viernes, 27 de julio de 2012

EMBRYOLOGY


Pregnancy



Pregnancy is the fertilization and development of one or more offspring, known as an embryo or fetus, in a woman's uterus. In a pregnancy, there can be multiple gestations, as in the case of twins or triplets. Childbirth usually occurs about 38 weeks after conception; in women who have a menstrual cycle length of four weeks, this is approximately 40 weeks from the start of the last normal menstrual period (LNMP). Human pregnancy is the most studied of all mammalian pregnancies. Conception can be achieved through sexual intercourse or assisted reproductive technology.
An embryo is the developing offspring during the first 8 weeks following conception, and subsequently the term fetus is used henceforth until birth. 40% of pregnancies in the United States and United Kingdom are unplanned, and between a quarter and half of those unplanned pregnancies were unwanted pregnancies.
In many societies’ medical or legal definitions, human pregnancy is somewhat arbitrarily divided into three trimester periods, as a means to simplify reference to the different stages of prenatal development. The first trimester carries the highest risk of miscarriage (natural death of embryo or fetus). During the second trimester, the development of the fetus can be more easily monitored and diagnosed. The beginning of the third trimester often approximates the point of viability, or the ability of the fetus to survive, with or without medical help, outside of the uterus.

Complications of pregnancy


Complications of pregnancy are the symptoms and problems that are associated with pregnancy. There are both routine problems and serious, even potentially fatal problems. The routine problems are normal complications, and pose no significant danger to either the woman or the fetus. Serious problems can cause both maternal death and fetal death if untreated.

Back pain
§  Common, particularly in the third trimester when the patient's center of gravity has shifted.
§  Treatment: mild exercise, gentle massage, heating pads, paracetamol (acetaminophen), and (in severe cases) muscle relaxants or narcotics

Carpal tunnel syndrome
§  Occurs in between an estimated 21% to 62% of cases, possibly due to edema.

Constipation
§  Cause: decreased bowel motility secondary to elevated progesterone (normal in pregnancy), which causes the "smooth muscle" along the walls of the intestines to relax. Thus, making sure that the future mother will absorb as much nutrients from her diet as possible in order to nourish the fetus and herself. As a side effect the feces can get extremely dehydrated and hard to pass.
§  Treatment: increased PO fluids, stool softeners, bulking agents Drinking plenty of water and eating fruit and fiber enriched foods often help
A woman experiencing sudden defecation should report this to her practitioner.
Contractions
§  occasional, irregular, painless contractions that occur several times per day are normal and are known as Braxton Hicks contractions
§  Caused by: dehydration
§  Treatment: fluid intake
§  regular contractions (every 10-15 min) are a sign of preterm labor and should be assessed by cervical exam.
Dehydration
§  Caused by: expanded intravascular space and increased Third spacing of fluids
§  Treatment: fluid intake
§  Complication: uterine contractions, which may occur because dehydration causes body release of ADH, which is similar to oxytocin in structure. Oxytocin itself can cause uterine contractions and thus ADH can cross-react with oxytocin receptors and also cause contractions.
Edema
§  Caused by: compression of the inferior vena cava (IVC) and pelvic veins by the uterus leads to increased hydrostatic pressure in lower extremities.
§  Treatment: raising legs above the heart, patient sleeps on her side.
Gastroesophageal Reflux Disease (GERD)
§  Caused by: relaxation of the lower esophageal sphincter (LES) and increased transit time in the stomach (normal in pregnancy)
§  Treatment: antacids, multiple small meals a day, avoid lying down within an hour of eating, H2 blockers, proton pump inhibitors
Hemorrhoids
§  Caused by: increased venous stasis and IVC compression leading to congestion in venous system along with increased abdominal pressure secondary to constipation.
§  Treatment: topical anesthetics, steroids, treatment of constipation
Pica
§  cravings for nonedible items such as dirt or clay. Caused by Iron deficiency which is normal during pregnancy and can be overcome with Iron supplements or prenatal vitamins. Commonly, avoid ice chips; it may worsen anemia
Lower abdominal pain
§  Caused by: rapid expansion of the uterus and stretching of ligaments such as the round ligament.
§  Treatmentparacetamol (acetaminophen)(kulot)
Increased urinary frequency
§  Caused by: increased intravascular volume, elevated GFR (glomerular filtration rate), and compression of the bladder by the expanding uterus. Patients are advised to continue fluid intake despite this. Urinalysis and culture should be ordered to rule out infection, which can also cause increased urinary frequency but typically is accompanied by dysuria(pain when urinating).
Varicose veins
§  Caused by: relaxation of the venous smooth muscle and increased intravascular pressure.
§  Treatment: elevation of the legs, pressure stockings
§  relieve swelling and pain with warm sitz bath.
§  Avoid obesity, lengthy standing or sitting, constrictive clothing and constipation and bearing down with bowel movements
Diastasis recti or abdominal separation
During pregnancy, many women experience a separation of their stomach muscles, known as diastasis recti. In order to understand this condition, it is important to understand the muscle that it affects. This particular condition affects the rectus abdominis muscle, that muscle that gives you a “six pack”. (See figure)
The rectus abdominis muscle is divided down the middle by the tendinous line called the linea alba.[3] It is kept in line by your transverse abdominal and your oblique abdominal muscles. During pregnancy, the growth of the fetus exerts pressure on abdominal cavity muscles, in particular the rectus abdominis. In pregnancies that experience rapid fetus growth or women with particularly weak abdominal muscles, this pressure can sometimes causes the rectus abdominis muscle to separate along the linea alba, creating a split between the left and right sides of the rectus abdominis.
About one-third of all pregnant women experience diastasis recti at some point in their pregnancy, however it is much more likely to occur during the second trimester or third trimester of pregnancy. However, separation also frequently occurs during labor and delivery, or with women carrying more than one baby. Many cases of diastasis recti correct themselves after birth, but some do not. In cases where it persists, exercise may help improve the condition, and sometimes surgery is needed to correct the problem to prevent pain and future complications.

