1. Reproductive System

2. Cell Cycle Produces gametes by meiosis

3. Cell Cycle Meiosis reduces the number of chromosomes in half

4. Cell Cycle Gametes have only 23 chromosomes

5. Homologous Chromosomes 2 chromosomes that make up a chromosome pair in cells

6. Homologous Chromosomes Contain similar genes

7. Homologous Chromosomes The exception is the sex chromosomes

8. Homologous Chromosomes The female contains two X chromosomes

9. Homologous Chromosomes The male has an X and a Y chromosome

10. Homologous Chromosomes The other 22 pairs of chromosomes are called autosomes

11. Diploid Cell A cell with a full set of chromosomes

12. Haploid Cell One with only one chromosome from each pair

13. Haploid Cell Gametes are the only haploid cells

14. Haploid Cell Eggs and spermatoza

15. Male Reproductive System Testes A system of ducts Several supporting structures Penis

16. Scrotum Cutaneous outpouching of the abdomen that supports the testes

17. Scrotum Internally a vertical septum divides it into two sacs, each containing a single testis

18. Testes Paired oval-shaped glands in the scrotum

20. Testes Contain seminiferous tubules ( in which sperm cells are made)

23. Testes Sertoli Cells - Embedded among the spermatogenic cells in the tubules

24. Sertoli Cells Nourish spermatocytes, spermatids, and spermatozoa

25. Sertoli Cells Control movements of spermatogenic cells

26. Sertoli Cells Controls the release of spermatozoa into the lumen of the seminiferous tubule

27. Sertoli Cells Secretes fluid for sperm transport and the hormone inhibin

28. Sertoli Cells Inhibin decreases FSH when the rate of spermatogenesis is too high

29. Testes Leydig cells – found in the spaces between adjacent seminiferous tubules secrete testosterone

30. Spermatogenesis Process by which seminiferous tubules of the testes produce sperm

31. Spermatogenesis Spermatogonia – stem cells

32. Spermatogenesis Spermatogonia undergo mitosis to produce future stem cells and primary spermatocytes

33. Spermatogenesis Diploid primary spermatocytes undergo meiosis I forming haploid secondary spermatocytes

34. Spermatogenesis Meiosis II results in haploid spermatids

35. Spermatogenesis Spermiogenesis – maturation of the spermatids into spermatozoa

36. Mature Sperm Consist of a head, midpiece, and tail

37. Mature Sperm The head contains a specialized lysosome called an acrosome

38. Mature Sperm The acrosome has an enzyme that helps penetrate the egg

39. Mature Sperm The midpiece is rich in mitochondria for ATP production

40. Mature Sperm ATP is essential for the motility of flagellum

41. Mature Sperm They are produced at the rate of about 100-300 million per day

42. Mature Sperm Have a life expectancy of 48 hours within the female reproductive tract

43. Hormonal Control of Spermatogenesis At puberty Gonadotropin releasing hormone increases, which stimulates the A.P. secretion of FSH and LH

44. Hormonal Control of Spermatogenesis FSH initiates spermatogenesis

45. Hormonal Control of Spermatogenesis LH assists spermatogenesis and stimulates the production of testosterone by the Leydig cells

46. Testosterone Controls the growth, development, functioning, and maintenance of sex organs

47. Testosterone Stimulates bone growth, protein anabolism, increases in muscle size, and sperm maturation

48. Testosterone It increases libido and stimulates the development of secondary sex characteristics

49. Testosterone It reduces LH secretion, which decreases testosterone production

50. Secondary Male Sex Characteristics Wide shoulders

51. Secondary Male Sex Characteristics Narrow hips

52. Secondary Male Sex Characteristics Male hair patters

53. Secondary Male Sex Characteristics Thick and oily skin

54. Secondary Male Sex Characteristics Enlarged larynx with a deeper voice

55. Ducts The duct system of the testes includes the 1.Seminiferous tubules 2.Straight tubules 3.Rete Testis 4.Epididymis 5.Ductus Deferens 6.Ejaculatory Duct 7.Urethra

56. Epididymis Comma-shaped organ that lies along the posterior border of the testis

58. Epididymis Sperm are transported out of the testes through the ductus epididymis

59. Ductus Epididymis Lined by stereocilia

61. Ductus Epididymis Site of sperm maturation and storage

62. Ductus Epididymis Sperm may remain in storage here for at least a month

63. Vas Deferens Stores sperm and propels them toward the urethra during ejaculation

65. Ejaculatory Ducts Formed by the union of the ducts from the seminal vesicles and ducti deferens

67. Ejaculatory Ducts Function to eject spermatozoa into the prostatic urethra

69. Male urethra Serves as a passageway for semen and urine

70. Seminal Vesicles Secretes a viscous alkaline fluid that contains fructose that nourish and promote the fertilizing capability of sperm

72. Seminal Vesicles The alkaline fluid helps neutralize acid in the male urethra and female reproductive tract

73. Seminal Vesicles The fructose is for ATP production by sperm

74. Prostate Gland Secretes a milky, slightly acidic fluid

76. Bulbourethral Glands Secretes mucus for lubrication and an alkaline substance that neutralizes acid

78. Semen Average volume 2.75 ml

79. Semen Contains 50-150 million spermatozoa/ml

80. Semen The average sperm count has declined from 113 million/ml to 66 million/ml over the past 44 years

81. Semen May be due to estrogens in meat, marijuana, environmental toxins, alcohol, and lead exposure

82. Penis Male organ of copulation that consists of a 1.Root 2.Body 3.Glans penis 4.foreskin

84. Penis Spongy tissue in shaft composed of 1.Two dorsal corpora cavernosa 2.Ventral corpos spongiosum

86. Penis Arterioles (which are normally constricted) supply blood to blood sinuses

87. Penis The blood sinuses become filled with blood during erection

88. Erection Mediated by a parasympathetic reflex

89. Erection Neurons and vascular endothelial cells release nitric oxide which leads to arteriolar smooth muscle relaxation

90. Erection This vasodilation increases blood flow into the penis

91. Ejaculation Propulsion of semen from the urethra to the exterior is a sympathetic reflex

92. Female Reproductive System Ovaries Uterine tubes Uterus Vagina Vulva Mammary Glands

94. Ovaries Paired glands that are homologous to the testes

96. Ovaries Located in the upper pelvic cavity on either side of the uterus

97. Ovarian Cortex Contain ovarian follicles and consists of oocytes in various stages of development

99. Primordial follicles Contain the primary oocyte surrounded by a single layer of flattened epithelial cells

101. Primordial follicles Contain 46 chromosomes stuck in prophase of meiosis 1

102. Primordial follicles A woman is born with 2 million primordial follicles

103. Primordial follicles During childhood, most undergo atresia

104. Primordial follicles By puberty, only 400,000 are left

105. Primordial follicles Each month, about 20 primordial follicles mature into primary follicles

106. Primary follicles Primary oocyte surrounded by one to several layers of cuboidal epithelial cells that make estrogen

108. Primary follicles These epithelial cells are called granulosa cells

109. Primary follicles In between the oocyte and granulosa cells is a glycoprotein called the zona pelucida

110. Primary follicles Outside the granulosa cells are two layers of connective tissue called 1.Theca externa 2.Theca interna

111. Primary follicles Many primaries undergo atresia

112. Primary follicles Some become secondary follicles

113. Secondary Follicles Have a fluid filled antrum

115. Secondary follicles As the menstrual cycle progresses toward midcycle all of the secondaries undergo atresia except one

116. Secondary follicles One follicle will become the dominant follicle- the Graafian follicle

118. Graafian Follicle The primary oocyte will complete meiosis I and go through part of meiosis II, but pause at metaphase II

119. Graafian Follicle It’s now called the secondary oocyte

120. Graafian Follicle The follicle expel the secondary oocyte by a process called ovulation

121. Immature ovum Surrounding it is the zona pelucida and a layer of follicular cells called the corona radiata

123. Corpus luteum Contains the remnants of an ovulated follicle and produces 1.Progesterone 2.Estrogen 3.Relaxin 4.Inhibin

124. Corpus luteum It eventually degenerates into a corpus albicans

125. Oogenesis Occurs in the ovaries

126. Oogenesis It results in the formation of a single haploid secondary oocyte

127. Oogenesis Meisosis II is not complete until fertilization

128. Ovarian Medulla Contains 1.Blood vessels 2.Lymphatics 3.Nerves

130. Uterine Tube Transport ova from the ovaries to the uterus

132. Uterine Tube Normal sites of fertilizaiton

133. Uterine Tube Fimbriae – are projections of the tubes that help capture the ovulated immature ovum

135. Uterine Tube The fallopian tube is the usually the site of fertilization

136. Uterine Tube Ciliated cells and peristaltic contractions help move a secondary oocyte toward the uterus

137. Uterus An organ the size and shape of an inverted pear

139. Uterus Functions in the transport of spermatozoa, menstruation, implantation of a fertilized ovum, development of a fetus during pregnancy, and labor

