FORMS OF REPRODUCTION1. Sexual reproduction2. Asexual reproduction a. Budding A new individual is formed as an outgrowth or bud on an older organism (e.g. cnidarians, sponges, bryozoans & tunicates) a. Fission An individual divides into two halves, usually equal, after which each grows to the original form. The nucleus divides, and then the cytoplasm. (e.g. protozoans) a. Sporulation Nucleus divides repeatedly and then the cytoplasm subdivides so that a part of it surrounds each of the many daughter nuclei (e.g. paramecium) a. Fragmentation An individual breaking into parts, each part is capable of growing into a complete individual (e.g.flatworms) a. Vegetative reproduction
Classification of organisms based on thesex organ/s present:• Monoecious If both male and female reproductive systems are in one individual. flatworms and earthworms.• Dioecious The sexes are separate, that is, an individual may only have one of the male or female reproductive systems. Nematodes, arthropods, and other invertebrates, and all vertebrates. Hermaphrodite Applied to monoecious species and also to occasional abnormal individuals of dioecious species that contain both male and female systems.
• Some animals (gastropods and oysters) change sex during the course of their life:• Protandry if the sperm are produced before the eggs.• Protogyny if eggs are produced before the sperm.
HUMAN REPRODUCTIVE SYSTEMA. FEMALE REPRODUCTIVE SYSTEM - Production of female gametes - Receives sperm and provides a milieu where fertilization of the egg by sperm can take place. - Provides for the development of the embryo. - Production of the female hormone to control development of female secondary sexual characteristics.
PARTS & FUNCTIONS1. Ovaries2. Oviducts/fallopian tubes3. Uterus/womb4. Vagina5. Vulva a. Clitoris b. Urethral opening c. Labia majora d. Labia minora e. Vaginal orifice
FEMALE MENSTRUAL CYCLEEvents in Menstrual Cycle:• Menstruation Sloughing away of the compact and spongy layers of the endometrium by bleeding.• Ovulation release of the oocyte from the follicle.
Phases of Menstrual Cyclea. Flow/Menstrual phase (menstruation) Time of uterine bleeding This indicates that egg has not been fertilized. This lasts for an average of 4 (3-7) days.a. Follicular Growth phase Growth of follicles Under the influence of FSH, the ovarian follicle develops and produces the hormone estrogen. As estrogen increases, the uterine linings thicken. T This phase lasts for 8-10 days. Ovulation marks the end of this phase.a. Luteal/Secretory phase Production of the corpus luteum (yellow body) which secretes progesterone. At this stage, estrogen and progesterone prepares the uterine wall for the fertilized egg. This phase lasts for 13-14 days. If there is no fertilization, corpus luteum atrophies and progesterone decreases resulting to flow phase.
• Menarche onset of menses.• Menopause or climacteric cessation of menses.
MALE REPRODUCTIVE ORGAN SYSTEM• FUNCTIONS: production of male gametes. transfer of male gametes to female reproductive system. production of male hormones which control the development of male secondary sex characteristics.
PARTS AND FUNCTION1. Testis (pl. testes) Male gonads or reproductive organs. Paired oval glandular structure within an external sac (scrotum) which is continuous with the abdominal cavity. During birth, the testis descend from the abdominal cavity to the scrotum which is initially continuous with the abdominal cavity through the inguinal canal. After descent, the inguinal canal normally closes when connective tissues pug it. Cryptorchidism the condition in which the testes fail to descend into the scrotum. Hernia A condition in which a loop of intestine tangle into the scrotum when the connective tissues plugging the inguinal canal break which usually happens when the individual is doiung a strenuous activity such as lifting of heavy objects.
• Castration removal of testes.• Eunuch the term for a person whose testes have been removed.
PARTS AND FUNCTION Two Functional Parts ofTestes: a. Seminiferous tubules Produce sperms. a. Interstitial cells Produce the male sex hormone testosterone.
2. Duct System a. Epididymis Coiled tube on the surface of the testes which act as storage of sperm cells. Sperms are routinely stored here for a maximum of one month and are released from the epididymis during ejaculation. a. Vas deferens b. Urethra
PARTS AND FUNCTION3. Accessory organs produce seminal fluid which combines with sperms to form the semen. a.Seminal vesicle b.Prostate gland c.Cowper’s gland4. Penis Male copulatory organ. The tip is covered with a fold of thin skin called foreskin or prepuce which is surgically removed by circumcision.
