Male Reproductive System PDF 202410

22069 Maternity and Child Health Care-Theory 202410 Reproductive Health Male Reproductive System Aya Halahleh  Reproductive health Reproductive health is a state of complete physical, mental and social well-being...

22069 Maternity and Child Health Care-Theory 202410 Reproductive Health Male Reproductive System Aya Halahleh  Reproductive health Reproductive health is a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity, in all matters relating to the reproductive system and to its functions and processes. Reproductive health implies that people are able to have a satisfying and safe sex life and that they have the capability to reproduce and the freedom to decide if, when and how often to do so.  Components of Reproductive Health There are three essential components of sexual and reproductive health care- 1. Family planning – It has a significant impact on the well-being of families and especially women. With better family planning and the use of contraceptives, one can avoid unwanted pregnancies, and space births and also protect themselves from STDs. 2. Sexual health – It refers to a respectful and positive approach towards sexual relationships. It is a very important prerequisite for good reproductive health. 3. Maternal health – It refers to the maintenance of a woman’s health during pregnancy and after childbirth.  Reproductive Health Care Reproductive Health Care: is defined as “the entire set of methods, techniques and services that contribute to reproductive health and its well being through prevention and solution of various problems related to reproductive health.” Reproductive health includes health related to sex for the purpose of individual sex and the enhancement of human relationships (sexual health), and is not simply limited to counseling and care related to reproduction and sexually transmitted infections  Reproductive rights Reproductive rights are basic right of all couples and individuals to decide freely and responsibly the number, spacing and timing of their children and to have the information and means to do so, and the right to attain the highest standard of sexual and reproductive health.  Gender Gender refers to the characteristics of women, men, girls and boys that are socially constructed. This includes norms, behaviours and roles associated with being a woman, man, girl or boy, as well as relationships with each other. As a social construct, gender varies from society to society and can change over time.(WHO) Sex vs Gender  Sex vs. Gender Sex refers to a set of biological attributes in humans and animals. It is primarily associated with physical and physiological features including chromosomes, gene expression, hormone levels and function, and reproductive/sexual anatomy. Sex is usually categorized as female or male but there is variation in the biological attributes that comprise sex and how those attributes are expressed.  Sex vs. Gender Gender refers to the socially constructed roles, behaviors, expressions and identities of girls, women, boys, men, and gender diverse people. It influences how people perceive themselves and each other, how they act and interact, and the distribution of power and resources in society. Gender identity is not confined to a binary (girl/woman, boy/man) nor is it static; it exists along a continuum and can change over time. There is considerable diversity in how individuals and groups understand, experience and express gender through the roles they take on, the expectations placed on them, relations with others and the complex ways that gender is institutionalized in society.  Sex Determination and Differentiation Nucleated cells contain 46 chromosomes, diploid ❑ 22 pairs of homologous autosomes ❑ 1 pair of sex chromosomes, xx female, xy male. Eggs and sperms are haploid(‫)أحادية العدد‬, 22 autosomes and one sex chromosome. Sperm determines sex of zygote. Sex Determination and Differentiation Primary sex characteristics are internal organs and external genitalia that distinguish males from females Body shape Beard and body hair Muscular development Lowering of voice Libido  The Embryonic Structure Male accessory structure develop from Wolffian ducts: epididymis, vas deferens, and seminal vesicle. Müllerian ducts develop into the upper portion of the vagina, the uterus, and the Fallopian tubes. Without SRY gene, gonads(‫ )الغدد التناسلية‬develop into ovaries. The uterus differentiates from the fetal Müllerian ducts. A. Before the embryonic to fetal transition, the gonads and reproductive ducts (Wolffian; blue and Müllerian; red) of the urogenital ridge are bipotential. B. In the presence of the Y chromosome, the gonads of the bipotential urogenital ridge differentiate into testes, which produce both MIS to eliminate the Müllerian ducts and testosterone to stimulate differentiation of the Wolffian ducts into the male internal reproductive tract structures. C. In the absence of SRY, ovaries differentiate, Wolffian ducts degenerate, and Müllerian ducts develop into a simple columnar epithelial tube that will differentiate into the oviducts, uterus, cervix, and upper portion of the vagina. Hormonal Regulation of the Body System  Hormonal Regulation of the Reproductive System Regulation of the reproductive system is a process that requires the action of hormones from the pituitary gland, the adrenal cortex, and the gonads. During puberty, in both males and females, the hypothalamus produces gonadotropin- releasing hormone (GnRH), which stimulates the production and release of follicle stimulating hormone (FSH) and luteinizing hormone (LH) from the anterior pituitary gland. These hormones regulate the gonads (testes in males and ovaries in females); they are called gonadotropins. In both males and females, FSH stimulates gamete production and LH stimulates production of hormones by the gonads. An increase in gonad hormone levels inhibits GnRH production through a negative feedback loop.  The Brain Directs Reproduction Gonadotropin-releasing hormones (GnRH) from hypothalamus control release from the anterior pituitary of: ▪ Follicle stimulating hormone (FSH) regulates gametogenesis in gonads ▪ Luteinizing hormone (LH) controls production of steroid hormones  Sex steroids are closely related to one another. Aromatase converts androgens to estrogens. Both sexes produce androgens and estrogen. Androgens predominate in males. Most testosterone comes from testes Estrogens are dominant in females Ovary produces estrogens. Adrenal gland secretes small amounts of sex steroids.  