Homework assignment #4 (25 points): This assignment is optional. If you decide to complete it, turn it in at the beginning of the "final" exam.  Each question is worth one point unless otherwise noted.

Name:

I.  Short answer

1. What is a mixed nerve?

2. Draw a somatic motor pathway. Label the location of neuron cell body(ies), effector.

3. What is the neurotransmitter released at effector nerve endings of somatic motor pathways?

4. Circle the appropriate underlined term: somatic motor output is excitatory/inhibitory/may be excitatory/inhibitory.

5. In the space below draw and label an autonomic pathway. Include the following terms: ganglion, CNS, preganglionic neuron, postganglionic neuron, effector.

6. In the context of the autonomic nervous system what is a ganglion? Use no more than one sentence.

7. Where are cell bodies of parasympathetic preganglionic neurons located?

8. What are parasympathetic ganglia called? Where are they located?

9. Most parasympathetic output to organs in ventral cavity travels via what nerve? Is this nerve composed of preganglionic or postganglionic fibers?

10. What are sympathetic chain ganglia? Where are they located?

11. What are prevertebral sympathetic ganglia? Where are they located?

12. Match the following terms with the neurons types listed below: (0.5 point each)

a. adrenergic neurons.

b. cholinergic neurons.

Neuron type	Matching term
preganglionic parasympathetic neurons
somatic motor neurons
postganglionic parasympathetic neurons
preganglionic sympathetic neurons
postganglionic sympathetic neurons.
stimulation of adrenal medulla mimics effect of these neurons

13. Where can a preganglionic sympathetic fiber synapse with a postganglionic fiber?

15. Indicate the effect of increased parasympathetic or sympathetic discharge on each of the following parameters. (0.5 point each)

In the appropriate column mark "+" if the discharge increases the parameter, "-" if the discharge decreases the parameter, and "none" if the discharge has no effect on the parameter.

Parameter	Sympathetic	Parasympathetic
Heart rate
Skeletal muscle blood vessel diameter
Abdominal viscera blood vessel diameter
Enzyme secretion by digestive organs
Motility of small intestine
Secretion of epinephrine by adrenal medulla
Sweat gland activity
Insulin production by pancreas
Diameter of bronchioles
Blood glucose levels

II.  Multiple choice (0.5 points each)

16.  Somatic motor pathways:

1. are inhibitory.

2. are excitatory.

3. are both inhibitory and excitatory.

4. innervate smooth muscle.

5. are composed of a two neuron chain.

17.  Thoracic spinal nerves:

1. contain only motor axons.

2. contain only afferent fibers.

3. contain somatic and autonomic fibers.

4. contain only myelinated axons.

5. contain only sensory axons.

18.  All cranial nerves:

1. are mixed nerves.

2. only innervate structures in the head and neck.

3. are somatic motor.

4. originate in the brainstem.

5. none of the above is true.

  19.  The brachial plexus:

1. arises from the accessory cranial nerve.

2. arises from spinal nerves in the thoracolumbar region of the cord.

3. provides innervation to the upper limbs.

4. arises mostly from cervical spinal nerves.

5. c and d are true.

  20.   The ventral rami of the majority of these spinal nerves do not form plexuses:

1. cervical nerves.

2. thoracic nerves.

3. lumbar nerves.

4. sacral nerves.

5. ventral rami of all of above form plexuses.

21.  Parasympathetic ganglia:

1. are found in the paravertebral chain.

2. are located very close to the spinal cord.

3. are usually intramural ganglia.

4. are prevertebral ganglia.

5. are located on the walls of the aorta.

22.  The sympathetic nervous system:

1. is also known as the craniosacral ANS division.

2. is also known as the thoracolumbar ANS division.

3. arises mostly from the brain.

4. regulates anabolic, vegetative functions.

5. is a single neuron motor pathway.

23.  Which of the following is/are mostly under sympathetic innervation:

1. skeletal muscle blood vessels.

2. small intestine.

3. salivary glands.

4. bronchioles.

5. heart.

24.  Which of the following is true of both somatic efferent pathways and sympathetic nervous system pathways?

1. fibers pass through the dorsal roots of spinal nerves.

2. the neuron emerging from the CNS releases epinephrine at its synapse.

3. a chain of two neurons exists between the CNS and the effector.

4. neurons always myelinated.

5. the neuron emerging from the CNS releases acetylcholine at its synapse.

25.  All of the following characterize the ANS except:

1. two neuron efferent chain.

2. presence of nerve cell bodies in the CNS.

3. presence of nerve cell bodies in the ganglia.

4. two neuron afferent chain.

5. a division of the PNS.

Extra credit (1 point)

26.  The secretions of the adrenal medulla:

1. supplement effects of parasympathetic innervation.

2. supplement the effects of sympathetic innervation.

3. supplement the effects of vagus nerve activity.

4. are predominantly epinephrine.

5. b and d are true.