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Unit 2: The continuation of life

Higher Human Biology. Unit 2: The continuation of life. Reproduction revision!. Lesson Aims:. To revise the structure and function of the male reproductive system. To revise the structure and function of the female reproductive system. Fertilisation video clip. Reproduction Revision .

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Unit 2: The continuation of life

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  1. Higher Human Biology Unit 2: The continuation of life Reproduction revision! Mrs Smith Ch15 Sex organs and hormonal control

  2. Lesson Aims: • To revise the structure and function of the male reproductive system. • To revise the structure and function of the female reproductive system. Fertilisation video clip Mrs Smith Ch15 Sex organs and hormonal control

  3. Reproduction Revision • All living things reproduce and produce offspring similar to themselves. • If they did not then eventually the species would become extinct.

  4. Sex cells – sperm In males, the sex cells are called sperm. tail middle piece head nucleus containing DNA cell membrane Sperm are produced in sex organs called testes.

  5. Sex cells – egg In females, the sex cells are called eggs. nucleus containing DNA cytoplasm membrane jelly coat Eggs are produced in sex organs called ovaries.

  6. Sexual Reproduction • This is when 2 types of sex cells or gametes are produced which then joins together at fertilisation to produce the new individual. • In animals the gametes are egg and sperm. An egg is so big that this is how big a sperm looks next to it. The egg is much larger because it has a food supply.

  7. fertilisation Zygote - Sperm enters the egg. The sperm nucleus fuses with egg nucleus to create a single cell.

  8. Fertilisation http://www.youtube.com/watch?v=vyWuMo3bzRU&feature=relmfu

  9. After fertilisation…. 1 cell – fertilised egg

  10. Cell division 2 Cells

  11. 4 cells…

  12. 8 cells…leading to a ball of cells

  13. Revision. The female reproductive system

  14. Revision: The male reproductive system

  15. Male or female?

  16. Roles of the reproductive system

  17. Fertilisation and implantation

  18. The placenta How does an embryo receive food and oxygen and how does it get rid of waste? An embryo forms a structure called the placenta, which attaches to the uterus wall. umbilical cord The umbilical cord joins the fetus to the placenta. In the placenta, food and oxygen diffuse from the mother’s blood into the blood of the foetus. Carbon dioxide and waste products diffuse from the blood of the foetus into the mother’s blood.

  19. How does the placenta work?

  20. Placenta Maternal and foetal blood separated by a thin barrier

  21. Summary: Role of the Placenta • Nourishment • Food from the mother • Gaseous exchange • Oxygen from mother • Carbon Dioxide from embryo to mother • Excretion • Waste materials from embryo to mother

  22. Higher Human Biology Unit 2: The continuation of life Chapter 15: Sex organs and hormonal control! Mrs Smith Ch15 Sex organs and hormonal control

  23. What you need to know: The arrangements Reproduction Fertility and its control: i Structure and function of reproductive organs. Structure of testes and ovaries and their function. The contribution to fertilisation of the secretions of the prostate gland and the seminal vesicles. ii Hormonal control. The influence of the pituitary hormones, follicle stimulating hormone (FSH) and luteinising hormone (LH) on the testes and the ovaries. The influence of testosterone on the testes. The influence of the ovarian hormones, oestrogen and progesterone, on the uterus and the pituitary. Changes during the menstrual cycle and control of these changes through interaction of hormones. Continuous fertility in the male compared with cyclical fertility in the female. Mrs Smith Ch15 Sex organs and hormonal control

  24. The words you need to know: boys and girls! Pituitary gland Negative feedback Self-regulating Endocrine glands Hormones Inhibits Mrs Smith Ch15 Sex organs and hormonal control

  25. The boy words you need to know! Testes Motile Prostaglandins Testosterone Spermatozoa Sperm Duct Seminal vesicles Prostrate Gland Interstitial cells ICSH FSH Semen Mrs Smith Ch15 Sex organs and hormonal control

  26. The girl words you need to know! Menstrual cycle Uterus Graafian Follicle Oviducts Luteal phase Oestrogen Follicular phase Endrometrium Progesterone Corpus luteum Ovaries LH Mrs Smith Ch15 Sex organs and hormonal control

