reproductive and hormonal functions of the male
TRANSCRIPT
Reproductive and hormonal functions of the male
Dr. Sadaf Mumtaz
31-1-11
Physiological Anatomy
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.
Spermatogenesis
Spermiogenesis
• Production of extremely specialized, mobile spermatozoa from spermatids is known as spermiogenesis
Functions of Sertoli cells
• Blood testes barrier
• Nourishment to developing sperm cells
• Phagocytosis
• Seminiferous tubule fluid
• Androgen binding protein
• Inhibin
Structure of a spermatozoan
• Maturation• Storage• Physiology
– Speed= 1-4mm/min
– pH of medium
– Temperature
– Life expectancy
Estrogen
Growth hormone promotes early division of spermatogonia
Hormonal factors that stimulate spermatogenesis
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
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.
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
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
Acrosome ReactionHyaluronidase 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
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
Effect of sperm morphology and motility on fertility
Biosynthesis of testosteroneCholesterol
Pregnenolone
17α- Hydroxypregnenolone
Dehydroepiandrosterone
Androstenedione
Testosterone
Dihydrotestosterone
Role of androgens in females
Normal Levels
Excretion
Role of estrogens in males
Plasma testosterone levels at various ages in human males
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
Feedback regulation of hypothalmic-pituitary testicular axis in males
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
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
Adiposogenital syndrome
Thanks
• 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.