In male The negative feedback loop of the male reproductive system: GnRH, secreted by the hypothalamus, stimulates the production of FSH and LH from the pituitary gland. These hormones encourage the development of sperm cells within the testicles, which then produce inhibin and inhibit the production of GnRH, FSH and LH in a negative feedback loop.  In female Regulation of the female reproductive system: Hormonal regulation of the female reproductive system involves hormones from the hypothalamus, pituitary, and ovaries. GnRH secreted by the hypothalamus stimulates the release of FSH, which es the growth of egg cells, andstimulat LH, which signals for the the ovulation of an egg from its follicle. The ovaries, in turn, secrete hormones that play a role in female sexual characteristics.  Male Reproduction Anatomy External genitalia Penis ( urethra, corpus spongiosum, corpora cavernosa) and scrotum that contains testes (lower temperature). Internal organs Prostate gland, the seminal vesicles, and the bulbourethral (Cowper's) glands Testes produce sperm and hormones.  Male External Structures External genital organs of the male include the testes (which are encased in the scrotal sac) and the penis. Scrotum. The scrotum is a rugated, skin-covered, muscular pouch suspended from the perineum. Its functions are to support the testes and to help regulate the temperature of sperm. Testes. The testes are two ovoid glands, 2 to 3 cm wide, that lie in the scrotum. Each testis is encased by a protective white fibrous capsule and is composed of several lobules, with each lobule containing interstitial cells (Leydig’s cells) and a seminiferous tubule. Seminiferous tubules produce spermatozoa. Leydig’s cells are responsible for the production of testosterone  Although spermatozoa are produced in the testes, they reach maturity, surrounded by semen, in the external structures through a complex sequence of regulatory events. First, the hypothalamus releases GnRH, which in turn influences the anterior pituitary gland to release FSH and LH. FSH is then responsible for the release of androgen-binding protein (ABP). LH is responsible for the release of testosterone. ABP binding of testosterone promotes sperm formation. As the amount of testosterone increases, a feedback effect on the hypothalamus and anterior pituitary gland is created that slows the production of FSH and LH and ultimately decreases or regulates sperm production.  Penis. The penis is composed of three cylindrical masses of erectile tissue in the penis shaft: two termed the corpus cavernosa, and a third termed the corpus spongiosum. The urethra passes through these layers of erectile tissue, making the Penis serve as the outlet for both the urinary and the reproductive tracts in men.  Male Internal Structures The male internal reproductive organs are the epididymis, the vas deferens, the seminal vesicles, the ejaculatory ducts, the prostate gland, the urethra, and the bulbourethral glands (see Fig. 5.2).  Male Internal Structures Epididymis. which is responsible for conducting sperm from the tubule to the vas deferens, the next step in the passage to the outside. Because each epididymis is so tightly coiled, its length is extremely deceptive: It is actually over 20 ft long. Some sperm are stored in the epididymis, and a portion of the alkaline fluid that will surround sperm at maturity (semen, or seminal fluid that contains a basic sugar and mucin, a form of protein) is produced by the cells lining the epididymis.  Sperm are immobile and incapable of fertilization as they pass or are stored at the epididymis level. It takes at least 12 to 20 days for them to travel the length of the epididymis and a total of 64 days for them to reach maturity. This is one reason that aspermia (absence of sperm) and oligospermia (20 million sperm/mL) are problems that do not appear to respond immediately to therapy but rather only after 2 months  Vas Deferens (Ductus Deferens) The vas deferens is an additional hollow tube surrounded by arteries and veins Protected by a thick fibrous coating. It carries sperm from the epididymis through the inguinal canal into the abdominal cavity, where it ends at the seminal vesicles and the ejaculatory ducts. Seminal Vesicles. The seminal vesicles are two convoluted pouches that lie along the lower portion of the posterior surface of the bladder and empty into the urethra by way of the ejaculatory ducts. These glands secrete a viscous alkaline liquid that has a high sugar, protein, and prostaglandin content. Sperm become increasingly motile with this added fluid, because it surrounds them with nutrients and a more favorable PH.  Ejaculatory Ducts. The two ejaculatory ducts pass through the prostate gland and join the seminal vesicles to the urethra. Prostate Gland. The prostate is a chestnut-sized gland that lies just below the bladder. The urethra passes through the centre of it, like the hole in a doughnut. The prostate gland secretes a thin, alkaline fluid. This alkaline fluid further protects sperm from being immobilized by the naturally low pH level of the urethra. In middle life, many men develop benign hypertrophy of the prostate. This swelling interferes with both fertility and urination. A benign condition, it can be relieved by medical therapy or surgery but needs to be differentiated from prostate cancer (Parsons, 2007).  Bulbourethral Glands. Two bulbourethral or Cowper’s glands lie beside the prostate gland and empty via short ducts into the urethra. Like the prostate gland and seminal vesicles, they secrete an alkaline fluid that helps counteract the acid secretion of the urethra and ensure the safe passage of spermatozoa. Semen, therefore, is derived from the prostate gland (60%), the seminal vesicles (30%), the epididymis (5%), and the bulbourethral glands (5%). Urethra. The urethra is a hollow tube leading from the base of the bladder, which, after passing through the prostate gland, continues to the outside through the shaft and glans of the penis. It is approximately 8 in (18 to 20 cm) long. Like other urinary tract structures, it is lined with mucous membrane. Sperm Semen analysis  Semen analysis Aspermia: absence of semen Azoospermia: absence of sperm Hypospermia: low semen volume Hyperspermia: high semen volume Oligozoospermia: Very low sperm count Asthenozoospermia: poor sperm motility Teratozoospermia: sperm carry more morphological defects than usual Necrozoospermia: all sperm in the ejaculate are dead