lamina /lam·i·na/ (lam´ĭ-nah) pl. la´minae [L.]
basal lamina
lamina [lam´ĭ-nah] (L.)
basal (baz´
l),
1. layer; a thin, flat plate of a larger composite structure.
2. l. of vertebra.
basal lamina
1. the layer of the basement membrane lying next to the basal surface of the adjoining cell layer, comprising two layers, the electron-lucent lamina lucida and the electron-dense lamina densa.
2. sometimes, the entire basement membrane.
3. l. basalis.
lamina basa´lis
1. one of the pair of longitudinal zones of the embryonic neural tube, from which develop the ventral gray columns of the spinal cord and the motor centers of the brain.
2. basal l. (1).
lamina basila´ris the posterior wall of the cochlear duct, separating it from the scala tympani.
Bowman's lamina see under membrane.
lamina choroidocapilla´ris the inner layer of the choroid, composed of a single-layered network of small capillaries.
lamina cribro´sa
1. fascia cribrosa.
2. (of ethmoid bone) the horizontal plate of ethmoid bone forming the roof of the nasal cavity, and perforated by many foramina for passage of olfactory nerves.
3. (of sclera) the perforated part of the sclera through which pass the axons of the retinal ganglion cells.
lamina den´sa see basal l. (1).
elastic lamina
epithelial lamina the layer of ependymal cells covering the choroid plexus.
lamina lu´cida see basal l. (1).
nuclear lamina a tightly woven meshwork that lines the nuclear side of the inner nuclear membrane; it is believed to control the shape of the nucleus.
lamina pro´pria
1. the connective tissue layer of mucous membrane.
2. the middle fibrous layer of the tympanic membrane.
lamina ra´ra lamina lucida; see basal l. (1). In the lung alveoli and renal glomeruli, one may occur on each side of the lamina densa.
reticular lamina
1. a layer of the basement membrane, adjacent to the connective tissue, seen in some epithelia.
2. l. reticularis.
lamina reticula´ris the perforated hyaline membrane covering the organ of Corti.
Rexed's laminae , spinal laminae an architectural scheme used to classify the structure of the spinal cord, based on the cytological features of the neurons in different regions of the gray substance. 
)
Rexed's laminae in a cross section of the spinal cord at approximately the level of the seventh cervical vertebra (C7).
lamina spira´lis
1. a double plate of bone winding spirally around the modiolus, dividing the spiral canal of the cochlea into the scala tympani and scala vestibuli.
2. a bony projection on the outer wall of the cochlea in the lower part of the first turn.
terminal lamina of hypothalamus the thin plate derived from the telencephalon, forming the anterior wall of the third ventricle of the cerebrum.
lamina of vertebra , lamina of vertebral arch either of the pair of broad plates of bone flaring out from the pedicles of the vertebral arches and fusing together at the midline to complete the posterior part of the arch and provide a base for the spinous process.
| basal lamina n. The ventral division of the lateral walls of the neural tube in the embryo, containing the neuroblasts that give rise to the somatic and visceral motor neurons. Also called ventral plate of neural tube. |
basal lamina
Etymology: Gk, basis + L, lamina, plate
a thin, noncellular layer of ground substance lying just under epithelial surfaces. Constituting the amorphous portion of the basement membrane, it can be examined with an electron microscope. Also called basement lamina.
lamina [lam´ĭ-nah] (L.)
2. vertebral lamina.
basal lamina (lamina basa´lis) the layer of the basement membrane lying next to the basal surface of the adjoining cell layer composed of an electron-dense lamina densa and an electron-lucent lamina lucida.
lamina basila´ris the posterior wall of the cochlear duct, separating it from the scala tympani.
lamina choroidocapilla´ris the inner layer of the choroid, composed of a single-layered network of small capillaries.
lamina cribro´sa
1. fascia cribrosa.
