Nursing 10th Notes Reproductive Systems PDF

Summary

These notes detail the male and female reproductive systems, including primary and secondary sex organs, and their functions. The text describes processes like sperm production, ovulation, and fertilization. Key components such as the testes, ovaries, uterine tubes, and uterus are explained.

Full Transcript

Male Reproductive System Asst. Prof. A. Taha Demirbaş Sexual Reproduction Sexual reproduction involves two parents producing genetically unique offspring Gametes are; Sperm (spermatozoon): Small, motile, mainly DNA. Egg (ovum): Large, nutrient-rich. Humans are classified by chromosome...

Male Reproductive System Asst. Prof. A. Taha Demirbaş Sexual Reproduction Sexual reproduction involves two parents producing genetically unique offspring Gametes are; Sperm (spermatozoon): Small, motile, mainly DNA. Egg (ovum): Large, nutrient-rich. Humans are classified by chromosomes: XY (male) and XX (female) Reproductive System Overview While the female system; The male system; - produces eggs, - produces and delivers sperm - receives sperm, - facilitates fertilization, - harbors the fetus, - gives birth, and - nourishes offspring Reproductive System Overview Primary Sex Organs (Gonads): Male: Testes (produce sperm) Female: Ovaries (produce eggs) Secondary Sex Organs: Male: Ducts, glands, and penis (storage, survival, and transport of sperm) Female: Uterine tubes, uterus, and vagina (fertilization and fetal development) Reproductive System Overview Classification by Location: External Genitalia: Found in the perineum and mostly visible (e.g., penis, vulva) Internal Genitalia: Located in the pelvic cavity (e.g., uterus, ovaries), except for the male testes and scrotal ducts Reproductive System Overview Secondary Sex Characteristics: Features developing during adolescence to distinguish sexes and attract mates, including; pubic/axillary hair, male facial hair, female breasts, body fat distribution, muscularity, and voice pitch Male Genital Organs Male Perineum Scrotum The testes housed in the scrotum It is divided into two compartments by an internal septum, marked externally by the perineal raphe Scrotum The scrotum also houses the spermatic cord, which contains blood vessels, lymphatics, nerves, connective tissue, and the ductus deferens The cord passes through the inguinal canal into the pelvic cavity Scrotum The scrotum regulates testicular temperature to 35°C via: 1.Cremaster muscle: Moves testes closer or farther from the body 2.Dartos muscle: Wrinkles the scrotum to reduce heat loss 3.Pampiniform plexus: Cools arterial blood These mechanisms are essential for sperm production Testis The testes are oval organs (4 cm x 3 cm x 2.5 cm) They are covered by the tunica vaginalis and a fibrous capsule called the tunica albuginea Internally, connective tissue septa divide the testes into 200–300 lobules, each containing 1–3 seminiferous tubules for sperm production Testis Abdominal Phase:The testes develop near the kidneys in the abdominal cavity Inguinal Phase:Around the 7th month of gestation, the testes pass through the inguinal canal into the scrotum Scrotal Phase:By birth, the testes are typically positioned in the scrotum Testis Seminiferous Tubules: Lined with germinal epithelium (germ cells and sustentacular cells) Sustentacular Cells (Sertoli): Provide nutrients, form the blood–testis barrier (BTB), and secrete inhibin and androgen- binding protein Interstitial Cells (Leydig): Found between tubules; secrete testosterone Rete Testis: A network for sperm transport, where sperm partially mature before moving to the epididymis. Testis Arterial Supply: Testicular artery from the abdominal aorta, with low blood flow and oxygenation Venous Drainage: Pampiniform plexus, which cools arterial blood Veins drain into the: Right: Inferior vena cava Left: Left renal vein Ducts After leaving the testis, sperm travel through several ducts to reach the urethra: 1.Efferent Ductules: About 12 small ducts on the posterior testis 2.Duct of the Epididymis: Sperm mature and are stored here for 40– 60 days. Unused sperm are reabsorbed 3.Ductus Deferens (Vas Deferens): A muscular tube (45 cm long) extending from the epididymis through the spermatic cord and pelvic cavity Ends in a widened ampulla, where it unites with the seminal vesicle duct Ducts 4. Ejaculatory Duct: Formed by the union of the ductus deferens and seminal vesicle duct. Passes through the prostate gland and empties into the urethra 5. Urethra: Shared by the urinary and reproductive systems, consisting of the prostatic, membranous, and spongy regions During ejaculation, the internal urethral sphincter prevents urine from mixing with semen These 5 ducts facilitate sperm transport, maturation, and delivery during ejaculation (sympathetic activation) Accessory Glands The male reproductive system has three sets of accessory glands that contribute to semen production and reproductive function: 1. Seminal Vesicles: Pair of