What are different types of human cells?
Human cells are very specialized in performing millions of specific tasks that allow people not only to live in their biological environment, but also to change these environments to their liking. Hundreds of different types of human cells are necessary to perform these diverse tasks. Classification of human cell types can be performed on many sets of criteria, including a source of origin, tissue or system function or life pattern.
The classification of human cell types by their source of origin is achieved by studies of human development or embryology. During the first six to eight days, three primary layers of germs develop. The outer layer, ectoderm, eventually creates cells of the epidermis, including skin, nails and hair and nervous system. The inner layer, endoderm, becomes an epithelial lining of the digestive system and associated glands and tissues. Mesoderm, between the other two layers, sells cells of muscle and skeletal systems and lymphatic and vascular systems.
histology or studying tissues classifies types of human cells according to primary tissue function. Epithelial cells are found throughout the body, including skin and lining or covering parts of the digestive tract and heart, glands, blood vessels and other places requiring smooth and dense protection. The digestive system includes several specialized cell types such as nephrons in the kidneys, the villa of the small intestine and the liver cells. The cells of the circulatory and respiratory systems are relatively diverse, including red and white blood cells and alveoli of the lungs.
muscle, skeletal and joint systems control how people move. Muscle cells are three types: smooth, striped or heart. Skeletal cells are primarily bone and cartilage cells. The articular system includes connective tissue cells that form ligaments and tendons.
neurons are the main cells of the nervous system and are characterized by the ability to receive and transmit chemical signals. SensoryRic systems include many specialized cells such as the retinal cell in the eye, and the pressure and heat sensing cells in the skin. The hearing is achieved by a complicated line of conductivity of physical sound through the bones and heads of drums and by connecting with the nervous system of vibrations of specialized hair cells of inner ear. Other systems with specialized cells include reproductive, endocrine, lymphatic and urinary systems.
types of human cells can also be organized by the cell cycle phase in which they exist. Labile cells have a specific life range and basically are constantly reproduced. These include cell tract cells, bone marrow and lung alveoli.
Stable cells can be reproduced as the body requires. The liver cell is regenerated as needed, while the kidney cell cannot. Permanent tissue cells are considered irreplaceable by the body and include examples of the eye and red blood cell lens. Somatic stem cells and neurons were in this category, but they turned out to be withCopy regeneration. All these cells are still exposed to the aging of the individual body through poorly understood mechanisms.