By Lennart Nilsson, 1965

Is Sex necessary for species to be created and Is Sex necessary for species to be created and maintained?maintained?

We do not even in the least know the final cause of sexuality; Why new beings should be produced by the union of the two sexual elements, instead of by a process of parthenogenesis.

––––– Charles Darwin

So why Sex? So why Sex? Did it occur by accident? Did it occur by accident? A dice played with universe by God?A dice played with universe by God?

Bryaninops-yongei- 海鞭虾虎鱼

Sex is incredibly magic.

The physiology related

with sex is complex

biological activity

Reproductive functions of the male and female

Pregnancy

Lactation

Estrogen

Progesterone

Androgens

(Testosterone)

(Dihydrotestosterone)

(Androstenedione)

Hormone-Producing cells

OvumSpermGerm cells

OvariesTestisGonad Gland

FemaleMale

Reproductive and Hormonal Functions of the Male

I. Spermatogenesis

II. Male Sex Hormones

Seminiferous tubule

Male Reproductive System

Interstitial cells(Leydig cells)

Spermatids

Mitosis

Meiosis

Spermatozoa(23

chromosomes)

Temperature: Cryptorchidism Disease: Inflammation/Tuberculosi

s X-Ray Smoking & Drinking

Factors Impacting Sperm

Functions of Testis

Spermatogenesis --- Seminiferous tubule; Synthesis and Release of Androgens such as testosterone

etc --- Interstitial Cells;

Under influence of FSH and LH released from anterior pituitary gland respectively.

Functions of Testosterone

To cause descent of the testes into scrotum; Effects on development of adult primary and

secondary sexual characteristics

(Distribution of body hair; Baldness; Voice; Acne; Protein formation and muscle etc…..)

Female Physiology Before Pregnancy and Female

Hormones

1. Female Hormonal System?

2. Ovarian Follicle growth?

3. Secretion of estrogen and progesterone?

4. Interplay between Hypothalamic-Pituitary

and ovarian Hormones?

5. Relations between Ovarian hormones and

menstruation?

Hypothalamus

I. Female Hormone System

Gonadotropin Hormone:

Follicle-Stimulating Hormone (FSH)

Luteinizing Hormone (LH)

Estrogen/Progesterone; Inhibin

Gonadotropin-Releasing Hormone (GnRH)

Cyclical Secretion of FSH and LH

FSH and LH secreted by the anterior pituitary gland in cyclical rhythm regulate the cyclical ovarian changes and subsequent secretion of ovarian hormones.

LH

FSH

Female sexual cycle in 28 days

Importance: surge of LH and FSH?

II. Ovarian Follicle growth

Ovum

Follicle cells Granulosa

Thecal cells

Proliferation and Secretion of Hormones are regulated by FSH and LH.

Histology of Ovarian Follicle

Ovulation

6-12

Granulosa & Theca cells

Lutein cells

Luteal PhaseFollicular Phase

Estrogen

Granulosa cells

Estrogen

Progesterone

(Inhibin)Hormone

Lutein cellsCell type

Estrogen

Progesterone

Ovarian Cycle

III. Sex Hormone Secretion in Ovarian Cycle

Functions of the Ovarian Hormones

Estrogen Effect on the Uterus and external female sex organs; Effect on the Fallopian Tubes and Breast; Effect on the Skeleton; Effect on Protein Deposition, fat deposition and Body metabolism; Effect on Hair Distribution and Skin; Effect on electrolyte Balance; Negative and Positive feedback effect on Anterior Pituitary Gland;

Progesterone Effect on the Uterus, Fallopian tubes and Breast;

Effect on the body temperature; Feedback effect on Anterior Pituitary Gland

Before Ovulation After Ovulation

IV. Interplay between Hypothalamic-Pituitary and ovarian Hormones

GnRH induces Anterior Pituitary Gland to Secret LH

and FSH;

LH and FSH regulate the follicle growth and

subsequent estrogen and progesterone secretion;

Negative feedback effects of estrogen and

progesterone on LH and FSH secretion;

Positive feedback effect of estrogen before ovulation

-- LH surge

Hypothalamus

GnRH

FSH LH

Estrogen

EstrogenProgesterone

⑥ Ovulation

Hypothalamus

GnRH①

③ Estrogen

(Low level)

④ Estrogen(High Leve

l)

⑧ Estrogen

Progesterone(Inhibin)

⑦ Corpus Luteum

⑨ Corpus Albicans

② FSH、 LH

LH Surge

⑤ LH↑FSH↑

Interplay between FSH/LH and Ovarian Hormones

Menstrual phase

Proliferative phase

Secretory phase

V. Relations between Ovarian hormones and menstruation