1. Reproduction
Chapter 43

2. Types of Reproduction
• Asexual
– No exchange of genetic material
– fission
• bacteria
• sea anemone
– Fragmentation w regeneration
• Sea star
• Mitosis

3. Fission

4. Fragmentation & Regeneration

5. Parthenogenesis

6. Asexual Reproduction
• Benefits
– Don’t need a mate
– Simpler
– Faster
– Less risk
– Energetically less costly
• Drawbacks
– No genetic variation

7. Sexual Reproduction
• Exchange genetic material
• 2+ individuals
• Meiosis & gametes required
• Most organisms
• Complex strategies

8. Sexual Reproduction
• Benefits
– Genetic variation
• Drawbacks
– need a mate
– More complex
– slower
– Energetically costly
– Risk of disease/ predation

9. Hermaphrodite
• 1 individual contains
both male and female
reproductive parts

17. Sexual reproduction terminology
• gonads
• gametogenesis
• Gametes
– Ovum
– sperm
• copulation
• Insemination
• fertilization
• zygote

18. fertilization
• External
– Limited to water
• Internal
– In or near female
reproductive parts
– Typically requires
copulatory organ
• Insemination vs
Fertilization

19. Reproduction System
• Reproductive organs
• Reproductive tract
• Accessory glands & organs

20. Reproductive Organs
• Gonads
• Function
– Produce sex cells- Gametes
– Produce hormones

21. Gamete Production
• Male
– Testes
• Spermatozoa (sperm)
– ~100-300 million/ day
– Ave 1000 per second
• Production begins at puberty
• Female
– Ovaries
• Oocyte (egg)
– 1/ month
• Production begins in embryo
– Cell division arrested in meiosis
– Division resumes at puberty

22. Spermatozoa

23. Oocyte

24. Reproductive Tract
• Ducts that receive, store, transport gametes
• Male
– Ducts are continuous with gonads
– Immune privileged
• Female
– Ducts are discontinuous with gonads

25. Female Reproductive
• Gonads
– Paired ovaries
• Reproductive tract
– Oviduct
• Aka Uterine tubes
• Aka Fallopian tubes
– Uterus
– Vagina
• Accessory glands
– Mammary
– Greater vestibular
– Paraurethral

26. Ovaries
• Gonads
– Paired ovaries
• Located in female pelvis
• Function
– Oogenesis- oocyte production
• Begins in fetus (10-30 weeks after conception)
• At birth 2 Million immature ova
– Arrested at prophase I (Diploid)
– At sexual maturity (200,000 per)
– Hormone production

27. Female reproductive cycle
• Ovarian cycle
– Growth & release of ovum
• Menstrual cycle
– Preparation for embryo implantation
• Hormone regulated
http://www.sumanasinc.com/webcontent/animations/content/

29. ovulation
• Ejection of ovum from ovary
– Stimulated by hormones
– 1 per 28 days
– Stimulated by Brain (lH)
• Alternate between ovaries
• Released into oviduct
– New cycle in opposite ovary

30. Female Reproductive Tract

31. Oviduct • Oviduct extends from
ovaries to uterus
• Ovaries are not directly
connected to tube
• Function
– Draw ovulated oocyte
into tube
– Transports egg to uterus
• Cilia
• Smooth muscle
– Site of fertilization

32. Site of Fertilization

33. http://www.youtube.com/watch?v=hAgOk3-loUY&NR=1

34. Ectopic Pregnancy

35. Tubal Ligation

36. Uterus
• Site of implantation
• Made of muscle & lined
with special blood
engorged tissue
• Will form placenta if
egg fertilized

37. Cervix
• Regulates entrance to
uterus
• Protects upper
reproductive tract

38. Cervical Mucus
• Protects upper
reproductive tract from
pathogens
• Fertile mucus
– Spinn
• Thins during ovulation

39. Endometrium
• Specialized lining
• Thickens in response to
estrogen & progesterone
produced by ovary
(Corpus Luteum)

41. Human Chorionic Gonadotropin
• hCG
• Produced by developing
placenta
• Keeps Corpus Luteum
actively secreting
Progesterone maintaining
endometrium
• May cause morning sickness

42. Pregnancy Test
• Measure hCG

43. Lining tissue will fuse with embryo
tissue to form placenta

44. Menstruation replaces the endometrial
lining
Stimulated by a drop in estrogen & progesterone

45. Cervix Dilates During Childbirth
• Blocks pathogens from
entering uterus during
pregnancy
• Expelled as cervix starts
to dialate

46. Hormonal Birth Control
• Synthetic estrogen &
progesterone
• Prevent ovulation
– Inhibit follicle
development
• Cause thickening of
cervical mucus
• Pill, patch, NuvaRing

47. Vagina
• Elastic muscular 3-4” tube extending
from the cervix to the exterior
• Hymen
– Epithelial fold at entrance into vagina
• Protective mucus
– Alkali mucus neutralizes acidic pH
– Transudate
• Symbiotic Bacteria
– Lactobacilli
• Rugae
• Function
– Passage for menstrual substances
– Copulatory structure & sperm receptacle
– Birth canal

48. Vagina structure allows Expansion

49. External Genitalia
• Referred to as pudendum “shameful”
• Mons pubis
– Thick adipose pad covering & cushioning bone
• Labia majora
– Outer folds of skin
– Covered w/ pubic hair
– Contain glands associated with hair
• Labia minora
– Inner folds of skin
– Devoid of pubic hair
• Clitoris
– Cylindrical mass of erectile tissue
– Anterior union of labia minora

50. Accessory Glands
• Aid in reproduction &
sexual reproduction

51. Mammary Gland
• Secondary sexual
characteristic
• Produces nutrients and
passive immune system
• Produce 2 types of milk
– Collostrum
– Mature Milk