  27. Lesson Aims: • Expand on the structure and function of the male reproductive system • To learn about sperm production and hormonal control • Expand on the structure and function of the female reproductive system • To learn about egg production and hormonal control Fertilisation video clip Mrs Smith Ch15 Sex organs and hormonal control

  28. Learning Intentions Success Criteria Understanding The Continuation of Life Describe the structure & function of the testes Explain the contribution to fertilisation of the secretions of the prostate gland and the seminal vesicle

  29. Male Reproductive System Made up of testicles, duct system, accessory glands and penis. Functions: • produce hormones • produce sperm • store sperm • deposits sperm inside vagina during sexual intercourse Mrs Smith Ch15 Sex organs and hormonal control

  30. FYI - sperm • The average man produces roughly 525 billion sperm cells over his lifetime and releases, in one way or another, more than one billion of them per month and anywhere from 40 million to 1.2 billion in a single ejaculation. Mrs Smith Ch15 Sex organs and hormonal control

  31. Sperm (spermatozoa) production • Testosterone produced in interstitial cells stimulates sperm production. Testosterone passes directly into the bloodstream. • Sperm formed by meiosis in seminiferous tubules. • These tubules unite to form coiled tubes which connect to the SPERM DUCT. (Free swimming sperm leave the testes by this duct. Mrs Smith Ch15 Sex organs and hormonal control

  32. Sperm mother cell Spermatozoa Interstitial cell

  33. Accessory Glands • Fertilisation is dependent on; • Motility of sperm which requires a fluid medium. • a source of energy • The semen released by the male during ejaculation contains sperm from the testes and fluid secretions from the seminal vesicles and the prostate gland. Mrs Smith Ch15 Sex organs and hormonal control

  34. The Accessory Glands con’t Seminal vesicles:secrete viscous liquid containing: • Fructose: Provides energy source for motility following there release after male ejaculation. • Prostaglandins: (Hormone like compounds)Stimulate contraction in the female reproductive tract. These movements help the sperm reach the oviduct at a much faster rate than could be achieved by swimming alone. Prostate Gland: • Secretes a thin lubricating fluid containing enzymes which maintains the fluid medium atOPTIMUM VISCOSITY for sperm motility.

  35. Where is your pituitary gland?–Hormonal Control. The Pituitary gland is located in the centre of the brain and produces many hormones Hormones are chemical messengers produced by an animal’s endocrine glands and secreted directly into the bloodstream. When a hormone reaches a certain target tissue, it brings about a specific effect.

  36. Pituitary gland • Pituitary gland is a gland that produces many hormones. • Two of these are called GONADOTROPIC hormones because their target are the gonads (reproductive organs). • FSH –Follicle stimulating hormone. • In men - ICSH – Interstitial Cell Stimulating hormone. In women – LH – Luteinising hormone • These hormones are released at puberty. Mrs Smith Ch15 Sex organs and hormonal control

  37. Influence of testosterone • Testosterone stimulates sperm production. • It also activates the prostrate gland and seminal vesicles to produce their secretions. SELF REGULATION OF TESTESTORONE • As the concentration of testosterone builds-up in the bloodstream, it reaches a level where it INHIBITS the secretion of FSH and ICSH by the anterior pituitary. • This leads to a decrease in testesterone concentration, soon followed by a resumption of the activity by the anterior pituitary. • This makes gonadotropic hormone again and the cycle starts again. Mrs Smith Ch15 Sex organs and hormonal control

  38. ICSH ICSH Influence of pituitary Hormonal on testes – negative feedback! This type of self-regulating mechanism is called NEGATIVE FEEDBACK CONTROL. FSH in the bloodstream promotes sperm production in the seminiferous tubules. ICSH stimulates interstitial cells to produce male sex hormone TESTOSTERONE Mrs Smith Ch15 Sex organs and hormonal control

  39. Learning Intentions Success Criteria Understanding The Continuation of Life Describe the structure & function of the ovaries Explain the influence of pituitary hormones on the ovaries. Explain the influence of ovarian hormones on the uterus and pituitary gland

  40. Female Reproductive System Made up of uterus, oviducts, ovaries and vagina. Functions: • produces ova (eggs). • Receives sperm from penis. Mrs Smith Ch15 Sex organs and hormonal control

