Search results
Results from the WOW.Com Content Network
67821. Anatomical terms of muscle. [edit on Wikidata] The arrector pili muscles, also known as hair erector muscles, [1] are small muscles attached to hair follicles in mammals. Contraction of these muscles causes the hairs to stand on end, [2] known colloquially as goose bumps (piloerection). [3]
The Gene Ontology system does not treat fimbriae as a distinct type of appendage, using the generic pilus (GO:0009289) type instead. This appendage ranges from 3–10 nanometers in diameter and can be as much as several micrometers long. Fimbriae are used by bacteria to adhere to one another and to adhere to animal cells and some inanimate objects.
The enteric nervous system functions to control the gastrointestinal system. Nerves that exit from the brain are called cranial nerves while those exiting from the spinal cord are called spinal nerves. The nervous system consists of nervous tissue which, at a cellular level, is defined by the presence of a special type of cell, called the ...
The human nervous system consists of two main parts: the central nervous system (CNS) and the peripheral nervous system (PNS). The CNS contains the brain and spinal cord. The PNS consists mainly of nerves, which are long fibers that connect the CNS to every other part of the body. The PNS includes motor neurons, mediating voluntary movement ...
Mollusca is a phylum of protostomic invertebrate animals, whose members are known as molluscs or mollusks[ a ] (/ ˈmɒləsks /). Around 76,000 extant species of molluscs are recognized, making it the second-largest animal phylum after Arthropoda. [ 4 ] The number of additional fossil species is estimated between 60,000 and 100,000, [ 5 ] and ...
Torsion is the rotation of the visceral mass, mantle, and shell 180˚ with respect to the head and foot of the gastropod. This rotation brings the mantle cavity and the anus to an anterior position above the head. In some groups of gastropods (Opisthobranchia) there is a degree of secondary detorsion or rotation towards the original position ...
Neuropil. Neuropil (or " neuropile ") is any area in the nervous system composed of mostly unmyelinated axons, dendrites and glial cell processes that forms a synaptically dense region containing a relatively low number of cell bodies. The most prevalent anatomical region of neuropil is the brain which, although not completely composed of ...
Layers of the Alimentary Canal.The wall of the alimentary canal has four basic tissue layers: the mucosa, submucosa, muscularis, and serosa. The enteric nervous system in humans consists of some 500 million neurons [11] (including the various types of Dogiel cells), [1] [12] 0.5% of the number of neurons in the brain, five times as many as the one hundred million neurons in the human spinal ...