Obstetrics is the field of study concentrated on pregnancy and the postpartum period. As a medical specialty, obstetrics is combined with gynecology under the discipline known as obstetrics and gynecology, a surgical field. Prenatal care is important in screening for various complications of pregnancy; this includes routine office visits with physical exams and routine lab tests: Complete blood count Blood type General antibody screen for HDN Rh D negative antenatal patients should receive RhoGam at 28 weeks to prevent Rh disease. Rapid plasma reagin to screen for syphilis Rubella antibody screen Hepatitis B surface antigen Gonorrhea and Chlamydia culture PPD for tuberculosis Pap smear Urinalysis and culture HIV screenGenetic screening for Down syndrome and trisomy 18, the national standard in the United States, is evolving away from the AFP-Quad screen for Down syndrome, done in the second trimester at 16–18 weeks; the newer integrated screen can be done at 10 plus weeks to 13 plus weeks with an ultrasound of the fetal neck and two chemicals PAPP-A and βHCG.
It gives an accurate risk profile early. A second blood screen at 15 to 20 weeks refines the risk more accurately; the cost is higher than an "AFP-quad" screen due to the ultrasound and second blood test, but it is quoted to have a 93% pick up rate as opposed to 88% for the standard AFP/QS. This is an evolving standard of care in the United States. MSAFP/quad. Screen – elevations, low numbers or odd patterns correlate with neural tube defect risk and increased risks of trisomy 18 or trisomy 21 Ultrasound either abdominal or transvaginal to assess cervix, placenta and baby Amniocentesis is the national standard for women over 35 or who reach 35 by mid pregnancy or who are at increased risk by family history or prior birth history. Hematocrit Group B Streptococcus screen. If positive, the woman receives IV penicillin or ampicillin while in labor—or, if she is allergic to penicillin, an alternative therapy, such as IV clindamycin or IV vancomycin. Glucose loading test – screens for gestational diabetes.
Most doctors do a sugar load in a drink form of 50 grams of glucose in cola, lime or orange and draw blood an hour later. The standard modified criteria have been lowered to 135 since the late 1980s. Obstetric ultrasonography is used for dating the gestational age of a pregnancy from the size of the fetus, determine the number of fetuses and placentae, evaluate for an ectopic pregnancy and first trimester bleeding, the most accurate dating being in first trimester before the growth of the foetus has been influenced by other factors. Ultrasound is used for detecting congenital anomalies and determining the biophysical profiles, which are easier to detect in the second trimester when the foetal structures are larger and more developed. Specialised ultrasound equipment can evaluate the blood flow velocity in the umbilical cord, looking to detect a decrease/absence/reversal or diastolic blood flow in the umbilical artery. X-rays and computerized tomography are not used in the first trimester, due to the ionizing radiation, which has teratogenic effects on the foetus.
No effects of magnetic resonance imaging on the foetus have been demonstrated, but this technique is too expensive for routine observation. Instead, obstetric ultrasonography is the imaging method of choice in the first trimester and throughout the pregnancy, because it emits no radiation, is portable, allows for realtime imaging; the safety of frequent ultrasound scanning has not be confirmed. Despite this, increasing numbers of women are choosing to have additional scans for no medical purpose, such as gender scans, 3D and 4D scans. A normal gestation would reveal a gestational sac, yolk sac, fetal pole; the gestational age can be assessed by evaluating the mean gestational sac diameter before week 6, the crown-rump length after week 6. Multiple gestation is evaluated by the number of placentae and amniotic sacs present. Other tools used for assessment include: Fetal screening is used to help assess the viability of the fetus, as well as congenital abnormalities. Fetal karyotype can be used for the screening of genetic diseases.
