Function of male and female Function of male and female reproductive systemreproductive system

Formation of sexual fitches of the Formation of sexual fitches of the organism at fetal periodorganism at fetal period

In fetus testosterone is secreted by genital ridges under influence In fetus testosterone is secreted by genital ridges under influence of male chromosome “Y” at 7th week of fetation. Later fetal testes of male chromosome “Y” at 7th week of fetation. Later fetal testes secrete testosterone under influence of human chorionic secrete testosterone under influence of human chorionic gonadotropin from placenta. gonadotropin from placenta.

Action of testosterone in fetus causes development of penis, Action of testosterone in fetus causes development of penis, scrotum, prostate, seminal vesicles and male genital duct; scrotum, prostate, seminal vesicles and male genital duct; suppresses formation of female genital organs; causes descent of suppresses formation of female genital organs; causes descent of testes through inguinal canal into scrotum during last two months testes through inguinal canal into scrotum during last two months of gestation. Regulation of testosterone in fetus occurs due to of gestation. Regulation of testosterone in fetus occurs due to human chorionic gonadotropin from placenta that causes Laydig human chorionic gonadotropin from placenta that causes Laydig cell formation in testes and so testosterone secretion. Absence of cell formation in testes and so testosterone secretion. Absence of “Y” chromosome and testosterone in blood results in development “Y” chromosome and testosterone in blood results in development of female fetus.of female fetus.

Peculiarities of pubertal and prepubertal periodsPeculiarities of pubertal and prepubertal periods

Puberty period in male is period, during which Puberty period in male is period, during which secondary sexual characters begin to develop and secondary sexual characters begin to develop and capability of sexual reproduction is attained. It capability of sexual reproduction is attained. It begins normally at age of 12-13. begins normally at age of 12-13.

Processes probably in amigdala causes Processes probably in amigdala causes hypothalamus to begin secretion luteinising hypothalamus to begin secretion luteinising human releasing hormone that stimulates anterior human releasing hormone that stimulates anterior pituitary glandto secrete luteinising hormone and pituitary glandto secrete luteinising hormone and follicle stimulating hormone and then testosteron follicle stimulating hormone and then testosteron secretion by Leydig cells. secretion by Leydig cells.

Peculiarities of pubertal and prepubertal Peculiarities of pubertal and prepubertal periodsperiods

Laydig cells that secret testosterone are non-existent in Laydig cells that secret testosterone are non-existent in childhood, but abundant in newborn male infant and in childhood, but abundant in newborn male infant and in adult male after puberty. Testosterone in target cells is adult male after puberty. Testosterone in target cells is converted into dihydrotestosterone and 5-alfa- converted into dihydrotestosterone and 5-alfa- androstanediol. Some actions of testosterone depend upon androstanediol. Some actions of testosterone depend upon this convertion, while others do not. this convertion, while others do not.

Testosterone that is not uptaken by target cells is Testosterone that is not uptaken by target cells is degraded by liver into androsterone, degraded by liver into androsterone, dehydroepiandrosterone and conjugated as glucuronides dehydroepiandrosterone and conjugated as glucuronides or sulfates. Conjugated products of degraded testosterone or sulfates. Conjugated products of degraded testosterone are excreted in bile or in urine. Mechanism of testosterone are excreted in bile or in urine. Mechanism of testosterone action is protein-formation mechanism. action is protein-formation mechanism.

Peculiarities of pubertal and prepubertal periodsPeculiarities of pubertal and prepubertal periods Characters of body, which make their appearance Characters of body, which make their appearance

