Reproductive System PDF

 Reproductive System is the human organ system responsible for the production and fertilization of gametes (sperm or eggs) and, in females, the carrying of a fetus. Both male and female reproductive systems have organs called gonads that produce gametes. Gamete is a haploid cell that com...

 Reproductive System is the human organ system responsible for the production and fertilization of gametes (sperm or eggs) and, in females, the carrying of a fetus. Both male and female reproductive systems have organs called gonads that produce gametes. Gamete is a haploid cell that combines with another haploid gamete during fertilization, forming a single diploid cell called a zygote. Besides producing gametes, the gonads also produce sex hormones. Sex hormones are endocrine hormones that control the development of sex organs before birth, sexual maturation at puberty, and reproduction once sexual maturation has occurred. Other reproductive system organs have various functions: Maturing gametes Delivering gametes to the site of fertilization Provide an environment for the development and growth of the offspring SCROTUM Loose pouch-like sac of skin that hangs behind the penis. Fibro-muscular pouch divided by a median septum (raphe) forming 2 compartments, each of which contains a testis, epididymis, and part of the spermatic cord Vertical septum, or partition, of subcutaneous tissue in the center divides it into two parts, each containing one testis. Function: protective function and acts as a climate control system for the testes. (For normal sperm development, the testes must be slightly cooler than the body temperature. Special muscles in the wall of the scrotum allow it to contract and relax, moving the testicles closer to the body for warmth and protection or farther away from the body to cool the temperature. (Spermatogenesis requires a temperature of three to five degrees Fahrenheit below body temperature. If it becomes too cool on the outside, the cremaster muscle will contract to bring the testes closer to the body for warmth)  SCROTUM Loose pouch-like sac of skin that hangs behind the penis. Fibro-muscular pouch divided by a median septum (raphe) forming 2 compartments, each of which contains a testis, epididymis, and part of the spermatic cord Vertical septum, or partition, of subcutaneous tissue in the center divides it into two parts, each containing one testis. Function: protective function and acts as a climate control system for the testes. (For normal sperm development, the testes must be slightly cooler than the body temperature. Special muscles in the wall of the scrotum allow it to contract and relax, moving the testicles closer to the body for warmth and protection or farther away from the body to cool the temperature. (Spermatogenesis requires a temperature of three to five degrees Fahrenheit below body temperature. If it becomes too cool on the outside, the cremaster muscle will contract to bring the testes closer to the body for warmth) MALE REPRODUCTIVE SYSTEM Testes Small, ovoid organs within the scrotum Tunica Albuginea – Cartilaginous tissue capsule surrounding the testes Septa – Divide each testis into cone-shaped testicular lobules Lobules – Contains Seminiferous Tubules Seminiferous Tubules – Site of sperm development Produce male gametes (Spermatogonia to Spermatozoa) “-gonia” Immature (Before Puberty) “-ozoa” Mature (After Puberty) Site of Spermatogenesis = Formation of Sperm  MALE REPRODUCTIVE SYSTEM Testes Seminiferous Tubules – Site of sperm development Site of Spermatogenesis = Formation of Sperm Sertoli Cells = Forms blood-Testes Barrier Secretes Androgen-binding protein in response to FSH Follicle-Stimulating Hormone Men - It plays a role in the production of sperm. Essentially, it helps keep the reproductive system in check. Women - FSH stimulates the growth of ovarian follicles before the release of an egg during ovulation. Secretes Inhibin (negative feedback for FSH) Leydig Cells “ Interstitial Cells” = Secretes Testosterone in response to LH Luteinizing Hormone “Interstitial Cell Stimulating Hormone” Men - LH stimulates the production of testosterone by the testes. Essentially, it works hand-in-hand with FSH to regulate the reproductive processes. Women - It triggers ovulation and stimulates the ovaries' production of estrogen and progesterone. CELLS IN THE SEMINIFEROUS TUBULES 1.Germ / Sex Cells / Gametes 2.Sertoli / Nurse / Sustentacular Cells = Provides Nutrition 3.Myoid Cells  INTRATESTICULAR CELLS Straight Tubules “Tubular Rectus” (Simple Cuboidal & Sertoli Cells) Rete Testis (Simple Cuboidal) Efferent Ductules (Alternating simple cuboidal non- ciliated and simple columnar ciliated)  EPIDIDYMIS Comma-shaped structure on the posterior side of the testis Pseudostratified columnar epithelium EPIDIDYMIS 3 Parts: 1. Head Composed of viz: 2. Body 1. Principal Cells – 3. Tail Columnar Cells w/ Stereocilia 2. Stem Cells 3. Smooth Muscle Cells  DUCTUS DEFERENS / VAS DEFERENS Emerges from the tail of the Epididymis Contains many elastic fibers The epithelial lining is pseudostratified w/ Stereocilia With very