Chemical Messengers 3. Hormones â¢Longârange messengersâ¢Secreted into blood by endocrine glands in response to appropriate signalâ¢Exert effect on target cells some distance away from release site 4.hemical Messengers 3. Hormones â¢Longârange messengersâ¢Secreted into blood by endocrine glands in response to appropriate signalâ¢Exert effect on target cells some distance away from release site 4.
Scale box in millimeters. Vesicular texture is a volcanic rock texture characterized by a rock being pitted with many cavities (known as vesicles) at its surface and inside.
The process of using and reusing synaptic vesicles is a fascinating one. Vesicles are manufactured in the cell body, not in the endfoot. Fresh vesicles, filled with neurotransmitter substance and various complexes of enzymes, are shipped from the cell body down the axon to the endfeet of the neuron.