under influence of sex hormones at puberty are called under influence of sex hormones at puberty are called secondary sexual characters. In male they include: 1) secondary sexual characters. In male they include: 1) body hears – testosterone causes increase hair growth body hears – testosterone causes increase hair growth over pubis, male pattern is convex, upward along over pubis, male pattern is convex, upward along linea alba, on chest, on face and on back; 2) baldness linea alba, on chest, on face and on back; 2) baldness – testosterone causes decrease hair growth on top of – testosterone causes decrease hair growth on top of head, producing baldness; 3) voice – testosterone head, producing baldness; 3) voice – testosterone causes hypertrophy of pharyngeal mucosa and causes hypertrophy of pharyngeal mucosa and enlargement of larynx, which first causes “cracking enlargement of larynx, which first causes “cracking voice”, and then causes typical masculine bass voice; voice”, and then causes typical masculine bass voice; 4) skin – testosterone increases skin thickness, 4) skin – testosterone increases skin thickness, secretion of sebaceous gland and acne; 5) secretion of sebaceous gland and acne; 5) subcutaneous fat – testosterone decreases subcutaneous fat – testosterone decreases subcutaneous fat. subcutaneous fat.

Peculiarities of pubertal and prepubertal Peculiarities of pubertal and prepubertal periodsperiods

Testosterone increases spermatogenesis in Testosterone increases spermatogenesis in seminiferous tubules. Anabolic effect of testosterone seminiferous tubules. Anabolic effect of testosterone – increases protein synthesis, causes positive nitrogen – increases protein synthesis, causes positive nitrogen balance, decreases blood urea level, increases muscle balance, decreases blood urea level, increases muscle development and creatin content in muscles, increases development and creatin content in muscles, increases bone thickness, narrows pelvic outlet and lengthens bone thickness, narrows pelvic outlet and lengthens it, increases strength of pelvis for load bearing. it, increases strength of pelvis for load bearing.

Testosterone due to metabolic effect increases also Testosterone due to metabolic effect increases also red blood cells count, Na and water reabsorbtion in red blood cells count, Na and water reabsorbtion in distal tubuls in kidney, increases libido (sexual distal tubuls in kidney, increases libido (sexual appetite) by directly acting on central nervous system.appetite) by directly acting on central nervous system.

Peculiarities of pubertal and prepubertal Peculiarities of pubertal and prepubertal periodsperiods

Period during which monthly sexual cycles begin in Period during which monthly sexual cycles begin in female is called as puberty period begins at 11-15 female is called as puberty period begins at 11-15 years of life. At this age anterior pituitary gland years of life. At this age anterior pituitary gland begins to secrete luteinising hormone and follicle begins to secrete luteinising hormone and follicle stimulating hormone that causes changes in ovaries stimulating hormone that causes changes in ovaries and uterus that result in monthly sexual cycles in and uterus that result in monthly sexual cycles in female. female.

During childhood granulosa cells secrete oocyte During childhood granulosa cells secrete oocyte maturation-inhibiting factor that keeps ovum in its maturation-inhibiting factor that keeps ovum in its primordial state. There are two types of ovarian primordial state. There are two types of ovarian hormones: estrogenes (most important is estradiol) hormones: estrogenes (most important is estradiol) and progestins (most important is progerterone). and progestins (most important is progerterone).

Action of estrogenesAction of estrogenes Action of estrogenes is based on protein formation Action of estrogenes is based on protein formation

mechanism, so slight positive nitrogen balance develops, fat mechanism, so slight positive nitrogen balance develops, fat desposition in subcutaneous tissue, breast, buttocks and thighs desposition in subcutaneous tissue, breast, buttocks and thighs occur, in blood cholesterole level decreases and fibrinogen occur, in blood cholesterole level decreases and fibrinogen level rises. Estrogenes cause increase in size and wall level rises. Estrogenes cause increase in size and wall masculature in vagina; simple cuboidal epithelium is masculature in vagina; simple cuboidal epithelium is converted to stratified epithelium, which is more resistant to converted to stratified epithelium, which is more resistant to trauma and infections. trauma and infections.

Estrogenes increase glycogene disposition, so pH in vagina Estrogenes increase glycogene disposition, so pH in vagina becomes more acidic due to conversion of glycogen into lactic becomes more acidic due to conversion of glycogen into lactic acid by bacteria. External genitalia increase in size and acid by bacteria. External genitalia increase in size and increases fat deposition in mons pubis and labia majora under increases fat deposition in mons pubis and labia majora under the influence of estrogenes. Increase of uterus in size, its the influence of estrogenes. Increase of uterus in size, its vascularity, proliferation of epithelium and proliferation of vascularity, proliferation of epithelium and proliferation of glandular tissue in fallopian tubes are also occurs. glandular tissue in fallopian tubes are also occurs.