glands located posterior to the bladder, associated with each ductus deferens Secretes fluid into the ejaculatory ducts 2. Prostate Gland: Surrounding the urethra and ejaculatory ducts Empties secretions into the urethra Common site of urogenital dysfunctions in older men 3. Bulbourethral (Cowper) Glands: Small spherical glands near the penile bulb Lubricate the penis and neutralize residual urine acidity, protecting sperm Penis The penis functions to deposit semen into the vagina (ejeculation=sympathetic activation) External parts: Shaft and glans (expanded head with urethral opening) Internal parts: Root and erectile tissues (corpus spongiosum and corpora cavernosa) Dimensions: Flaccid: 8–10 cm; erect: 13–18 cm Foreskin (prepuce): Covers the glans; often removed by circumcision Penis Erectile Tissues: Corpus spongiosum: Surrounds the urethra, forms the glans, and terminates in the root as the bulb Corpora cavernosa: Paired tissues, anchored to the pubic arch by crura Penis Blood Supply:Internal pudendal arteries: Supply the erectile tissues via dorsal and deep arteries Erection mechanism: Deep arteries dilate, filling lacunae with blood, causing swelling and elongation (parasympathetic activation) Female Reproductive System Asst. Prof. A. Taha Demirbaş Reproductive System Overview Classification by Location: External Genitalia: Found in the perineum and mostly visible (e.g., penis, vulva) Internal Genitalia: Located in the pelvic cavity (e.g., uterus, ovaries), except for the male testes and scrotal ducts Reproductive System Overview Primary Sex Organs (Gonads): Male: Testes (produce sperm) Female: Ovaries (produce eggs) Secondary Sex Organs: Male: Ducts, glands, and penis (storage, survival, and transport of sperm) Female: Uterine tubes, uterus, and vagina (fertilization and fetal development) Ovarium They produce egg cells (ova) and sex hormones Measuring 3 cm x 1.5 cm x 1 cm, is located in the ovarian fossa of the posterior pelvic wall The ovary has a tunica albuginea capsule and is divided into: Medulla: Contains fibrous tissue with arteries and veins Cortex: Houses ovarian follicles, where eggs develop and are released during ovulation Ovaries are smooth in childhood, become corrugated during reproductive years due to follicular growth And shrink after menopause, largely consisting of scar tissue Ovarium The ovaries and internal genitalia are supported by several connective tissue ligaments: Ovarian ligament: Attaches the medial ovary to the uterus Suspensory ligament: Attaches the lateral ovary to the pelvic wall, carrying ovarian vessels, lymphatics, and nerves Mesovarium: Anchors the ovary to the broad ligament, a peritoneal fold that supports the uterus and uterine tube Ovarium The ovary receives blood from: 1.The ovarian branch of the uterine artery (via the mesovarium) 2.The ovarian artery (via the suspensory ligament) These arteries anastomose near the ovary, supplying it with blood Ovarium Oogenesis is the process of egg production, involving meiosis to produce haploid gametes Unlike spermatogenesis, it: Occurs in a rhythmic pattern called the ovarian cycle, rather than continuously Produces one functional gamete from each germ cell (oogonium), while the other daughter cells become polar bodies that degenerate Ovarium Ovulation occurs around day 14 of the menstrual cycle and lasts only 2–3 minutes. The process involves: 1. Follicle Rupture: A stigma forms on the ovarian surface, and the mature follicle releases the oocyte 2. Formation of Corpus Luteum: The ruptured follicle collapses and fills with granulosa and theca interna cells, forming the corpus luteum The corpus luteum secretes progesterone, preparing the uterus for potential pregnancy 3. If Pregnancy Does Not Occur: The corpus luteum undergoes involution by days 24–26, becoming an inactive scar called the corpus albicans 4. If Pregnancy Occurs: The corpus luteum remains active for about 3 months, producing progesterone until the placenta takes over These ovarian events are synchronized with changes in uterine histology Uterine Tubes The ovulated oocyte enters the uterine tube (oviduct or fallopian tube), a 10 cm ciliated canal connecting the ovary to the uterus Infundibulum: Trumpet-shaped distal end with fimbriae Ampulla: Middle, longest segment Isthmus: Narrow portion near the uterus Mesosalpinx: Part of the broad ligament enclosing the uterine tube Function:The wall contains smooth muscle aiding movement The mucosa has ciliated and secretory peg cells Cilia and muscle contractions propel the oocyte toward the uterus Uterus The uterus is a thick, muscular chamber that opens into the roof of the vagina and typically tilts forward over the bladder Its primary functions are: Harboring the fetus during pregnancy Providing nutrition via the placenta, partly formed by uterine tissue Expelling the fetus at the end of gestation Uterus Shape: Pear-shaped with: Fundus: Broad superior curvature Body (Corpus): Central portion Cervix: Narrow inferior