| ganglionic crest | A group of embryonic cells that separate from the neural plate during neurulation and migrate to give several different lineages of adult cells: the spinal and autonomic ganglia, the glial cells of the peripheral nervous system and nonneuronal cells, such as chromaffin cells, melanocytes and some haemopoietic cells. (18 Nov 1997) |
|---|---|
| ganglionic layer of cerebellar cortex | The layer of Purkinje cells between the molecular and granular layers of the cerebellar cortex. Synonym: stratum neuronorum piriformium, ganglionic layer of cerebellar cortex, layer of piriform neurons, Purkinje's layer, stratum gangliosum cerebelli. (05 Mar 2000) |
| ganglionic layer of cerebral cortex | Layer 5 of the cortex cerebri. (05 Mar 2000) |
| ganglionic layer of optic nerve | <anatomy, nerve> The inner layer of multipolar neurons in the retina consisting of the relatively large neurons that give rise to the fibres of the optic nerve. Synonym: stratum ganglionare nervi optici. (05 Mar 2000) |
| ganglionic layer of retina | The intermediate layer of neurons in the retina composed largely of bipolar cells. Synonym: internal nuclear layer of retina, stratum ganglionare retinae, stratum nucleare internum retinae. (05 Mar 2000) |
| ganglionic motor neuron | See: motor neuron. (05 Mar 2000) |
| ganglionic saliva | Submaxillary saliva obtained by direct irritation of the gland. (05 Mar 2000) |
| ganglionic stimulants | Agents that mimic neural transmission by stimulation of the nicotinic receptors on postganglionic autonomic neurons. Drugs that indirectly augment ganglionic transmission by increasing the release or slowing the breakdown of acetylcholine or by non-nicotinic effects on postganglionic neurons are not included here nor are the non-specific cholinergic agonists. (12 Dec 1998) |
| ciliary ganglionic plexus | An autonomic plexus lying on the ciliary muscle, derived from the oculomotor, trigeminal, and sympathetic. Synonym: plexus gangliosus ciliaris. (05 Mar 2000) |
| alpha blocking | The attenuation of the occipital alpha rhythm (8-14 Hz brain waves as seen on an electroencephalogram), produced by opening the eyes or by intense mental concentration. (05 Mar 2000) |
| antibodies, blocking | Antibodies that inhibit the reaction between antigen and other antibodies or sensitised T-lymphocytes (e.g., antibodies of the IgG class that compete with IgE antibodies for antigen, thereby blocking an allergic response). Blocking antibodies that bind tumours and prevent destruction of tumour cells by cytotoxic T-lymphocytes have also been called enhancing antibodies. (12 Dec 1998) |
| blocking | 1. Obstructing; arresting of passage, conduction, or transmission. 2. In psychoanalysis, a sudden break in free association occurring when a painful subject or repressed complex is touched. 3. Sudden cessation of thoughts and speech, which may indicate the presence of a severe thought disorder or a psychosis. (05 Mar 2000) |
| blocking activity | The repression or elimination of electrical activity in the brain by the arrival of a sensory stimulus. (05 Mar 2000) |
| blocking antibody | An antibody used in a reaction to prevent some other reaction taking place, for example one antibody competing with another for a cell surface receptor. See: desensitisation. (18 Nov 1997) |
| Rh blocking test | A test for nonagglutinating Rh antibodies: an Rh agglutination test is first carried out; if the test for Rh agglutinins is negative, then 1 drop of anti-Rho agglutinating serum of moderate titre is mixed with the patient's serum containing Rh-positive test cells; if after incubating for from 1 to 2 hr at 37캜 no agglutination occurs, Rho-blocking antibodies are assumed to be present in the patient's serum. (05 Mar 2000) |