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Olfactory Epithelium
The olfactory epithelium is a specialized epithelium, epithelial tissue inside the nasal cavity that is involved in olfaction, smell. In humans, it measures and lies on the roof of the nasal cavity about above and behind the nostrils. The olfactory epithelium is the part of the olfactory system directly responsible for detecting odors. Structure Olfactory epithelium consists of four distinct cell types: * Olfactory receptor neuron, Olfactory sensory neurons * Supporting cells * Basal cells * Brush cells Olfactory sensory neurons The olfactory receptor neurons are sensory neurons of the olfactory epithelium. They are bipolar neurons and their apical poles express odorant receptors on cilium, non-motile cilia at the ends of the dendritic knob, which extend out into the airspace to interact with odorants. Odorant receptors bind odorants in the airspace, which are made soluble by the serous secretions from olfactory glands located in the lamina propria of the mucosa.Ross, MH, '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Olfactory Placode
In embryology, the nasal placode (or olfactory placode) gives rise to the olfactory epithelium of the nose. Two nasal placodes arise as thickened ectoderm from the frontonasal process. They give rise to the nose, the philtrum of the upper lip, and the primary palate. Development During the fifth week of human embryonic development, the placodes increase in size. In the sixth week of development the centre of each placode grows inwards to form the two nasal pits. The invaginations will give rise to the olfactory epithelium that lines the roof of the nasal cavity. The nasal pits are oval shaped and they leave a raised margin which is divided into a medial nasal process and a lateral nasal process. The medial and lateral nasal process of each placode gives rise to the nose, the philtrum of the upper lip and the primary palate The palate () is the roof of the mouth in humans and other mammals. It separates the oral cavity from the nasal cavity. A similar structure is f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glomerulus (olfaction)
The glomerulus (: glomeruli) is a spherical structure located in the olfactory bulb of the brain where synapses form between the terminals of the olfactory nerve and the dendrites of mitral, periglomerular and tufted cells. Each glomerulus is surrounded by a heterogeneous population of juxtaglomerular neurons (that include periglomerular, short axon, and external tufted cells) and glial cells. All glomeruli are located near the surface of the olfactory bulb. The olfactory bulb also includes a portion of the anterior olfactory nucleus, the cells of which contribute fibers to the olfactory tract. They are the initial sites for synaptic processing of odor information coming from the nose. A glomerulus is made up of a globular tangle of axons from the olfactory receptor neurons, and dendrites from the mitral and tufted cells, as well as, from cells that surround the glomerulus such as the external tufted cells, periglomerular cells, short axon cells, and astrocytes. In mammals, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neural Crest Cells
The neural crest is a ridge-like structure that is formed transiently between the epidermal ectoderm and neural plate during vertebrate development. Neural crest cells originate from this structure through the epithelial-mesenchymal transition, and in turn give rise to a diverse cell lineage—including melanocytes, craniofacial cartilage and bone, smooth muscle, dentin, Peripheral nervous system, peripheral and enteric neurons, adrenal medulla and glia. After gastrulation, the neural crest is specified at the border of the neural plate and the non-neural ectoderm. During neurulation, the borders of the neural plate, also known as the neural folds, converge at the dorsal midline to form the neural tube. Subsequently, neural crest cells from the roof plate of the neural tube undergo an Epithelial-mesenchymal transition, epithelial to mesenchymal transition, delaminating from the neuroepithelial cell, neuroepithelium and migrating through the periphery, where they differentiate into ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nasal Placode
In embryology, the nasal placode (or olfactory placode) gives rise to the olfactory epithelium of the human nose, nose. Two nasal Neurogenic placode, placodes arise as thickened ectoderm from the frontonasal process. They give rise to the human nose, nose, the philtrum of the upper lip, and the primary palate. Development During the fifth week of human embryonic development, the placodes increase in size. In the sixth week of development the centre of each placode invagination, grows inwards to form the two nasal pits. The invaginations will give rise to the olfactory epithelium that lines the roof of the nasal cavity. The nasal pits are oval shaped and they leave a raised margin which is divided into a medial nasal process and a lateral nasal process. The medial and lateral nasal process of each placode gives rise to the nose, the philtrum of the upper lip and the primary palate. References External links * https://web.archive.org/web/20130509194720/http://embryology.me ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Embryonic Development
In developmental biology, animal embryonic development, also known as animal embryogenesis, is the developmental stage of an animal embryo. Embryonic development starts with the fertilization of an egg cell (ovum) by a sperm, sperm cell (spermatozoon). Once fertilized, the ovum becomes a single diploid cell known as a zygote. The zygote undergoes mitosis, mitotic cell division, divisions with no significant growth (a process known as cleavage (embryo), cleavage) and cellular differentiation, leading to development of a multicellular embryo after passing through an organizational checkpoint during mid-embryogenesis. In mammals, the term refers chiefly to the early stages of prenatal development, whereas the terms fetus and fetal development describe later stages. The main stages of animal embryonic development are as follows: * The zygote undergoes a series of cell divisions (called cleavage) to form a structure called a morula. * The morula develops into a structure called a bla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Embryonic Olfactory Epithelium