congenital disorder

A congenital disorder, or congenital disease, is a condition existing at birth and often before birth, or that develops during the first month of life (neonatal disease), regardless of causation. Of these diseases, those characterized by structural deformities are termed "congenital anomalies"; that is a different concept  which involves defects in or damage to a developing fetus.
A congenital disorder may be the result of genetic abnormalities, the intrauterine (uterus) environment, errors of morphogenesis,infection, or a chromosomal abnormality. The outcome of the disorder will depend on complex interactions between the pre-natal deficit and the post-natal environment Animal studies indicate that the mother's (and possibly the father's) diet, vitamin intake, and glucose levels prior to ovulation and conception have long-term effects on fetal growth and adolescent and adult disease Congenital disorders vary widely in causation and abnormalities. Any substance that causes birth defects is known as a teratogen.
The older term congenital disorder does not necessarily refer to a genetic disorder despite the similarity of the words. Some disorders can be detected before birth through prenatal diagnosis (screening).






Neonatal Care


A neonatal intensive care unit (NICU) is an intensive care unit specializing in the care of ill or premature newborn infants. The first official ICU for neonates was founded in 1961 at Vanderbilt University by Dr. Mildred Stahlman, officially termed a NICU when Dr. Stahlman used a ventilator off-label for a baby with breathing difficulties, for the first time ever in the world.
A NICU is typically directed by one or more neonatologists and staffed by nurses, nurse practitioners, pharmacists, physician assistants, resident physicians, and respiratory therapists. Many other ancillary disciplines and specialists are available at larger units. The term neonatal comes from neo, "new", and natal, "pertaining to birth or origin".


FEMALE REPRODUCTIVE SYSTEM


Female Reproductive System



The human female reproductive system contains two main parts: the uterus, which hosts the developing fetus, produces vaginal and uterine secretions, and passes the male's sperm through to the fallopian tubes; and the ovaries, which produce the female's egg cells. These parts are internal; the vagina meets the external organs at the vulva, which includes the labia, clitoris and urethra. The vagina is attached to the uterus through the cervix, while the uterus is attached to the ovaries via the Fallopian tubes. At certain intervals, the ovaries release an ovum, which passes through the Fallopian tube into the uterus.
If, in this transit, it meets with sperm, the sperm penetrate and merge with the egg, fertilizing it. The fertilization usually occurs in the oviducts, but can happen in the uterus itself. The zygote then implants itself in the wall of the uterus, where it begins the processes of embryogenesis and morphogenesis. When developed enough to survive outside the womb, the cervix dilates and contractions of the uterus propel the fetus through the birth canal, which is the vagina.
The ova are larger than sperm and have formed by the time a female is born. Approximately every month, a process of oogenesis matures one ovum to be sent down the Fallopian tube attached to its ovary in anticipation of fertilization. If not fertilized, this egg is flushed out of the system through menstruation.

 Dysmenorrhea 



Dysmenorrhea is a gynecological medical condition of pain during menstruation that interferes with daily activities, as defined by ACOG and others. Still, dysmenorrhea is often defined simply as menstrual pain, or at least menstrual pain that is excessive. This article uses the dysmenorrhea definition of menstrual pain that interferes with daily activities, and uses the term menstrual pain as any pain during menstruation whether it is normal or abnormal.
Menstrual pain is often used synonymously with menstrual cramps, but the latter may also refer to menstrual uterine contractions, which are generally of higher strength, duration and frequency than in the rest of the menstrual cycle.
Dysmenorrhea can feature different kinds of pain, including sharp, throbbing, dull, nauseating, burning, or shooting pain. Dysmenorrhea may precede menstruation by several days or may accompany it, and it usually subsides as menstruation tapers off. Dysmenorrhea may coexist with excessively heavy blood loss, known as menorrhagia.
Secondary dysmenorrhea is diagnosed when symptoms are attributable to an underlying disease, disorder, or structural abnormality either within or outside the uterus. Primary dysmenorrhea is diagnosed when none of these are detected.

 Amenorrhea


Amenorrhea is defined as delay of menstruation. There are 2 types of amenrrhea:
a)Primary amenorrhea is defined as no period by age 16 and
b)Secondary amenorrhea is defined as period beginning at the appropriate age, but later stops for more than 3 cycles or 6 months. Women who have a delay of period used to think that may be pregnant. In fact, there are many causes
of amenorrhea. In this article, we will discuss how to treat amenorrhea with nutritional supplements.


Ovarian cyst 


An ovarian cyst is any collection of fluid, surrounded by a very thin wall, within an ovary. Any ovarian follicle that is larger than about two centimeters is termed an ovarian cyst. An ovarian cyst can be as small as a pea, or larger than an orange.
Most ovarian cysts are functional in nature and harmless (benign). In the US, ovarian cysts are found in nearly all premenopausal women, and in up to 14.8% of postmenopausal women.
Ovarian cysts affect women of all ages. They occur most often, however, during a woman's childbearing years.
Some ovarian cysts cause problems, such as bleeding and pain. Surgery may be required to remove cysts larger than 5 centimeters in diameter.

Endometriosis


Endometriosis is a disorder of the female reproductive system. The uterus is composed of 3 layers: the perometrium (the outer layer), the myometrium (the muscle or middle layer), and the endometrium (the inner layer).
Each month during a woman's menstrual cycle, the endometrium grows and thickens to prepare for implantation of a fertilized ovum. When the endometrium reaches its full thickness, an egg is released from the ovaries. If the egg is fertilized, it attaches to the thickened endometrium. However, if the egg is not fertilized, the endometrial layer is sloughed off as a normal part of the menstrual cycle.
Endometriosis is a condition in which endometrial cells become attached to tissues surrounding the uterus, such as the fallopian tubes, the ovaries, or the large or small intestines.


MALE REPRODUCTIVE SYSTEM


Male Reproductive System


All living things reproduce. Reproduction — the process by which organisms make more organisms like themselves — is one of the things that sets living things apart from nonliving things. But even though the reproductive system is essential to keeping a species alive, unlike other body systems it's not essential to keeping an individual alive.

In the human reproductive process, two kinds of sex cells, or gametes, are involved. The male gamete, or sperm, and the female gamete, the egg or ovum, meet in the female's reproductive system to create a new individual. Both the male and female reproductive systemsare essential for reproduction.
Humans, like other organisms, pass certain characteristics of themselves to the next generation through their genes, the special carriers of human traits. The genes parents pass along to their offspring are what make kids similar to others in their family, but they're also what make each child unique. These genes come from the father's sperm and the mother's egg, which are produced by the male and female reproductive systems.
Understanding the male reproductive system, what it does, and the problems that can affect it can help you better understand your son's reproductive health.
Gynecomastia


Gynecomastia is the abnormal development of large mammary glands in males resulting in breast enlargement.  The condition can occur physiologically in neonates (due to female hormones from the mother), in adolescence, and in the elderly (Both in adolescence and elderly it is an abnormal condition associated with disease or metabolic disorders). In adolescent boys the condition is often a source of distress, but for the large majority of boys whose pubescent gynecomastia is not due toobesity, the breast development shrinks or disappears within a couple of years.

Disorders

Disorders that most commonly affect the scrotum are hydroceles, an accumulation of fluid that surrounds the testicle; varicoceles, dilated veins appearing in the scrotum; and spermatoceles, sperm-filled cysts found in the head of the epididymis. Tumors or cancer of the testicle may also present as a mass in the scrotum.
Hydroceles are painless fluid collections around the testis, which often go away without treatment, especially when present during the first year of life.
Varicoceles are commonly associated with impaired fertility in the adult male and can be corrected through surgery so that fertility is restored or impairment prevented.
Spermatoceles, unlike hydroceles, which surround the testicles, are specifically located at the head of the epididymis.
The three most common disorders that affect the scrotum, the sac beneath the penis that holds the testicles, include: 



  • Hydroceles, the collection of fluid within a section of the scrotum called the tunica vaginalis;
  • Varicoceles, which is an enlarged group of veins above the testicles and along the vas deferens, a blood vessel-rich cord that connects the epididymis to the prostate gland; and
  • Spermatoceles, which are sperm-filled cysts at the head of the epididymis, a coil of tubes behind the testicles where sperm are stored.
 Prostate Cancer


Prostate cancer is a form of cancer that develops in the prostate, a gland in the male reproductive system. Most prostate cancers are slow growing; however, there are cases of aggressive prostate cancers. The cancer cells may metastasize (spread) from the prostate to other parts of the body, particularly the bones and lymph nodes. Prostate cancer may cause pain, difficulty in urinating, problems during sexual intercourse, or erectile dysfunction. Other symptoms can potentially develop during later stages of the disease.
Rates of detection of prostate cancers vary widely across the world, with South and East Asia detecting less frequently than in Europe, and especially the United States.Prostate cancer tends to develop in men over the age of fifty. Globally it is the sixth leading cause of cancer-related death in men (in the United States it is the second) Prostate cancer is most common in the developed world with increasing rates in the developing world.However, many men with prostate cancer never have symptoms, undergo no therapy, and eventually die of other unrelated causes. Many factors, including genetics and diet, have been implicated in the development of prostate cancer