The skin, or integumentary system, is the body's largest organ. It protects us from the outside world, and is our first defense against bacteria, viruses and other pathogens. Our skin also helps regulate body temperature and eliminate waste through perspiration.
An insulin pump with a subcutaneous injection site. A subcutaneous injection is administered as a bolus into the subcutis, the layer of skin directly below the dermis and epidermis, collectively referred to as the cutis. Subcutaneous injections are highly effective in administering vaccines and medications such as insulin, morphine, diacetylmorphine and goserelin.
BTW: TB is intradermal not subq. IM injections need to go into the muscle for optimal absorption and include many meds such as antibiotics, vaccinations. Muscles can absorb more fluid in the shot as well (so can be a Bigger volume). Subcutaneous (subq) goes into the deeper layers of the skin but not into muscle. Examples are insulin, epinephrine, lovenox; the volume is a lot less as well. Subcutaneous is just under the skin and IM means intramuscular, or into the muscle. subcutaneous is a smaller and thinner needle that is just injected under the skin, it is usually around 1/3 of an inch and the gage of the needle is small almost always. IM is a longer needle and the gage is thicker, this is due to the fact that it has to be injected into the muscle.