Stinging hairs on the stem of a stinging nettle, Urtica dioica. The sting comes from the longer hairs (the short ones are harmless); these have silicified tips which break off when the nettle is brushed against or stroked (not grasped). The sting penetrates the skin, injecting a mixture of acetylcholine & histamine; the former is a neurotransmitter substance normally produced at nerve terminals, the latter a chemical mediator normally produced by mast cells & responsible for many of the unpleasant symptoms of allergic reactions.
px | px | dpi | = | cm | x | cm | = | MB |
Details
Creative#:
TOP10173489
Source:
達志影像
Authorization Type:
RM
Release Information:
須由TPG 完整授權
Model Release:
N/A
Property Release:
N/A
Right to Privacy:
No
Same folder images: