Presentation is loading. Please wait.

Presentation is loading. Please wait.

ADVANCED PHYSIOLOGY REPRODUCTION Instructor Terry Wiseth.

Similar presentations


Presentation on theme: "ADVANCED PHYSIOLOGY REPRODUCTION Instructor Terry Wiseth."— Presentation transcript:

1 ADVANCED PHYSIOLOGY REPRODUCTION Instructor Terry Wiseth

2 Male System Testes  paired oval bodies  about 1.5 in long

3 Tunica Albuginea  Outer covering  white fibrous connective tissue

4 Tunica Vaginalis  Inner covering  visceral peritoneum

5 Testes Development Develop in the abdominal cavity descend through the inguinal canal into the scrotum before birth lower temperature necessary for spermatogenesis

6 Temperature Normal body temperature is too hot thus is lethal to sperm  so the testes are outside of the abdominal cavity  where the temperature is about 2° C (3.6° F) lower

7 Temperature a woman’s body temperature is lowest around the time of ovulation  to help insure sperm live longer to reach the egg If a man takes too many long, very hot baths  sperm count can be reduced

8 Scrotal Sac Divided into lobules  containing coiled seminiferous tubules  empty into a central network of tubules called the rete testis

9 Cellular Components Interstitial Cells Sertoli Cells

10 Interstitial Cells Leydig Cells lie between seminiferous tubules Secrete testosterone

11 Sertoli Cells in lower epithelial layers within seminiferous tubules Form blood-testes barrier cells joined by tight junctions

12 Sertoli Cells Supply nutrients to spermatids Secrete inhibin  depresses FSH production Secrete androgen-binding protein (ABP)  concentrates androgens in tubules Secrete Müllerian-inhibiting factor (MIF)  involved in testes descent

13 Spermatogenesis production of sperm requires 9 weeks

14 Spermatogonia 2N stem cells form basal layer of the seminiferous tubule Separated by blood-testis barrier from spermatocytes which contain different membrane antigens Mitotically divide to form primary spermatocytes

15 Primary Spermatocytes 1N cells Undergo meiosis I (reduction division) to form two haploid secondary spermatocytes

16 Secondary Spermatocytes 1N cells Complete meiosis II to form four haploid spermatids connected by cytoplasmic bridges

17 Spermatids 1N Undergo structural change (spermiogenesis) to form spermatozoa

18 Sperm 1N Head contains nucleus and acrosomal cap containing enzymes Midpiece contains two centrioles + microtubules, mitochondrial spiral Tail contains flagellum surrounded by fibrous sheath

19 Spermatogenesis

20 Epididymis long coiled tube about ft long Composed of head, body and tail Receives sperm from the rete testis

21 Epididymis Functions Sperm storage and maturation Recycles damaged sperm Prevents premature capacitation

22 Ductus Deferens vas deferens tube continuous with the epididymis Carries sperm to the seminal vesicle from the testes

23 Vasectomy involves making a small slit in each scrotum cutting the vas deferens near where they begin tying off the cut ends to prevent sperm from leaving the scrotum not designed to be a reversible operation

24 Vasectomy

25

26 Spermatic Cord composed of:  ductus deferens  testicular artery testicular vein  lymphatics  nerves wrapped with connective tissue

27 Spermatic Cord extends from testes to the deep inguinal ring In abdominal cavity the ductus deferens curves posterior to the bladder Expands to form the ampulla and joins the duct of the seminal vesicle

28 Seminal Vesicles pouch-like glands that empty into the ductus deferens at the ejaculatory duct Secrete viscous alkaline fluid that constitutes about 60% of semen

29 Seminal Fluid Fluid contains:  Fructose  for ATP production for sperm  Alkaline  Neutralizes acid in female reproductive system

30 Seminal Fluid Fluid contains:  Prostaglandins  Increases sperm motility and viability  decrease mucous viscosity at cervix  stimulate female uterine contractions to move the semen up into the uterus  Semenogelin  causes sperm coagulation after ejaculation

31 Capacitation Sperm become motile when mixed with seminal fluid Secretions of female tract make sperm capable of fertilization

32 Ejaculatory Duct short duct extends from the ductus deferens to urethra

33 Prostate Gland large gland surrounds prostatic urethra and ejaculatory ducts Secretes thin white slightly acidic fluid about 25% of semen

34 Prostate Enlargement The prostate needs a lot of zinc to function properly insufficient dietary zinc can lead to enlargement  potentially can constrict the urethra to the point of interfering with urination

35 Prostate Surgery Mild cases of prostate hypertrophy can often be treated by adding supplemental zinc to the man’s diet severe cases require surgical removal of portions of the prostate  if not done very carefully can lead to problems with urination or sexual performance