2. (of ethmoid bone) the horizontal plate of ethmoid bone forming the roof of the nasal cavity, and perforated by many foramina for passage of olfactory nerves.
3. (of sclera) the perforated part of the sclera through which pass the axons of the retinal ganglion cells.
lamina den´sa an electron-dense layer of the basal lamina, consisting mainly of collagen fibrils and proteoglycans; it closely follows the plasma membrane of the basal aspect of the adjacent cell layer, from which it is separated by the lamina lucida (or the lamina rara in the renal glomerulus and pulmonary alveolus).
lamina du´ra a layer of the alveolar bone that is thin and particularly compact and appears as a line on dental x-rays. Called also bundle bone.
epithelial lamina the layer of ependymal cells covering the choroid plexus.
lamina fus´ca the pigmentary layer of the sclera.
lamina lu´cida an electron-dense layer of the basal lamina lying between the lamina densa and the adjoining cell layer; in the pulmonary alveolus and renal glomerulus it is divided into the internal and external laminae rarae.
lamina pro´pria
1. the connective tissue layer of mucous membrane.
2. the middle fibrous layer of the tympanic membrane.
lamina ra´ra
1. in the renal glomerulus and pulmonary alveolus, one of the layers of lamina lucida surrounding the lamina densa; the lamina rara externa is on the epithelial side and the lamina rara interna is on the endothelial side.
2. a term sometimes used as a synonym for lamina lucida.
reticular lamina a layer of the basement membrane, adjacent to the connective tissue, seen in some epithelia; it is of variable thickness and is composed of condensed connective tissue with a reticulum of collagen fibers.
Rexed's laminae an architectural scheme used to classify the structure of the spinal cord, based on the cytological features of the neurons in different regions of the gray substance. It consists of nine laminae (I–IX) that extend throughout the cord, roughly paralleling the dorsal and ventral columns of the gray substance, and a tenth region (lamina X) that surrounds the central canal and consists of the dorsal and ventral commissures and the central gelatinous substance.
spiral lamina (lamina spira´lis)
1. a double plate of bone winding spirally around the modiolus, dividing the spiral canal of the cochlea into the scala tympani and scala vestibuli.
2. a bony projection on the outer wall of the cochlea in the lower part of the first turn.
terminal lamina of hypothalamus the thin plate derived from the telencephalon, forming the anterior wall of the third ventricle of the cerebrum.
vertebral lamina (lamina of vertebral arch) either of the pair of broad plates of bone flaring out from the pedicles of the vertebral arches and fusing together at the midline to complete the dorsal part of the arch and provide a base for the spinous process of the vertebra.
basal (baz´
l),adj 1. describing the minimal functions necessary for life.
adj 2. located at or forming the base of a structure.
n 3. the fundamental structures from which an organism is derived.
adj 2. located at or forming the base of a structure.
n 3. the fundamental structures from which an organism is derived.
basal bone,
n portion of the jawbones that forms the body of the maxilla or mandible.
basal lamina,
n a layer composed of the lamina densa and the lamina lucida. It is an extracellular matrix that lies beneath the epithelium and is believed to inhibit cell migration. The term is usually associated with electron microscopy, whereas the term
basement membrane is usually associated with light microscopy.
basement membrane is usually associated with light microscopy.
basal layer,
n See stratum basale.
basal metabolic rate (BMR)
n a type of basal rate, or energy exchange, determined by means of a clinical test of oxygen consumption in a subject who has had a good night's rest, has fasted for 12 to 14 hours, and has been physically, mentally, and emotionally at rest for 30 minutes; usually indicated as a percentage of the normal calorie production per surface area, the normal values ranging between plus and minus 20%.
basal metabolism,
n See basal metabolic rate.
basal seat,
n the oral tissues and structures that support a denture.
basal seat area,
n See area, basal seat.
basal seat outline,
n an outline on the mucous membrane or on a cast of the entire area that is to be covered by a denture.
basal surface,
n See surface, basal.
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