| neurons | Any of the conducting cells of the nervous system. A typical neuron consists of a cell body, containing the nucleus and the surrounding cytoplasm (perikaryon); several short radiating processes (dendrites); and one long process (the axon), which terminates in twiglike branches (telodendrons) and may have branches (collaterals) projecting along its course. (12 Dec 1998) |
|---|---|
| neurons, afferent | Neurons which convey sensory information centrally from the periphery. (12 Dec 1998) |
| neurons, efferent | Neurons which send impulses peripherally to activate muscles or secretory cells. (12 Dec 1998) |
| olfactory neurons | Sensory neurons from the lining of the nose. They are the only neurons that continue to divide and differentiate throughout an organisms life. (18 Nov 1997) |
| olfactory receptor neurons | Neurons in the olfactory epithelium with proteins (receptors, odourant) that bind, and thus detect, odourants. Olfactory receptor neurons are bipolar. They send to the surface of the epithelium apical dendrites with non-motile cilia from which project odourant receptor molecules. Their unmyelinated axons synapse in the olfactory bulb of the brain. Unlike other neurons, they can be generated from precursor cells in adults. (12 Dec 1998) |
| A layer | <molecular biology> Right handed double helical DNA with approximately 11 residues per turn. Planes of base pairs in the helix are tilted 20 deg away from perpendicular to the axis of the helix. Formed from B DNA by dehydration. (18 Nov 1997) |
| ameloblastic layer | The internal layer of the enamel organ. Synonym: enamel layer. (05 Mar 2000) |
| anterior elastic layer | A transparent homogeneous acellular layer, 6 to 9 um thick, lying between the basal lamina of the outer layer of stratified epithelium and the substantia propria of the cornea; considered to be a basement membrane. Synonym: lamina limitans anterior corneae, anterior elastic layer, Bowman's membrane, lamina elastica anterior, limiting layers of cornea. (05 Mar 2000) |
| anterior layer of rectus abdominis sheath | The portion of the rectus sheath that lies anterior to the muscle, consisting in its upper two-thirds of contributions from the aponeuroses of the external and internal oblique muscles, and in its lower third (below the arcuralt line) of contributions from the aponeuroses of all three muscles of the anterolateral abdominal wall. Synonym: lamina anterior vaginae musculi recti abdominis. (05 Mar 2000) |
| anterior limiting layer of cornea | A transparent homogeneous acellular layer, 6 to 9 um thick, lying between the basal lamina of the outer layer of stratified epithelium and the substantia propria of the cornea; considered to be a basement membrane. Synonym: lamina limitans anterior corneae, anterior elastic layer, Bowman's membrane, lamina elastica anterior, limiting layers of cornea. (05 Mar 2000) |
| bacillary layer | The layer of the retina next to the pigment layer and containing the visual receptors. See: retina, granular layers of retina, neuroepithelial layer of retina. Synonym: bacillary layer. (05 Mar 2000) |
| basal cell layer | The deepest layer of the epidermis, composed of dividing stem cells and anchoring cells. Synonym: basal cell layer, columnar layer, germinative layer, palisade layer, stratum basale, stratum cylindricum, stratum germinativum. (05 Mar 2000) |
| basal layer | The outermost layer of the endometrium which undergoes only minimal changes during the menstrual cycle. Synonym: basal layer. Synonym: stratum basale epidermidis. (05 Mar 2000) |
| basal layer of choroid | The transparent, nearly structureless inner layer of the choroid in contact with the pigmented layer of the retina. Synonym: basal lamina of choroid, basal layer of choroid, Bruch's membrane, Henle's membrane, lamina vitrea, vitreous lamella, vitreous membrane. (05 Mar 2000) |
| basal layer of ciliary body | The inner layer of the ciliary body, continuous with the basal layer of the choroid and supporting the pigment epithelium of the ciliary retina. Synonym: lamina basalis corporis ciliaris, basal layer of ciliary body. (05 Mar 2000) |