Female reproductive system Female reproductive system VideoVideo

Action of estrogenesAction of estrogenes Estrogenes inhibit luteinizing hormone and follicle Estrogenes inhibit luteinizing hormone and follicle

stimulating hormone secretion by negative feedback stimulating hormone secretion by negative feedback mechanism, so ovarian function decreases. This effect mechanism, so ovarian function decreases. This effect is used as oral contraception. Secondary sexual is used as oral contraception. Secondary sexual characters are also get developed due to estrogenes. characters are also get developed due to estrogenes.

They initiate growth of breast, cause development of They initiate growth of breast, cause development of stroma and duct system, cause fat deposition in stroma and duct system, cause fat deposition in breast, causes skin to become smooth and soft due to breast, causes skin to become smooth and soft due to increase skin vascularity, broadens pelvis, larynx increase skin vascularity, broadens pelvis, larynx retains its prepubertal size and voice remains high-retains its prepubertal size and voice remains high-pitched.pitched.

ProgesteroneProgesterone Progesterone promotes secretory changes in uterine Progesterone promotes secretory changes in uterine

endometrium and fallopian tubes during secretory endometrium and fallopian tubes during secretory faze of menstrual cycle, promotes development of faze of menstrual cycle, promotes development of lobule and alveoli in breast; causes alveolar cells to lobule and alveoli in breast; causes alveolar cells to proliferate, enlarge and become secretory. Onset of proliferate, enlarge and become secretory. Onset of menstruation is called menarche. menstruation is called menarche.

Progesterone inhibits ovulation by inhibiting release Progesterone inhibits ovulation by inhibiting release of luteinizing hormone and follicle stimulating of luteinizing hormone and follicle stimulating hormone. Progesterone causes also slight retention of hormone. Progesterone causes also slight retention of Na+, Cl- and water from renal tubules and completes Na+, Cl- and water from renal tubules and completes aldosterone in this action. aldosterone in this action.

Formation and mechanism Formation and mechanism of sexual motivationof sexual motivation

In male pathway of afferent sexual sensations In male pathway of afferent sexual sensations includes the next: psychic or physical stimulation of includes the next: psychic or physical stimulation of sensory end organs, spreading impulses by pudendal sensory end organs, spreading impulses by pudendal nerve, sacral plexus, sacral portion of spinal cord and nerve, sacral plexus, sacral portion of spinal cord and then undefined areas of cerebrum and limbic system.then undefined areas of cerebrum and limbic system.

Afferent pathway in female includes psychic or Afferent pathway in female includes psychic or sexual stimulation, spreading excitation through sexual stimulation, spreading excitation through pudendal nerve to sacral segment of spinal cord and pudendal nerve to sacral segment of spinal cord and through analyzing systems to limbic system.through analyzing systems to limbic system.

Anatomy of the MaleAnatomy of the MaleReproductive SystemReproductive System

The male reproductive system consists of the testes The male reproductive system consists of the testes (sing.,(sing., testis), a series of ducts, accessory glands, and testis), a series of ducts, accessory glands, and supporting structures.supporting structures.

The ducts include the epididymides (sing., The ducts include the epididymides (sing., epididymis), ductus deferentiaepididymis), ductus deferentia (sing., deferens; also (sing., deferens; also vas deferens), and urethra.vas deferens), and urethra.

Accessory glandsAccessory glands include the seminal vesicles, include the seminal vesicles, prostate gland, and bulbourethral glands.prostate gland, and bulbourethral glands.

Supporting structures include the scrotum and penisSupporting structures include the scrotum and penis

Sagittal section of the male pelvis showing the Sagittal section of the male pelvis showing the male reproductive structuresmale reproductive structures

Sperm cells are very temperature-sensitive and don’t Sperm cells are very temperature-sensitive and don’t developdevelop normally at usual body temperatures. normally at usual body temperatures.