thick muscularis SPERMATIC CORD A.Blood Vessels B.Nerves C.Ductus Deferens  EJACULATORY DUCT Formed by the short duct from the seminal vesicle and the ampulla of the ductus deferens; These ducts project into the prostate gland and end by opening into the urethra. Pseudostratified and Simple Columnar ACCESSORY GLANDS 1. Seminal Vesicles  Exocrine glands in which production of their viscid, yellowish secretion depends on testosterone  Lined by simple or pseudostratified columnar epithelial cells rich in secretory granules  Components of Seminal Fluid:  Fructose  Prostaglandin  Fibrinogen  ACCESSORY GLANDS 2. Prostate Gland  Dens Organ that resembles a walnut in shape and size; which is seen at the neck of the Bladder  Releases Prostate- Specific Antigen (PSA), and Acid Phosphatase = Indicators of Prostate Cancer  Prostate assisted Ejaculation ACCESSORY GLANDS 3. Bulbourethral Gland “Cowper’s Gland”  Pair of Tubulo-acinar Glands  Secretory units are surrounded by smooth muscle cells and lined by a mucus- secreting(Alkaline pH) “Pre-Ejaculate” simple columnar epithelium  URETHRA Extends from the urinary bladder to the distal end of the penis and is a passageway for both urine and male reproductive fluids 3 Parts: 1.Prostatic 2.Membranous 3.Spongy / Penile Urethra PENIS Male organ of copulation Lined with pseudostratified columnar epithelium Consists of 3 cylindrical masses of erectile tissue plus the penile urethra, surrounded by skin. 3 Columns of Erectile Tissue: 2 Corpora Cavernosa (Dorsum & Side) 1 Corpus Spongiosum (Ventral) Tunica Albuginea = Covers the Corpora Cavernosa Glans Penis = Cap formed from an expansion of corpus spongiosum Foreskin “Prepuce” = Loose fold of skin that covers the Glans Penis Raphe = an irregular ridge that marks the midline of the external part of the scrotum that extends from the anus, over the scrotal sac, and onto the inferior aspect of the body of the penis  OVARIES Almond-shaped bodies producing the female gametes “oocytes” (Egg cells) Ovarian / Germinal Epithelium (Simple Cuboidal) Continuous with the mesothelium and overlying a layer of dense connective tissue capsule, the tunica albuginea, like that of the testis 2 Parts: Cortex = Dense, Outer part of the ovary Medulla = Loose, Inner part of the ovary  CORPUS LUTEUM Is a temporary endocrine structure in female ovaries that is crucial to reproductive health. Progesterone Production After ovulation, the corpus luteum forms from the follicle and secretes progesterone, essential for maintaining the uterine lining for a potential pregnancy. Support for Early Pregnancy If fertilization occurs, the corpus luteum produces progesterone until the placenta takes over, supporting early pregnancy development. Estrogen Production It also produces some estrogen, which helps regulate the menstrual cycle and prepare the uterine lining. UTERINE / FALLOPIAN TUBES “Oviducts” Regions: Infundibulum Ampulla Isthmus Uterine / Intramural Part Histology: Mucosa is lined by simple columnar epithelium on a lamina propria of loose connective tissue  UTERUS A pear-shaped organ with thick, muscular walls Parts: Fundus Body Isthmus Cervix Layers: Perimetrium Myometrium Endometrium Site of Implantation Thickening due to Estrogen & Progesterone Sloughs off (Corpus Luteum) OXYTOCIN Oxytocin, often dubbed the “love hormone,” plays a key role in social bonding, sexual reproduction, childbirth, and the period after childbirth. Childbirth Oxytocin stimulates uterine contractions during labor and helps with the delivery process. Breastfeeding It promotes the ejection of milk from the mammary glands. Bonding It enhances bonding between mother and infant and social bonding and trust between adults. Emotional Regulation It influences emotional responses and helps reduce stress and anxiety.  VAGINA Female organ for copulation From Vulva – Cervix Layers: Mucosa – Stratified Squamous Epithelium Muscular – Smooth Muscle Adventitia – Dense Elastic Connective Tissue Rugae = Ridges Fornix = Superior, Domed-part Hymen = Covers the vaginal opening, or orifice  BARTHOLIN’S GLAND “Greater Vestibular Glands” Provides lubricating mucus during sexual arousal Homologous with the Male’s Bulbourethral Gland EXTERNAL GENITALIA Stratified Squamous Epithelium Vestibule Labia Minora Labia Majora Clitoris  CLITORIS Composed of: Corpora Cavernosa Glans Clitoris Parts: Root Consists of 2 Crura Body Formed by the unattached parts of the 2 Corpora Cavernosa Erect when the female is aroused Most sensitive erogenous zone of the female reproductive organ BREAST Mammary Gland Compound Tubuloalveolar Glands; resemble highly modified apocrine sweat Glands Areola Thin skin covering the nipple Contains sebaceous glands and abundant sensory nerves Connective tissue of the nipple is rich in smooth muscle fibers that run parallel to the lactiferous sinuses and produce nipple erection when they contract  BREAST Lactiferous Ducts Excretory Ducts that emerge independently in the nipples Myoepithelial Cells Surround the alveoli and contract to expel milk Star-shaped Suspensory Ligaments “Cooper’s Ligaments” Strong fibrous processes that support the breasts