Collection of organs and cells that secrete chemical signals into the bloodstream.
What are the six categories of chemical signals in animals? what are their functions?
Autocrine signal- Act on the same cell that secrete them.
Paracrine signal- Diffuse locally and act on neighboring cells.
Endocrine signal- Hormones carried between cells by blood or other body fluids.
Neural Signal-Diffuse a short distance between neurons.
Neuroendocrine signal- Are released from neurons but are carried by blood or other body fluids and act on distant cells.
Pheromones- Are released into the environment and act on a different individual.
What are glands?
Organs that secret endocrine signals for the production of hormones.
What happens when an action potential arrives at a synapse?
It triggers the release of neurotransmitter that bind to receptors on the postsynaptic cell and induce a change in membrane potential- altering the tendency for the postsynaptic cell to fire action potentials.
How are information about the internal or external environment gathered?
Gathered at the receptor and then integrated by the neurons in the central nervous system (CNS) prior to the production of a hormonal signal. Neurons in the CNS respond by releasing neuroendocrine signals that:
Act on effector cells directly
Stimulate cells in the endocrine system, which respond by producing a hormone.
What are the 3 types of signaling pathway ?
Direct from an endocrine cell
Direct from CNS
CNS-to-endocrine-system are regulated by negative feedback or feedback inhibitors.