Testicles: Facts, Function & Diseases
My problem is, I'm trying to access the functions from outside the class or object but I can't seem to do that without getting a syntax error. I assume because the variables or methods are out of scope. Then how can I call the methods that exist in the class? I want the object to display the circumference of any object I create. Please help! For objects use 'null' instead. In the male fetus, the testes develop near the kidneys, then descend into the scrotum just before birth. Testosterone is produced in the testes which stimulates the production of sperm as well as give secondary sex characteristics beginning at puberty.
The two testicles are each held in a fleshy sac called the scrotum. The major function of the scrotal sac is to keep the testes cooler than thirty-seven degrees Celsius ninety-eight point six degrees Fahrenheit. The external appearance of the scrotum varies at different times in the same individual depending upon temperature and the subsequent contraction or relaxation of two muscles.
These two muscles contract involuntarily when it is cold to move the testes closer to the heat of the body in the pelvic region. This causes the scrotum to appear tightly wrinkled. On the contrary, they relax in warm temperatures causing the testes to lower and the scrotum to become flaccid.
The temperature of the testes is maintained at about thirty-five degrees Celsius ninety-five degrees Fahrenheit , which is below normal body temperature. Temperature has to be lower than normal in order for spermatogenesis sperm production to take place. The two muscles that regulate the temperature of the testes are the dartos and cremaster muscles:. The dartos muscle is a layer of smooth muscle fibers in the subcutaneous tissue of the scrotum surrounding the scrotum. This muscle is responsible for wrinkling up the scrotum, in conditions of cold weather, in order to maintain the correct temperature for spermatogenesis.
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The cremaster muscle is a thin strand of skeletal muscle associated with the testes and spermatic cord. This muscle is a continuation of the internal oblique muscle of the abdominal wall, from which it is derived. Seminiferous Tubules. Each testis contains over yards of tightly packed seminiferous tubules. The seminiferous tubules are the functional units of the testis, where spermatogenesis takes place. Once the sperm are produced, they moved from the seminiferous tubules into the rete testis for further maturation.
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In between the seminiferous tubules within the testes, are instititial cells, or, Cells of Leydig. They are responsible for secreting the male sex hormones i. A Sertoli cell a kind of sustentacular cell is a 'nurse' cell of the testes which is part of a seminiferous tubule. Its main function is to nurture the developing sperm cells through the stages of spermatogenesis. Because of this, it has also been called the "mother cell.
Other functions During the Maturation phase of spermiogenesis, the Sertoli cells consume the unneeded portions of the spermatazoa. The sperm are transported out of the testis and into the epididymis through a series of efferent ductules. The testes receive blood through the testicular arteries gonadal artery. Venous blood is drained by the testicular veins. The right testicular vein drains directly into the inferior vena cava. The left testicular vein drains into the left renal vein. The seminiferous tubules join together to become the epididymis. The epididymis is a tube that is about 2 inches that is coiled on the posterior surface of each testis.
Within the epididymis the sperm incomplete their maturation full maturation occur in female genital tract and their flagella become mobile. This is also a site to store sperm, nourishing them until the next ejaculation. Smooth muscle in the wall of the epididymis propels the sperm into the ductus deferens. Vasa efferentia from the rete testis open into the epididymis which is a highly coiled tubule. The epididymis has three parts- 1 head or caput epididymis- it is the proximal part of the epididymis. It carries the sperms from the testis.
The cauda epididymis continues to form less convoluted vas deferens. The ductus vas deferens, also called sperm duct, or, spermatic deferens, extends from the epididymis in the scrotum on its own side into the abdominal cavity through the inguinal canal. The inguinal canal is an opening in the abdominal wall for the spermatic cord a connective tissue sheath that contains the ductus deferens, testicular blood vessels, and nerves. The smooth muscle layer of the ductus deferens contracts in waves of peristalsis during ejaculation. The pair of seminal vesicles are posterior to the urinary bladder.
They secrete fructose to provide an energy source for sperm and alkalinity to enhance sperm mobility. The duct of each seminal vesicle joins the ductus deferens on that side to form the ejaculatory duct. There are two ejaculatory ducts. Each receives sperm from the ductus deferens and the secretions of the seminal vesicle on its own side. Both ejaculatory ducts empty into the single urethra. The prostate gland is a muscular gland that surrounds the first inch of the urethra as it emerges from the bladder.
The smooth muscle of the prostate gland contracts during ejaculation to contribute to the expulsion of semen from the urethra. The bulbourethral glands also called Cowper's glands are located below the prostate gland and empty into the urethra. The alkalinity of seminal fluid helps neutralize the acidic vaginal pH and permits sperm mobility in what might otherwise be an unfavorable environment. The penis is an external genital organ. The distal end of the penis is called the glans penis and is covered with a fold of skin called the prepuce or foreskin.
Human Physiology/The male reproductive system - Wikibooks, open books for an open world
Within the penis are masses of erectile tissue. Each consists of a framework of smooth muscle and connective tissue that contains blood sinuses, which are large, irregular vascular channels. The urethra, which is the last part of the urinary tract, traverses the corpus spongiosum and its opening, known as the meatus, lies on the tip of the glans penis. It is both a passage for urine and for the ejaculation of semen.
The components of semen come from two sources: sperm, and "seminal plasma". Seminal plasma, in turn, is produced by contributions from the seminal vesicle, prostate, and bulbourethral glands. The seminal plasma provides a nutritive and protective medium for the spermatozoa during their journey through the female reproductive tract.
The normal environment of the vagina is a hostile one for sperm cells, as it is very acidic from the native microflora producing lactic acid , viscous, and patrolled by immune cells. The components in the seminal plasma attempt to compensate for this hostile environment. Basic amines such as putrescine, spermine, spermidine and cadaverine are responsible for the smell and flavor of semen. These alkaline bases counteract the acidic environment of the vaginal canal, and protect DNA inside the sperm from acidic denaturation. A World Health Organization report described normal human semen as having a volume of 2 ml or greater, pH of 7.
The erection of the penis is its enlarged and firm state. It depends on a complex interaction of psychological, neural, vascular and endocrine factors. The term is also applied to the process that leads to this state. A penile erection occurs when two tubular structures that run the length of the penis, the corpora cavernosa, become engorged with venous blood. This is a result of parasympathetic nerve induced vasodilation. This may result from any of various physiological stimuli.
The corpus spongiosum is a single tubular structure located just below the corpora cavernosa, which contains the urethra, through which urine and semen pass during urination and ejaculation, respectively. This may also become slightly engorged with blood, but less so than the corpora cavernosa.
An erection results in swelling and enlargement of the penis. Erection enables sexual intercourse and other sexual activities sexual functions , though it is not essential for all sexual activities. Emission is the term used when sperm moves into the urethra. Ejaculation is the term used when sperm is forced out of the urethra and the penis. These are both stimulated by sympathetic nerves. A spermatozoon or spermatozoan pl. Spermatagonia divides several times during the process of sperm development. The entire process of sperm formation and maturation takes about weeks.
The separate divisions that take place and what happens in each are as follows:.