36 Prostate Fluid Fluid contains:  Citrate  for ATP production in Kreb's cycle  Proteolytic enzymes  liquefy coagulated semen after minutes in vagina  Acid phosphatase  function unknown  Seminal plasmin  antibiotic, destroys bacteria

37 Prostate Fluid Prostate secretions are alkaline to buffer:  residual urine which tends to be acidic  the acidity of the woman’s vagina

38 Bulbourethral Glands Cowper's gland  pea-size  posterior and lateral to membranous urethra

39 Bulbourethral Fluid bulbourethral fluid is secreted just before emission of the semen alkaline mucoid  neutralizes acid  coats and lubricates urethra prior to semen passage

40 Urethra conducts urine or sperm away from the body Urethra leads the length of the penis

41 Urethra conducts urine or sperm away from the body Urethra leads the length of the penis

42 Penis 3 cylindrical columns of erectile tissue In relaxed state the central arteries are constricted reducing inflow

43 Penis In excited state the central arteries dilate (PNS) blood fills the vascular channels causing an erection and compresses the veins reducing venous outflow

44 Arousal arteries become filled with blood from the arteries that supply them and the pressure seals off the veins that drain these areas causing an erection  necessary for insertion of the penis into the woman’s vagina

45 Glans Penis The head of the penis very sensitive to stimulation covered by the foreskin or prepuce

46 Circumcision Removal of prepuce Medically, circumcision is not a necessity  rather a cultural “tradition”

47 Circumcision Males who have not been circumcised need to keep the area between the glans and the prepuce clean Prevents microorganism growth on accumulated secretions

48 Circumcision evidence that uncircumcised males who do not keep the glans/prepuce area clean  slightly more prone to penile cancer

49 Ejaculation Ejaculation is a sympathetic reflex causing peristaltic waves  extending from the ductus deferens to the penis the bladder sphincter is closed

50 Male Sexual Development Genetic  XX chromosomes are female  XY are male, male determines offspring sex in humans

51 Male Sexual Development Before 6 weeks gonadal development is same for male and female At 6-7 weeks the SRY gene becomes active  Sex-determining Region of Y- chromosome

52 Male Sexual Development interstitial cells form and secrete testosterone  causes the gonads to differentiate into testes and form primary sexual characteristics

53 Testosterone Affects brain development Sexual behavior Sexual drive

54 Testosterone If no testosterone is secreted the gonads form ovaries  female is default

55 Puberty At puberty hypothalamus secretes GnRH  stimulates the anterior pituitary to secrete FSH  which stimulates the seminiferous tubule to develop and sperm production to occur

56 Puberty The anterior pituitary releases LH  which stimulates interstitial cells to secrete testosterone

57

58 Testosterone promotes skeletal and muscular growth increases BMR 5-10% responsible for secondary sexual characteristics  hair, voice, muscle essential for sperm production

59 Female Reproductive System

60 Female System Ovaries  About 2 inches long

61 Ovaries Medulla  central portion containing loose connective tissue, vessels and nerves

62 Ovaries Cortex  dense connective tissue and ovarian follicles

63 Ovaries Tunica albuginea  white fibrous connective tissue layer  outer surface layer of simple cuboidal epithelium

64 Oviducts Also called Fallopian tubes about 4 inches long Extends from ovary to uterus

65 Infundibulum fimbriated mouth near but not in direct contact with ovary produces local currents that sweep the ovulated oocyte into the uterine tube

66 Oviduct Mucosa inner layer of ciliated columnar epithelium and secretory cells with microvilli

67 Oviduct Muscularis 3 layers of smooth muscle produces peristaltic action that carries ova

68 Uterus thick, muscular walls The lining of the uterus is called the endometrium

69 Uterus has a rich capillary supply to bring food to any embryo that might implant there

70 Fundus portion above the uterine tube entrance

71 Body tapering central portion

72 Cervix The bottom end of the uterus is called the cervix

73 Cervix The cervix secretes mucus, the consistency of which varies with the stages in the menstrual cycle

74 Cervical Mucous At ovulation  this cervical mucus is clear, runny, and conducive to sperm Post-ovulation  the mucus gets thick and pasty to block sperm

75 Cervical Mucous If a woman becomes pregnant  the cervical mucus forms a plug to seal off the uterus and protect the developing baby

76 Cervical Mucous removal of cervical plug carries the risk of introducing pathogens into the nearly-sterile uterine environment

77 Myometrium thick muscular wall containing 3 layers of smooth muscle

78 Myometrium Contains arteries with radial branches to endometrium

79 Endometrium inner glandular epithelium and underlying connective tissue  Stratum basalis  Stratum functionalis

80 Stratum Basalis permanent layer gives rise to stratum functionalis each month supplied by branching arterioles

81 Stratum Functionalis temporary layer lost each month supplied by arterioles branching from the radial arteries

82 Vagina thin-walled fibromuscular tube leading from the cervix to the external genitalia  serves as a repository for sperm  serves as the birth canal

83 Vagina Acidic environment that reduces microbial growth  neutralized by alkaline semen

84 Vagina the openings of the vagina and urethra are susceptible to bacterial infections  if fecal bacteria are wiped towards them

85 Vagina parents who are toilet- training a toddler usually wipe her from back to front  thus “imprinting” that sensation as feeling “right” to her

86 Vagina little girls should be taught to wipe themselves from the front to the back  help prevent vaginal and bladder infections

87 Labia Minor 2 thin folds cover the separate vaginal and urethral openings unlike the male, the female has separate opening for the urinary tract and reproductive system

88 Clitoris at the anterior end of labia minor erectile tissue homologous to the penis  change shape when a female is sexually aroused contains many nerve endings in a sensitive glans covered by a prepuce

89 Clitoris This is the most sensitive point for female sexual stimulation Some cultures do a procedure, similar to circumcision  a puberty ritual in teenage girls in which the prepuce is cut  exposing the extremely- sensitive clitoris

90 Labia Major 2 outer thicker folds covered by pubic hair

91 Hymen a membrane that partially covers the opening of the vagina This is torn by the woman’s first sexual intercourse  or other causes like injury or vigorous physical activity

92 Hormonal Regulation of Female System Monthly Cycle

93 Female Sexual Development When fetal gonads differentiate into ovaries the oogonia are formed  these are not true eggs, yet, and will never complete meiosis and become such unless/until first fertilized by a sperm

94 Female Sexual Development mitotic proliferation of the oogonia is complete well before birth  About 2,000,000 oogonia per ovary Only several hundred of these “eggs” will actually be released during a woman’s reproductive years

95 Puberty By puberty the oogonia have developed into primary oocytes that undergo prophase I and are arrested Virtually no sexual hormone activity between birth and puberty

96 Puberty After puberty each month a group of primary oocytes are stimulated to reach metaphase II just prior to ovulation If sperm penetration occurs meiosis is completed

97 Oogenesis Production of active ova occurs monthly in ovarian cycle Primary oocyte is surrounded by a primordial follicle which grows and matures each month

98 Oogenesis Cytokinesis is unequal, secondary oocytes are haploid (1N)

99 Ovulation after the onset of puberty, due to the stimulation of follicle-stimulating hormone (FSH) one “egg” per cycle matures and is released from its ovary

100 Follicle a follicle consists of one precursor egg cell (oogonia) surrounded by special cells to nourish and protect it

101 Graffian Follicle a follicle consists of one precursor egg cell (oogonia) surrounded by special cells to nourish and protect it

102 Ovulation Ovulation is the release of a mature “egg” due to the stimulation of leutenizing hormone (LH)

103 Ovulation Leutenizing hormone (LH)  stimulates the remaining follicle cells to turn into a corpus luteum

104 Ovulation Corpus luteum  secretes progesterone to prepare the uterus for possible implantation

105 Corpus Luteum If an egg is not fertilized and does not implant, the corpus luteum disintegrates when it stops producing progesterone, the lining of the uterus breaks down and is shed

106 Menstrual Cycle

107 Estrogen Progesterone

108 Menstrual Cycle Estrogen Progesterone

109 Menstrual Cycle Estrogen Progesterone

110

111

112

113

114 Oviducts Each “egg” is released into the abdominal cavity near the opening of one of the oviducts or Fallopian tubes Cilia in the oviduct set up currents that draw the egg in

115 Feritilization If sperm are present in the oviduct the egg:  will be fertilized near the far end of the Fallopian tube

116 Feritilization After fertilization  the embryo will start to divide and grow as it travels to the uterus

117 Oviduct The trip down the Fallopian tube takes about a week as the cilia in the tube propel the unfertilized “egg” or the embryo down to the uterus

118 Progesterone progesterone secreted by the corpus luteum has been stimulating the endometrium to thicken  in preparation for possible implantation

119 Implantation when a growing embryo reaches the uterus it will implant in the endometrium and begin to secrete its own hormones to maintain the endometrium

120 Sloughing If the “egg” was not fertilized it dies and disintegrates as the corpus luteum also disintegrates, its progesterone production falls, and the unneeded, built-up endometrium is shed

