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.