Methods of production
While getting bitten by a snake might strike fear in people, the fangs are not where the venom comes from, they are mearly methods of transfer. The place where the venom is made is in special glands located on the head of the animal. The venom glands differentiate into false and true venom glands.
False venom glands (a misleading name no doubt) are made up either from mucus producing supralabial glands that run on either side of the head extending as a continuous strip from near the snout to below and well behind the eye. These then lead to several ducts that lead to the bases of many maxillary teeth. Alethinophidians are known to have this type of arrangement.
Most colubrids have a different arrangement. Rather than use those modified salivary glands they use a larger gland known as the Duvernoy's gland. This gland is situated right under the skin, above and near the angle of the jaw. These glands open from a duct at the base of one or more posterior usually enlarged fangs that may or may not be grooved. These glands do not have a lumen (central storage chamber) so the snakes must give off a continous stream of venom into their prey which means that they must continue to hold on to the animal to ensure envenomation.
True venom glands are made uf thick connective tissue. They contain a lumen, a separate compressor muscle and a duct connecting them to a single fang on each side of the jaw. These glands dominate all elapids and viperids (along with some atractaspidids)
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