Anatomy and Physiology of Animals/Glossary/M-N

A-B | C-D | E-F | G-H | I-J | K-L | M-N | O-P | Q,R,S | T,U,V,W,X,Y,Z WordMeaningMMacrophageA large phagocytic cell present in many tissuesMammary glandThe milk producing glandMandibleThe bone of the lower jawMarrowThe soft sponge like material in the cavities of boneMatrixThe substance of a tissue in which the more specialised structures are embeddedMaxillaThe bone of the upper jawMedialTowards the midlineMediastinumThe tissue that separates the two sides of the lungMedullaInner part of an organMedulla oblongataThe part of the brain stem or hind brainMeiosisThe type of cell division for production of gametes. Halves the number of chromosomesMelaninThe dark pigment in the skin and hairMelatonin The hormone produced by the pineal glandMembraneA thin, flexible sheet of tissueMeningesThe membranes covering the brain and spinal cordMesenteryThe membrane attaching the small intestine to the abdominal wallMetacarpalsThe bones of the “hand”MetastasisThe distant spread of disease especially a malignant tumour from its site of originMetatarsalsThe five bones of the foot that connect the “ankle” to the toesMicrofilamentsA solid contracting strand in the cytoplasm of cells that brings about cell contraction.MicrotubuleA hollow rod of protein in the cytoplasm of all eukaryotic cells and in cilia, flagella, and the cytoskeletonMicrovilliThe microscopic fingerlike projections from the membrane of the cells covering the villi of the small intestineMiddle ear The cavity in the skull between the eardrum and inner ear housing the auditory ossiclesMilk teethThe first set of teeth in a young animalMinute volumeThe volume of air inspired or expired during a minute of normal tidal breathingMitochondrionThe organelle in cell cytoplasm that produces energyMitosisThe cell division for growth and repair. Produces 2 cells identical to parent and each otherMolarsThe more posterior cheek teethMonocyteThe largest leukocyte. It is phagocytic and has no granules in the cytoplasmMonosaccharideThe simplest carbohydrate. Also known as simple sugarMorulaThe solid mass of cells produced by successive divisions of the fertilized ovumMucusA thick fluid secretionMyelinThe fatty insulating coating to an axon of a neuronNNasal cavityThe space just inside the nostrilNegative feedbackControl in which the stimulus initiates actions that reverse or reduce the stimulusNephronThe functional unit of the kidneyNerveA bundle of nerve fibresNerve impulseThe nerve “current’ that passes along a neuronNeuronA nerve cellNeurotransmitterMolecules released at a synapse to transmit the nerve impulse from one neuron to the nextNeutral fatA fat or triglyceride. Biological compound consisting of three fatty acids linked to one glycerol moleculeNeutrophilWhite blood cell with granules in the cytoplasm involved in phagocytosisNictitating membraneThe third eyelid in the cat, tuatara and crocodilesNormal salineA 0.9% solution of sodium chlorideNuclear membraneThe double layered membrane that surrounds the nucleusNucleolusThe spherical body within the nucleus, containing RNANucleusThe spherical or oval body in the cell that contains the DNANutrientA chemical substance in food that provides energy or assists various body processes