Preganglionic fibers are myelinated, whereas postganglionic fibers are unmyelinated

Question : Preganglionic fibers are myelinated, whereas postganglionic fibers are unmyelinated : 2150427

TRUE/FALSE. Write 'T' if the statement is true and 'F' if the statement is false.

1) Preganglionic fibers are myelinated, whereas postganglionic fibers are unmyelinated.

2) Parasympathetic stimulation of blood vessels causes vasoconstriction and increased blood pressure.

3) Fibers from the cranial and sacral regions of the spinal cord contribute to the sympathetic division.

4) Postganglionic sympathetic fibers are relatively long compared to those of the parasympathetic division.

5) The sympathetic and parasympathetic divisions can be distinguished by the amount of branching of the post-ganglionic fibers.

6) Postganglionic sympathetic fibers release norepinephrine and are called cholinergic fibers.

7) Adrenergic postganglionic neurons release the hormones norepinephrine and epinephrine.

8) All parasympathetic postganglionic fibers of the head travel through the trigeminal nerve (V) to their final destinations.

9) The cardiac center of the medulla oblongata regulates the diameter of blood vessels.

10) Vagal stimulation of the heart decreases heart rate, resulting in a drop in blood pressure.

11) Sympathetic trunk ganglia contain the cell bodies of sensory neurons and are located in the dorsal root of the spinal cord.

12) The main integration center of the ANS is the amygdala.

13) Because the fibers of the sympathetic division arise from the thoracic and lumbar regions of the spinal cord, they cannot innervate structures of the head or pelvis.

14) Parasympathetic stimulation of the pelvic organs causes defecation, voiding of urine, and erection.

15) Parasympathetic fibers innervate the sweat glands, arrector pili, and smooth muscles of the arteries.

SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question.

16) Vasoconstriction and bronchodilation result from stimulation by the ________ division.

17) Autonomic fibers emerging from the craniosacral region of the spinal cord belong to the ________ division.

18) Postganglionic fibers of the parasympathetic system are called ________ because they release the neurotransmitter acetylcholine.

19) The ________ nervous system consists of complete three-neuron reflex arcs that exist entirely within the wall of the digestive tube.

20) During development, all neurons with cell bodies in the PNS derive from the ________.

21) The cell bodies of postganglionic parasympathetic fibers to the pupil and lens of the eye are located in the ________ ganglion.

22) The ________ plexus is a network through which branches of the vagus pass to the intestines and liver.

23) Autonomic fibers to the pelvic organs pass through the pelvic plexus, also known as the ________ plexus.

24) Visceral reflexes that do not involve the CNS but instead synapse in sympathetic ganglia are called ________ reflex arcs.

25) Sympathetic preganglionic fibers leaving the thoracic spinal nerves may ascend within the ________ before synapsing so that they can exit near the head.

26) Gray rami communicantes contain ________ sympathetic fibers that travel to peripheral structures.

27) The sensation of pain from a visceral organ that is perceived in the skin or outer body is the phenomenon called ________.

28) The primary integrating center of the ANS is the ________ of the diencephalon.

29) The adrenal medulla is comprised of modified sympathetic ________ neurons which secrete epinephrine and norepinephrine.

30) Congenital megacolon, or Hirschsprung's disease, is a birth defect in which the ________ innervation of the distal region of the large intestine fails to develop normally.

ESSAY. Write your answer in the space provided or on a separate sheet of paper.

31) Contrast the structure of the somatic and autonomic motor neurons.

32) Identify three anatomical differences that distinguish the sympathetic division from parasympathetic division.

33) The sympathetic and parasympathetic divisions differ markedly in the branching of the postganglionic fibers. Explain the anatomical difference and its significance.

34) Explain the relationship between the vagus and pelvic splanchnic nerves, the cardiac and pulmonary plexus, celiac plexus, and hypogastric plexus.

35) Describe the correct pathway that a nerve impulse to blood vessels and hair follicles (glands and arrector pili muscles) in the dermis must travel using the following structures: ventral ramus, dorsal root, ventral root, sympathetic trunk, gray ramus communicans, white ramus communicans, and spinal nerve.

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Anatomy and physiology 1 Year Ago 302 Views
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