The testes and epididymides,The testes and epididymides, in which the sperm cells in which the sperm cells develop, are located outside the bodycavity in the develop, are located outside the bodycavity in the scrotum, where the temperature is lower. scrotum, where the temperature is lower.

The ductusThe ductus deferentia lead from the testes into the deferentia lead from the testes into the pelvis, where they join thepelvis, where they join the ducts of the seminal ducts of the seminal vesicles to form the ampullae. Extensions ofvesicles to form the ampullae. Extensions of the the ampullae, called the ejaculatory ducts, pass through ampullae, called the ejaculatory ducts, pass through thethe prostate and empty into the urethra within the prostate and empty into the urethra within the prostate. prostate.

The urethra,The urethra, in turn, exits from the pelvis and passes in turn, exits from the pelvis and passes through the penis tothrough the penis to the outside of the body.the outside of the body.

ScrotumScrotum The The scrotumscrotum contains the contains the testes and is divided intotestes and is divided into two two internal compartments by an internal compartments by an incomplete connective tissueincomplete connective tissue septum. septum.

Externally, the scrotum is Externally, the scrotum is marked in the midline by anmarked in the midline by an irregular ridge, the irregular ridge, the rapheraphe, , which continues posteriorlywhich continues posteriorly to to the anus and anteriorly onto the anus and anteriorly onto the inferior surface ofthe inferior surface of the the penis. penis.

The outer layer of the scrotum The outer layer of the scrotum includes the skin, aincludes the skin, a layer of layer of superficial fascia consisting of superficial fascia consisting of loose connective tissue,loose connective tissue, and a and a layer of smooth muscle called layer of smooth muscle called the the dartos dartos (dartoЇs; to skin)(dartoЇs; to skin) muscle.muscle.

PerineumPerineum The area between the thighs, which is bounded by the The area between the thighs, which is bounded by the

symphysissymphysis pubis anteriorly, the coccyx posteriorly, pubis anteriorly, the coccyx posteriorly, and the ischial tuberositiesand the ischial tuberosities laterally, is called the laterally, is called the perineumperineum. .

The perineum isThe perineum is divided into two triangles by a set of divided into two triangles by a set of muscles, the superficial transversemuscles, the superficial transverse and deep and deep transverse perineal muscles, that runs transverselytransverse perineal muscles, that runs transversely between the two ischial tuberosities. between the two ischial tuberosities.

The anterior,The anterior, or or urogenital triangle, urogenital triangle, contains the contains the base ofbase of the penis and the scrotum. The smaller the penis and the scrotum. The smaller posterior, or posterior, or anal, triangle,anal, triangle, contains the anal contains the anal openingopening..

Testicular Testicular HistologyHistology

The The testes testes are are small ovoid organs, small ovoid organs, each about 4–5 cmeach about 4–5 cm long, within the long, within the scrotum. scrotum.

They are both They are both exocrineexocrine and and endocrine glands. endocrine glands.

Sperm cells form a Sperm cells form a major part of the major part of the exocrineexocrine secretions secretions of the testes, and of the testes, and testosterone is the testosterone is the major endocrinemajor endocrine secretion of the secretion of the testes.testes.

The outer part of each testis is a thick, The outer part of each testis is a thick, white capsule consistingwhite capsule consisting of mostly of mostly fibrous connective tissue called the fibrous connective tissue called the tunica albugineatunica albuginea. .

Connective tissue of the tunicaConnective tissue of the tunica albuginea enters the testis and forms albuginea enters the testis and forms incomplete incomplete septasepta. The septa divide . The septa divide each testis into about 300–400each testis into about 300–400 cone-cone-shaped shaped lobules. lobules.

The substance of the testis between The substance of the testis between thethe septa includes two types of tissue: septa includes two types of tissue: seminiferous seminiferous (semi-nifer-u˘s;(semi-nifer-u˘s; seed seed carriers) carriers) tubules tubules in which sperm cells in which sperm cells develop and a loosedevelop and a loose connective tissue connective tissue stroma that surrounds the tubules and stroma that surrounds the tubules and containscontains clusters of endocrine cells clusters of endocrine cells called called interstitial cells, interstitial cells, or or Leydig Leydig cells,cells, which secrete testosterone.which secrete testosterone.

