Reference Terms
from Wikipedia, the free encyclopedia
Placenta
The placenta is an ephemeral (temporary) organ present only in female placental vertebrates during gestation (pregnancy). All mammals other than monotremes and (most) marsupials utilise placentas in reproduction, and are known as placental mammals. Also, some species of snakes utilise placentas.
The placenta is composed of two parts, one of which is genetically and biologically part of the fetus, the other part of the mother. It is implanted in the wall of the uterus, where it receives nutrients and oxygen from the mother's blood and passes out waste. This interface forms a barrier, the placental barrier, which filters out some substances which could harm the fetus. However, many other substances are not filtered out, including alcohol and some chemicals associated with smoking cigarettes. Several types of viruses, such as Human Cytomegalovirus, may also cross this barrier; this often leads to various degrees of birth defects in the infant. The placenta is connected to the fetus via the umbilical cord, which is composed of blood vessels and connective tissue. When the fetus is delivered, the placenta is delivered afterwards (and for this reason is often called the afterbirth).
Related Stories
1
2
Health & Medicine News
February 2, 2026
Feb. 2, 2026 Chronic stress can damage the gut’s protective lining, triggering inflammation that may worsen depression. New research shows that stress lowers levels of a protein called Reelin, which plays a key role in both gut repair and brain health. ...
Feb. 2, 2026 MMS has long been promoted as a miracle cure, but new research shows it’s essentially a toxic disinfectant. While it can kill bacteria, it only works at levels that also damage human cells and beneficial gut microbes. Scientists warn that homemade ...
Feb. 1, 2026 Researchers studying nearly 2 million older adults found that cerebral amyloid angiopathy sharply raises the risk of developing dementia. Within five years, people with the condition were far more likely to be diagnosed than those without it. The ...
Feb. 1, 2026 When the brain rests, it usually replays recent experiences to strengthen memory. Scientists found that in Alzheimer’s-like mice, this replay still occurs — but the signals are jumbled and poorly coordinated. As a result, memory-supporting brain ...
Feb. 1, 2026 Middle age is becoming a tougher chapter for many Americans, especially those born in the 1960s and early 1970s. Compared with earlier generations, they report more loneliness and depression, along with weaker physical strength and declining memory. ...
Feb. 1, 2026 Researchers found that small doses of an antibiotic can coax gut bacteria into producing a life-extending compound. In worms, this led to longer lifespans, while mice showed healthier cholesterol and insulin changes. Because the drug stays in the ...
Feb. 1, 2026 Researchers in Bangladesh have identified a bat-borne virus, Pteropine orthoreovirus, in patients who were initially suspected of having Nipah virus but tested negative. All had recently consumed raw date-palm sap, a known pathway for bat-related ...
Jan. 31, 2026 Statins are a cornerstone of heart health, but muscle pain and weakness cause many patients to quit taking them. Scientists have now identified the precise molecular trigger behind these side effects. They found that statins jam open a critical ...
Jan. 31, 2026 Lowering salt in everyday foods could quietly save lives. Researchers found that modest sodium reductions in bread, packaged foods, and takeout meals could significantly reduce heart disease and stroke rates in France and the U.K. The key advantage ...
Jan. 30, 2026 People who naturally stay up late may be putting their hearts under added strain as they age. A large study tracking more than 300,000 adults found that middle-aged and older night owls had poorer overall heart health and a higher risk of heart ...
Jan. 30, 2026 Men start developing heart disease earlier than women, with risks rising faster beginning around age 35, according to long-term research. The difference is driven mainly by coronary heart disease, not stroke or heart failure. Traditional risk ...
Jan. 30, 2026 A new drug developed by Australian researchers has shown promising results in reducing sepsis in a Phase II clinical trial involving 180 patients. The carbohydrate-based treatment works by calming a dangerous immune reaction that can cause organ ...
Latest Headlines
updated 12:56 pm ET
Jan. 30, 2026 Researchers have discovered how pancreatic cancer reprograms its surroundings to spread quickly and stealthily. By using a protein called periostin, the tumor remodels nearby tissue and invades ...
Jan. 30, 2026 A fast-aging fish is giving scientists a rare, accelerated look at how kidneys grow old—and how a common drug may slow that process down. Researchers found that SGLT2 inhibitors, widely used to ...
Jan. 30, 2026 A new imaging technology called fast-RSOM lets researchers see the smallest blood vessels in the body without invasive procedures. It can detect early dysfunction in these vessels — a quiet warning ...
Jan. 30, 2026 Two decades after a breast cancer vaccine trial, every participant is still alive—an astonishing result for metastatic disease. Scientists found their immune systems retained long-lasting memory ...
Jan. 30, 2026 Scientists at Mount Sinai have unveiled a bold new way to fight metastatic cancer by turning the tumor’s own defenses against it. Instead of attacking cancer cells head-on, the experimental ...
Jan. 29, 2026 Collagen pills sound like a shortcut to younger skin, but solid evidence doesn’t back them up. Higher-quality studies show little benefit, and your body doesn’t absorb collagen in the way ads ...
Jan. 29, 2026 An experimental drug once known for helping control type 2 diabetes may also fight heart disease. Researchers found IC7Fc lowered cholesterol, blood fats, and artery-clogging plaques while calming ...
Jan. 29, 2026 Scientists in Sweden and Norway have uncovered a promising way to spot Parkinson’s disease years—possibly decades—before its most damaging symptoms appear. By detecting subtle biological ...
Jan. 29, 2026 Scientists in South Korea have discovered that one of the most common malignant brain tumors in young adults may begin years before a tumor can be seen. IDH-mutant glioma, long treated by removing ...
Jan. 29, 2026 Ozempic, Mounjaro, and Zepbound can drive impressive weight loss, but stopping them is often followed by rapid weight regain. Researchers found that ...