explain breifly about kinds of immunity
Answers
Answer:
INNATE IMMUITY.
Plants and animals have what is called innate immunity. Innate immunity is the first line of defense against pathogens. It involves several cell types, proteins, and even an organ. The organ involved is your skin. Yes, skin is part of the first line of defense. It protects you and prevents pathogens from getting inside your body.
So, what are some ways a pathogen gets inside? Air, food, or a break in the skin are some ways a pathogen enters. A pathogen entering through food or air has mucus to go through. The mucosal surfaces prevent pathogens from attaching to cells and causing disease. A set of proteins called the complement system is also involved. The complement system attacks the pathogen and marks it for destruction.
A pathogen getting through skin and mucus will have to deal with several types of cells including phagocytes, eating cells, and natural killer (NK) cells before it can cause disease. Pathogens have warning flags on their surface that say: 'I don't belong here'.
Neutrophils, macrophages, and dendritic cells are all phagocytes. They recognize the warning flag, attack the pathogen, and eat it - a process known as phagocytosis. If a pathogen is too big for one cell alone, several cells attack at once.
NK cells on the other hand, identify infected cells (host cells) and activate the host cell's death receptor pathway or give the cell a lethal injection (injecting enzymes that degrade proteins). Host cells even try to fight back by turning off machinery that would help the pathogen and sending out distress signals.
If pathogens make it through all this, it's time for adaptive immunity to step in, and they do this with the help of dendritic cells.Adaptive Immunity
Adaptive immunity works slower than innate, and is more specific. There are two types: passive and active. Passive immunity occurs when antibodies are passed from one person to another, as through transfusion for example.
ACTIVE IMMUNITT.
involves two types of white blood cells - T-cells and B-cells. Dendritic cells, after they have eaten and digested the pathogen, present the pathogen pieces to T-cells, which activates (turns on) the T-cells.
CCELL-MEDIATED IMMUNITY.
T-cells are formed in the thymus and cruise around until activated. Since T-cells require direcdirect contact with other cell t-cell immuty.
Explanation:
The Qulliq, a type of oil lamp made by the arctic peoples, are also known as soapstone lamps. This kind of lamp was the single most important article of furniture for the Inuit peoples in their dwellings.
Ancient Egyptian Scarab signet/amulets were most commonly made from glazed steatite.[5]
Soapstone is used for inlaid designs, sculpture, coasters, and kitchen countertops and sinks. The Inuit often used soapstone for traditional carvings. Some Native American tribes and bands make bowls, cooking slabs, and other objects from soapstone; historically, this was particularly common during the Late Archaic archaeological period.[6]
Locally quarried soapstone was used for gravemarkers in 19th century northeast Georgia, US, around Dahlonega, and Cleveland, as simple field stone and "slot and tab" tombs.
Small blocks of soapstone (8" x 10" x 1") were heated on the cookstove or near the fire and used to warm cold bedclothes or to keep hands and feet cozy while sleighing.
Soapstone is relatively abundant in northern Europe. Vikings hewed soapstone directly from the stone face, shaped it into cooking pots, and sold these at home and abroad.[7] In Shetland, there is evidence these vessels were used for processing marine and dairy fats.[8] Several medieval buildings have survived here which are constructed with soapstone, amongst them Nidaros Cathedral.[3]
Soapstone is sometimes used for construction of fireplace surrounds, cladding on wood-burning stoves,[9][10] and as the preferred material for woodburning masonry heaters because it can absorb, store, and evenly radiate heat due to its high density and magnesite (MgCO3) content. It is also used for countertops and bathroom tiling because of the ease of working the material and its property as the "quiet stone". A weathered or aged appearance occurs naturally over time as the patina is enhanced.
The ancient trading city of Tepe Yahya in southeastern Iran was a center for the production and distribution of soapstone in the fifth to third millennia BC.[11] It was also used in Minoan Crete. At the Palace of Knossos, archaeological recovery has included a magnificent libation table made of steatite.[12] The Yoruba people of West Nigeria used soapstone for several statues, most notably at Esie, where archaeologists have uncovered hundreds of male and female statues about half of life size. The Yoruba of Ife also produced a miniature soapstone obelisk with metal studs called "the staff of