This can be obtained via amniocentesis or chorionic villus sampling Foetal haematocrit for the assessment of foetal anemia, Rh isoimmunization, or hydrops can be determined by percutaneous umbilical blood sampling, done by placing a needle through the abdomen into the uterus and taking a portion of the umbilical cord. Fetal lung maturity is associated with. Reduced production of surfactant indicates decreased lung maturity and is a high risk factor for infant respiratory distress syndrome. A lecithin:sphingomyelin ratio greater than 1.5 is associated with increased lung maturity. Nonstress test for fetal heart rate Oxytocin challenge test A pregnant woman may have intercurrent diseases, that is, other diseases or conditions that may become worse or be a potential risk to the pregnancy. Diabetes mellitus and pregnancy deals with the interactions of diabetes mellitus and pregnanc
The brain is an organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. The brain is located in the head close to the sensory organs for senses such as vision; the brain is the most complex organ in a vertebrate's body. In a human, the cerebral cortex contains 14–16 billion neurons, the estimated number of neurons in the cerebellum is 55–70 billion; each neuron is connected by synapses to several thousand other neurons. These neurons communicate with one another by means of long protoplasmic fibers called axons, which carry trains of signal pulses called action potentials to distant parts of the brain or body targeting specific recipient cells. Physiologically, the function of the brain is to exert centralized control over the other organs of the body; the brain acts on the rest of the body both by generating patterns of muscle activity and by driving the secretion of chemicals called hormones. This centralized control allows coordinated responses to changes in the environment.
Some basic types of responsiveness such as reflexes can be mediated by the spinal cord or peripheral ganglia, but sophisticated purposeful control of behavior based on complex sensory input requires the information integrating capabilities of a centralized brain. The operations of individual brain cells are now understood in considerable detail but the way they cooperate in ensembles of millions is yet to be solved. Recent models in modern neuroscience treat the brain as a biological computer different in mechanism from an electronic computer, but similar in the sense that it acquires information from the surrounding world, stores it, processes it in a variety of ways; this article compares the properties of brains across the entire range of animal species, with the greatest attention to vertebrates. It deals with the human brain insofar; the ways in which the human brain differs from other brains are covered in the human brain article. Several topics that might be covered here are instead covered there because much more can be said about them in a human context.
The most important is brain disease and the effects of brain damage, that are covered in the human brain article. The shape and size of the brain varies between species, identifying common features is difficult. There are a number of principles of brain architecture that apply across a wide range of species; some aspects of brain structure are common to the entire range of animal species. The simplest way to gain information about brain anatomy is by visual inspection, but many more sophisticated techniques have been developed. Brain tissue in its natural state is too soft to work with, but it can be hardened by immersion in alcohol or other fixatives, sliced apart for examination of the interior. Visually, the interior of the brain consists of areas of so-called grey matter, with a dark color, separated by areas of white matter, with a lighter color. Further information can be gained by staining slices of brain tissue with a variety of chemicals that bring out areas where specific types of molecules are present in high concentrations.
It is possible to examine the microstructure of brain tissue using a microscope, to trace the pattern of connections from one brain area to another. The brains of all species are composed of two broad classes of cells: neurons and glial cells. Glial cells come in several types, perform a number of critical functions, including structural support, metabolic support and guidance of development. Neurons, are considered the most important cells in the brain; the property that makes neurons unique is their ability to send signals to specific target cells over long distances. They send these signals by means of an axon, a thin protoplasmic fiber that extends from the cell body and projects with numerous branches, to other areas, sometimes nearby, sometimes in distant parts of the brain or body; the length of an axon can be extraordinary: for example, if a pyramidal cell of the cerebral cortex were magnified so that its cell body became the size of a human body, its axon magnified, would become a cable a few centimeters in diameter, extending more than a kilometer.
These axons transmit signals in the form of electrochemical pulses called action potentials, which last less than a thousandth of a second and travel along the axon at speeds of 1–100 meters per second. Some neurons emit action potentials at rates of 10–100 per second in irregular patterns. Axons transmit signals to other neurons by means of specialized junctions called synapses. A single axon may make as many as several thousand synaptic connections with other cells; when an action potential, traveling along an axon, arrives at a synapse, it causes a chemical called a neurotransmitter to be released. The neurotransmitter binds to receptor molecules in the membrane of the target cell. Synapses are the key functional elements of the brain; the essential function of the brain is cell-to-cell communication, synapses are the points at which communication occurs. The human brain has been estimated to contain 100 trillion synapses; the functions of these synapses are diverse: some are excitatory.
