When a pathogen comes in contact with your body, it has to breach the first line of defense to get inside. Your skin and mucus membranes are the main barrier here. Mucus traps the pathogens, and then is forced out of your body when you cough or blow your nose. Your skin also secretes chemicals that have antiviral properties, killing viruses on contact. If the pathogens get through that defense, the next line is non-specific immunity cells that patrol your tissues engulfing pathogens. There are other cells that do this, like macrophages, but the dendritic cells are most important for activating the third line of defense in your body.
Dendritic cells reside in your tissues, waiting for an invader to arrive. When they do find one, they engulf it and digest it. After they do this, they select pieces of the invader called antigens and put them on their surfaces. The dendritic cells migrate back to lymph nodes, key locations in your body filled with immune cells. There, they show the antigens, called antigen presentation, to two types of lymphocytes, T-cells and B-cells, activating them for a full immune response.
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<span>The high surface tension helps the paper clip - with muchhigher density - float on the water. The property of the surface of a liquid that allows it to resist an external force, due to the cohesive nature of its molecules.</span>
Answer:
The organ above is responsible for filtering wastes from the digestion of proteins and cleaning the blood of excess salts. It is found in the lower back. It is the <u>kidney </u> and is part of the <u>excretory</u> system.
Explanation:
Kidneys are a pair of a bean-shaped organ which are located in the back abdominal area, under the rib cage. The major function of kidneys is to filter waste from the blood. The waste materials from the food we consume is filtered by the kidneys. Other functions of the kidney include maintaining the fluid balance of the body.
The kidney is one of the major organ of the excretory system along with the ureters and urinary bladder.
Explanation:
Determining a substance's physical or chemical identity. What are the two main requirements for identification? The adoption of testing procedures that give characteristic results for specific standard materials and the number and type of tests needed to identify a substance to exclude all other substances.
