KEY CONCEPT Germs cause many diseases in humans.

1. KEY CONCEPTGerms cause many diseases in humans.

2. Germ theory states that microscopic particles cause certain diseases. • Germ theory proposes that microorganisms cause diseases. • proposed by Louis Pasteur • led to rapid advances in understanding disease

3. Koch’s postulates support the theory. (DON”T COPY) • Disease-causing agents are called pathogens. (COPY)

4. There are different types of pathogens. • Bacteria are single-celled organisms. • cause illness by destroying cells • release toxic chemicals

5. Viruses are genetic material surrounded by a protein coat. • force host cells to make more viruses • very small

6. take nutrients from host cells • occur in warm and damp places • Fungi can be multicellular or single-celled.

7. use host cells to complete their life cycles • take nutrients from host cell • Protozoa are single-celled organisms.

8. grow and feed on a host • possibly kill the host • Parasites are multicellular organisms.

9. READ BUT DON’T COPY • Different pathogen cause common infectious diseases.

10. Pathogens can enter the body in different ways. (READ BUT DON’T COPY) • Pathogens can be transferred by direct or indirect contact. • Indirect contact does not require touching an infected individual. • touching an infected surface • breathing in infected air

11. READ BUT DON’T COPY • Vectors carry a pathogen and transmit it into healthy cells. • Direct contact requires touching an infected individual. Includes: • kissing • sexual intercourse • hand shaking tick

12. 31.2: Immune System KEY CONCEPTThe immune systems consists of organs, cells, and molecules that fight infections.

13. 31.2: Immune System Many body systems protect you from pathogens. • The immune system is the body system that fights off infection and pathogens. • Many other tissues and systems help the immune system. • Skin is a physical barrier to infection. • Mucous membranes trap pathogens entering the body. • The circulatory system transports immune cells.

14. 31.2: Immune System Cells and proteins fight the body’s infections. • White blood cells attack infections inside the body. • Phagocytes engulf and destroy pathogens. • T cells destroy infected cells. • B cells produce antibodies. READ BUT DON’T COPY

15. 31.2: Immune System READ BUT DON’T COPYImmunity prevents a person from getting sick from a pathogen. • In all immunity, pathogens are destroyed before you get sick. • Passive immunity occurs withoutan immune response. • mother’s milk • genetics • Active immunity occurs after aspecific immune response

16. 31.3: Immune Responses KEY CONCEPTThe immune system has many responses to pathogens and foreign cells.

17. 31.3: Immune Responses • In fever, body temperature increases. • Low fevers stimulate white blood cells to mature. • High fevers can cause seizure, brain damage, and even death.

18. 31.3: Immune Responses (READ BUT DON’T COPY) The immune system rejects foreign tissues. • Tissue rejection occurs in organ or tissue transplants. • Tissue rejection is the result of an immune response. • immune system detects protein markers on the donor tissue • makes antibodies against the donor’s tissue (READ BUT DON’T COPY)

19. 34.1: Reproductive Anatomy KEY CONCEPT Female and male reproductive organs fully develop during puberty.

20. uterus fallopian tube ovary cervix pubic bone urinary bladder rectum urethra vagina 34.1: Reproductive Anatomy The female reproductive system produces ova. • There are two main functions of the female reproductive system. • produce ova, or egg cells • provide a place where a zygote develops

21. 34.1: Reproductive Anatomy • Estrogen has three main functions. • develop female sexual characteristics • develop eggs • prepare uterus for pregnancy

22. urinary bladder seminal vesicle vas deferens pubic bone prostate gland rectum penis urethra epididymis bulbourethral gland scrotum testis 34.1: Reproductive Anatomy The male reproductive system produces sperm. • There are two main functions of the male reproductive system. • produce sperm cells • deliver sperm to the female reproductive system

23. 34.1: Reproductive Anatomy • Testosterone has two main functions. • developing male sexual characteristics • producing sperm

24. 34.2: Reproductive Processes KEY CONCEPT Human reproductive processes depend on cycles of hormones.

