Human Reproductive System PDF

LESSON 1: Human Reproductive System morphological and physiological structure of the male reproductive system is different from the female reproductive system external and internal parts differ in size, shape, and function MRS - produces sperm FRS - receives sper...

LESSON 1: Human Reproductive System morphological and physiological structure of the male reproductive system is different from the female reproductive system external and internal parts differ in size, shape, and function MRS - produces sperm FRS - receives sperm Morphological - structure Physiological - function Without the fusion of the sperm cell produced in the testis of the male organ with the egg cell produced from the female ovaries, reproduction will not occur. Male Parts and Functions 1. Urethra - the tube that passes through the penis to the outside of the body which carries urine and sperm 2. Penis - soft, tubular organ that hangs in front of the body; internal sexual organ through which the sperm is delivered into the female’s body; contains erectile tissue, penis becomes larger and stiffer due to increase flow of blood during ejaculation erectile tissue - elastic fiber, collagen fibers, smooth muscles, arteries, and veins ejaculation - semen is pushed out of the body through the urethra 3. Testis (plural: testes/testicles) - coiled tubules from which sperm are produced; produce male sex hormones called testosterone for the production of sperm 4. Epididymis - coiled J-shaped tube at the back of each testicle; stores sperm for 2-4 days after being produced 5. Vas Deferens - tube that receives sperm from the epididymis of each testicle 6. Scrotum - a pouch of skin that hangs from the penis; houses the testes and protects the sperm by keeping temperature slightly lower than normal body temperature for the sperm to survive Male Glands(release chemical substances) and Ducts 1. Vas Deferens - 18-inch(45 cm) tube that loops over the urinary bladder 2. Urethra- common tube where urine and semen passes; valve within prevents mixing of urine and sperm; urinary bladder: urine, vas deferens: semen 3. Seminal Vesicles - pair at the base of the urinary bladder that secrete a thick fluid that nourishes sperm prostate gland 4. Ejaculatory Ducts - tubes lined with muscle; muscles contract to force semen out of the body during ejaculation; between seminal vesicles and vas deferens sperm - cell semen - fluid: contains nutrients Process of the Release of Sperm 1. Testis 2. Epididymis 3. Vas Deferens  4. Seminal Vesicles 5. Urethra Sperm Cell unique structure located in the testis; fertilizes the egg Males have two testes found inside the scrotum. It produces millions of sperm cells which can be observed only under a microscope. In the testes, sperm is located in the Seminiferous Tubules. (produce, maintain, and store sperm) Female Parts and Functions 1. Ovaries - small and almond-shaped organs; located inside; one on each side of the body, a few inches below the waist Ovulation - release of egg cells 2. Fallopian Tube - two tubes that extend each ovary into the uterus; houses the egg until fertilization Fertilization- when sperm fuses with the female act during intercourse; further forms an egg that implants in the uterus of the female 3. Uterus/Womb - hollow, muscular, pear-shaped organ between two ovaries; where the fertilized egg will develop and grow into offspring; if the egg remains unfertilized, uterine wall sheds and passes through the vagina: menstrual discharge 4. Cervix - narrow structure within an inch-long canal connecting the lower end of the uterus to the upper portion of the vagina; allows fluids such as menstrual blood to pass through the vagina; widens during birth 5. Vagina/Birth Canal - the hollow tube leading from the cervix to the outside of the body; an elastic wall that allows it to expand during childbirth and sexual intercourse 6. Vulva - external genitalia Mon Veneris/Pubis - hairy, skin-covered pad of fat over the pubic bone Labis Minora - small lips covered with modified skin; two inner skin folds that surround the opening of the vagina Labis Majora - large lips covered with pubic hair; two marked folds of skin that extend from the mons pubis downward and backward Clitoris - small, almond shaped; erectile tissue; located above the vaginal opening and urethra Vaginal Orifice - opening of the vagina; where the baby exits; menstrual blood exits Roles of Hormones in the Reproductive System carry out specific roles during puberty, ovulation, pregnancy, and development reproductive glands are controlled by the pituitary gland which is controlled by the hypothalamus Hypothalamus - releases chemical signals to the pituitary gland among others to start producing hormones responsible for the production Follicle-stimulating Hormones (FSH) Luteinizing Hormone (LH) both males and females produce these hormones  affect testes in men, ovaries in woman LH of the male sends signals in the testes to produce testosterone with FSH to control the production of sperm and the growth of facial hair. In females, the pituitary hormones LH and FSH stimulate the ovaries to produce estrogen and progesterone. responsible for producing ova or mature egg cells Gland Hormone Function Testes Testosterone regulates development of the male sex organs while still an embryo; (Male) controls sex drive and secondary sex characteristics at puberty Ovaries Estrogen controls sex drive and regulates the development of female sex (Female) characteristics at puberty Progesterone controls the development of endometrium (mucus membrane lining the womb) during the menstrual cycle and the maintenance of the uterus during pregnancy Pituitary Prolactin stimulates the production of milk in mammary glands LH females: stimulate ovulation, maturation of egg cells, and progesterone production; males: stimulate sperm and testosterone production FSH females: stimulates maturation of egg cells in the ovary and estrogen production; males: stimulates sperm production LESSON 2: MENSTRUAL CYCLE Menstruation Monthly period Monthly shedding of the lining of the uterus(endometrium) Endometrium - innermost lining layer of the uterus Menstrual Cycle Most females begin to menstruate between the ages of 10 to 15 1. The menstrual cycle begins when an egg matures or ripens in any one of the ovaries. At the same time, the endometrium starts to thicken for a possible pregnancy. 