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The epidermis is the main component of the dermal tissue system of leaves (diagrammed below), and also stems, roots, flowers, fruits, and seeds; it is usually transparent (epidermal cells have fewer chloroplasts or lack them completely, except for the guard cells.) The cells of the epidermis are structurally and functionally variable.
The dermal papillae are part of the uppermost layer of the dermis, the papillary dermis, and the ridges they form greatly increase the surface area between the dermis and epidermis. Because the main function of the dermis is to support the epidermis, this greatly increases the exchange of oxygen, nutrients, and waste products between these two ...
The epidermis is the outermost of the three layers that comprise the skin, the inner layers being the dermis and hypodermis. [1] The epidermal layer provides a barrier to infection from environmental pathogens [2] and regulates the amount of water released from the body into the atmosphere through transepidermal water loss.
Plant anatomy or phytotomy is the general term for the study of the internal structure of plants.Originally, it included plant morphology, the description of the physical form and external structure of plants, but since the mid-20th century, plant anatomy has been considered a separate field referring only to internal plant structure.
The integumentary system is the set of organs forming the outermost layer of an animal's body. It comprises the skin and its appendages, which act as a physical barrier between the external environment and the internal environment that it serves to protect and maintain the body of the animal. Mainly it is the body's outer skin.
In a growing fetus, fingerprints form where the cells of the stratum basale meet the papillae of the underlying papillary layer of the dermis, resulting in the formation of the ridges on the fingers. Fingerprints are unique to each individual and are used for forensic analyses because the patterns do not change with the growth and aging processes.
Feathers develop from the dermal papillae. Feathers begin to form from feather follicles, which are invaginations starting in the epidermis down to the dermis. It is in the dermis that the follicle and the pulp cavity begin to form the feather. The pulp cavity is the space that contains the feather follicle.
The plant cuticle is a layer of lipid polymers impregnated with waxes that is present on the outer surfaces of the primary organs of all vascular land plants. It is also present in the sporophyte generation of hornworts, and in both sporophyte and gametophyte generations of mosses. [2]