Male Reproductive System PDF

Okay, here is the conversion of the image into a structured markdown format: # THE HUMAN REPRODUCTIVE SYSTEM ### MALE REPRODUCTIVE SYSTEM - The male reproductive system is composed mainly of four main parts: - the external genitalia - reproductive organs or gonads - reproductive ducts...

Okay, here is the conversion of the image into a structured markdown format: # THE HUMAN REPRODUCTIVE SYSTEM ### MALE REPRODUCTIVE SYSTEM - The male reproductive system is composed mainly of four main parts: - the external genitalia - reproductive organs or gonads - reproductive ducts - and the reproductive glands ### Male External Genitalia - **Penis** - It is the copulatory organ which is a long muscular shaft and with bulb-shaped tip called the glans. The structure is supported, covered, and protected by the foreskin or the prepuce. Erection of the penis is necessary for copulation and this occurs when the male becomes sexually aroused. Erection happens because spaces called sinuses within the erectile tissue of the penis become filled with blood. - **Scrotum** - It is a pouch which hangs behind the penis and is suspended from the pubis. It is a continuation of the abdominal wall and is divided into two sacs, each containing and supporting a testis. It holds and protects the testes. It also contains many nerves and blood vessels. ### Male Reproductive Organs or Gonads - **Testes** - They are the male reproductive organs or gonads. These organs are contained inside the scrotum. Each testis is an oval organ which is about 5 cm in length. In early fetal life, the testes lie within the abdominal cavity, but at about two months prior to birth, the testes leave the abdomen and descend into the scrotum. - Each testis is made up of several microscopic coiled tubules called seminiferous tubules. In these tubules, formation of sperm cells or spermatogenesis take place. Moreover, the interstitial cells of Leydig of the testes are found scattered in between the seminiferous tubular tissues. These cells produce the male hormones like testosterones and androgens. ### Male Reproductive Ducts - There are series of tubular structure that originate initially from the microscopic tubules (seminiferous tubules) that make up the testes. They all function as pathway of the sperms that are produced and released from the testes: there are three reproductive ducts found in a male, namely: epididymis, vas deferens, and urethra. - **Epididymis** - It is a mass of coiled tubes cupping the posterior aspect of a testis. It extends for about 3.5 cm from an enlarged anterior end at the top of the testis tapering downward towards the lower back of the testis. - **Vas Deferens** - Also known as sperm duct or ductus deferens - It is a continuation of the epididymis which moves up into the pelvic cavity. Its length is about 30 cm. It initially ascends between the epididymis to enter the abdomen. This duct lies within the spermatic cord which also contains blood vessels, nerves, and lymphatic vessels. - **Urethra** - It is a tubelike organ which extends from the tip of the urinary bladder to the tip of the penis. This duct transports and discharges both urine from the urinary bladder and semen which contains the sperms. ### Male Reproductive Glands - There are three reproductive glands that secrete fluids to complete the semen or seminal fluid. These glands provide fluids that supply nourishment to the sperm cells and lubrication to the internal duct system. These glands are the seminal vesicles, the prostate gland, and the bulbourethral glands or Cowper's glands. - **Seminal Vesicles** - They are dilated saclike structures attached top the ends of the vas deferens and attached to one side of the urinary bladder. These contains fructose. About 70% of the semen is the secretion of the seminal vesicles. The tubes of each seminal vesicle ends in a straight, narrow duct which joins the vas deferens to form a one-inch ejaculatory duct. This duct penetrates the base of the prostate gland and opens into the urethra. - **Prostate Gland** - It is a conical structure lying below the urinary bladder. It surrounds the ejaculatory ducts and the first inch of the male urethra. It produces a thin, milky, alkaline fluid which helps in maintaining the viability of the sperms. - **Bulbourethral Glands** - Also known as Cowper's glands, are two glands, each almost about the size of a pea. These are located on the sides of the urethra just below the prostate gland. These secrete a lubricating mucous, a clear, slippery fluid that empties directly into the urethra. This portion of the seminal fluid serves to lubricate the urethra and to neutralize any acidity that may occur along the length of the male urethra. #### Seminal Fluid - It is a slightly alkaline mixture of sperm cells and secretions from the accessory glands. - The volume of semen in a single ejaculation may vary from 1.5 to 6.0 ml. There are usually between 50 to 150 million sperm per milliliter of semen. Sperm counts below 10 to 20 million per milliliter usually present fertility problems. Although only one sperm actually penetrates and fertilizes the avum, it takes several million sperm in an ejaculation to ensure that fertilization will take place. https://training.seer.cancer.gov/anatomy/reproductive/male/glands.html The image shows a diagram of the male reproductive system with the following labels: urinary bladder, vas deferens, urethra, glans, scrotum, seminal vesicle, prostate gland, ejaculatory duct, Cowper's gland, epididymis and testis. Here is a table summarizing the text: | | | | :-------------------- | :--------------------- | | **External Genitalia**| **Organs or Gonads** | | Penis | Testes | | Scrotum | | | **Ducts** | **Glands** | | Epididymis | Seminal vesicles | | Vas Deferens | Prostate Gland | | Urethra | Bulbourethral Glands |