25. potential egg Meiosis I Completed first polar body Meiosis II Completed only after sperm enters second polar body ovum (egg) 34.2: Reproductive Processes Eggs mature and are released according to hormonal cycles. • meiosis produces eggs and polar bodies • each egg has 23 chromosomes • meiosis is completed at fertilization

26. fallopian tube uterus 5 to 7 days to uterus follicle ovary egg cell egg released uterine wall corpus luteum 34.2: Reproductive Processes • Hormones, including estrogen stimulate the release of eggs. • Begins with ovulation (release of an egg from ovary) • egg travels into fallopian tube, then to uterus

27. 34.2: Reproductive Processes READ BUT DON’T COPY Eggs mature and are released according to hormonal cycles. • The menstrual cycle has three phases. • 1. endometrium sheds • 2. ovulation occurs • 3. corpus luteum forms

28. 34.2: Reproductive Processes • The menstrual cycle stops at menopause. • cycle continues until a woman’s mid-40’s or 50’s • decline in hormone levels make cycles irregular • eventually, cycle stops altogether

29. potential sperm Meiosis I Meiosis II 4 sperm cells 34.2: Reproductive Processes Sperm production in the testes is controlled by hormones. • Hormones stimulate sperm production. • one sex cell divides into four sperm • each sperm has 23 chromosomes

30. 34.2: Reproductive Processes Fertilization occurs when a sperm cell joins an egg cell. • Sperm penetrates an egg. • membrane keeps out other sperm • nucleus of sperm joins with egg • zygote formed

31. 34.2: Reproductive Processes (READ BUT DON’T COPY) • Multiple zygotes can result from fertilization. • identical twins from the same egg • fraternal twins from two separate eggs • Infertility makes reproduction difficult or impossible.

32. HIV 34.2: Reproductive Processes (READ BUT DON’T COPY) Sexually transmitted diseases affect fertility and overall health. • Sexually transmitted diseases (STDs) are passed from one person to another during sexual contact. • bacterial STDs include chlamydia, syphilis, gonorrhea • viral STDs include hepatitis B, genital herpes, human papillomavirus, and HIV

33. A parasite causes trichomoniasis, which can affect fertility. 34.2: Reproductive Processes (READ BUT DON’T COPY) • Viral STDs can be treated, but there is no cure for these diseases. • STDs attack reproductive organs. • can cause infertility • untreated, some can be fatal • Bacterial STDs can be treated, and in many cases, cured with antibiotics • STDs can be avoided by abstinence or by using a condom.

34. 32.3 KEY CONCEPT Development progresses in stages from zygote to fetus.

35. blastocyst uterine wall Implantation of blastocyst The fertilized egg implants into the uterus and is nourished by the placenta and umbilical cord. • ectoderm develops into skin and nervous system • The zygote becomes a blastocyst and implants in the uterus. READ BUT DON’T COPY • mesoderm develops into Internal tissues and organs • endoderm develops into digestive organs and their lining

36. placenta umbilical cord uterus amniotic sac • The blastocyst becomes an embryo. • Embryonic membranes protect and nourish the embryo. • amniotic sac cushions embryo. • placenta connects mother and embryo. • umbilical cord connects embryo to placenta.

37. A zygote develops into a fully formed fetus in about 38 weeks. • Human pregnancies are divided into trimesters. • 1st trimester: body plan and early development • Leave a few lines for notes here

38. 2nd trimester: fetus more active, developed • Leave a few lines for notes here

39. 3rd trimester: all organs fully formed • Leave a few lines for notes here • After about 38 weeks, fetus is ready to be born.

40. READ BUT DON’T COPYThe mother affects the fetus, and pregnancy affects the mother. • The fetus depends on the mother for all its nutrition. • mother's diet must support fetal health • mother must avoid toxic chemicals

41. READ BUT DON’T COPY • The mother’s health is affected by pregnancy in a number of ways. • increase in Calories and body weight • pregnancy hormones affecting homeostasis • regular medical checkups needed