Question

Эпителивльные ткани-...

Answer 1

Это пограничные ткани,которые располагаются на границе с внешней средой,покрывают  поверхность тела и слизистых оболочек внутренних органов,выстилают его полости и образуют большинство желез.

Answer 2

Epithelial Tissues

Epithelial tissues are one of the four basic types of animal tissues, along with connective, muscle, and nervous tissues. They are found throughout the body, covering all body surfaces, lining body cavities and hollow organs, and forming glands. Epithelial tissues serve various functions, including protection, secretion, absorption, and sensation.

Epithelial tissues are classified based on their shape and arrangement of layers. The shapes include squamous (flat and scale-like), cuboidal (cube-shaped), and columnar (column-shaped). The arrangement of layers can be simple (single layer) or stratified (multiple layers).

Epithelial tissues are avascular, meaning they do not have blood vessels. They rely on diffusion from the underlying connective tissue for nourishment and waste removal.

Functions of Epithelial Tissues: 1. Protection: Epithelial tissues protect underlying structures from mechanical injury, chemical injury, and invasion by microorganisms. 2. Secretion: Some epithelial cells are specialized to produce and secrete various substances, such as hormones, enzymes, mucus, and sweat. 3. Absorption: Certain epithelial cells are involved in the absorption of nutrients and other substances from the external environment or body cavities. 4. Sensation: Epithelial tissues contain sensory nerve endings that detect changes in the environment.

Types of Epithelial Tissues: - Simple Squamous Epithelium: Found in areas where rapid diffusion or filtration is required, such as the air sacs of the lungs and the lining of blood vessels. - Simple Cuboidal Epithelium: Found in kidney tubules and various glands, where secretion and absorption occur. - Simple Columnar Epithelium: Found in the lining of the digestive tract, where it can be specialized for absorption or secretion. - Stratified Squamous Epithelium: Forms the outer layer of the skin and lines the mouth, throat, vagina, and anal canal, providing protection against abrasion and infection. - Stratified Cuboidal and Columnar Epithelia: Found in specific glands and ducts, providing protection and secretion.

Conclusion: Epithelial tissues play crucial roles in the body, serving as protective barriers, secretory surfaces, and sites for absorption. Their diverse shapes and arrangements allow them to fulfill various functions in different parts of the body.