Biomedical subjects

M A Peacock

Publications and source records attributed to M A Peacock.

22 records · Page 2Linked to original sources

PubMed1979

The growth of elastic cartilage.

Level lines of the specific growth rate and field lines of the gradient of the specific growth rate of developing ear cartilage have been computed. A single centre of maximum specific growth rate occurs in the midline and moves with time from the tip towards the base. Its movement is consistent with the progressive increase in area of the ear cartilage and with its consequent changes in form. The relationships of the centre for maximum specific growth rate to other maxima for the rates of production of cellular material, intercellular material, cell surface area and for material derivatives of intercellular volume fraction, cell volume fraction and cell surface density are discussed.

Animals↗

PubMed1978

The velocity field of growing ear cartilage.

The velocity vector field of the growing rabbit ear cartilage has been investigated between 12 and 299 days. Empirical curves have been computed for path lines and for velocities between 12 and 87 days. The tissue movement has been found to behave as an irrotational flow of material. Stream lines and velocity equipotential lines have been calculated and provide akinematic description of the changes during growth. The importance of a knowledge of the velocity vector in physical descriptions of growth and morphological differentiation at the tissue and cellular levels is emphasized.

Animals↗

PubMed1978

Adipose tissue cells in cold-acclimatised sheep.

The morphology and lipid content of adipose tissue from sheep subjected to cold acclimatisation were examined. In two sheep the perirenal adipose tissue contained virtually no triglyceride (less than 2 mg/100 mg wet tissue) and the appearance on electron microscopy was typical of that of a depleted white fat cell. The morphological, chemical and physiological evidence indicates that, in the sheep, white adipose tissue does not revert to brown adipose tissue during depletion resulting from cold acclimatisation.

Acclimatization↗

PubMed1977

The fine structure of developing elastic cartilage.

The fine structure of the elastic cartilage of the pinna has been examined in young rabbits aged from 1 day to 1108 days. Changes associated with growth and development are related not only to age but also to the actual situation in the pinna. In the midline, progressive changes are seen from the tip to the base. The changes in the chondroblasts with time are compared with those described in hyaline cartilage. Structures occur that, except for the presence of crystals, are apparently morphologically identical with the matrix vesicles of calcifying cartilage. These matrix vesicles, however, become very prominent with age, and aggregations of them appear to be released into the intercellular tissue from vacuoles at the periphery of the chondroblasts. There is no obvious association with calcification. Occasional single cilia, desmosomes and giant mitochondria are seen. Elastica is present at birth, and eventually every cell is separated from its neighbours by a partial investment of elastica. The quantity of matrix seems to increase with time, and with distance from the tip of the ear. This is accompanied by a marked increase in cell size with time.

Age Factors↗