Presentation Urinary and Reproductuve Systems

Module 8: Urinary, and Male and Female Reproductive Systems BIOT 106 - Summary of Human Anatomy and Physiology

The Urinary System It is formed by: • -The 2 Kidneys • -The 2 Ureters • -The Bladder • -The Urethra

The Kidneys  Paired organ  Have the shape of a bean  Dark red color  Are located behind the parietal peritoneum  Have two faces, an anterior and a posterior  Two borders, a convex lateral one and a concave medial one, this one corresponding to the renal hilum, where the renal artery, renal vein, and the ureter are found

Ureters  The ureters are two long tubes which measure between 25 and 30 cm long and 6mm in diameter.  Each ureter is located along the peritoneum from the renal hilum to the posterior part of the bladder, in which it enters slightly on an angle.  Ureters are conduits which transport urine from the kidneys to the bladder.  The smooth muscle layers of its walls contract to push urine up to the bladder through peristalsis.

Urinary Bladder  The urinary bladder is a smooth and foldable muscular sac that stores urine temporarily.  It is located in the retroperitoneal area, in the posterior part of the pubic symphysis.  The wall of the bladder has three layers of smooth muscle, known together as the detrusor muscle, and its mucous is a special type of epithelium, the transitional epithelium.  These two structural characteristics make the bladder be unique in its urine storage function.  The ureters end in the bladder (meatus) and together with the internal urethral sphincter form a trinagular region in its base called trigone.

Urethra  The urethra is a thin-walled tuve which transports urine through peristalsis from the bladder to the outside of the body.  The longitude and relative function of the urethra is different in the two sexes.  In women the urethra measures between 3 and 4 cm long and itsexternal orifice is in anterior form to the vagina.  In men, the urethra measures approximately 20 cm long and it has three regions: the prostatic urethra, the membranous urethra, and the spongy urethra

Male Reproductive System  The primary reproductive organs in men are the testicles or male gonads, which have an exocrine function (the production of sperm), and an endocrine function (the production of testosterone). The accessory reproductive structures are conduits or glands which help transport sperm to the exterior of the body or to the female reproductive tract. (they are the bulbourethral glands, the prostate, and the seminal vesicles).

Male Reproductive System Testicles System of Ducts • The testicles are a paired organ • The annexed organs which form the located immediately under the penis, male system of ducts, which they have the approximate size of a transports spermatozoa in the body, prune, measuring approximately 4 are the epididymis, the vas deferens, cm long and 2,5 cm wide. and the urethra. • Each testicle is surrounded by 7 layers which from the outside in are: scrotum, dartos, subcutaneous celullar layer, external spermatic fascia, internal spermatic fascia and vaginal tunica and albuginea tunica

Epididymis  Is a strongly coiled tube, approximately 6 meters long, which covers the superior part of the testicle and that also runs along its back side.  The epididymis is the first part of the male system of ducts and provides a temporary storage place for immature spermatozoa that reach it from the testicle.  When a man is sexually stimulated and ejaculates, the walls of the epididymis contract to pump sperm to the next part of the system of conduits, the vas deferens.

Annex Glands  Among the annex glands we include seminal vesicles, which are two: the prostate, which is one, and the bulborethral glands. These glands produce semen, the fluid which contains sperm and which is expeled from the male reproductive tract during ejaculation.

Seminal Vesicles  The seminal vesicles, located at the base of the bladder, produce close to 60% of the seminal fluid, the liquid volume of semen. Its dense and yellowish secretion is rich in sugar (fructose), vitamin C, prostaglandins, and other substances that feed and actívate the sperm that passes through the tract. The conduit of each seminal vesicle joins the vas deferens on the same side to form the ejaculating conduit. Like this, sperm and seminal fluid enter together to the urethra during ejaculation.

Prostate  The prostate is a unique circular gland and has a shape resembling a peach pit. It surrounds the superior part (prostatic) of the urethra, just below the bladder. The secretion of the prostatic gland is a milky fluid which plays a role at the time of activating spermatozoa. During ejaculation, the liquid enters the urethra through various small conduits. Since the prostate is located immediately before the rectum, its size and texture may be touched in a digital examination (with the fingers) through the anterior wall of the rectum.