Descent of the TestesDescent of the Testes((Approximately Approximately

2 months2 months))

The testes develop The testes develop as retroperitoneal as retroperitoneal organs in the organs in the abdominopelvicabdominopelvic cavity, and each cavity, and each testis is connected testis is connected to the scrotumto the scrotum by a by a gubernaculumgubernaculum a a fibromuscular fibromuscular cord. cord.

Descent of the TestesDescent of the Testes((Approximately 3 Approximately 3

monthsmonths)) The testes move The testes move

from the from the abdominalabdominal cavity cavity through the through the inguinal canals inguinal canals to to the scrotum. the scrotum.

Cryptorchidism Cryptorchidism is failure of one or is failure of one or bothboth of the testes of the testes to descend into to descend into the scrotum.the scrotum.

Descent of the TestesDescent of the Testes((Approximately Approximately

birthbirth))

As they move into the As they move into the scrotum,scrotum, each testis is each testis is preceded by an preceded by an outpocketing of the outpocketing of the peritoneumperitoneum called the called the process vaginalisprocess vaginalis. .

The superiorThe superior part of part of each process vaginalis each process vaginalis usually becomes usually becomes obliterated, andobliterated, and the the inferior part remains inferior part remains as a small, closed sac, as a small, closed sac, the the tunicatunica vaginalis.vaginalis.

Descent of the TestesDescent of the Testes((AdultAdult))

The tunica vaginalis The tunica vaginalis surrounds most ofsurrounds most of the testis the testis in much the same way that in much the same way that the pericardium surroundsthe pericardium surrounds the heart. the heart.

The visceral layer of the The visceral layer of the tunica vaginalis covers the tunica vaginalis covers the anterioranterior surface of the surface of the testis, and the parietal layer testis, and the parietal layer lines the scrotum.lines the scrotum.

The tunica vaginalis is a The tunica vaginalis is a serous membrane serous membrane consisting of aconsisting of a layer of layer of simple squamous simple squamous epithelium that rests on a epithelium that rests on a basementbasement membrane.membrane.

Inguinal HerniaInguinal Hernia Normally, the inguinal canals are closed, but they do Normally, the inguinal canals are closed, but they do

represent weak spotsrepresent weak spots in the abdominal wall. in the abdominal wall. Inguinal Inguinal hernias hernias are abnormalare abnormal openings in the abdominal wall openings in the abdominal wall in the inguinal region through whichin the inguinal region through which structures such as structures such as a portion of the small intestine can protrude. a portion of the small intestine can protrude.

These hernias can be quite painfulThese hernias can be quite painful and even very and even very dangerous, especially if a portion of the small intestine dangerous, especially if a portion of the small intestine isis compressed so its blood supply is cut off. compressed so its blood supply is cut off. Fortunately, inguinal hernias canFortunately, inguinal hernias can be repaired be repaired surgically. Males are much more prone to inguinal surgically. Males are much more prone to inguinal hernias thanhernias than are females because a male’s inguinal are females because a male’s inguinal canals are larger and weakenedcanals are larger and weakened because the testes pass because the testes pass through them on their way into the scrotum.through them on their way into the scrotum.

Sperm Cell DevelopmentSperm Cell Development

A cross section of a mature seminiferous A cross section of a mature seminiferous tubule reveals thetubule reveals the various stages of sperm cell various stages of sperm cell development, a process called development, a process called spermatogenesisspermatogenesis..

In addition,In addition, tight junctions between the tight junctions between the sustentacular cells form a sustentacular cells form a bloodblood--testestestes barrier, barrier, which isolates the sperm cells from which isolates the sperm cells from the immune systemthe immune system

The seminiferous The seminiferous tubules contain tubules contain two types of cells, two types of cells, germ cells germ cells andand sustentacularsustentacular, or , or Sertoli cells. Sertoli cells.

