{"id":85,"date":"2015-12-08T21:28:17","date_gmt":"2015-12-08T21:28:17","guid":{"rendered":"http:\/\/brooksidepress.org\/ob-ped\/?page_id=85"},"modified":"2016-12-21T15:56:27","modified_gmt":"2016-12-21T15:56:27","slug":"1-08-internal-organs","status":"publish","type":"page","link":"https:\/\/brooksidepress.org\/ob-ped\/lessons\/lesson-1-the-reproductive-systems\/section-ii-the-male-reproductive-system\/1-08-internal-organs\/","title":{"rendered":"1-08. INTERNAL ORGANS"},"content":{"rendered":"

a. Testes<\/strong>. The testes are the primary organs of reproduction in the male.<\/p>\n

The\u00a0male testes correspond to the female ovaries.<\/p>\n

(1) Description\/information.<\/span> The testes are located in the scrotum.<\/p>\n

They\u00a0are oval structures enclosed in a fibrous capsule. The testes are covered by a dense\u00a0layer of white fibrous tissue called the tunica albuginea. This tissue layer extends\u00a0inward and divides each testis into a series of internal compartments called lobules.\u00a0Each of the 200 to 300 lobules contains one to three tightly coiled tubules called the\u00a0seminiferous tubules.<\/p>\n

(2) Functions<\/span>. The seminiferous tubules produce sperm by a process called\u00a0spermatogenesis.<\/p>\n

As well as producing sperm, the testes produce the male hormone\u00a0testosterone. Interstitial cells within the testes produce this hormone, which is essential\u00a0for the development of the male secondary sex characteristics. If testosterone is not\u00a0produced in a male body, growth of hair on the face and body, deepening of the voice,\u00a0and an increase in skeletal mass do not occur. Also, sperm will not develop without\u00a0testosterone.<\/p>\n

(3) Sperm<\/span>. The seminiferous tubules produce sperm by a process called\u00a0spermatogenesis. Sperm can be defined as the reproductive cells of the male. Each\u00a0seminiferous tubule is packed with sperm in various stages of development. Beginning\u00a0at about puberty, a male produces about 300 million sperm cells each day. As a male\u00a0grows older, the production of sperm decreases. Males continue to produce sperm\u00a0throughout life.<\/p>\n

(a) Description\/information. Compared to a female ovum, a sperm cell\u00a0is very small, but it is well shaped to reach out and penetrate a female ovum. A sperm\u00a0cell has a head, a middle section, and a tail. The head is flat and oval shaped (ideal for\u00a0penetration and attachment) and contains the nucleus of the cell. The middle section is\u00a0made up of substances that make useable energy to propel the tail. And the long tail\u00a0acts like a whip to move the sperm. When the head penetrates the ovum, the tail\u00a0separates from the rest of the sperm.<\/p>\n

<\/a><\/p>\n

(b) Chromosomes in a sperm cell. The nucleus in the head of a sperm\u00a0cell contains chromosomes. A mature sperm has 23 chromosomes. An immature\u00a0sperm cell has 46 chromosomes, one an X (female) chromosome and the other a Y\u00a0(male) chromosome. A reduction division takes place to form a mature cell which has\u00a023 chromosomes. At that time, an X chromosome (female) goes to one sperm cell, and\u00a0a Y (male) chromosome goes to the other sperm cell. If an ovum is joined by a sperm\u00a0with an X chromosome, the combination will form a female. If a sperm with a Y\u00a0chromosome joins an ovum, a male is formed.<\/p>\n

b. Epididymis<\/strong>. At the upper and posterior part of each testis is the epididymis–an elongated, triangular tube which is 16 to 20 feet in length.<\/p>\n

Each comma-shaped tube\u00a0is positioned along the posterior side of a testis and is mostly made up of a tightly coiled\u00a0tube called the ductus epididymis. Sperm mature in the epididymis tubes. These tubes\u00a0link the testes proper with the ductus deferens. Sperm are stored in the epididymis\u00a0tubes until they are ejaculated and enter the vas deferens.<\/p>\n

c. Ductus (Vas) Deferens<\/strong>. At its tail, the epididymis becomes less coiled, its\u00a0diameter increases, and the tubes become known as the ductus deferens or the vas\u00a0deferens.<\/p>\n

