Hormonal control of spermatogenesis

1. Hormonal control of
spermatogenesis
Anushka Gautam
Roll no. 28
Batch 56

2. Physiological Anatomy

3. Spermatogenesis
• Complex process by which relatively
undifferentiated primordial germ cells, the
spermatogonia, proliferate and are
converted into extremely specialized,
motile spermatozoa each bearing a
randomly distributed haploid set of 23
chromosomes.

4. Spermatogenesis

5. Spermiogenesis
• Production of extremely specialized,
mobile spermatozoa from spermatids is
known as spermiogenesis

6. Functions of Sertoli cells
• Blood testes barrier
• Nourishment to developing sperm cells
• Phagocytosis
• Seminiferous tubule fluid
• Androgen binding protein
• Inhibin

7. Structure of a spermatozoan
• Maturation
• Storage
• Physiology
– Speed= 1-4mm/min
– pH of medium
– Temperature
– Life expectancy

8. Estrogen
Growth hormone promotes
early division of spermatogonia
Hormonal factors that stimulate spermatogenesis

9. Function of Seminal vesicles
• Fructose and citric acid (nutrient value)
• Prostaglandins
– Make female cervical mucus more receptive to sperm
movement
– Causes backward, reverse peristaltic contractions in
the uterus and fallopian tubes
• Fibrinogen
– Forms meshwork of a clot

10. Function of Prostate Gland
• Secrete an alkaline fluid that neutralizes the acidic
vaginal secretions
– Calcium
– Citrate ions
– Phosphate ion
– A clotting enzyme --Acts on fibrinogen from the seminal
vesicle
– A profibrinolysin – Seminal clot is broken down by fibrinolysin,
releasing mobile sperm.

11. Semen
• Sperm and Fluid from
– Vas deferens 10%
– Seminal vesicles 60%
– Prostate gland 30%
– Mucus glands especially bulbourethral glands
– pH 7.5
– Life span 24-48hrs at body temperature

12. Capacitaion
• Uterine and fallopian tube fluid
• Floating vesicles from semniferous
tubules containing cholesterol added to
the acrosomal part of the sperm
• Membrane becomes permeable to
Calcium ions
– Activity of the flagelum
– Release of acrosomal contents

13. Acrosome Reaction
Hyaluronidase Proteolytic enzymes
Depolymerizes hyaluronic acid polymers in
the intercellular cement that hold the
ovarian granulosa cell together
Digest proteins in the structural
elements of tissue cells that
still adhere to ovum

14. Abnormal Spermatogeneis
• Infections
• Temperature
• Cryptorchidism
– Failure of testes to descend from abdomen
into scrotum at or near time of birth of a fetus
• Effect of sperm count on fertility
– 120million/ml (35-200million/ml) average of
400million in 3.5ml of ejaculate

15. Effect of sperm morphology and motility on
fertility

16. Biosynthesis of testosterone
Cholesterol
Pregnenolone
17α- Hydroxypregnenolone
Dehydroepiandrosterone
Androstenedione
Testosterone
Dihydrotestosterone
Role of androgens in females
Normal Levels
Excretion
Role of estrogens in males

17. Plasma testosterone levels at various ages in
human males

18. Functions of testosterone
• Fetal life
• Descent of testes
• Adult primary sexual characters
• Secondary sexual characters
– Distribution of body hairs
• Baldness
– Effect on voice
• Skin
• Protein formation and muscle development
• Bone matrix and calcium retention
• BMR
• RBCs
• Electrolyte and water balance

19. Feedback regulation of hypothalmic-pituitary testicular axis in males

20. Puberty
• The period when endocrine and gametogenic
functions of the gonads have first developed to
the point where reproduction is possible.
– Thelarche
– Pubarche
– Menarche
– Adrenarche
• Control of onset of puberty
• Male climacteric

21. Abnormalities of male sexual Function
• Prostate gland
– Beningn prostatic fibroadenoma
– Cancer of prostate gland
• Hypogonadism
– Fetus
– Before puberty
• Eunuchism ---infantile sex organs, height,
muscles, voice, hairs.
– After puberty –sexual organs regress

22. Adiposogenital syndrome

23. Thanks

24. • Vegetative functions are those bodily
processes most directly concerned with
maintenance of life. This category
encompasses nutritional, metabolic, and
endocrine functions including eating,
sleeping, menstruation, bowel function,
bladder activity, and sexual performance.
These functions can be altered by a wide
variety of psychologic states.