PowerPoint ® Lecture Slides prepared by Leslie Hendon, University of Alabama, Birmingham HUMAN ANATOMY fifth edition MARIEB | MALLATT | WILHELM 24 Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings The Reproductive System PART 6

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Figure 24.25a, b Childbirth  Parturition – 266 days after fertilization  Labor – events that expel the infant from the uterus

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Childbirth Figure 24.25c, d

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Reproductive System Cancers in Males  Testicular cancer  Affects 1 of 50,000 males  Commonly from early-stage spermatogenic cells  Increase of 50% from 1974 – 1990  Cured in 95% of cases

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Reproductive System Cancers in Males  Prostate cancer  Slow-growing – arises from peripheral glands  Risk factors  Fatty diet  Genetic predisposition

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Reproductive System Cancers in Females  Ovarian cancer – arises from cells in the germinal epithelium  Endometrial cancer – arises from the endometrium of the uterus  Cervical cancer – slow-growing, arises from epithelium at the tip of the cervix

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Reproductive System Cancers in Females  Breast cancer – Second most common cause of cancer deaths in women  97% occurs in women over 50  Treatment  Surgical removal of the mass (lumpectomy)  Radiation therapy  Administration of selected hormones  Chemotherapy

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Embryonic Development of the Sex Organs  5 – 6 week embryo is sexually indifferent  Mesonephric ducts – future male ducts  Paramesonephric ducts – future female ducts

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Embryonic Development of the Sex Organs  Development of the internal reproductive organs Figure (1 of 3)

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Embryonic Development of the Sex Organs  Male embryos – sexual differentiation begins in week seven  Mesonephric duct becomes  Epididymis  Ductus deferens  Ejaculatory duct  Paramesonephric ducts degenerate

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Embryonic Development of the Sex Organs  Female embryos – sexual differentiation begins in week eight  Cortical portion of immature ovaries form ovarian follicles  Paramesonephric duct becomes  Uterus  Uterine tubes  Superior part of vagina  Mesonephric ducts degenerate

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Embryonic Development of the Sex Organs Figure (2 of 3)

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Embryonic Development of the Sex Organs Figure (3 of 3)

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Embryonic Development of the Sex Organs  Development of the external genitalia Figure 24.27a

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Embryonic Development of the Sex Organs Figure 24.27b, c

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Decent of the Gonads Figure 24.28a–c

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Puberty  Period of life between ages 10 – 15  Reproductive organs grow to their adult size  Events of puberty occur in the same sequence in all individuals  Age at which events of puberty occur varies widely

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Puberty  Male secondary sex characteristics  Enlargement of the scrotum and testes (about age 13)  Appearance of pubic, axillary, and facial hair  Lengthening of vocal folds – deepening voice  Musculoskeletal system increases in mass  Sexual maturation – mature sperm in semen

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Puberty  Female secondary sex characteristics  Budding breasts (around age 11)  Menarche – the first menstruation  Other estrogen-induced secondary sex characteristics  Increase in subcutaneous fat  Widening and lightening of the bones of the pelvic girdle  Appearance of axillary and pubic hair  Estrogen-induced growth spurt from age 12 – 17

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Menopause  Female reproductive peak – late 20s  Around age 35 – rate of follicle degeneration increases  Ovulation and menstruation cease – age 46 – 54  Ovaries stop secreting estrogen  Reproductive organs and breasts begin to atrophy