Reproductive System notes for 410Berry A&P course - NPHS

1. The Reproductive System

2. The Reproductive System
• Primary sex organs
▫ Testes
▫ Ovaries
• Accessory sex organs
▫ Glands
▫ External genitalia

3. The Male Reproductive System

4. The Male Reproductive System
• The scrotum
▫ Skin and superficial fascia surrounding the testes
▫ Positioning provides an environment 3˚ cooler
than body temperature

5. The Male Reproductive System

6. The Scrotum – Containing the Testes
and Spermatic Cord

7. The Testes
• Epididymis
▫ Comma-shaped structure on posterior testis
▫ Duct of the epididymis is 6m long (when uncoiled)
▫ 20-day journey for sperm to move through

8. Spermatogenic Cells
• Spermatogenesis
▫ Sperm formation
 400 million sperm formed per day
▫ Begins at puberty
▫ Process takes 75 days

9. The Epididymis

10. The Urethra
• Carries sperm from ejaculatory ducts to
“outside”

11. Accessory Glands
• The seminal vesicles
▫ Lie on the posterior surface of the urinary bladder
▫ Secretes about 60% of the volume of semen
 Fluid contains
 Fructose to nourish sperm
 Substances to enhance sperm motility
 Prostaglandins
 Substances that suppress immune response
against semen
 Enzymes that clot and then liquefy semen

12. Accessory Glands
• The prostate gland
▫ Encircles the prostatic urethra
▫ Consists of 20 – 30 glands
▫ Secretes about 25 – 30% of seminal fluid
▫ Contains substances that
 Enhance sperm motility
 Enzymes that clot and then liquefy semen

13. Accessory Glands
Figure 24.9a, b

14. Accessory Glands
• The bulbourethral glands
▫ Pea-sized glands inferior to the prostate gland
▫ Produce a mucus
 Neutralizes traces of acidic urine
 Lubricates urethra

15. The Penis
• External anatomy
▫ Shaft – body
▫ Glans penis – distal expanded end
▫ Prepuce – foreskin
 Removed during circumcision
• Internal Anatomy
▫ Three erectile bodies

16. The Female Reproductive
System

17. The Female Reproductive System
• Produces gametes (ova)
• Prepares to support a developing embryo
• Undergoes changes according to the menstrual
cycle

18. Female Internal Reproductive Organs

19. The Female Reproductive System

20. The Ovaries
• Small, almond-shaped organs
▫ Produce ova
• Held in place by ligaments and mesenteries

21. Internal Structure of the Ovaries
• Ovarian cortex – houses developing oocytes
• Follicles – multicellular sacs housing oocytes

22. Structure of the Ovary

23. The Ovarian Cycle
• Follicular phase
▫ Days 1 – 13 of the ovarian cycle
▫ 6 – 12 follicles stimulated to develop
▫ Growth stimulated by FSH from anterior pituitary

25. The Ovarian Cycle
• Ovulation
▫ Occurs about halfway through each ovarian cycle
(Day 14)
▫ One mature oocyte exits from one ovary
 Swept into uterine tube
▫ Sudden increase in LH is signal for ovulation

27. The Ovarian Cycle
• Luteal phase
▫ Occurs after ovulation – days 15 – 28
▫ Remaining follicle becomes a corpus luteum
 Secretes progesterone
 Acts to prepare for implantation of an embryo
▫ If no implantation
 Corupus luteum dies

29. The Uterus
• Lies anterior to rectum – posterior to bladder
• Parts of the uterus
▫ Fundus – rounded superior portion
▫ Cervix – “neck” of uterus

30. The Uterine Cycle
• Series of cyclic phases of the endometrium
• Phases coordinate with the ovarian cycle
• Endometrial phases directed by FSH and LH
• Phases of uterine cycle
▫ Menstrual phase – days 1 – 5
 Stratum functionalis is shed
▫ Proliferative phase – days 6 – 14
▫ Secretory phase – days 15 – 28

32. Deep Structures of the External Genitalia
and Female Perineum

33. The Mammary Glands
• Breasts – modified sweat glands
▫ Glandular structure – undeveloped in
non-pregnant women
▫ Milk production – starts at or after childbirth

34. The Mammary Glands
Figure 24.21a, b

35. Conception & Pregnancy

36. Pregnancy
• Events leading to fertilization
▫ Fusion of oocyte and sperm plasma
membranes
▫ Cortical reaction
 Enzymes prevent any other sperm from binding
to the egg
▫ Fertilization – chromosomes of male and
female gametes join

37. Events Leading to Fertilization

38. Implantation
• Blastocyst begins implantation
▫ About six days after conception

39. Implantation

40. Implantation

41. Formation of the Placenta
• Embryonic and maternal tissues contribute to
the placenta

42. Anatomy of the Placenta
• Exchanges across the chorionic villi between
maternal and fetal blood
▫ Provide fetus with nutrients and oxygen
▫ Dispose of its wastes
▫ Allow hormonal signals to be sent to the mother
• By week 13 the placenta is fully formed

43. Anatomy of the Placenta

44. Anatomy of the Placenta
• Sugars, fats, and oxygen diffuse from mother
to fetus
• Urea and carbon dioxide diffuse from fetus to
mother
• Syncytiotrophoblast – secretes substances
that regulate events of pregnancy
• Maternal antibodies transported across
placenta
• Viruses, alcohol, and heroin cross the
placental barrier

45. Childbirth
• Parturition – 266 days after fertilization
• Labor – events that expel the infant from the
uterus

46. Childbirth

47. Homeostatic Imbalances

49. • Undescended testes:
▫ Cryptorchidism
▫ The most common genital abnormality in boys
▫ Caused when the testicles do not drop into the
scrotum shortly before birth
▫ Usually corrects itself, although may require
surgery is it doesn’t
▫ Can cause problems with fertility
▫ Can occur in women

50. • Inguinal hernia:
▫ A rupture in the abdominal fascia, allows the
intestines to protrude into the inguinal cavity
▫ The intestines cause a great deal of pressure in the
groin
▫ Can be very painful
▫ Severe hernias require surgery

51. 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

52. Reproductive System Cancers in Males
• Prostate cancer
▫ Slow-growing – arises from peripheral glands
▫ Risk factors
 Fatty diet
 Genetic predisposition

54. • Yeast infection:
▫ A vaginal yeast infection is irritation of the vagina
and the area around it
▫ Yeast infections are caused by overgrowth of the
fungus Candida albicans.
▫ Small amounts of yeast are always in the vagina,
but when too much yeast grows, you can get an
infection
▫ Yeast infections are very common
▫ About 75 percent of women have one during their
lives

55. • Ovarian cysts:
▫ A cyst is a fluid-filled sac
▫ Many ovarian cysts don't cause symptoms. Others
can cause:
 Pressure, swelling, or pain in the abdomen
 Pelvic pain
 Dull ache in the lower back and thighs
 Problems passing urine completely
 Pain during your period
 Abnormal bleeding
 Nausea or vomiting

56. 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

57. 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

58. Puberty

59. 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

60. 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

61. 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

62. Menopause

63. 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