BIOL 2160 Chapter : Chapter 5 Chemical Messengers
Document Summary
Chapter 5 chemical messengers: mechanisms of intercellular communication, direct communication through gap junctions, indirect communication through chemical messengers. Make chart ^ on top, on sides chemical messengers. Released by cell, moves to target cell by diffusion. Ex; histamine-released with tissue damage and causes dilation of local blood vessels. Testosterone-moves from the leydig cells into the seminiferous tubules (hormone or paracrine messenger bc on outside of s. tubules are leydigs, help manufacture healthy sperm. ) Messengers of nervous system: released from neuron by exocytosis, diffuses to very close target cell across a synapse, fig 5. 2b. Hormones: messenger of endocrine system, released from endocrine gland into blood, transported in blood to target, target cell = cells in body with receptors specific to the hormone, fig 5. 2d-receptor always on surface of cell. Neurohormones: hormones released from the axons of neurons, adh & oxytocin in posterior pituitary, inhibiting & releasing hormones into the portal system going to the anterior pituitary.