Preventive healthcare consists of measures taken for disease prevention, as opposed to disease treatment. Just as health comprises a variety of physical and mental states, so do disease and disability, which are affected by environmental factors, genetic predisposition, disease agents, lifestyle choices. Health and disability are dynamic processes which begin before individuals realize they are affected. Disease prevention relies on anticipatory actions that can be categorized as primal, primary and tertiary prevention; each year, millions of people die of preventable deaths. A 2004 study showed that about half of all deaths in the United States in 2000 were due to preventable behaviors and exposures. Leading causes included cardiovascular disease, chronic respiratory disease, unintentional injuries and certain infectious diseases; this same study estimates that 400,000 people die each year in the United States due to poor diet and a sedentary lifestyle. According to estimates made by the World Health Organization, about 55 million people died worldwide in 2011, two thirds of this group from non-communicable diseases, including cancer and chronic cardiovascular and lung diseases.
This is an increase from the year 2000, during which 60% of deaths were attributed to these diseases. Preventive healthcare is important given the worldwide rise in prevalence of chronic diseases and deaths from these diseases. There are many methods for prevention of disease, it is recommended that adults and children aim to visit their doctor for regular check-ups if they feel healthy, to perform disease screening, identify risk factors for disease, discuss tips for a healthy and balanced lifestyle, stay up to date with immunizations and boosters, maintain a good relationship with a healthcare provider. Some common disease screenings include checking for hypertension, hypercholesterolemia, screening for colon cancer, depression, HIV and other common types of sexually transmitted disease such as chlamydia and gonorrhea, colorectal cancer screening, a Pap test, screening for osteoporosis. Genetic testing can be performed to screen for mutations that cause genetic disorders or predisposition to certain diseases such as breast or ovarian cancer.
However, these measures are not affordable for every individual and the cost effectiveness of preventive healthcare is still a topic of debate. Preventive healthcare strategies are described as taking place at the primal, primary and tertiary prevention levels. In the 1940s, Hugh R. Leavell and E. Gurney Clark coined the term primary prevention, they worked at the Harvard and Columbia University Schools of Public Health and expanded the levels to include secondary and tertiary prevention. Goldston notes that these levels might be better described as "prevention and rehabilitation", though the terms primary and tertiary prevention are still in use today; the concept of primal prevention has been created much more in relation to the new developments in molecular biology over the last fifty years, more in epigenetics, which point to the paramount importance of environmental conditions - both physical and affective - on the organism during its fetal and newborn life. Primal prevention has been propounded as a separate category of "health promotion".
This health promotion par excellence is based on the'new knowledge' in molecular biology, in particular on epigenetic knowledge, which points to how much affective - as well as physical - environment during fetal and newborn life may determine each and every aspect of adult health. This new way of promoting health consists in providing future parents with pertinent, unbiased information on primal health and supporting them during their child's primal period of life; this includes adequate parental leave - ideally for both parents - with kin caregiving and financial help where needed. Another related concept is primordial prevention which refers to all measures designed to prevent the development of risk factors in the first place, early in life. Primary prevention consists of traditional "health promotion" and "specific protection." Health promotion activities are non-clinical life choices. For example, eating nutritious meals and exercising daily, that both prevent disease and create a sense of overall well-being.
Preventing disease and creating overall well-being, prolongs our life expectancy. Health-promotional activities do not target a specific disease or condition but rather promote health and well-being on a general level. On the other hand, specific protection targets a type or group of diseases and complements the goals of health promotion. Food is much the most basic tool in preventive health care; the 2011 National Health Interview Survey performed by the Centers for Disease Control was the first national survey to include questions about ability to pay for food. Difficulty with paying for food, medicine, or both is a problem facing 1 out of 3 Americans. If better food options were available through food banks, soup kitchens, other resources for low-income people and the chronic conditions that come along with it would be better controlled A "food desert" is an area with restricted access to healthy foods due to a lack of supermarkets within a reasonable distance; these are ofte