The Reproductive System

1
The Reproductive System
2
Reproduction

• Primary function to produce offspring
• genetic material passed from generation to
  generation
• Sharing intimate feelings with another person

3
Some terms to know

• Gonads the organs in the body that produce the
  sex cells (GAMETES)
• Male testes --gt Sperm
• Female ovaries --gt Ova or Egg cells
• Ducts transport and secrete
• Glands secrete

4
Testes

• Paired organs located inside the scrotum
• Located outside the body to ensure proper temp
  for sperm production

5
Function of the testes

• Produce and mature sperm
• maturation of sperm takes approximately 74 days
• Protect sperm and sperm development--Sertoli
  cells
• Produce testosterone Leydig cells

6
Functions of Testosterone

• the principle male hormone
• produced by Cells of Leydig
• responsible for the male secondary sexual
  characteristics
• growth and development
• maintenance of sex organs
• bone growth
• influences sexual behavior
• influences final maturation of sperm cells

7
Seminiferous Tubules

• tightly coiled tubules in testes
• Spermatogenesis occurs
• Spermatogonia immature Sperm Cell
• Spermatozoa mature Sperm Cell
• Interstitial Cells (Cells of Leydig) endocrine
  cells produce and secrete testosterone

8
Epididymis

• 7 m long
• Head - superior, receives spermatozoa
• Body
• Tail - leads to ductus deferens

9
Epididymis

• Functions
• 1) Monitors and adjusts tubular fluid
• 2) Recycles damaged spermatozoa
• 3) Stores sperm and facilitates maturation

10
Ductus (Vas) Deferens

• long duct (18 inches) passageway for sperm from
  epididymis to urethra
• enters the body through the pelvic floor called
  the Inguinal Canal

11
Ejaculatory Ducts

• union of seminal vesicles and the ductus
  (vas)deferens
• eject sperm into the prostatic urethra prior to
  ejaculation

12
Urethra

• passageway for sperm and urine to the external
  environment
• measures about 8 inches in length
• 4 sections of the Urethra

13
Urethra
1. prostatic urethra 2. Membranous urethra
1
3. spongy urethra
2
3
14
Urethra
4
4. external urethral orifice
15
Accessory Male Sex Glands

• secrete most of the liquid portion of Semen
• provides a liquid, nutrious medium for the
  support of sperm cells

16
Seminal Vesicles

• Paired, on posterior wall of urinary bladder
• Tubular ( 15 cm)
• Produce 60 of semen, hormones, fructose, etc.
• Activate sperm (leading to motility)

17
Prostate Gland

• about the size of a chestnut located inferior to
  the urinary bladder - surrounds the urethra
• secretes a fluid rich in citric acid, prostatic
  acid, phosphatase, and prostaglandins
• makes up about 13 - of the semen
• often site of cancerous growth in males

18
Bulbourethral Glands (Cowpers Glands)

• Pea size, paired, at base of penis
• Produce about 10 of semen
• Alkaline mucus -neutralize acidic nature of
  female vagina

19
Semen (Seminal Fluid)

• mixture of sperm and secretions of accessory
  glands
• 2.5 - 5.0 ml of semen per ejaculation (1/2 tsp)
• 300-500 million sperm per ejaculation
• if less than 100 million sperm-- male is
  considered infertile

20
MALE EXTERNAL GENITALIA
21
SCROTUM

• supports and protects testes
• continuation of abdominal wall skin
• Separated by a structure called the raphe

22
SCROTUM

• Dartos muscle in dermis
• Cremaster muscle - continuous with abdominal
  wall muscles
• Involuntary contraction in response to TEMP
  changes
• Temp must be 2-3o Lower than body temp

23
Penis

• used to introduce sperm into the female vagina
  during intercourse
• Voids urine (urination)
• cylindrical in shape

24
Three parts of penis

• Body 3 cylindrical masses of tissue
• Corpora Cavernosa Penis ( 2)
• Corpus Spongiosum Penis
• Made of erectile tissue filled with blood sinuses

25
Penis (cont)

• Root--portion attached to pubic area
• Bulb--attached to abdominal wall
• Crus--Attached to muscles that aid in erection

26
Glans penis

• Slightly enlarged portion of the corpus
  spongiosum
• Separated from body by corona
• Contains many nerve endings
• Uncircumcised glans contains prepuce or foreskin

27
Penis erection

• With sexual stimulation, arteries dilate, veins
  constrict, large quantities of blood enter
  sinuses and an erection occurs
• Erections occur also to maintain health of penis

28
End of male REPRODUCTIVE System

• QUESTIONS?

