Reproduction System Dr Robert B Mbelwa MD dar

Reproduction System Dr Robert B. Mbelwa MD (dar) Msc Physiology (Makerere)

Definition of terms • Sexual reproduction: -Is a physiological process that creates a new organism by combining the genetic material of two organisms in a process that start with meiosis, a specialized type of cell division • Reproductive system: - is a system of sex organs within an organism which work together for the sake of sexual reproduction

Function • Is not for homeostasis of the individual – A person can survive indefinitely without a reproductive system • Is for continuation of the species – i. e continuation of genes beyond the lifespan of a single individual

Organization of reproductive system • Comprises of 1. Primary reproductive organs (gonads) 2. Secondary reproductive tracts 3. External genitalia

Ctd - General Reproductive System Organization A. Primary Reproductive Organs (Gonads) v Testes (male) and Ovaries (female) Ø Whose main functions are to 1. Produce gametes – Sperm and Ova 2. Produce and secrete sex steroid hormones – testosterone, estrogen and progesterone – responsible for gamete development, development of reproductive tract and secondary sex characteristics

General Reproductive System Organization B. Secondary Reproductive Organs 1. Reproductive tract • tube connecting gametes to external environment 2. accessory sex glands • Produce supportive secretions C. External Genitalia – visible portions of reproductive tract – sexual stimulation

Male Reproductive System 1. Primary sex organs Ø Testis 2. Accessory organs 1. Duct system 1. 2. 3. Epididymis Vas deferens Urethra 2. Glands 1. 2. 3. Seminal vesicle Prostate Bulbourethral 3. Penis

Purpose of Male reproductive system 1. To produce, maintain and transport sperm (the male reproductive cells) and protective fluid (semen) 2. To discharge sperm within the female reproductive tract during sex 3. To produce and secrete male sex hormones responsible for maintaining the male reproductive system

External structures • Unlike the female reproductive system; most of the male reproductive system is located outside the body • This external structures include • The penis: - Male organ used in intercourse & urination: • Scrotum: -contains testicles (testes) and act as climate control system for the testes • Testicles: -responsible for making testosterone & sperm generating

Testes • Sperm production • Secretion of testosterone – Interstitial cells

Internal organs of the male reproductive system (accessory organs)

1. Epididymis Ø Ø 2. Duct System Transport & Stores sperm until ejaculation Mature and gain motility Vas deferens Ø Peristaltic contractions propel /transport mature sperm toward urethra Ø Terminates at ejaculatory duct (seminal vesicle) 3. Urethra Ø Ø Tube carrying urine from bladder to outside the body Ejaculates semen during orgasm Copyright © The Mc. Graw-Hill Companies

Glands 1. Seminal Vesicles (seminal fluid) – Alkaline fluid • • 2. Prostate i. ii. 3. Fructose- energy for sperm movement prostaglandins- assist in fertilization Fluid that helps to nourish the sperm Sperm activating enzyme Bulbourethrals – Clears , slippery fluid which Lubricates the urethra and neutralizes acidity • Sperm + glandular secretions = semen – 2 – 5 ml, 110 million sperm per ml

Male external genitalia Penis • Copulatory organ in males • Erectile tissue – Corpora spongiosum – Corpora cavernosa

Female reproductive function Same as in male Gametogenesis Hormone production Copulatory organs Nurture and develop embryo

Purpose Female reproductive • External female reproductive structures • Enable sperm to enter the body • Protect the internal genital organs from infectious organisms

Female reproductive function • Internal female reproductive structures • Vagina • Uterus • Ovaries • Fallopian tubes

Female Reproductive System Internal structures • Primary Sex organ – Ovaries • Accessory Organs – Duct system • Uterine tubes • Uterus • Vagina

Duct System 1. Uterine tubes – Receives oocytes – Site for fertilization 2. Uterus – Receive, nourish fertilized ovum – Site of embryological and fetal development 3. Vagina – Copulatory organ – Birth canal

Female Reproductive System – External genitalia • • • Mons pubis Labia vestibule Greater vestibular gland clitoris

The External Genitalia • External genitalia are collectively called the vulva or pudendum Ø mons pubis - mound of fat over pubic symphysis bearing most of the pubic hair Ø labia majora – pair of thick folds of skin and adipose tissue inferior to the mons • Enclose and protect other external reproductive organs • Contains sweat and oil secreting glands Ø labia minora – medial to labia majora are thin hairless folds Ø clitoris - erectile, sensory organ with no urinary role • primary center for erotic stimulation Ø vestibular bulbs - erectile tissue deep to the labia majora • cause the vagina to tighten around the penis, enhancing sexual stimulation Ø greater and lesser vestibular and paraurethral glands open into vestibule for lubrication

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