Grade 9 Science - Human Reproduction

Transcription

1 Grade 9 Science - Human Reproduction The human reproductive system is a series of organs that work together for one purpose: reproduction (creating new humans). Each part has a specific role in the reproductive process which it performs without conscious effort on the part of the human. Word Bank ** the word bank was an in-class exercise to begin distinguishing between science vocabulary and slang. Don t worry! All the words you Just like a human body will breathe, digest, and pump blood without the human having to think about it! The processes that the reproductive system performs are started and regulated by hormones. will need to know for the quiz are in this booklet! These internal processes are not the same as the actions humans use to reproduce (sexual intercourse). This booklet will include: - Structure & Anatomy - Function & Processes - Intro to Hormones - The Menstrual Cycle - Miscellaneous Facts 1

2 What is it called? Ovary Fallopian Tubes (oviducts) Uterus Endometrium Cervix Vagina Vulva Labia Clitoris Perineal area Pubic hair What is it/ is it for / does it do? - Female gonad, where eggs are produced - Almond shaped, ~3cm long - Females have 2 ovaries, which take turns releasing eggs - Path for egg between ovary and uterus - Fimbria at end of tube guide egg into tube - Cilia lining tube move egg towards the uterus - womb where fertilized egg develops - Approximately size and shape of a pear - 3 layers: outer, muscle, lining - Uterine lining (innermost layer of uterus) - Tissue rich in blood vessels - Shed from the body if pregnancy does not occur - valve less than 1cm diameter (dilates ~10cm for birth) - Produces mucus which changes throughout the menstrual cycle to allow sperm through more or less easily - Elastic (can stretch and return to its shape), muscular canal from cervix out of body - Very particular ph level (acidic), keeps itself clean - External female genitalia (the parts that can be seen and need to be kept clean) - Latin: lip - Minora: inner tissue that surrounds and protects urethral & vaginal openings, produces oils, no pubic hair - Majora: outer tissue surrounding the rest of the vulva, has pubic hair - Cylindrical organ between labia minora & majora - Many nerve endings, blood vessels - sensitive - Similar tissue to penis, but NO urinary function (or menstrual) - Female: area between vulva and anus - Male: area between scrotum and anus - Develops at puberty - Several theories as to purpose, including: Warmth, protects genitals from friction, pheromone diffuser 2

3 Female Reproductive Anatomy Side View (internal) ureter fallopian tube uterus cervix rectum anus ovary bladder urethra vagina pubic hair Bottom View (external) fallopian tube (oviduct) Front View (internal) uterus labia minora Vaginal opening clitoris urethral opening vulva endometrium (uterine lining) Labia majora anus vagina cervix 3

4 Male Reproductive Anatomy (side view - internal) bladder seminal vesicle prostate gland anus penis cowper s gland Vas deferens urethra scrotum epididymis testis & seminiferous tubules 4

5 What is it called? What is it/ is it for / does it do? Scrotum - Sac of tissue that supports and protects testes (external) Testes (singular: testis) Seminiferous Tubules - Male gonads: a.k.a. testicles - Where sperm cells are produced - Located outside body because sperm need specific temperature to develop healthily - Coiled tubes inside testes - Where meiosis happens & sperm develop Epididymis - Coiled tubes beside testes where mature sperm are stored Vas Deferens - Tubes for sperm to travel from epididymis to urethra Seminal Vesicles - Produce sticky, sugar-rich fluid for sperm to travel in Prostate Gland Cowper s Gland Urethra Penis - Produces fluid containing zinc, citric acid, & other enzymes to nourish & protect sperm - Fluid from prostate makes up about 1/3 of semen - Produces alkaline fluid called pre-ejaculate which neutralizes acidic urine traces in the urethra and lubricates the urethra to protect sperm during ejaculation - Tube through the penis that provides a path for urine and semen to exit the body (at different times) - Organ composed of spongy tissue, mostly blood vessels - Erection is blood filling these vessels: there are no muscles in the shaft of the penis (only at the base) - Part of male external anatomy Semen - Mixture of sperm cells & the fluids produced by prostate and seminal vesicles, exits the penis through ejaculation 5

6 Both the male and the female reproductive systems are governed by hormones which are released by the pituitary gland. Hormones travel through the bloodstream. When they come into contact with different _tissues (groups of cells)_, they cause those _cells_ to act in certain ways. When puberty begins in a human, the pituitary gland produces Follicle Stimulating Hormone (FSH), which travels to the gonads and signals that they should produce gametes. Other hormones also begin to develop secondary sexual characteristics in males and females. In Males, FSH reaches the testes and promotes: 1. _development of seminiferous tubules 2. _development of sperm cells (meiosis!) 3. _production of testosterone In Females, FSH reaches the ovaries and promotes: 1. _maturing and releasing eggs (~ 1 per month) 2. _producing reproductive hormone ESTROGEN Testosterone directs secondary sexual characteristics including: - Deepening of voice - production of facial, underarm, and pubic hair - broadening of the shoulders Estrogen is responsible for developing female secondary sexual characteristics including: - Deposits of fat in breasts and hips - Growth of pubic and underarm hair 6

7 Hormones and the Menstrual Cycle Female humans experience changes to their reproductive systems before and after _ovulation (releasing an egg) in a cycle that lasts approximately one month. Lutenizing Hormone is released by the Pituitary Gland. It causes: 1. _The release of a mature egg from a follicle 2. _The remains of the follicle turn into the corpus luteum_ The corpus luteum produces progesterone_ and some estrogen. Both estrogen and progesterone stimulate the thickening of the uterine lining. When the level of progesterone reaches a certain level, the pituitary gland begins to produce more FSH, and the cycle begins again. - Menstruation refers to: the shedding of the endometrium (the period ) - The menstrual flow consists mainly of: blood and dead cells (not just blood!) - The average menstrual cycle takes: between days and is measured from the first day of menstruation (bleeding) to the first day of the next menstruation - The menstruation part of the cycle lasts, on average: 2 to 7 days **every menstrual cycle is unique. The best indicator of whether it is normal is whether it is normal for you, so getting to know your cycle is an excellent idea 7