end Size: Approximately 7 cm long, 4 cm wide at the fundus, and 2.5 cm thick, slightly larger in women who have been pregnant Uterus The lumen of the uterus is roughly triangular, with its upper corners connecting to the uterine tubes Cervical Canal: Connects the uterus to the vagina Opens into the uterus via the internal os and into the vagina via the external os Contains cervical glands that secrete mucus to block microbial entry from the vagina Near ovulation, the mucus thins to facilitate sperm passage Uterus The uterine wall has three layers: Perimetrium: Outer serosa of simple squamous epithelium Myometrium: Thick middle layer of smooth muscle, responsible for labor contractions Endometrium: Inner mucosa with two layers Stratum functionalis: Shed during menstruation Stratum basalis: Regenerates the functionalis and supports embryo attachment during pregnancy Uterus The uterus is supported by: 1.The muscular floor of the pelvic outlet 2.Peritoneal folds forming supportive ligaments: 1. Broad ligament: Includes the mesosalpinx (supports uterine tube) and mesometrium (supports uterus) 2. Cardinal ligaments: Support the cervix and upper vagina 3. Uterosacral ligaments: Attach the uterus to the sacrum 4. Round ligaments: Extend from the uterus to the labia majora via the inguinal canals Uterus The peritoneum creates two key pouches: Vesicouterine pouch: Between the uterus and bladder Rectouterine pouch: Between the uterus and rectum Uterus The uterine blood supply is crucial for the menstrual cycle and pregnancy: The uterine arteries branch from the internal iliac arteries and travel through the broad ligament to the uterus These arteries give rise to arcuate arteries, which encircle the uterus and anastomose with each other Smaller branches extend through the myometrium and into the endometrium, forming spiral arteries Spiral arteries coil toward the endometrial surface, rhythmically constricting and dilating to regulate blood flow in the mucosa Uterus The uterine histology changes throughout the menstrual cycle, which averages 28 days and consists of the following phases: 1.Proliferative Phase (Days 6–14): 1. Endometrial tissue is rebuilt after menstruation. 2. Under estrogen influence, the functional layer regenerates, and the endometrium thickens to 2–3 mm 2.Secretory Phase (Days 15–26): 1. Endometrial thickening continues, driven by progesterone from the corpus luteum 2. Glands grow larger and coil, accumulating glycogen, making the endometrium 5–6 mm thick for potential embryonic implantation Uterus 3. Premenstrual Phase (Days 26–28): Corpus luteum involution causes spiral artery spasms, leading to ischemia, necrosis, and degeneration of the stratum functionalis Necrotic tissue mixes with blood and fluid to form menstrual fluid 4. Menstrual Phase (Day 1): The cycle restarts as menstrual fluid is discharged vaginally The first day of discharge marks day 1 of the new cycle Vagina The vagina is an 8–10 cm tube with roles in menstrual discharge, sexual intercourse, and childbirth Structure: Thin but distensible wall with three layers: adventitia, muscularis, mucosa Lacks glands; lubricated by transudation and cervical mucus Surrounds the cervix with blind spaces called fornices Vagina Rugae: Transverse ridges enhance stimulation during intercourse Hymen: Membrane at the vaginal orifice, typically ruptured by intercourse Epithelium: Transforms from simple cuboidal (childhood) to stratified squamous (puberty, due to estrogens) Produces glycogen, which bacteria ferment into lactic acid, creating a low pH (3.5–4.0) to inhibit pathogens External Genitalia The external female genitalia, collectively called the vulva or pudendum, occupy most of the perineum and include: 1.Mons pubis: Fatty mound over the pubic symphysis, covered with skin and pubic hair 2.Labia majora: Thick folds of skin and adipose tissue, with hair on the outer surface but hairless medially 3.Labia minora: Thinner, entirely hairless folds, enclosing the vestibule, which contains the vaginal and urethral orifices 4.Clitoris: Sensory organ similar to the penis with corpora cavernosa but no urinary role It has a glans, body, and crura attaching it to the pubic arch. External Genitalia Erectile Tissues and Glands: Vestibular bulbs: Erectile tissues near the vagina, which engorge with blood during arousal, enhancing stimulation Greater vestibular (Bartholin) glands: Lubricate the vulva and vagina during arousal, analogous to male bulbourethral glands Lesser vestibular glands: Also aid in lubrication Paraurethral (Skene) glands: Near the urethral orifice, may produce fluid during orgasm ("female ejaculation") and are homologous to the male prostate These structures contribute to lubrication, sensory stimulation, and sexual function Homologous Organs in the Genital System Homologous structures arise from the same embryonic tissue and adapt to male or female functions in the reproductive system

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