140. Uterus Cervix – connects the vaginal cavity to the uterine cavity

141. Uterus Cervix – firm unless it is softened by relaxin during labor and delivery

142. Histology of the Uterus 1.Perimetrium 2.Myometrium 3.Endometrium

143. Perimetrium Part of the visceral peritoneum

144. Myometrium Consists of three muscle layers and has oxytocin receptors

146. Endometrium Divided into the 1.Stratum Functionalis 2.Stratum Basalis

148. Endometrium Spiral arteries supply the endometrium

149. Cervix Secretory cells of the cervix produce a cervical mucus

151. Cervix At mid cycle the mucus is thin and receptive to sperm

152. Cervix During most of the menstrual cycle the mucus is thick

153. Vagina 10 cm in the adult

155. Vagina Functions as a passageway for spermatozoa and the menstrual flow

156. Vagina It is acidic in order to inhibit microorganisms and sperm

157. Vagina The vaginal orifice in virgins is partially covered by the hymen

158. Vulva External genitalia of the female

160. Vulva It consists of 1. Mons pubs – rounded fatty eminence overlying the pubic symphysis

162. Vulva 2. Labia majora – covered with hair

164. Vulva 3. Labia minora – thinner folds that are devoid of hair, they atrophy after menopause

166. Vulva 4. Clitoris – homologous to the penis

168. Vulva 5. Vestibule – cleft between labia minora where vaginal orifice opens to the outside

170. Vulva 6. Vaginal orifice

172. Vulva 7. Urethral orifices – between the clitoris and the vaginal orifice

174. Vulva 8. Hymen

176. Mammary Glands Milk producing glands that lie over the pectoralis major and serratus anterior muscle

178. Mammary Glands Milk secreting cells (alveoli) are clustered in small compartments (lobules) within the breasts

179. Mammary Glands 1.Alveoli 2.Mammary ducts 3.Lactiferous ducts 4.Lactiferous sinuses 5.Nipple

181. Mammary Glands Function to synthesize milk and secretion and ejection of milk (lactation)

182. Mammary Glands Areola is the pigmented skin that surrounds the nipple

183. Mammary Glands Develop at puberty under the stimulation of rising estrogen and progesterone levels

184. Phases of the Female Reproductive Cycle 1.Menstrual cycle 2.Preovulatory phase 3.Ovulation 4.Postovulatory phase

185. Menstrual Cycle First five days of cycle

186. Menstrual Cycle About 20 small follicles in each ovary begin to develop

187. Menstrual Cycle Stratum functionalis layer of the endometrium is shed discharging blood, tissue fluid, mucus, and epithelial cells

189. Menstrual Cycle It is shed due to declining progesterone at the end of the previous cycle

190. Preovulatory phase Between menstruation and ovulation

191. Preovulatory phase Lasting from days 6-13 in a 28 day cycle

192. Preovulatory phase Primary follicles develop into secondary follicles

193. Preovulatory phase A single secondary follicle develops into a Graafian or mature follicle

194. Preovulatory phase Maturing follicles secrete estrogen

195. Preovulatory phase The mature follicle continues to increase its estrogen production due to increasing levels of LH

196. Preovulatory phase Estrogen stimulates endometrial repair; a new stratum functionalis is formed

197. Ovulation Rupture of the Graafian or mature follicle with release of the secondary oocyte into the pelvic cavity

198. Ovulatation LH transforms the ruptured follicle into the corpus luteum

199. Ovulation Occurs on day 14

200. Ovulation The high levels of estrogen during the last part of the preovulatory phase exerts a positive feedback on LH and GnRH to cause ovulation

201. Ovulation GnRH promotes release of FSH and LH

202. Ovulation LH surge brings about the ovulation

203. Ovulation Increased body temperature due to progesterone, which increases just prior to ovulation

204. Ovulation Clear cervical mucus due to high estrogen

205. Ovulation Corpus luteum secretes estrogens and progesterone due to LH

206. Postovulatory phase Days 15-28

207. Postovulatory phase Time between ovulation and the onset of the next menstrual period

208. Postovulatory phase Estrogen and progesterone are secreted in large quantities by the corpus luteum

209. Postovulatory phase If fertilization and implantatin do not occur, estrogen and progesterone secreted by the corpus luteum inhibit LH

210. Postovulatory phase So Corpus luteum loses its support

211. Postovulatory phase The copus luteum degenerates and becomes the corpus albicans

212. Postovulatory phase The decreased levels of estrogen and progesterone initiatates another menstrual phase

213. Postovulatory phase Because estrogen and progesterone levels drop, there is less negative feedback on the Hyp. and A.P.

214. Postovulatory phase FSH and LH begin to rise a bit at the end of the cycle, causing another round of follicular development (about 20)

215. Postovulatory phase If fertilization and implantation do occur, the corpus luteum is maintained until the placenta takes over

216. Postovulatory phase Corpus luteum is maintained by human chorionic gonadotropin (hCG) from the developing placenta

217. Postovulatory phase The corpus luteum secretes estrogens and progesterones to support pregnancy and breast development for lactation

218. Postovulatory phase Once the placenta begins secreting estrogen and progesterone, the role of corpus luteum becomes minor

219. Postovulatory phase Endometrium thickens in anticipation of implantation