4C9923A8-B78D-454A-805C-5C91C5C94B7D.pdf

# Male Reproductive System ## Structures and Functions ### Ovary - Inside: Sertoli cells - Outside: Seminefrous tubule - Pructose - Seminal vescicle ### Seminal Vesicle - Fructose - Alkaline solution - Nourishes sperms - Cowper's gland - Neutralizing alkaline solution (lubricant) ### Urinary b...

# Male Reproductive System ## Structures and Functions ### Ovary - Inside: Sertoli cells - Outside: Seminefrous tubule - Pructose - Seminal vescicle ### Seminal Vesicle - Fructose - Alkaline solution - Nourishes sperms - Cowper's gland - Neutralizing alkaline solution (lubricant) ### Urinary bladder ### Prostate gland - Secretes alkaline fluid (passes through urethra just before sperm passage) - Neutralizes the acidic medium (lubricant) ### Urethra - Urino-genital duct ### Vas deferens ### Epididymis - A tube coiled around itself (25m) - Comes from testis; leads to vas deference - Sperm storage - Moves out of the abdominal cavity at the end of pregnancy. - Surrounded by scrotum (descends outside the body to maintain their temp. suitable for sperm production) ### Penis - Spongy body/urinogenital organ - Urethra - Urine + neutralize acidity + alkaline fluid + fructose ### Testes - Sperm production - Consists of a large no. of seminiferous tubules - Seminiferous tubules are lined internally with dividing primary germ cells - Inside each seminiferous tubule: - Sertoli cells secrete nutritive medium nourishing sperms inside the testis. - Interstitial cells → function: found among semi-nefrous tubules. Secrete testosterone + androsterone - Secondary sex characteristics – growth of prostate, Sertoli cells, seminal vesicle. ### Sperm - Inside: Sertoli cells - Outside: Fructose, sugar - Sperm nutrition ### Sperm Formation - **Seminefrous tubules:** sperm formation, sertoli cells (sperm nutrition), immunity, maturity. - **Interstitial cells:** testosterone ### Sperm Structure - Acrosome: secretes hyalourunase. Dissolves part of ovum coat during fertilization. - Nucleus: 23 chromosomes, 23 DNA, 2 centrides + division - Mitochondria: Energy - Tail axis: fertilization - Caudal piece: movement ### Sperm Production - Germ cells undergo spermatogenesis. - The process begins with spermatogonia (2n), which undergo mitosis to produce more spermatogonia. - The spermatogonia then undergo a period of growth to become primary spermatocytes (2n), which undergo meiosis I to produce secondary spermatocytes (n). - The secondary spermatocytes undergo meiosis II to produce spermatids (n). - The spermatids undergo a series of changes known as spermatogenesis, becoming sperm (n) which includes a head, neck, middle piece, and tail. - The process of spermatogenesis is regulated by follicle-stimulating hormone (FSH) and testosterone. - FSH stimulates the production of sperm cells in the seminiferous tubules. - Testosterone, primarily produced by the interstitial cells, promotes the development of secondary sex characteristics. ## Female Reproductive System ### Structures and Functions ### Ovary - Size: peeled almond - Finger-like processes: pick up the ovum ### Vagina - Muscular tube - Starts from cervix to genital opening - Lined with a membrane that secretes mucous to moisten the vagina. - Over secretion leads to infertility (sperms won't be able to pass through the vagina) - Contains folds that allow its expansion during delivery ### Uterus - Present between pelvis bones - Expands during pregnancy - Lined internally with cilia (elastic muscular sac) - Uterine wall provides the endometrium - Endometrium: glandular connective tissue rich in food and nutrients. ### Cervix - Neck of the uterus - Narrow opening at the lower end of the uterus - Leads to vagina ### Fallopian tubes - Direct ova towards the fallopian tube/uterus (covido duct) - Funnel directly in front of the ovary to ensure the fall of ova inside it. - 1st third of fallopian tube (Ambula) ### Notes - Female gonads appear after 12 weeks of pregnancy (3 months). - Ovum stays alive from 1 to 2 days - Corpus luteum's lifespan: 3 months - Menstrual cycle: 2 weeks (pregnancy) - If it degenerates before 3 months in pregnancy, abortion occurs. ### Uterus Layers - The uterus is made up of 3 layers. ### Hormones - Two ovaries secrete puberty hormones by the age of 45: - Estrogen - Progesterone - The two ovaries become inactive (menopause) ### Endometrium - The hormonal secretion of the endometrium becomes wrinkled. - FSH and LH - Progesterone - Estrogen ### Oogensis - The process of development of female gametes (ova) - Primary germ cells (2n) are called oogonia - Oogonia (2n) undergo mitosis to produce more oogonia - Some oogonia begin to grow and become primary oocytes (2n) - The primary oocyte begins meiosis I, but stops in prophase I. - At puberty, meiosis I resumes and the primary oocyte completes meiosis I, producing a secondary oocyte (n). - The secondary oocyte begins meiosis II and stops at metaphase II. - Meiosis I resumes when the secondary oocyte is fertilized, completing meiosis II. - Results in a mature ovum that can unite with the sperm ## The Menstrual Cycle - The period in which the female ovary is active, about 28 days. - Ovaries alternate, producing one ovum every 28 days. - About 13 ova are released per year. - Phase no. 1: Proliferation (10 days) - Anterior lobe of pituitary gland secretes FSH, which stimulates a few follicles to develop in the ovary to form graffian follicle, enclosing an ovum - During the growth of the graffian follicle, it secretes estrogen in the blood —> grows that endometrium - Ovum matures within 10 days - Graffian follicle develops within those 10 days ## Fertilization - Highest chance of fertilization: 12th - 16th day - Oocyte is ready to be fertilized: 14th – 15th day - From the beginning of menstruation (through 12 days) - The oocyte surrounds itself with a protective coat after fertilization to prevent passage of any other sperms. - After 1 day from fertilization, the zygote divides by mitosis in the beginning of the fallopian tube into 2 cells (blastomeres), then to 4 cells on the next day. - Morula: cellular division is repeated - Morula descends and is pushed along the uterine tube by ciliary action + muscle contraction till it reaches the uterus. - Becomes implanted among the folds of the thick endometrium at the end of the 1st week 14th day. - 21st-23rd day ### Embryonic Membranes - Chorion: surrounds amnion + forms placenta + protects embryo - Amnion: inner membrane surrounding the embryo - Contains amniotic fluid which protects the embryo against dryness & shocks. ## Ovulation (14 days) - Starts when anterior lobe of pituitary gland secretes LH, in the 14th day from the beginning of the menstrual cycle - The graffian follicle ruptures and liberates the ovum into the fallopian tube (14th day from the beginning of menstruation). - Corpus luteum is formed from the GF remains. - Corpus luteum produces progesterone/estrogen (inhibits menstruation) - Increases the thickness of endometrium (inhibits menstruation) - Increases the blood supply (preparing the uterus to receive the embryo)