The HUMAN BODY Chapters 34 and 35 Reproductive and Immune Systems

Chapter 34.3 Reproductive System Objectives –Name and discuss the structures of the male reproductive system –Name and discuss the structures of the female reproductive system

REPRODUCTIVE SYSTEM Function- ensure continuation of species by producing gametes and hormones Male Female Introduction to Reproductive System

Male Reproductive System Scrotum Testes Epididymis Vas Deferens Glands –Seminal Vesicles –Prostate Gland –Bulbourethral Glands Urethra (in Penis) Penis Glans Penis Male Reproductive System

Female Reproductive System Ovaries Fimbrae Fallopian Tubes (oviduct) Uterus Cervix Vagina Vulva Clitoris Female Reproductive System

Menstrual Cycle Usually 28 days in length Occurs in females 4 phases: –Follicular –Ovulation –Luteal –Menstruation

Follicular Phase Follicle (cluster of cells surrounding an egg) helps egg mature FSH (Follicle Stimulating Hormone) & LH (Lutenizing Hormone) are increased- help egg mature Estrogen is low, but increases to cause uterine lining to thicken

Ovulation Process when egg is released from follicle Egg travels through Fallopian tube (it can be fertilized here) Caused by spike in FSH & LH

Luteal Phase Ruptured follicle turns yellow (Corpus Luteum) Estrogen and Progesterone are released to complete lining development During first 2 days, increased chance of pregnancy

If egg is NOT fertilized…Menstruation Egg and Corpus Luteum will disintegrate Estrogen and Progesterone levels decrease  causing lining to detach (menstruation) Low estrogen levels trigger stimulation of FSH & LH to start process again

If egg IS fertilized…Pregnancy Egg is fertilized by sperm in the Fallopian tube Zygote implants into wall of uterus Hormones continue to be released to keep lining and start baby’s development Conception

Check-in

Chapter 34.4 Fertilization and Development Objectives –Describe fertilization and the early stages of development –Identify the major events of later stages of development

Fertilization & Development Zygote/Embryo implants into uterine wall, cells begin to divide By 3 rd week, placenta forms (organ by which mother and child exchange gases and nutrients)

First Trimester Development By 3 months, most of the baby’s major organs have formed

Second Trimester Development At about 4 months or so, the mother starts to visibly look pregnant Fetal heartbeat heard with stethoscope Mother feels fetus move

Third Trimester Development Organ systems mature Fetus doubles in size

Childbirth After 9 months, child is fully developed and ready to be born Oxytocin (hormone) released  causes contraction of uterine walls Cervix dilates (opens) Amniotic sac breaks (“water breaks”) Uterus contracts to push baby out through the vagina The “after-birth” follows- placenta, amniotic sac, umbilical cord still attached

BABY!!!

Chapter 35.2 Defenses Against Infection Objectives –Describe the body’s nonspecific defenses against invading pathogens –Describe the function of the immune system’s specific defenses

Immune System Function: –Defends the body against pathogens (foreign invaders) that may cause disease

Lines of Defense: Non-Specific 1 st line- Skin: –Helps prevent germs from entering the body –Secretions (mucus, sweat, tears, oil, etc.) kill many disease-causing bacteria

Line of Defense: Non-Specific 2 nd line: Inflammatory Response –Uses White Blood Cells produced in the Thymus gland and bone marrow Extra WBCs contained in lymph nodes, spleen –Blood supply increases in affected area –White blood cells attack the invading organisms many blood cells and dead germs in one area  area becomes swollen, warm, and painful

Inflammatory Response Inflammatory Response Video clip

Line of Defense: Non-Specific 2 nd line: Fever –Increase body temperature may slow/stop growth of pathogen

Line of Defense: Specific 3 rd line: Immune Response Uses “antibodies”: proteins that recognize and bind to specific antigens Antigens: a substance that triggers a response (on outside of pathogen)

Immunity Active Immunity Immunity produced by exposure to an antigen, as a result of the immune response (ex. Vaccines) Passive Immunity Short-term immunity caused when antibodies produced by other animals for a pathogen are injected into the body

References Process of Conception. Colgren Communications Discovery Education. 18 November 2009 Fetal development pictures (by week) Fetal development pictures