Cortex:medulla ratio

Histological data indicated that there was a preferential involution of the cortex of the th3nnuses. Mice fed zinc adequate diet had a cortex-to-medulla ratio of 1.9 whereas those maintained on zinc-deficient diet had a cortical area 0.75 times that of the medulla (Fraker et al., 1978). Since the cortex houses the immature thymocytes, this suggested that zinc deficiency had a... 

The structure, organization, and ratio of matrix and fibrous proteins contribute to the physiochemical properties of keratinous tissues. For example, a primary difference between hair and nails is the arrangement of fibrous proteins and the concentration of matrix proteins present in each tissue. In cells destined to form the cortex of hair, fibrous proteins are oriented to form filaments which cluster to form fibrils. In the keratogenous zone, fibrils undergo lateral fusion to ultimately produce the cortex. The medulla also contains keratin which has been characterized as a collection of irregular fibrous proteins. Fibrous proteins form a trabecular framework comprising 95% of the medulla, and medullary proteins are less resistant to chemical degradation than proteins in the cortex. The cell membrane complex. 

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