FUNCTIONS OF SEMINAL FLUIDS• Serve as vehicle for the transport of sperm.• Lubricates the passage of the sperm.• Buffers or protects sperm, from the harmful effects of acids in the female genital tract.• Contains sugar (mostly fructose) which sperms can use as source of energy.•
Composition and Source of Seminal Fluid• The following structures secrete the substances that together make up the seminal fluid and semen. – testes and epididymis (secretion contributes about 5% of the seminal fluid) – seminal vesicles (secretion contributes 30%) – prostrate gland (secretion contributes the bulk of the seminal fluid which is about 60%) – bulbourethral gland glands (secretion constitutes less than 5% of the volume)
GAMETOGENESIS• TYPES Spermatogenesis production of sperm cells. Oogenesis production of female gamete or egg cell.
FERTILIZATION• TYPES: External fertilization common among aquatic animals like fishes and amphibians. Internal fertilization common among terrestrial animals like mammals, birds, reptiles and a few aquatic animals, such as sharks.
• Zygote the resulting cell from the union of sperm cell and egg cell.• Embryo the term for the zygote that has undergone one cell division that soon be implanted in the uterus and remains there during the ensuring 9 months of pregnancy.• Gestation the other term of pregnancy.• Parturition
ESTROUS CYCLE• comprises the recurring physiologic changes that are induced by reproductive hormones in most mammalian placental females.• start after puberty in sexually mature females and are interrupted by anestrous phases or pregnancies.• typically estrous cycles continue until death.• some animals may display bloody vaginal discharge, often mistaken for menstruation, also called a "period".
Differences from the menstrualcycle• animals that have estrous cycles reabsorb the endometrium if conception does not occur during that cycle while animals that have menstrual cycles shed the endometrium through menstruation instead.• In species with estrous cycles, females are generally only sexually active during the estrus phase of their cycle This is also referred to as being "in heat." In contrast, females of species with menstrual cycles can be sexually active at any time in their cycle, even when they are not about to ovulate.
Four phases• Proestrus one or several follicles of the ovary are starting to grow. this phase can last as little as one day or as long as 3 weeks, depending on the species. Under the influence of estrogen the lining in the uterus (endometrium) starts to develop. Some animals may experience vaginal secretions that could be bloody. The female is not yet sexually receptive.• Estrus female is sexually receptive ("in heat“) A signal trait of estrus is the lordosis reflex, in which the animal spontaneously elevates her hindquarters. In some species, the vulvae are reddened. Ovulation may occur spontaneously in some species (e.g. cow), while in others it is induced by copulation (e.g. cat).
• Metestrus During this phase, the signs of estrogen stimulation subside and the corpus luteum starts to form. The uterine lining begins to secrete small amounts of progesterone. This phase typically is brief and may last 1 to 5 days. In some animals bleeding may be noted due to declining estrogen levels.• Diestrus is characterised by the activity of the corpus luteum that produces progesterone. In the absence of pregnancy the diestrus phase (also termed pseudo- pregnancy) terminates with the regression of the corpus luteum. The lining in the uterus is not shed, but will be reorganised for the next cycle.• Anestrus sexual cycle rests. This is typically a seasonal event and controlled by light exposure through the pineal gland that releases melatonin. induced by time of year, pregnancy, lactation, significant illness, and possibly age.
SOME FUNCTIONAL PROBLEMS OF THEREPRODUCTIVE SYSTEM • Impotence - The inability of a male to produce or maintain an erection. • Hypogonadism - A lack of function of the gonads, in regards to either hormones or gamete production. • Ectopic pregnancy - When a fertilized ovum is implanted in any tissue other than the uterine wall. • Hypoactive sexual desire disorder - A low level of sexual desire and interest. • Female sexual arousal disorder - A condition of decreased, insufficient, or absent lubrication in females during sexual activity • Premature ejaculation - A lack of voluntary control over ejaculation.
BIRTH CONTROL METHODS• Intrauterine device (IUD) is a small device that is placed in the uterus to prevent pregnancy.• Use of pills• Barrier methods a. Diaphragm/cervical cap b. Condom c. Spermicides d. Suppository• Tubal ligation• Vasectomy• Coitus interruptus• Fertility awareness (periodic abstinence or natural family planning)