Answer: Release of acetylcholine from the synaptic vesicles
Explanation: Acetylcholine is a neurotransmitter of nerve impulses within the central and peripheral nervous systems. It is formed during the esterfication reaction between acetic acid and choline. After its formation, acetylcholine is transprted to a vesicle, where a transporter protein actively pumps the choline into the vesicle. Acetylcholine is stored until a need arises for it to be released.
Ans.
Different barriers present in the body prevent entry of disease causing agents or pathogens from entering into body and provide protection against them. These barriers include various physical, chemical, and biological barriers.
Physical barrier include skin and coughing and sneezing. Skin provides first line of defense by preventing entry of pathogens, and coughing and sneezing that expels harmful agents out of the body.
Chemical barriers include lysozyme, acids, and oil secretion. Lysozyme is an enzyme that kills bacteria by targeting their cell wall, while oil and acid prevent microbial growth by providing non-favorable environment for them.
Biological barriers include phagocytes and Langerhans cells. Phagocytes are immune cells that engulf and destroy pathogens and Langerhans cells are antigen-presenting cells that help in elimination of pathogens.
Phagocytosis is the engulfing of solid particle like substances by wbc which is neutrophils.
<span>the ingestion of liquid into a cell by the budding of small vesicles from the cell membrane.</span>
An open flame or burning flame
