Page 88 - PG 101-Course notes مذكرة النظري 24-25 with spec

Medicinal plants (PG 101) Level 1 Clinical Pharmacy-PharmD

➢ In the region of the primary permanent tissues, cells are arranged from out-
ward to inward as follows:

1- Dicot Stem

▪ Tissues of stem arranged from outside inwards as follows:

1-Epidermis 2-Cortex 3-Stele

1- Epidermis single row of cells they are tangentially elongated cells in T.S. generally

bears stomata and hairs and covered with cuticle.

2- Cortex (ground tissue): narrow, it may be differentiated into:

a- Hypodermis: collenchyma in nature devoid of contents.

b-Ground parenchyma:

o Outer region: usually contain chloroplasts (chlorenchyma).

o Middle region: may show sclerenchyma or secretory structures (oil cells,

glands or laticeferous ducts) or idioplasts of ca-ox crystals.

c- Endodermis: The innermost layer of cortex of dicot stems contains starch grains

and is called starch sheath.

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