52. Paraurethral Gland
• Grafenberg
• Female homologous to
prostate
• Secretes during sexual
arousal/ climax

53. Reproduction System
• Reproductive organs
• Reproductive tract
• Accessory glands & organs

54. Male Reproductive System
• Reproductive organs
– Testis
– Scrotum
• Reproductive tract
– Epididymis
– Vas Deferens
– Spermatic cord
• Accessory glands & organs
– Seminal vesicles
– Prostate gland
– Bulbourethral gland
– Penis

55. Testis
• Paired gonads inside of
scrotum
• Function
– Spermatogenesis- sperm
formation
– Hormone production
• Androgens- testosterone

56. Gamete Production
• Testes
– Spermatozoa (sperm)
– ~100-300 million/ day
– Production begins at puberty
• Spermatogenesis- VERY temperature sensitive
• Optimal temperature ~3-4C below body temp

57. Pendulous Testes

58. Scrotum • Bi-chambered external pouch of skin
• Function
– Houses testes
– Protects testes
– Regulates testicular temperature
• Scrotum modifications for temperature
regulation & protection
– Pendulous- external
– Low insulation
– Sweat glands
– Blood vessels- countercurrent blood
flow
– Muscles
– Nerves

59. Low Insulation
• Little insulating fat
• Sparce hair
• Sweat glands

60. Muscles
• Contraction pulls testis closer to
body
– Cold- contraction
– Warm- relaxation

61. Blood Vessels
• Countercurrent blood flow
• Cool venous blood surrounds
incoming arteries
• Actively cools incoming blood &
warms outgoing blood
– Testes always surrounded by cool
blood
Testes

62. Scrotum Nerves
• Behavioral protection

63. Testis Structure
• Seminiferous tubules
– Contain Sertoli cells
• Interstitial (Leydig) cells

64. Seminiferous Tubules
• Actual site of spermatogenesis
• 800+ coiled tubes
– Maximizes surface area
• Bulk of testes tissue

65. Spermatogonia undergo meiosis to
produce sperm

66. Sperm in Seminiferous tubules

67. Sertoli Cells
• Form blood testes
barrier
• Protects from
pathogens, mutagens,
immune cells

68. Testes also produce Male Hormones

71. Testosterone Levels

72. Testosterone Levels

73. Testosterone Levels

74. Sperm Path
Male reproductive tract continuous- Isolates sperm

75. Epididymis
• Single coiled tubule
– 6M long
• Function
– Secretes/absorbs nourishing fluid
– Recycles damaged spermatozoa
– Stores spermatozoa
• Up to 2 weeks
• Allows time for maturation

76. Vas Deferens
• Aka Ductus Deferens
• Single tubule carries sperm
from epididymis into
abdominal cavity
– 45 cm long
• Muscular tube
• Passes thru inguinal canal
• Connects to urethra at
prostate

77. Accessory Glands
• Seminal vesicle
• Prostate
• Bulbourethral gland
• Secrete seminal fluid
– Nourish, activate & protect sperm
• Semen (seed)
– Glandular secretions (99%) & sperm
(1%)
– ~2-5 mls per ejaculation
– ~50-200 million sperm per ml of
ejaculate
• 100-700 million per ejaculation
• 50 reach egg

78. Seminal Vesicle
• Paired glands behind bladder
• Secretes (50-70% semen)
– Fructose
• “sugar”
• Energy source
– Prostaglandins
• Activate sperm motility
• Stimulate contractions of female
reproductive tract
– Fibrinogen
• Clotting factors
• Slows sperm
– Vitamin C

79. Prostate
• Large solid single gland
• Located at base of bladder
• Houses prostatic urethra
• Secretes (20-30%)
– Enzymes
• Aid in activating sperm motility
• Antibiotic
• Mucus degradation
– Alkaline fluid
• Neutralize female reproductive tract
– Citric acid, proteolytic enzymes
– Antioxidants
– ???secretions of unknown function

80. Prostate Cancer • Most common cancer in men
– 3rd most common cause of death in men
• Disease of well developed nations
• Diet & lifestyle
– High fat diet
– High testosterone levels
– Cadmium exposure
– Low rates in Japanese & vegetarians
• By age 80 70% men will have it

81. Bulbourethral Gland
• Small paired gland
• Located at the base of the
penis
• Secretes alkaline mucus
– Neutralize urinary acids
– Lubrication
– “pre-cum”

82. Penis
• Copulatory & excretory organ
• Excretory
– Penile urethra
– Carries urine & sperm
• Copulatory
– 3 cylindrical masses or erectile
tissue
– 2 corpora cavernosa (rt & lt)
– Corpus spongiosum

83. Corpora Cavernosa
• Right & left
• Primary erectile tissue
• Paired superior masses
• Provides the majority of rigidity
& length
– Pulls urethra taught by pushing
glans
• Crus
– posterior expansions
– “anchor” tissue against pelvic bone

84. Corpora Spongiosum
• Secondary erectile tissue
• Contains Penile urethra
• Glans
– Anterior expansion
• Prepuce
– Folds of skin covering glans

85. Erectile Tissue
• Muscle holds chambers
closed
• Relaxation of muscles
opens chambers
• Blood vessels open
• Chambers become
blood filled to result in
erection

86. Rich Blood Supply

87. Viagra
• Dilates blood vessels

88. Viagra Health Risks
• Effects blood flow
– Lowers blood pressure
– Heart attack
• Effects color vision
• Opens arteries in brain
• Addiction

89. Cold Shower

90. Prepuce
• Foreskin
• Protects
• Produces smegma
– Waxy substance