| primitive perivisceral cavity | The space between the ectoderm and endoderm in the gastrula. Synonym: primitive perivisceral cavity. (05 Mar 2000) |
|---|---|
| primitive pit | The depression in the primitive node that serves to connect the notochordal canal with the surface ectoderm and the yolk sac. These connections are referred to as the neurenteric canal. (05 Mar 2000) |
| primitive reticular cell | A cell with processes making contact with those of other similar cell's to form a cellular network; along with the network of reticular fibres, the reticular cell's form the stroma of bone marrow and lymphatic tissues. (05 Mar 2000) |
| primitive ridge | One of the paired ridge's on either side of the primitive groove. (05 Mar 2000) |
| primitive streak | An ectodermal ridge in the midline at the caudal end of the embryonic disk from which arises the intraembryonic mesoderm; achieved by inward and then lateral migration of cells; in human embryos, it appears on day 15 and gives a cephalocaudal axis to the developing embryo. Synonym: germinal streak. (05 Mar 2000) |
| neuroectodermal tumour, primitive | A malignant brain tumour sharing common features and biologic properties with medulloblastoma. Some pathologists and clinicians use the terms interchangeably: they both can disseminate throughout the nervous system and, in some cases, systemically. most lesions arise from the posterior fossa in children under five years of age. The tumour often produces hydrocephalus and symptoms of increased intracranial pressure. Papilledema is often present. (12 Dec 1998) |
| absolute terminal innervation ratio | The number of motor endplates divided by the number of terminal axons related to them. (05 Mar 2000) |
| amino-terminal | <biochemistry> The end of a protein or polypeptide chain with the unattached amino group or the aminoacyl residue containing it. Each amino acid in the chain has an amino group on one side, which is attached to the carboxyl group (COOH group) of the previous amino acid, and a carboxyl group on the other side (which is attached to the amino group of the next amino acid). The other end of the polypeptide chain is called the carboxyl terminal. Synonym: NH2-terminal. (14 Aug 2000) |
| amino-terminal residue | <biochemistry> The only amino acid residue in a polypeptide chain that has a free alpha-amino group, it defines the amino terminus of the polypeptide. (09 Oct 1997) |
| axonal terminal boutons | The somewhat enlarged, often club-shaped endings by which axons make synaptic contacts with other nerve cells or with effector cells (muscle or gland cells). As isolated, by homogenizing brain or spinal cord, they contain acetylcholine and the related enzymes. Terminals contain neurotransmitters of various kinds, sometimes more than one. These can be demonstrated by chemical analysis and immunocytochemical methods. See: synapse. Synonym: axonal terminal boutons, end-feet, neuropodia, pieds terminaux, synaptic boutons, synaptic endings, synaptic terminals, terminal boutons, bouton terminaux. (05 Mar 2000) |
| carboxyl terminal | The end of a polypeptide chain with the unattached carboxyl group (a -COOH group). Each amino acid in the middle of the chain has an amino group (a -NH2 group) on one side (which is attached to the carboxyl group of the previous amino acid) and a carboxyl group on the other side (which is attached to the amino group of the next amino acid). The other end of the polypeptide chain is called the amino terminal. (09 Oct 1997) |
| carboxyl-terminal residue | This amino acid residue defines the carboxylterminus of the polypeptide, its the only residue with a free alpha-carboxyl group. (09 Oct 1997) |
| carboxy terminal | The end of a peptide or protein having a free carboxyl (-COOH) group. (05 Mar 2000) |
| carboxy-terminal domain kinase | <enzyme> Protein kinase that phosphorylates the c-terminal repeat domain of the largest subunit of RNA polymerase II at serine residues Registry number: EC 2.7.1.- Synonym: ctd kinase, hs-ctd kinase, tfiih-associated ctd kinase (26 Jun 1999) |
| central terminal electrode | In electrocardiography, an electrode in which connections from the three limbs (right arm, left arm, and left leg) are joined and led to the electrocardiograph to form the indifferent electrode, theoretically at zero potential for the system. (05 Mar 2000) |