The sustentacular The sustentacular cells are also cells are also sometimessometimes referred referred to as to as nurse cells.nurse cells.

TestosteroneTestosterone Testosterone, produced by the interstitial cells, passes intoTestosterone, produced by the interstitial cells, passes into the the

sustentacular cells and binds to receptors. The combination ofsustentacular cells and binds to receptors. The combination of testosterone with the receptors is required for the sustentaculartestosterone with the receptors is required for the sustentacular cells to function normally. In addition, testosterone is cells to function normally. In addition, testosterone is converted toconverted to two other steroids in the sustentacular cells: two other steroids in the sustentacular cells: dihydrotestosteronedihydrotestosterone and and estrogenestrogen. .

The sustentacularThe sustentacular cells also secrete a protein called cells also secrete a protein called androgen-androgen-bindingbinding protein protein into the seminiferous tubules. into the seminiferous tubules. Testosteroneand dihydrotestosterone bind to androgen-binding Testosteroneand dihydrotestosterone bind to androgen-binding protein and areprotein and are carried along with other secretions of the carried along with other secretions of the seminiferous tubules toseminiferous tubules to the epididymis. Estradiol and the epididymis. Estradiol and dihydrotestosterone may be the activedihydrotestosterone may be the active hormones that promote hormones that promote sperm cell formation.sperm cell formation.

Scattered between the Scattered between the sustentacular cells are sustentacular cells are smaller germsmaller germ cells from cells from which sperm cells are which sperm cells are derived. The germ cells derived. The germ cells areare arranged so that the arranged so that the most immature cells are at most immature cells are at the periphery andthe periphery and the most the most mature cells are near the mature cells are near the lumen of the seminiferouslumen of the seminiferous tubules. tubules.

The most peripheral cells, The most peripheral cells, those adjacent to the those adjacent to the basementbasement membrane of membrane of the seminiferous tubules, the seminiferous tubules, are are spermatogoniaspermatogonia, which , which divide by mitosis.divide by mitosis.

SpermatogenesisSpermatogenesis

Some of the daughter Some of the daughter cells produced from cells produced from these mitotic these mitotic divisionsdivisions remain remain spermatogonia and spermatogonia and continue to produce continue to produce additional additional spermatogonia.spermatogonia.

The others divide The others divide through mitosis and through mitosis and differentiate todifferentiate to form form primary primary spermatocytesspermatocytes..

MeiosisMeiosis Meiosis beginsMeiosis begins when the primary spermatocytes when the primary spermatocytes

divide. Each primary spermatocytedivide. Each primary spermatocyte passes through the passes through the first meiotic division to become twofirst meiotic division to become twosecondary secondary spermatocytes. spermatocytes.

Each secondary spermatocyte undergoesEach secondary spermatocyte undergoes a second a second meiotic division to produce two even smaller cells meiotic division to produce two even smaller cells calledcalled spermatidsspermatids. .

Each spermatid undergoes the last phaseEach spermatid undergoes the last phase of of spermatogenesis called spermatogenesis called spermiogenesisspermiogenesis to to form a form a mature mature sperm cell, sperm cell, or or spermatozoonspermatozoon..

EachEach spermatid develops a head, midpiece, and a tail, spermatid develops a head, midpiece, and a tail, or flagellum.or flagellum.

After their release into After their release into the seminiferous the seminiferous tubules, the spermtubules, the sperm cells pass through the cells pass through the tubuli recti to the rete tubuli recti to the rete testis. testis.

From the reteFrom the rete testis, testis, they pass through the they pass through the efferent ductules, efferent ductules, which leave the testiswhich leave the testis and enter the and enter the epididymis to join the epididymis to join the duct of the epididymis. duct of the epididymis.

TheThe sperm cells then sperm cells then leave the epididymis, leave the epididymis, passing through the passing through the ductusductus epididymis, epididymis, ductus deferens, ductus deferens, ejaculatory duct, and ejaculatory duct, and urethra to reachurethra to reach the the exterior of the body.exterior of the body.

