Lecture 11/coordination

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Look at the hormone secreting cells of the hypothalamus and pituitary for examples (pp. 900-902)

2. Peripheral nervous system41.1 The other main way information flows around your body is through the peripheral nervous system. We'll come back to discuss the nervous system in more detail later. In addition to being responsible for collecting, processing and integrating information, the nervous system sends information to the periphery via neurons.

IMAGE imgs/220C_11Lecture01.gif

Cell Body

Neurons are made up of a cell bodythat contains the nucleus and organelles and a cytoplasmic extension called an axon. When neurons are stimulated, ions rush across their membranes, causing an influx of positive charges. The signal moves down the axon, essentially like the flow of electricity.

At the tip, the neuron releases neurotransmitters.
3. Comparison of two response systems

Q. Why are there two systems? How are they different?

Nervous system
Fast
short duration
direct electrical connection highly specific

Hormones
not as fast
longer duration
no direct connections necessary affects all tissues with receptors

Q. Can you think of a situation that calls for one or the other? - you've just steped on a hot coal, use nervous system (fast) - developmental control of the growth of an organ, use hormone (long duration)


Look at the hormone secreting cells of the hypothalamus and pituitary for examples (pp. 900-902) 2. Peripheral nervous system41.1 The other main way information flows around your body is through the peripheral nervous system. We'll come back to discuss the nervous system in more detail later. In addition to being responsible for collecting, processing and integrating information, the nervous system sends information to the periphery via neurons.

	Cell Body
Neurons are made up of a cell bodythat contains the nucleus and organelles and a cytoplasmic extension called an axon. When neurons are stimulated, ions rush across their membranes, causing an influx of positive charges. The signal moves down the axon, essentially like the flow of electricity. At the tip, the neuron releases neurotransmitters. 3. Comparison of two response systems Q. Why are there two systems? How are they different?
Nervous system Fast short duration direct electrical connection highly specific		Hormones not as fast longer duration no direct connections necessary affects all tissues with receptors
Q. Can you think of a situation that calls for one or the other? - you've just steped on a hot coal, use nervous system (fast) - developmental control of the growth of an organ, use hormone (long duration)