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3. Reproductive Physiology
 The gonads are endocrine glands whose
functions are:-
1. Gametogenesis (the production of germ cells)
2. Secretion of sex hormones
 Reproductive Physiology includes:-
 Male Reproductive Physiology
 Female Reproductive Physiology

4. Male Reproductive
Physiology

5. Contents
 Physiologic Anatomy of the Male Sexual
Organs
 STRUCTURE OF THE TESTES
 SPERMATOGENESIS
 FUNCTION OF SEX ACCESSORY GLANDS
 Testosterone
 REGULATION OF THE TESTES

6. epididymis
vas deferens
prostate gland
testes
seminiferous tubules
Cowper glands ejaculatory ducts
seminal vesicles

7. STRUCTURE OF THE TESTES
 The male gonads are the testes
 the testes have two functions:
 spermatogenesis
 secretion of testosterone

8. STRUCTURE OF THE TESTES
 The testes occupy the scrotum
 Scrotum lies outside the body cavity
 Scrotum is maintained at 35° to 36°C
 This lower temperature, essential for normal
spermatogenesis
 This lower temperature is maintained by a
countercurrent exchange heat mechanism

9. testis
Sertoli
cells
Leydig
cells
STRUCTURE OF THE TESTES

10. Sertoli cells
 The Sertoli cells lining the seminiferous tubules
 Sertoli cells, which support the developing sperm
 Sertoli cells have three important functions that
support spermatogenesis:-
1. Provide nutrients to the differentiating sperm
2. creating blood-testes barrier
3. Secrete an aqueous fluid into the lumen of the
seminiferous tubules (help to transport sperm into
the epididymis.)

11. seminiferous tubules

12. Sertoli cells
Leydig cells
Lumen (seminiferous tubules)

13. Leydig cells
 interstitial cells of Leydig
 Are Located Between the tubules in the testes
 Leydig cells is synthesis and secretion of
testosterone

14. SPERMATOGENESIS
 Location:-
 Spermatogenesis occurs along the length of the seminiferous
tubules
 Phases:-
 (1) Mitotic divisions of spermatogonia generate the
spermatocytes
 (2) meiotic divisions of the spermatocytes, which decrease the
chromosome number and produce haploid spermatids
 (3) spermiogenesis, in which spermatids are transformed into
mature sperm
 Period (spermatogenesis)
 requires about 74 days

15. spermatogonia
primary spermatocytes
Mitotic divisions
secondary spermatocytes
spermatids
meiotic division II
meiotic division I
spermatozoa.
differentiate

16. Hormonal Factors That Stimulate
Spermatogenesis
 Testosterone:- secreted by the Leydig cells is
essential for growth and division of the
testicular germinal cells
 Luteinizing hormone, stimulates the Leydig
cells to secrete testosterone
 Follicle-stimulating hormone, stimulates the
Sertoli cells; for the conversion of the
spermatids to sperm

17. spermatogonia
primary spermatocytes
Mitotic divisions
secondary spermatocytes
spermatids
meiotic division II
meiotic division I
spermatozoa.
differentiate
Testosterone
FSH
LH
Leydig cells

18. single spermatogonium
512 spermatids

19. acrosome

20. FUNCTION OF SEX ACCESSORY GLAN
 Epididymis
 the primary location for the maturation , acquire
motility and storage of sperm.
 The ampulla of the vas deferens
 storage area for sperm
 Nourishes (citrate and fructose) the ejaculated sperm
 seminal vesicles
 Nutritive (citrate and fructose) for the ejaculated
sperm
 Secrete prostaglandins and fibrinogen

21.  Prostaglandins are believed to aid fertilization
in two ways:-
 (1) Prostaglandins react with cervical mucus to
make it more penetrable by sperm
 (2) prostaglandins induce peristaltic
contractions in the female reproductive tract
FUNCTION OF SEX ACCESSORY GLAN

22.  prostate gland
 milky aqueous solution rich in citrate, calcium,
and enzymes
 Alkaline secretion:
 neutralizing acidic secretions from the vas
deferens and the vagina
FUNCTION OF SEX ACCESSORY GLAN

23. FUNCTION OF SEX ACCESSORY GLAN
semen
Secretions (90%)
male sex accessory
glands
sperm (10%)

24. Testosterone
 synthesis and secretion of testosterone
 Testosterone is synthesized and secreted by the
Leydig cells of the testes
 Chemistry of the Testosterone
 Steroid hormone
 Functions of Testosterone
 male secondary sex characteristics (endocrine effect)
 exert an important protein-anabolic (endocrine effect)
 (Testosterone + FSH) maintain spermatogenesis
(paracrine effect)

25. Dihydrotestosterone (DHT)
 Testosterone is converted to dihydrotestosterone
(DHT) by 5α reductase
 DHT formation is a way of amplifying the action of
testosterone in target tissues.
 Humans have two 5α reductase:-
 Type 1 5α reductase is present in skin throughout the
body and is the dominant enzyme in the scalp.
 Type 2 5α reductase is present in genital skin, the
prostate