  41. FYI - Eggs • Evidence suggests that eggs are formed in foetal life. About 400,000 immature eggs reside in each ovary at puberty. The menstrual cycle, as a biologic event, allows for ovulation of one egg typically each month. Thus over her lifetime a woman will ovulate approximately 400 to 450 times. All the other eggs dissolve. • As a woman's total egg supply is formed in foetal life, to be ovulated decades later, it has been suggested that this long lifetime may make the chromatin of eggs more vulnerable to division problems, breakage, and mutation than the chromatin of sperm, which are produced continuously during a man's reproductive life. This possibility is supported by the observation that foetuses and infants of older mothers have higher rates of chromosome abnormalities than those of older fathers. Mrs Smith Ch15 Sex organs and hormonal control

  42. The Female reproductive system continued. The role of the female in reproduction is not only to produce gametes but also…. • Houses and provides nutrients (food and oxygen) to the developing zygote (fertilized egg) and later the embryo and foetus. • Remove its waste products. • Gives birth to the offspring. • After delivering into the world, provide it with continued supply of food for a period of time.

  43. The ovaries are the site of ova production by meiosis Ova are contained in a developing Graafian follicle The Graafian follicle secretes the hormone oestrogen After ovulation, the Graafian follicle becomes the corpus luteum which secrete progesterone The Ovaries

  44. Corpus LuteumSEE SCHOLAR – Maturation of ova simulationhttp://courses.scholar.hw.ac.uk/vle/scholar/session.controller?action=viewContent&contentGUID=f65bd0a3-3b06-6409-554b-934e6eb2195a OVARY Graafian follicle developing egg Immature Graafian follicle

  45. Graafian follicle follicular liquid ovum Graafian Follicle Mrs Smith Ch15 Sex organs and hormonal control

  46. Pituitary Hormones & the Ovaries • F.S.H (Follicle Stimulating Hormone) • Stimulates the development of eggs (inside the structures called follicles) and the development and maturation of Graafian Follicle • Stimulates ovary to produce the hormone oestrogen • L.H (Lutenising Hormone) • Triggers ovulation • Brings about the development of the corpus luteum from the follicle • Stimulates corpus luteum to produce progesterone • Gonadotrophic hormones (FSH/LH) and ovarian hormones (Oestrogen/Progesterone) interact to control the female menstrual cycle.

  47. Effect of Ovarian Hormones on theUterus &Pituitary Gland • Gonadotrophic hormones (FSH/LH) and ovarian hormones (Oestrogen/Progesterone) interact to control the female menstrual cycle. • During puberty the anterior pituitary gland begins to secrete FSH & LH. These hormones are transported to the ovaries in the blood • Oestrogen and Progesterone are called the ovarian hormones since they are produced by the ovary. • Oestrogen • stimulates proliferation (cell division) of the lining of the uterus - the endometrium. And it is responsible for the repair after menstruation. • stimulates secretion of LH by the anterior pituitary gland • Progesterone • Promotes the thickening of the endometrium • Promotes vasularisation (many blood vessels), to create a spongy layer(of the endometrium) • Inhibits secretion of FSH and LH by the anterior pituitary gland

  48. Continual Fertility in Males • high level of testosterone has a negative feedback effect on the secretion of FSH and ICSH by the pituitary gland • relatively constant levels of testosterone, FSH and ICSH Cyclic Fertility in Females fluctuating levels of FSH, LH, oestrogen and progesterone only fertile for a few days before and after ovulation Continual Fertility vrs Cyclical Fertility Mrs Smith Ch15 Sex organs and hormonal control

  49. TASK – Complete card sorts • Also on SCHOLAR • Table 1.1 - Effects of pituitary hormoneshttp://courses.scholar.hw.ac.uk/vle/scholar/session.controller?action=viewContent&contentGUID=713b3f30-e1fb-1b8c-e143-c13651f07dad • Table 1.2 - Effects of ovarian hormones http://courses.scholar.hw.ac.uk/vle/scholar/session.controller?action=viewContent&contentGUID=1f1334fa-2e17-b3fe-c450-fec3e51ea083 • Once complete copy into notes or jotters

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