29
FEMALE REPRODUCTIVE SYSTEM
30
Ovaries

• the female gonads
• oogenesis occurs
• females are born with all egg cells as they will
  ever have (500,000)

31
Oogenesis

• Maturing of an oocyte (egg)
• Begins with primary follicles, ends with
  secondary ooctye
• other primary follicles donate material to
  developing egg

32
Ovarian follicles

• each month about 20 primary oocytes are
  stimulated to undergo meiosis
• usually only one of these 20 completes the
  process of oogenesis develops into a secondary
  oocyte

33
Graffian Follicle

• Oocyte continues to mature before released by
  ovary during ovulation
• Contains two parts
• Antrum and oocyte
• Secretes estrogen

34
Ovulation

• Process where secondary oocyte is released from
  ovary
• About day 14 of cycle

35
Corpus Luteum and Corpus Albicans

• Glandular body that develops after release of egg
• Secretes progesterone, estrogen, relaxin, inhibin
• Becomes corpus albicans if egg is NOT fertilized
• Stays in tact during pregnancy

36
Uterine (Fallopian) Tubes

• ducts transport ova from site of ovulation to
  uterus
• Infundibulum funnel shaped, open distal end
• Fimbriae little fingers on distal end

37
Uterine (Fallopian) Tubes

• Ampulla widest, longest portion of the uterine
  tubes
• fertilization usually occurs in this region
• Isthmus narrow, constricted, proximal end where
  the tubes attach to the uterus

38
Uterus

• serves as the site of menstruation, implantation
  of a fertilized ovum, and development and
  maintenance of fetus during pregnancy
• inverted pear shaped muscular organ
• has 3 sections or areas
• Fundus
• Body
• Cervix

39
Tissue Layers of the Uterus

• 3 tissue layers
• Perimetrium outermost layer
• Myometrium middle, muscular layer
• majority of the uterus
• consists of three layers of smooth muscle
• Endometrium innermost layer of the uterus
• Made of stratum functionalis and stratum basalis

40
Vagina

• tubular fibromuscular organ lined with mucous
  membrane
• passageway for sperm menstrual flow
• receptacle for penis during sexual intercourse
• lower portion of birth canal

41
FEMALE EXTERNAL GENITALIA
42
Female External Genitalia

• Vulva term used to describe female external
  genitalia
• Mons Pubis adipose tissue above the pubic
  symphysis, covered by skin and coarse pubic hair
• Labia Majora an area of longitudinal folds of
  tissue
• Labia Minora medial longitudinal folds of
  tissue

43
Female External Genitalia (cont)

• Vestibule the space between the Labia Minora
• Bulb of vestibule contain
• Greater Vestibular Glands (Bartholins)
• produce mucoid substance
• Provide lubrication for sexual intercourse

44
Female External Genitalia (cont)

• Clitoris small cylyndrical mass of nervous and
  erectile tissue
• Prepuce layer of skin from labia minora covers
  clitoris
• Hymen thin membrane partially covering the vagina

45
Mammary Glands (Breasts)

• modified sudoriferous glands (Sweat Glands)
• each gland contains 15 - 20 lobes or compartments
  separated by adipose tissue
• amount of adipose tissue between lobes determines
  breast size
• breast size is not related to milk production

46
Mammary Glands (Breasts)

• each lobe has compartments called lobules
• Inside lobules are milk secreting cells
• Nipple the raised area on the breast that an
  infant suckles to receive milk and stimulate
  lactation
• Areola the dark, circular, pigmented area that
  encircles the nipple

47
Lactation

• the process of milk production, secretion, and
  ejection

48
Menstrual and Ovarian Cycles

• Ovarian Cycle maturation and ovulation of an
  ovum
• Menstrual Cycle changes of the endometrial
  lining of the uterus
• preparation for implantation of a fertilized ovum
• correlated with each other and are under the
  influence of hormones

49
(No Transcript)
50
Endocrine influence

• Hypothalamus stimulates pituitary FSH and LH
• FSH ovarian follicles
• LH ovulation--stimulates production of estrogen,
  progesterone and relaxin
• Ovaries produce estrogen and progesterone