Ductus deferens are muscular tubes which are about 48 centimeters (18\u00a0inches) long. Two ductus deferens, one from each epididymis tube, lead up through the\u00a0inguinal canal into the pelvic cavity, cross to the posterior surface of the urinary bladder,\u00a0and unite with the ducts of the seminal vesicles to form the ejaculatory ducts. Each\u00a0ductus deferens stores sperm for a period of up to several months and propels sperm\u00a0toward the urethra during ejaculation.<\/p>\n

d. Seminal Vesicles<\/strong>. The seminal vesicles are two glandular pouches located\u00a0behind and below the urinary bladder.<\/p>\n

These tubular structures secrete a fluid which\u00a0activates the spermatozoa in the semen. The secretions contain sugar fructose and\u00a0prostaglandins. Fructose energizes the sperm, and prostaglandins assist ejaculation\u00a0and stimulate uterine contractions. Thus, both fructose and prostaglandins help sperm\u00a0move to the uterine tubes where fertilization occurs. Additionally, this fluid is slightly\u00a0alkaline, which helps protect sperm against the acid secretion of the vagina. Secretion\u00a0of the seminal vesicles makes up 60 percent of the ejaculate (fluid ejaculated).<\/p>\n

e. Ejaculatory Duct.<\/strong> Each ductus deferens and its corresponding seminal\u00a0vesicle come together to form a short tube called the ejaculatory duct.<\/p>\n

The ejaculatory\u00a0duct opens into the urethra within the prostate gland. The ejaculatory duct carries both\u00a0sperm and seminal vesicle fluid.<\/p>\n

f. Prostate Gland<\/strong>. This gland is a single, doughnut-shaped gland which is\u00a0about the size of a chestnut.<\/p>\n

The gland lies directly below the urinary bladder and\u00a0surrounds the prostatic part of the urethra. The prostate gland secretes a highly\u00a0alkaline fluid which protects sperm acidity in the urethra and vagina. Secretion from the\u00a0prostate gland is added to the sperm and seminal vesicle fluid. From 13 to 33 percent\u00a0of the volume of semen seminal vesicle fluid is prostate gland secretion. Prostate gland\u00a0secretion also contributes to sperm motility.<\/p>\n

g. Bulbourethral (Cowper’s) Glands.<\/strong><\/p>\n

(1) Description\/information. These are two small glands, about the size of\u00a0peas, located just below the prostate on either side of the urethra. These glands\u00a0secrete a mucous-like lubricating fluid into the membranous urethra. The glands also\u00a0secrete a substance that neutralizes urine. Ducts of these glands open into the spongy\u00a0urethra.<\/p>\n

(2) Semen. Semen (seminal fluid) is the fluid discharged at ejaculation by a\u00a0male. This fluid is made up of sperm in the secretions of the seminal vesicles, the\u00a0prostate gland, and the bulbourethral glands.<\/p>\n

h. Urethra<\/strong>. The urethra is the final duct of the reproductive system.<\/p>\n

This duct\u00a0acts as a passageway for sperm or urine. The urethra is about 20 cm (8 inches) long.<\/p>\n

The ejaculatory ducts pass sperm into the urethra which passes through the prostate\u00a0gland and through the penis to be ejaculated.<\/p>\n","protected":false},"excerpt":{"rendered":"

a. Testes. The testes are the primary organs of reproduction in the male. The\u00a0male testes correspond to the female ovaries. (1) Description\/information. The testes are located in the scrotum. They\u00a0are oval structures enclosed in a fibrous capsule. The testes are covered by a dense\u00a0layer of white fibrous tissue called the tunica albuginea. This tissue layer … Continue reading 1-08. INTERNAL ORGANS<\/span> →<\/span><\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"parent":24,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-85","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/brooksidepress.org\/ob-ped\/wp-json\/wp\/v2\/pages\/85","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/brooksidepress.org\/ob-ped\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/brooksidepress.org\/ob-ped\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/brooksidepress.org\/ob-ped\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/brooksidepress.org\/ob-ped\/wp-json\/wp\/v2\/comments?post=85"}],"version-history":[{"count":2,"href":"https:\/\/brooksidepress.org\/ob-ped\/wp-json\/wp\/v2\/pages\/85\/revisions"}],"predecessor-version":[{"id":430,"href":"https:\/\/brooksidepress.org\/ob-ped\/wp-json\/wp\/v2\/pages\/85\/revisions\/430"}],"up":[{"embeddable":true,"href":"https:\/\/brooksidepress.org\/ob-ped\/wp-json\/wp\/v2\/pages\/24"}],"wp:attachment":[{"href":"https:\/\/brooksidepress.org\/ob-ped\/wp-json\/wp\/v2\/media?parent=85"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}