Bulborethral Glands or Cowper’s Gland  Bulborethral glands are minuscule glands, the size of peas, located under the prostatic gland. They produce a thick and clear mucous which discharges into the penile urethra. This secretion is the first that passes through the urethra when a man is sexually excited. It cleans and clears the urethra from traces of urine, which is acidic, and serves as a lubricant during the sexual act.

External Genitals The external male genitals include the scrotum and the penis. The scrotum • The scrotum is a sac of skin which hangs outside the abdominal cavity, between the legs and at the base of the penis. The scrotum tends to hang freely from the body, providing the testicles with a lower temperatura than that of the body. . • The scrotum is a sac of skin which hangs outside the abdominal cavity, between the legs and at the base of the penis. The scrotum tends to hang freely from the body, providing the testicles with a lower temperatura than Thtehapteonf tishe body. • It is designed to introduce sperm in the female reproductive tract. The skin covered penis consists of an axis or body, which ends in a alongated tip, the glans. The skin that covers the penis is loose and it folds downward to form a skin fold, the prepuce, surrounding the closest extreme of the glans. Frequently, the prepuce is eliminated by a procedure known as circumcision. Internally, the spongy urethra is surrounded by three long areas of erectile tissue, a spongy tissue that fills with blood during sexual excitement. This makes the penis to become longer and rigid. This fact, calle dan erection, helps the penis to serve as a penetration organ so the semen can reach the female reproductive tract.

Female Reproductive System

Female The reproductive role of women is much Reproductive more complex than that of men. Not only System does it have to produce the female gametes (ova), but her body also has to feed and protect a developing fetus during nine months of gestation. The ovaries are the primary female reproductive organs. Like the testicles, the ovaries build an exocrine product (ova) and endocrine products (estrogens and progesterone). The other organs of the female reproductive system serve as accessory structures for the transport, feeding, or any other purpose that satisfies the needs of reproductive cells and/or the developing fetus.

Ovaries  The pair of ovaries has a very similar shape to that of almonds, but they are almost double the size. If we look at an ovary on the inside, we will see many minuscule structures resembling sacs called ovary follicles. Each follicle consists of an immature ovule, called ovocyte, surrounded by one or more layers of different cells called follicular cells. As a developing ovule inside a follicle begins to mature, the follicle increases in size and develops a central area full of fluid called antrum.

Fallopian Tubes  The Fallopian or uterine tubes form the initial part of the system of conduits. They receive the ovulated ovocyte and provide a place in which fertilization occurs. Each one of the Fallopian tubes measures approximately 10 cm long and extends from the ovary to end in the superior part of the uterus.

Uterus  The uterus, located in the pelvis between the bladder and the rectum, is a hollow organ which works to receive, retain and feed a fertilized ovule. In a woman who has never been pregnant, they have the shape and size of a pear. (During gestation, the uterus increases 20 times its size)  If fertilization occurs, the fertilized ovule (in reality the young embryo at the moment it reaches the uterus) is buried in the endometrium (process called implantation) and remains there during the rest of its development.

Vagina  The vagina is a tube of thin walls 8 to10 cm long. It is located between the bladder and the rectum and extends from the cervix to the exterior of the body. Frequenty known as the birth canal, the vagina provide a conduit for birth of children and for the menstrual flow to leave the organism. When receving the penis (and semen) during the sexual act, it is also the female copulation organ.

External Female Genitals  The female reproductive structures located in the exterior of the vagina are the external genitals. The external genitals, also known collectively as the vulva, consist of: the mount of Venus or pubis, the labia, the clitoris, the urethral and vaginal orífices, and the major vestibular gland.

Mammary Glands  Both sexes have mammary glands, but they only function in women. Since their biological role is to produce milk to feed the newborn, they are really important when reproduction has been achieved.