UrethraUrethra The The male urethra male urethra is about 20 cm long and extendsis about 20 cm long and extends from the from the

urinary bladder to the distal end of the penis. The urethra is a urinary bladder to the distal end of the penis. The urethra is a passageway for bothurine and male reproductive fluids. The passageway for bothurine and male reproductive fluids. The urethra is divided intourethra is divided into three parts: the prostatic part, the three parts: the prostatic part, the membranous part, and themembranous part, and the spongy part. spongy part.

The The prostatic prostatic (pros-tatik) (pros-tatik) urethra urethra is connected tois connected to the bladder the bladder and passes through the prostate gland. Fifteen to 30and passes through the prostate gland. Fifteen to 30 small small ducts from the prostate gland and the two ejaculatory ductsducts from the prostate gland and the two ejaculatory ducts empty into the prostatic urethra. empty into the prostatic urethra.

The The membranous urethra membranous urethra is theis the shortest part of the urethra shortest part of the urethra and extends from the prostate glandand extends from the prostate gland through the perineum, through the perineum, which is part of the muscular floor of thewhich is part of the muscular floor of the pelvis. pelvis.

The The spongy urethra, spongy urethra, also called the also called the penilepenile urethra,urethra, is by far is by far the longest part of the urethra and extends from thethe longest part of the urethra and extends from the membranous urethra through the length of the penis.membranous urethra through the length of the penis.

PenisPenis The The penis penis contains three contains three

columns of erectile tissue, and columns of erectile tissue, and engorgement of this erectile engorgement of this erectile tissue with blood causestissue with blood causes the the penis to enlarge and become penis to enlarge and become firm, a process called firm, a process called erectionerection..

The penis is the male organ of The penis is the male organ of copulation through which spermcopulation through which sperm cells are transferred from the cells are transferred from the male to the female. Two of the male to the female. Two of the erectileerectile columns form the columns form the dorsum and sides of the penis dorsum and sides of the penis and are called theand are called the corpora corpora cavernosacavernosa. The third column,. The third column, the the corpus spongiosumcorpus spongiosum

Seminal VesiclesSeminal Vesicles

The The seminal vesicles seminal vesicles are sac-shaped glandsare sac-shaped glands located next to the ampullae of the ductus located next to the ampullae of the ductus deferentia. deferentia.

Each gland is about 5 cm long and tapers into Each gland is about 5 cm long and tapers into a short ducta short duct that joins the ductus deferens to that joins the ductus deferens to form the ejaculatory duct. form the ejaculatory duct.

TheThe seminal vesicles have a capsule containing seminal vesicles have a capsule containing fibrous connective tissuefibrous connective tissue and smooth muscle and smooth muscle cells.cells.

Prostate GlandProstate Gland The The prostate gland prostate gland consists ofconsists of both glandular and muscular both glandular and muscular

tissue and is about the size andtissue and is about the size and shape of a walnut; that is, shape of a walnut; that is, about 4 cm long and 2 cm wide. It isabout 4 cm long and 2 cm wide. It is dorsal to the symphysis dorsal to the symphysis pubis at the base of the urinary bladder,pubis at the base of the urinary bladder, where it surrounds the where it surrounds the prostatic urethra and the two ejaculatoryprostatic urethra and the two ejaculatory ducts. ducts.

The gland is composed of a fibrous connectiveThe gland is composed of a fibrous connective tissue capsule tissue capsule containing distinct smooth muscle cellscontaining distinct smooth muscle cells and numerous fibrous and numerous fibrous partitions, also containing smooth muscle,partitions, also containing smooth muscle, that radiate inward that radiate inward toward the urethra. Covering these musculartoward the urethra. Covering these muscular partitions is a partitions is a layer of columnar epithelial cells that form saccularlayer of columnar epithelial cells that form saccular dilations dilations into which the columnar cells secrete prostatic fluid. Fifteeninto which the columnar cells secrete prostatic fluid. Fifteen to to 30 small prostatic ducts carry these secretions into the30 small prostatic ducts carry these secretions into the prostatic urethra.prostatic urethra.