2. The matured egg is released from the ovary. The lining of the uterus continuously thickens until it is ready to receive the fertilized egg. 3. The thickened uterus will serve as the home for the developing embryo. a. Embryo - An unborn human being in the very early stages of development. 4. If pregnancy doesn’t successfully happen, the endometrium breaks down or is destroyed and discharged from the blood. This discharge of blood and tissue is known as menstruation or menstrual period. 5. The menstrual cycle lasts 28 days, but some females have menstrual cycles as short as 21 days or as long as 35 days and are considered normal. 1-7 Days The uterus lining breaks down and menstruation occurs. 8-11 Days The lining of the womb thickens in preparation for the egg. 12-17 Days Ovulation occurs, usually on day 14. 18-25 Days If fertilization has not taken place the corpus luteum fades away. ○ Corpus Luteum A mass of cells that form in the ovary It is a temporary organ that appears every menstrual cycle and disappears if fertilization does not occur. It also produces progesterone during early pregnancy. 26-28 Days The uterine lining detaches leading to menstruation. 6. The endocrine system plays an important role in the menstrual cycle. 7. During the first half of the cycle (days 1-14), the pituitary hormone FSH stimulates an egg to mature inside one of the ovaries. 8. When the egg starts to develop it secretes estrogen, which causes the endometrium to also start to thicken. 9. In the middle of the menstrual cycle, which is about day 14, the level of LH starts to rise; thus, ovulation occurs. 10. The ovary releases the egg and travels into the fallopian tube. 11. It takes seven days for the egg to travel into the fallopian tube going to the uterus. 12. The production of progesterone increases after time the egg reaches the uterus. As progesterone increases, it maintains the growth of the endometrium. 13. If the eggs have not been fertilized, progesterone and estrogen levels drop. The endometrium breaks down and the unfertilized egg passes out of the body through the vagina. Highlight Events of a 28-Day Menstrual Cycle Phases of Menstrual Cycle 1. Proliferative Phase 2. Ovulation 3. Luteal Phase Phase Proliferative Phase Duration 1-13 Events During menstruation, the endometrium breaks down. In the ovary, the follicle matures and rebuilds the endometrium. Follicles - small sacs filled with fluid that are found inside a woman's ovaries  Phase Ovulation Duration 14 Events A secondary oocyte is released from an ovary. Oocyte - An egg before maturation. Phase Luteal Phase Duration 15-28 Events Formation of the corpus luteum; endometrium thickens and develops. Corpus Luteum - A temporary collection of cells that forms on the ovary each menstrual cycle if still getting a menstrual period The Development of Life 1. Gametogenesis The formation of the gamete. This is the first stage of development in which the sperm and egg form and develop inside the reproductive systems under the control of parental genes. 2. Fertilization The sperm penetrates an egg then fusion of their nucleus takes place. 3. Cleavage and Blastulation The fertilized egg undergoes a series of mitotic cell divisions and later becomes the early embryo. A fluid-filled cavity is formed inside the developing embryo. Blastulation - A very early stage of development when the zygote becomes a ball of cells with a fluid-filled center and an inner mass of cells 4. Gastrulation The process by which gastrula forms from a blastula to organize cell migration patterns in the embryo to form three germ layers 5. Organogenesis The process of formation of organs from three germ layers. 6. Growth and Tissue Specialization The organs acquire their unique structures and chemical properties. The Process of Fertilization and the Development of the Human Embryo 1. First Week of Development 2. The Embryo 3. The Fetus 1. First Week of Development Fertilization is the union of a sperm cell from a male and an egg cell from a female cell. After fertilization of the egg cell, the zygote travels in the fallopian tube to get nutrients from maternal secretions, then it will undergo the process of mitosis which forms cleavages. When it reaches the uterus, cleavages transform into a solid group of cells called morula, which later develop into a blastocyst. There is an inner cell mass of the blastocysts having a surface cell layer called the trophoblast. Secretion of chorionic gonadotropin from trophoblast helps to maintain the corpus luteum to grow and to secrete estrogens and progesterone. The hormones help the uterine lining to do its task during pregnancy. ○ Chorionic Gonadotropin is a hormone produced by the placenta during pregnancy ○ It helps thicken a person's uterine lining to support a growing embryo and tells the body to stop menstruation. Once the blastocyst is formed, it begins to adhere to the uterine lining. This process of attachment is also known as implantation. After the blastocyst has been implanted, it is now called an embryo. 2. The Embryo The embryo is the initial development stage in humans after fertilization. The bond that holds the embryo to the wall of the uterus is called the placenta. Approximately 25 days after fertilization, a cord forms between the embryo and the sac (called the placenta). This cord is referred to as the umbilical cord which is the embryo’s lifeline, meaning the embryo gets its oxygen and food from the other placenta through the umbilical cord. The developing embryo is enclosed in a sac of a thin sheet of tissue called the amniotic sac. Within this sac is the amniotic fluid where the embryo is suspended. This fluid serves as a shock absorber and helps the embryo to maintain its temperature. 3. The Fetus After two months, the embryo is about 1.2 inches (3cm) long and has a recognizable human form or a fetus. The fetus grows with the help of the placenta. The placenta connects to the developing embryo through the umbilical cord. 4th month - The fetus slightly moves and can be recognized. 7th month - The baby’s eyelashes are formed, and eyelids are recognizable 9th month - All the organs are well developed and the baby is ready to be born by then.