The Nervous System II: Anatomy Review
1. The somatic nervous system stimulates __Smooth__ muscle.
The autonomic nervous system stimulates _Skeletal___ muscle, __Cardiac___ muscle, and
_Glands___.
2. The autonomic nervous system (ANS) consists two divisions, each innervating the effector organs. The sympathetic nervous system (SNS) generally speeds up everything except digestion. The parasympathetic nervous system (PNS) generally slows down everything but digestion.
Signals from the SNS cause the heart rate to _rise___, while signals from the PNS cause the heart rate to _slow____.
Signals from the SNS cause smooth muscles of the intestine to _excite_ contractions, while signals from the PNS cause these muscles to slow__ contractions.
Signals from the SNS also cause the adrenal gland to secrete__ epinephrine and norepinephrine.
3. Neurons can excite or inhibit another neuron.
Exciting another neuron will increase the chances of a/an __excites___ in the second neuron.
Inhibiting another neuron will make the chances of a/an __inhibits______ less likely.
4. Axons from one neuron can synapse with the dendrites or soma of another axon.
These synapses are called _axosomatic___ (on dendrites) and __axodendritic____
(on soma). They carry input signals to the other neuron.
Axons from one neuron can synapse with the axon terminal of another neuron. These synapses are called
____axoaxonic___, and they regulate the amount of _chemical transmitters___ released by the other neuron.
5. The electrical synapse:
Electrical current flows from one neuron to another through __gap junction_.
These synapses are always (excitatory or inhibitory).
Advantages of the electrical synapses:
1. _fast_ signal conduction
2. __synchronized__ activity for a group of neurons.
6. The chemical synapse:
Chemical synapses are not as fast as electrical but are the most common type of synapse.
A chemical,