integument

Examples of integument in the following topics:

• The Life Cycle of an Angiosperm

  • The ovule, sheltered within the ovary of the carpel, contains the megasporangium protected by two layers of integuments and the ovary wall.
  • When a pollen grain reaches the stigma, a pollen tube extends from the grain, grows down the style, and enters through the micropyle, an opening in the integuments of the ovule.
  • The seed consists of a toughened layer of integuments forming the coat, the endosperm with food reserves, and the well-protected embryo at the center.
  • The formation of the seed completes the process of reproduction in seed plants (started with the development of flowers and pollination), with the embryo developed from the zygote and the seed coat from the integuments of the ovule.

• Sexual Reproduction in Angiosperms

  • A double-layered integument protects the megasporangium and, later, the embryo sac.
  • The integument will develop into the seed coat after fertilization, protecting the entire seed.
  • The integuments, while protecting the megasporangium, do not enclose it completely, but leave an opening called the micropyle.
  • As shown in this diagram of the embryo sac in angiosperms, the ovule is covered by integuments and has an opening called a micropyle.

• Development of the Integumentary System

  • The integument also includes appendages, primarily the sweat and sebaceous glands, hair, nails and arrectores pillorum (tiny muscles at the root of each hair that cause goose bumps).

• Development of the Seed

  • The seed, along with the ovule, is protected by a seed coat that is formed from the integuments of the ovule sac.
  • The seed coat forms from the two integuments or outer layers of cells of the ovule, which derive from tissue from the mother plant: the inner integument forms the tegmen and the outer forms the testa.

• Complex Tissue Structure

  • Epithelial tissues cover, line, protect, and secrete; these tissues include the epidermis of the integument: the lining of the digestive tract and trachea.

• Skin, Gills, and Tracheal Systems

  • Other animals, such as earthworms and amphibians, use their skin (integument) as a respiratory organ.

• Intercostal Nerves

  • Near the sternum, they cross in front of the internal mammary artery and transversus thoracis muscle, pierce the intercostales interni, the anterior intercostal membranes, and pectoralis major, and supply the integument of the front of the thorax and over the mamma, forming the anterior cutaneous branches of the thorax.

• Characteristics of Mammals

  • Mammalian integument, or skin, includes secretory glands with various functions.