26. REGULATION OF THE TESTES
FSH anterior lobe
Hypothalamus
GnRH
Leydig cells Sertoli cells
Inhibins
LH
testosterone
paracrine effects
Endocrine
effects
target organs

28. The Female Reproductive
System

29. The Female Reproductive System
 Physiologic Anatomy of the Female Sexual
Organs
 OOGENESIS
 Menstrual cycle
 ACTIONS OF ESTROGEN AND
PROGESTERONE

30. Physiologic Anatomy of the Female Sexual Organs
 The principal organs of the human female
reproductive tract, including the
 ovaries
 fallopian tubes
 Uterus
 vagina

31. 2 million ova
7 million ova
fetal life
Birth
childhood
1 million ova
puberty
>300,000 ova
> 500 Ova
Ovum per cycle
OOGENESIS
first meiotic division
primary oocytes
first meiotic division
( completed)
secondary oocyte

32. Menstrual cycle
 The menstrual cycle is a term used to describe
the monthly cycle of physiological events
which prepare the female for pregnancy
 The cycle ends in menstruation if pregnancy
dose not occur
 Duration-----(28 days)
 Average-------(21- 35 day)

33. menses
5
0 14
Progesterone
LH
Estrogens
28
endometrium increases
FSH
Follicular phase
FSH
Ovulatory phase luteal phase
–ve feedback

34.  The menstrual cycle in the female is cyclic
change that occur in the:-
 Ovaries (= ovarian cycle)
 Uterus (= uterine cycle)
 Other organs (e.g. cervix, vagina and breast)
Menstrual cycle

35. ovarian cycle
 Ovarian cycle may be divided into three
phases:-
1. Follicular phase
2. Ovulatory phase
3. Luteal phase

36.  Duration
 The onset of menses from the previous cycle until day 14 (0 ---
14) day
 Events of Follicular phase is mediated by FSH
 primordial follicle develops (growth) into a graafian follicle
 neighboring follicles become atretic
 remaining follicle is called the dominant follicle
 The follicular phase is dominated by estrogen
 Estrogen is secreted from theca and granulosa layers which
surrounded ovum
 estrogen inhibits FSH and LH secretion by the anterior
pituitary by negative feedback
Follicular phase

37. Ovulatory phase
 Ovulation occurs in midcycle
 Events of Ovulatory phase:-
 Increase of estrogen level towards midcycle exerts a
positive feedback on LH and FSH
 This positive feedback is called the FSH and LH surge
 The LH surge then causes ovulation of the mature
ovum:- distended follicle ruptures, and the ovum is
shed
 The ovum is picked up by the fimbriated ends of the
uterine tubes

38. Luteal phase
 Duration
 After ovulation and ending with the onset of menses
 Events of Ovulatory phase:-
 LH acts on the follicle ruptures to convert into carpus
luteum
 carpus luteum secretes estrogen and progesterone.
 estrogen and progesterone exert –ve feedback effect
on GnRH (Hypothalamus)

39. Uterine cycle
 uterine cycle may be divided into three
phases:-
1. proliferative phase
2. secretory phase
3. Menstrual phases

40. Proliferative phase
 Start after menstruation and continues to the
time of ovulation (5 day – day 14)
 It depends on the action of estrogen which
causes proliferation of endometrium
 The endometrium increases rapidly in
thickness from 0.5mm to 5mm (10 fold)

41. Secretory phase
 Start from ovulation to mensturation
 Depends on the action of progesterone
 Progesterone action:-
 endometrium becomes more highly
vascularized and slightly edematous
 Glands become coiled and tortuous and they
begin to secrete a clear fluid
 The length of endometrium in this phase is
constant

42. Menstrual phases
 Menstrual blood is:
1. 75% arterial blood
2. 25% venous blood
 Regression of the corpus luteum and the abrupt
loss of estradiol and progesterone cause the
endometrial lining to be sloughed
 Volume (30 – 80) mL
 Duration (3-8) day

43. ESTROGEN
 synthesis and secretion of estrogen
 Produced from (granulosa cell, carpus luteum and
placenta)
 Chemistry of the estrogen
 Steroid hormone
 Action of estrogen
 female secondary sex characteristics
 Estrogens produce duct growth in the breasts
 causes proliferation of endometrium
 increase the bulk of uterine muscle
 Facilitated effect of oxytocin on uterine muscle

44. Progesterone
 synthesis and secretion of the Progesterone
 Progesterone secreted by the corpus luteum, the
placenta
 Chemistry of the Progesterone
 Steroid hormone
 Action of the Progesterone
 antiestrogenic effect on the myometrial cells
 Maintenance of secretory activity of uterus during
luteal phase
 development of lobules and alveoli in the breast