Male reproductive irgans Male reproductive irgans VideoVideo

Sexual reaction in maleSexual reaction in male Male sexual act includes such processes: 1) erection; Male sexual act includes such processes: 1) erection;

2) lubrication; 3) emission; 4) ejaculation. 2) lubrication; 3) emission; 4) ejaculation. Psychical stimuli lead to excitation of corresponding Psychical stimuli lead to excitation of corresponding

centers in limbic system. Physical sexual stimulation centers in limbic system. Physical sexual stimulation cause afferent impulse through pudendal nerve cause afferent impulse through pudendal nerve integrated in sacral segment. Then afferent impulses integrated in sacral segment. Then afferent impulses through nervi erigentes from pelvic parasympathetic through nervi erigentes from pelvic parasympathetic nerve spread to penis and cause delation of arteries. nerve spread to penis and cause delation of arteries. Arterial blood builds up under high pressure in Arterial blood builds up under high pressure in erectile tissue and venous outflow occluded. erectile tissue and venous outflow occluded.

So, erectile tissue balloon up, penis become hard and So, erectile tissue balloon up, penis become hard and elongated that called as erection. Same parasympathetic elongated that called as erection. Same parasympathetic impulses that cause erection also stimulate urethral and bulbo-impulses that cause erection also stimulate urethral and bulbo-urethral glands to secrete mucous that lubricate during urethral glands to secrete mucous that lubricate during intercourse. intercourse.

When sexual stimulation becomes extremely intense, reflex When sexual stimulation becomes extremely intense, reflex centers of spinal cord (L1-2) send sympathetic centers of spinal cord (L1-2) send sympathetic impulsesthrough hypogastric plexus that cause contraction of impulsesthrough hypogastric plexus that cause contraction of vas deference, ampulla, prostate and lastly seminal vesicle. So, vas deference, ampulla, prostate and lastly seminal vesicle. So, semen emitted into internal urethra. After this afferent semen emitted into internal urethra. After this afferent signalsthrough pudendal nerve cause sympathetic stimulation signalsthrough pudendal nerve cause sympathetic stimulation and efferent signals from sacral sigment of spinal cord through and efferent signals from sacral sigment of spinal cord through hypogastric plexus lead to contraction of internal genital hypogastric plexus lead to contraction of internal genital organs that cause rhythmic increase in pressure of internal organs that cause rhythmic increase in pressure of internal urethra from outside. This provides ejaculation of semen from urethra from outside. This provides ejaculation of semen from internal urethra into deep vagina. Extremely pleasurable internal urethra into deep vagina. Extremely pleasurable sensations felt during emission and ejaculation, are called sensations felt during emission and ejaculation, are called male orgasm or male climax. male orgasm or male climax.

Sexual reaction in femaleSexual reaction in female Female sexual act includes such processes: 1) stimulation; 2) Female sexual act includes such processes: 1) stimulation; 2)

erection; 3) lubrication; 4) climax. Psychical stimuli lead to erection; 3) lubrication; 4) climax. Psychical stimuli lead to excitation of corresponding centers in limbic system. excitation of corresponding centers in limbic system.

Physical sexual stimulation cause afferent impulse through Physical sexual stimulation cause afferent impulse through pudendal nerve integrated in sacral segment. Parasympathetic pudendal nerve integrated in sacral segment. Parasympathetic signals that pass through nervi erigenes dilate arteries of signals that pass through nervi erigenes dilate arteries of erectile tissue in introitus and clitoris. So, blood accumulates erectile tissue in introitus and clitoris. So, blood accumulates in erectile tissue. Same parasympathetic signals also pass to in erectile tissue. Same parasympathetic signals also pass to Bartholin’s glands beneath labia minora and vaginal Bartholin’s glands beneath labia minora and vaginal epithelium that cause them to secrete mucus, which is essential epithelium that cause them to secrete mucus, which is essential for massaging action. Than during climax perineal muscles for massaging action. Than during climax perineal muscles contract rhythmically.contract rhythmically.