FIGURE 2

Reflexes in the autonomic and somatic nervous systems: On the left are reflexes involving the involuntary organs; on the right are reflexes involving skeletal muscles. (From RhoadesAnd Tanner, Medical Physiology, Little, Brown and Co., 1995).

FIGURE 3

From Sherwood, Human Physiology, 2nd Edition

FIGURE 8Parasympathetic Nervous System

Parasympathetic from Noback and Demarest, The Human Nervous Systems, 2nd edition, McGraw Hill, 1975

FIGURE 4

FIGURE 9

Distribution of chemical transmitter (ACh and Norepi) along the autonomic pathways. + = stimulatory, - = inhibitory

FIGURE 10

A receptor is both a transducer and a translator. It converts one form of energy, the stimulus, into a second form of energy, an electrical receptor potential. In turn, the receptor potential generates action potentials (APs). As a result, the receptor converts the information-containing signal to APs, altering the information itself.

FIGURE 11aCarotid sinus reflex. Nuerons of the sinus nerve excite neurons in the medulla. (+) indicatesExcitatory synapses, (-) inhbitoru. From A.M. Brown and D.W.

FIGURE 11B

The baroreceptor is much more responsive to increasing than decreasing pressure. Nevertheless, baroreceptors respond to both increases and decreases in blood pressure over a range of about 50 – 200 mm Hg. Also note that the frequency of firing APs increases as the mean blood pressure increases. This is due to the tonic component becoming more consequential at higher pressures. (From Berne and Levy, Physiology, Third Edition).

TABLE 1

From Rang et al., Pharmacology, Churchill Livingstone, 1995.

FIGURE 5From Sherwood, Human Physiology, 2nd ed., 1993.

FIGURE 6Sympathetic Nervous System

From Noback and Demarset,The Human Nervous System, 2nd edition, McGraw Hill, 1975.

FIGURE 7

The somatic pathway (left) and autonomic sympathetic pathway (right). For clarity, the two pathways are shown on opposite sides of the spinal segment; sympathetic and somatic motor neurons are actually present on both sides of the cord. Most sympathetic postganglionic axons run to effectors along sympathetic nerves, but some are found in spinal nerves along with the axons of somatic motor neurons. (From Moffett, Moffett and Schauf, Human Physiology, 2nd edition, Mosby, 1993).