Embryonic may refer to: *Of or relating to an embryo An embryo ( ) is the initial stage of development for a multicellular organism. In organisms that reproduce sexually, embryonic development is the part of the life cycle that begins just after fertilization of the female egg cell by the male sp ... * ''Embryonic'' (album), a 2009 studio album by the Flaming Lips *'' Embryonics'', a 2005 album by Alchemist {{Disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Olfactory Mucosa
The olfactory mucosa is the Neuroepithelial cell, neuroepithelial mucosa lining the roof and upper parts of the Nasal septum, septum and lateral wall of the nasal cavity which contains Bipolar neuron, bipolar neurons of the primary receptor neurons of the Olfactory pathways, olfactory pathway, as well as supporting cells. The neurons' Dendrite, dendrites project towards the nasal cavity while their axons ascend through the cribriform plate as the Olfactory nerve, olfactory nerves. The part of the nasal cavity that is lined with olfactory mucosa is known as the olfactory region (''pars olfactoria tunicae mucosae nasi''), while the rest of the nasal cavity that is lined by ordinary respiratory mucosa is known as the respiratory region. Structure Olfactory mucosa lines about 5cm2 of the posterosuperior parts of the lateral nasal wall. Parts of the nasal cavity lined by olfactory mucosa include: parts of the roof of the nasal cavity, the superior nasal concha and some upper parts ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trigeminal Nerve
In neuroanatomy, the trigeminal nerve (literal translation, lit. ''triplet'' nerve), also known as the fifth cranial nerve, cranial nerve V, or simply CN V, is a cranial nerve responsible for Sense, sensation in the face and motor functions such as biting and chewing; it is the most complex of the cranial nerves. Its name (''trigeminal'', ) derives from each of the two nerves (one on each side of the pons) having three major branches: the ophthalmic nerve (V), the maxillary nerve (V), and the mandibular nerve (V). The ophthalmic and maxillary nerves are purely sensory, whereas the mandibular nerve supplies motor as well as sensory (or "cutaneous") functions. Adding to the complexity of this nerve is that Autonomic nervous system, autonomic nerve fibers as well as special sensory fibers (taste) are contained within it. The motor division of the trigeminal nerve derives from the Basal plate (neural tube), basal plate of the embryonic pons, and the sensory division originates in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brush Cell
Respiratory epithelium, or airway epithelium, is ciliated pseudostratified columnar epithelium a type of columnar epithelium found lining most of the respiratory tract as respiratory mucosa, where it serves to moisten and protect the airways. It is not present in the vocal cords of the larynx, or the oropharynx and laryngopharynx, where instead the epithelium is stratified squamous. It also functions as a barrier to potential pathogens and foreign particles, preventing infection and tissue injury by the secretion of mucus and the action of mucociliary clearance. Structure The respiratory epithelium lining the upper respiratory airways is classified as ciliated pseudostratified columnar epithelium. This designation is due to the arrangement of the multiple cell types composing the respiratory epithelium. While all cells make contact with the basement membrane and are, therefore, a single layer of cells, their nuclei are not aligned in the same plane. Hence, it appears a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stratum Basale
The stratum basale (basal layer, sometimes referred to as ''stratum germinativum'') is the deepest layer of the five layers of the epidermis, the external covering of skin in mammals. The stratum basale is a single layer of columnar or cuboidal basal cells. The cells are attached to each other and to the overlying stratum spinosum cells by desmosomes and hemidesmosomes. The nucleus is large, ovoid and occupies most of the cell. Some basal cells can act like stem cells with the ability to divide and produce new cells, and these are sometimes called basal keratinocyte stem cells. Others serve to anchor the epidermis glabrous skin (hairless), and hyper-proliferative epidermis (from a skin disease).McGrath, J.A.; Eady, R.A.; Pope, F.M. (2004). ''Rook's Textbook of Dermatology'' (Seventh Edition). Blackwell Publishing. Pages 3.7. . They divide to form the keratinocytes of the stratum spinosum, which migrate superficially. Other types of cells found within the stratum basale ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CD117
Proto-oncogene c-KIT is the gene encoding the receptor tyrosine kinase protein known as tyrosine-protein kinase KIT, CD117 ( cluster of differentiation 117) or mast/stem cell growth factor receptor (SCFR). Multiple transcript variants encoding different isoforms have been found for this gene. KIT was first described by the German biochemist Axel Ullrich in 1987 as the cellular homolog of the feline sarcoma viral oncogene v-kit. Function KIT is a cytokine receptor expressed on the surface of hematopoietic stem cells as well as other cell types. Altered forms of this receptor may be associated with some types of cancer. KIT is a receptor tyrosine kinase type III, which binds to stem cell factor, also known as "steel factor" or "c-kit ligand". When this receptor binds to stem cell factor (SCF) it forms a dimer that activates its intrinsic tyrosine kinase activity, that in turn phosphorylates and activates signal transduction molecules that propagate the signal in the cell. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