51
Estrogen

• 6 different types
• development and maintenance of the female
  reproductive system
• helps control fluid and electrolyte balance
• Keeps heart strong
• Keeps bones strong

52
Progesterone

• hormone of maturation
• prepares the endometrial lining for implantation
• stimulates milk production and secretion
• Drop in progesterone starts menstrual cycle

53
Relaxin and Inhibin

• Relaxin produced by the corpus luteum during
  pregnancy
• Relaxin most prominent during the final
  trimester of pregnancy
• relaxes the pubic symphysis and helps dilate the
  cervix
• Inhibin is the negative feedback hormone for
  estrogen and progesterone

54
DEVELOPMENTandINHERITANCE
55
HUMAN DEVLOPMENT

• The continuous process of body changes
• Begins at fertilization
• Continues until death
• Two periods
• Prenatal Conception until birth
• Postnatal birth until death

56
Spermatogenesis vs. Oogenesis

• Spermatogenesis production maturation of sperm
• Oogenesis production maturation of egg

57
Prenatal Development

• changes that occur prior to Birth
• Divided into Two Periods
• The Embryonic Period
• fertilization until eight weeks
• The Fetal Period
• eight weeks until birth

58
(No Transcript)
59
Fertilization

• also called Conception
• union of sperm oocyte
• one sperm cell penetrates layers of the egg
• aided by enzyme on head of sperm
• oocyte cell membrane changes biochemically

60
The Embryonic Period

• first 8 weeks of life
• fertilized egg called Zygote
• first cell divisions of Zygote are called
• CLEAVAGE --result in ball of cells called
  Morula
• Morula turns into a large mass of cells called
  Blastocyst

61
Blastocyst Stages of Development

• Implantation attachment of the Blastocyst to
  the endometrium
• about 6 days after fertilization
• Blastocyst differentiates into primary Germ
  Layers (Endoderm, Mesoderm,
  Ectoderm)

62
Trophoblast Development and Implantation

• Becomes Trophoblast-- layers form (Chorion,
  Amnion, and Yolk Sac) begin to form around the
  embryo
• Called pregnancy when implanted

63
Embryonic Period

• 5 weeks after conception
• Bones begin to form, major blood vessels form
• other systems form
• Heart forms starts to beat
• Nervous system forms

64
Embryonic Development

• Development of Body Form
• weeks three to eight
• the embryo resembles a human like figure
• Development of Organs
• most major organs appear during the first eight
  weeks of development

65
Embryonic Period

• 8 weeks
• Resembles a human and is called a FETUSLatin
  word for OFFSPRING

66
Fetal Development

• 18 weeks
• Face looks human
• Joints form
• Bones ossify
• Rapid development of body organs

67
Fetal Development

• Can recognize sounds
• Urine forms

68
Fetal Development

• 18 weeks
• Rapid development of body organs

69
Fetal Development

• 20 weeks
• Lanugo appears-protects fetus from waste in
  amniotic fluid
• Fetal movements felt by mother
• Hair appears on head

70
Fetal Development

• 20 weeks

71
Fetal Development

• 24 weeks
• Sense of taste develops, lungs are ready to
  produce surfactant
• Substantial weight gain
• Eyelashs form
• Can survive outside womb (viable)

72
Fetal Development

• 30 weeks
• Head and body more proportionate
• In male, testes descend
• Fetus assumes upside down position
• Subcutaneous fat deposited

73
Fetal Development

• 40 weeks
• Additional subcutaneous fat accumulates
• Lungs secrete oxytocin
• Lanugo is shed
• Fetus is full term
• Is ready at 38 weeks

74
Fetal Development
75
Labor

• movement of the fetus through birth canal in
  response to uterine contractions
• Three Stages of Labor
• Stage One dilation effacement
• contractions push fetus against cervix
• amniotic sac ruptures
• cervix dilates
• Once cervix dilates to 10 cm Stage Two begins

76
Fetal Development

• Stage Two delivery and birth
• Stage Three expulsion of the placenta

77
Stages of Physical Development

• Neonate - newborn
• Infancy
• Toddlerhood
• Childhood
• Adolescence puberty
• Adulthood
• Middle Age
• Advanced Age