121 Hormonal Regulation of Monthly Ovarian Cycle Day 1 Rising levels of GnRH stimulate release of FSH and production of LH by anterior pituitary FSH stimulates proliferation of granulosa cells and the follicle grows Granulosa cells secrete follicular fluid producing small fluid-filled cavities which merge to form the fluid-filled antrum Increasing numbers of granulosa cells release estrogens and inhibin 6-8 Inhibin and estrogen decrease GnRH release and FSH release Higher levels of estrogen stimulate production and release of LH (positive feedback) LH accelerates growth and maturation of follicle (1 dominant ovum) While follicle migrates to ovarian surface, estrogen level increases sharply causing a surge of LH and 1 follicle ruptures and releases ovum. Other follicles degenerate forming atretic follicles. Estrogen levels fall. 15 LH levels are elevated for 2 days, cause follicle cells to be filled with lipid and yellow pigment (luteinized) forming a corpus luteum. The corpus luteum secretes progesterones and estrogens which inhibit the hypothalamus production of GnRH and decrease FSH and LH levels 26 Corpus luteum degenerates and forms the corpus albicans if there is no pregnancy. Decreasing levels of progesterone and estrogen result in renewed production of GnRH

122 Hormonal Regulation of Monthly Ovarian Cycle Day 1 Rising levels of GnRH stimulate release of FSH and production of LH by anterior pituitary FSH stimulates proliferation of granulosa cells and the follicle grows Granulosa cells secrete follicular fluid producing small fluid-filled cavities which merge to form the fluid-filled antrum Increasing numbers of granulosa cells release estrogens and inhibin

123 Hormonal Regulation of Monthly Ovarian Cycle Day 6-8Inhibin and estrogen decrease GnRH release and FSH release Higher levels of estrogen stimulate production and release of LH (positive feedback) LH accelerates growth and maturation of follicle (1 dominant ovum)

124 Hormonal Regulation of Monthly Ovarian Cycle Day 12-14While follicle migrates to ovarian surface, estrogen level increases sharply causing a surge of LH and 1 follicle ruptures and releases ovum Other follicles degenerate forming atretic follicles Estrogen levels fall

125 Hormonal Regulation of Monthly Ovarian Cycle Day 15LH levels are elevated for 2 days Cause follicle cells to be filled with lipid and yellow pigment (luteinized) forming a corpus luteum The corpus luteum secretes progesterones and estrogens which inhibit the hypothalamus production of GnRH and decrease FSH and LH levels

126 Hormonal Regulation of Monthly Ovarian Cycle Day 26Corpus luteum degenerates and forms the corpus albicans if there is no pregnancy Decreasing levels of progesterone and estrogen result in renewed production of GnRH

127 Uterine Cycle Day 1 Menses: degeneration and loss of the functional layer. Decrease in progesterones and estrogens stimulates the release of prostaglandins which cause the spiral arterioles to constrict. O 2 and nutrient deprivation causes endometrial necrosis, desquamation and bleeding. Only the stratum basalis remains Proliferation: restoration of the functional layer. Follicular cells secrete increasing amounts of estrogen. Stratum basalis cells proliferate producing the s. functionalis. Short straight endometrial glands form, spiral arterioles regrow Secretion: increased growth and secretion prepares uterus for implantation. Levels of progesterones and estrogens produced by the corpus luteum increase. Glands enlarge, coil into corkscrew shapes and secrete glycogen. Vascularization of the s. functionalis increases If fertilization does not occur, the corpus luteum degenerates and progesterone and estrogen levels decline.

128 Uterine Cycle Day 1Menses: degeneration and loss of the functional layer Decrease in progesterones and estrogens stimulates the release of prostaglandins which cause the spiral arterioles to constrict O 2 and nutrient deprivation causes endometrial necrosis, desquamation and bleeding Only the stratum basalis remains

129 Uterine Cycle Day 5-14 Proliferation: restoration of the functional layer Follicular cells secrete increasing amounts of estrogen Stratum basalis cells proliferate producing the s. functionalis Short straight endometrial glands form, spiral arterioles regrow

130 Uterine Cycle Day Secretion: increased growth and secretion prepares uterus for implantation Levels of progesterones and estrogens produced by the corpus luteum increase Glands enlarge, coil into corkscrew shapes and secrete glycogen Vascularization of the stratum functionalis increases

131 Uterine Cycle Day If fertilization does not occur, the corpus luteum degenerates and progesterone and estrogen levels decline

132 End Reproduction


Download ppt "ADVANCED PHYSIOLOGY REPRODUCTION Instructor Terry Wiseth."

Similar presentations


Ads by Google