Kot: A cat has more bones than a human; humans have 206, and the cat - 230

Evidence: 50 • authority: 92

The auditory nerve glial transition zone is a focal site of age-related immune-myelin interactions.. The auditory nerve (AN) glial transition zone (GTZ), where myelination shifts from Schwann cells in the peripheral AN to oligodendrocytes in the central AN, is a unique biological niche housed within the cochlear modiolus. Although age-related hearing loss (ARHL) is associated with AN degeneration, the neuroimmune mechanisms contributing to age-related myelin pathology and altered immune cell function remain poorly defined. We hypothesized that the AN GTZ is especially vulnerable to age-related immune activity which may contribute to AN degeneration and myelin pathology. Using an ARHL mouse…

Evidence: 41 • authority: 72

The Neanderthals were an extinct species of archaic humans of the genus Homo, and inhabited Europe and West-to-Central Asia until roughly 40,000 years ago. First discovered in 1856, the Neanderthal behaviour was depicted as primitive, unintelligent, and brutish for much of the early 20th century, and unevolved compared to the Cro-Magnons, their modern human contemporaries. Although knowledge and perception of Neanderthals have markedly changed in the scientific community since then, the image of the underdeveloped caveman archetype remains prevalent in popular culture. Nonetheless, it is debated if Neanderthals or any pre-modern species exhibited behavioural modernity. Neanderthal technolog…

Evidence: 41 • authority: 92

Paleogenomic sex inference of mammoth remains sheds light on the anthropogenic nature of bone accumulations.. Whether large accumulations of woolly mammoth (Mammuthus primigenius) bones reflect natural mortality or deliberate human resource exploitation has long been debated, with major implications for understanding Late Pleistocene human-megafaunal interactions. 1 , 2 , 3 , 4 , 5 Here, we use ancient DNA to investigate site-formation hypotheses by comparing genetic sex ratios from mammoth remains recovered in putative anthropogenic bone accumulations and from geographically dispersed, non-anthropogenic contexts. We studied genome-wide data from 521 woolly mammoths-including 100 mammoths f…

Evidence: 41 • authority: 72

This is a list of human anatomy mnemonics, categorized and alphabetized. For mnemonics in other medical specialties, see this list of medical mnemonics. Mnemonics serve as a systematic method for remembrance of functionally or systemically related items within regions of larger fields of study, such as those found in the study of specific areas of human anatomy, such as the bones in the hand, the inner ear, or the foot, or the elements comprising the human biliary system or arterial system.

Evidence: 41 • authority: 72

The vagina (pl.: vaginas or vaginae) is the elastic, muscular reproductive organ of the female genital tract through which mammals copulate and give birth. In humans, it extends from the vulval vestibule to the cervix (neck of the uterus). The vaginal introitus is normally partly covered by a thin layer of mucosal tissue called the hymen. The vagina also channels menstrual flow, which occurs in humans and closely related primates as part of the menstrual cycle. During sexual intercourse, the vaginal walls produce vaginal lubrication and create friction which stimulates the penis toward ejaculation, enabling fertilization. Along with pleasure and bonding, sexual activity can cause sexually t…

Evidence: 41 • authority: 72

Animal testing, also known as animal experimentation, animal research, and in vivo testing, is the use of non-human animals, as model organisms, in experiments that seek answers to scientific and medical questions. This approach can be contrasted with field studies in which animals are observed in their natural environments or habitats. Experimental research with animals is usually conducted in universities, medical schools, pharmaceutical companies, defense establishments, and commercial facilities that provide animal-testing services to the industry. The focus of animal testing varies on a continuum from pure research, focusing on developing fundamental knowledge of an organism, to applie…

Evidence: 41 • authority: 72

A mammal (from Latin mamma 'breast') is a vertebrate animal of the class Mammalia (). Mammals are characterized by the presence of milk-producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or hair, and three middle ear bones. These characteristics distinguish them from reptiles and birds, from which their ancestors diverged in the Carboniferous period over 300 million years ago. Around 6,640 extant species of mammals have been described and divided into 27 orders. The study of mammals is called mammalogy. The largest orders of mammals, by number of species, are the rodents, bats, and eulipotyphlans (including hedgehogs, moles and shrews). The next thr…

Evidence: — • authority: 38