix Figure 27.14a docsity.com Vagina Ovaries • Blood supply – ovarian arteries and the ovarian branch of the uterine artery • They are surrounded by a fibrous tunica albuginea, which is covered by a layer of epithelial cells called the germinal epithelium • Embedded in the ovary cortex are ovarian follicles docsity.com Ovaries • Graafian follicle – secondary follicle at its most mature stage that bulges from the surface of the ovary • Ovulation – ejection of the oocyte from the ripening follicle • Corpus luteum – ruptured follicle after ovulation docsity.com Ovaries Tunica Oo Granulosa - Secondary 4— Mesovarium and albuginea tay ocyte / cells follicle blood vessels Degenerating Primary if : A J corpus luteum Oi ae 1 —— i ‘corpus albicans | Hah) Bak (as tea? ene ) | pa Ea Si © Vesicular (Graatian) Germinal | follicle pes epithelium Primordial follicles Antrum Oocyte Zona Ovarian : pellucida ligament F if ‘ folliculi Medulla : . & Ovulated oocyte Corona Primary (a) Corpus luteum Developing radiata (b) follicle corpus luteum & Figure 27.12 docsity.com Uterine Tubes (Fallopian Tubes) and Oviducts • Receive the ovulated oocyte and provide a site for fertilization • Empty into the superolateral region of the uterus via the isthmus • Expand distally around the ovary forming the ampulla • The ampulla ends in the funnel-shaped, ciliated infundibulum containing fingerlike projections called fimbriae docsity.com Uterus • Cervix – narrow neck which projects into the vagina inferiorly • Cervical canal – cavity of the cervix that communicates with: – The vagina via the external os – The uterine body via the internal os • Cervical glands secrete mucus that covers the external os and blocks sperm entry except during midcycle docsity.com Supports of the Uterus • Mesometrium – portion of the broad ligament that supports the uterus laterally • Lateral cervical ligaments – extend from the cervix and superior part of the vagina to the lateral walls of the pelvis • Uterosacral ligaments – paired ligaments that secure the uterus to the sacrum • Round ligaments – bind the anterior wall to the labia majora docsity.com Uterine Wall • Composed of three layers – Perimetrium – outermost serous layer; the visceral peritoneum – Myometrium – middle layer; interlacing layers of smooth muscle – Endometrium – mucosal lining of the uterine cavity docsity.com Vagina • Thin-walled tube lying between the bladder and the rectum, extending from the cervix to the exterior of the body • The urethra is embedded in the anterior wall • Provides a passageway for birth, menstrual flow, and is the organ of copulation docsity.com Vagina • Wall consists of three coats: fibroelastic adventitia, smooth muscle muscularis, and a stratified squamous mucosa • Mucosa near the vaginal orifice forms an incomplete partition called the hymen • Vaginal fornix – upper end of the vagina surrounding the cervix docsity.com Mons pubis — Labia majora Clitoris (glans) Labia minora Vestibule Anus Opening of the duct of the greater vestibular gland Figure 27.16 docsity.com External Genitalia: Vulva (Pudendum) • Clitoris (homologous to the penis) – Erectile tissue hooded by the prepuce – The exposed portion is called the glans • Perineum – Diamond-shaped region between the pubic arch and coccyx – Bordered by the ischial tuberosities laterally docsity.com Mammary Glands • Modified sweat glands consisting of 15-25 lobes that radiate around and open at the nipple • Areola – pigmented skin surrounding the nipple • Suspensory ligaments attach the breast to underlying muscle fascia • Lobes contain glandular alveoli that produce milk in lactating women • Compound alveolar glands pass milk to lactiferous ducts, which open to the outside docsity.com Structure of Lactating Mammary Glands First rib Skin (cut) Pectoralis major muscle = Suspensory ligament i ‘> Adipose tissue £ x Lobe Tye a Areola Ty . aon Nipple = ~- 4 Opening of ——— ry ’ Ww lactiferous duct / ni £ a Lactiferous sinus a > Lactiferous duct ; PL Sm Lobule containing Or; SON se 2 alveoli teint ee tae | “ee Superficial —— i .-_ fascia \ ee intercostal a muscles ({b) Figure 27.17 docsity.com