Human Anatomy and Physiology - Problem Drill 15: The Autonomic Nervous System

Transcription

1 Human Anatomy and Physiology - Problem Drill 15: The Autonomic Nervous System Question No. 1 of 10 Which of the following statements is correct about the component of the autonomic nervous system identified in the image below? A Question #01 A. The sympathetic chain ganglia identified in the image are only present in the sympathetic nervous system. B. The letter A in the image identifies the pelvic nerves of the parasympathetic division. C. The letter A in the image identifies the pelvic nerves of the sympathetic division. D. The vagus nerve is identified in the image. E. A and B are correct. A. Correct! The sympathetic chain ganglia identified in the image are only present in the sympathetic nervous system. B. Incorrect! The letter A in the image is identifying the sympathetic chain ganglia. The letter A in the image is identifying the sympathetic chain ganglia. The sympathetic chain ganglia identified in the image are only present in the sympathetic nervous system. Only answer A is correct. The sympathetic division involves a sympathetic chain ganglia and sympathetic nerves, unlike the parasympathetic division. In addition to the parasympathetic and sympathetic divisions, the autonomic nervous system also includes the enteric division.

2 Question No. 2 of 10 The autonomic nervous system is dependent on sensory information to generate the appropriate motor response. Which of the following is an appropriate response of the autonomic nervous system? Question #02 A. Low blood oxygen levels lead to a decrease in the rate of breathing. B. Low blood oxygen levels lead to an increase in the rate of breathing. C. High blood pressure leads to an increase in heart rate. D. High blood pressure leads to an increase in heart rate and the force of contraction. E. The presence of food in the stomach activates the sympathetic division to increase motility and enzymatic action in the gastrointestinal tract. A decrease in blood oxygen levels would lead to an increase in the rate of breathing. B. Correct! Low blood oxygen levels lead to an increase in the rate of breathing. An increase in blood pressure would lead to a decrease in the heart rate. An increase in blood pressure would lead to a decrease in the heart rate and would not lead to an increase in the force of contraction. The presence of food in the stomach would provide sensory information to the autonomic nervous system. However, activation of the parasympathetic division would lead to an increase in motility and enzyme action. The autonomic nervous system generates a response, based on the information received from the sensory branch. For example, see the table below: Sensory Motor Low Blood Oxygen Levels Increase Breathing Rate High Blood Pressure Decrease Heart Rate Food in Stomach Increase Digestive Enzymes

3 Question No. 3 of 10 The parasympathetic division of the autonomic nervous system includes ganglia, which contain ganglionic neurons. Which of the following statements about the parasympathetic division ganglia is correct? Question #03 A. The post-ganglionic fibers that exit the spinal cord are cranial nerves, such as the facial nerve. B. Two of the parasympathetic division ganglia are the pterygopalatine and the submandibular. C. The otic and the facial nerve ganglia are two ganglia in the parasympathetic division. D. There are a total of 3 ganglia in the parasympathetic division: pterygopalatine, ciliary, and the otic ganglia. E. The vagus nerve synapses with the pterygopalatine ganglion. The preganglionic fibers exit the spinal cord as cranial nerves. B. Correct! The parasympathetic ganglia are: pterygopalatine, ciliary, submandibular, otic and the intramural ganglia. The otic is a ganglia of the parasympathetic division; however, the facial nerve ganglia is not. The parasympathetic ganglia are: pterygopalatine, ciliary, submandibular, otic and the intramural ganglia. The vagus nerve synapses with the intramural ganglia. In the parasympathetic division, the preganglionic nerve fibers exit the central nervous system as the cranial nerves. These cranial nerves then synapse in ganglia with the short ganglionic neuron. The ganglia of the parasympathetic division are: pterygopalatine, ciliary, submandibular, and the otic ganglion.

4 Question No. 4 of 10 The parasympathetic division of the autonomic nervous system has opposing functions of the sympathetic. Which of the following statements about the parasympathetic division is correct? Question #04 A. The parasympathetic division decreases the heart rate during its activation. B. The parasympathetic innervation leads to a decrease in intestinal motility. C. Stimulation of the parasympathetic division leads to a complete stop of all glandular activity. D. The parasympathetic division is known as the fight-or-flight system. E. The parasympathetic division has no impact on the digestion or absorption of food. A. Correct! As part of parasympathetic activation, the heart rate is decreased. B. Incorrect! Activation of this division of the autonomic nervous system leads to an increase in intestinal motility. Activation of the parasympathetic division leads to an increase in glandular activity, as the body prepares for digestion and absorption. The parasympathetic division is known as the rest-and-digest system. Activation of the parasympathetic division increases the activity of the gastrointestinal tract. The parasympathetic nervous system is known as the Wine and Dine or Rest and Digest system. It functions by decreasing the heart rate, increasing glandular activity, and increasing intestinal activity for digestion and absorption. Overall, the functions of the parasympathetic division lead to relaxation, food digestion, and absorption that leads to increased blood nutrients.

5 Question No. 5 of 10 The parasympathetic and sympathetic divisions use different neurotransmitters. Which of the following is the neurotransmitter used by the parasympathetic division? Question #05 A. Epinephrine. B. Norepinephrine. C. Acetylcholine. D. Epinephrine and acetylcholine. E. Muscarinic acid. Epinephrine is a neurotransmitter used by the sympathetic nervous system. B. Incorrect! Norepinephrine is a neurotransmitter used by the sympathetic nervous system. C. Correct! Acetylcholine is the neurotransmitter used by the parasympathetic nervous system. Acetylcholine is the neurotransmitter used by the parasympathetic nervous system; however, epinephrine is not. Muscarinic receptors are a type of receptor in the parasympathetic division. The sympathetic and parasympathetic divisions oppose each other but in a complementary fashion. For example, one can think of the sympathetic division as the accelerator and the parasympathetic division as the brake. The neurotransmitters are released by post-ganglion neurons. The parasympathetic division uses the neurotransmitter, acetylcholine. Its function includes, most frequently, opposing effects of norepinephrine.

6 Question No. 6 of 10 The parasympathetic division has its own unique receptors that are different from the sympathetic nervous system. Which of the following statements about the receptors of the parasympathetic division is correct? Question #06 A. The parasympathetic division utilizes alpha receptors. B. Nicotinic receptors are one of the receptors used by the parasympathetic division. C. Nicotinic and alpha receptors are both used by the parasympathetic nervous system. D. The nicotinic receptors used by the parasympathetic division are sensitive to epinephrine and norepinephrine. E. There are a total of three receptors used by the parasympathetic division: nicotinic, muscarinic and alpha receptors. The parasympathetic division uses nicotinic and muscarinic receptors. B. Correct! The parasympathetic division uses nicotinic and muscarinic receptors. Alpha receptors are used by the sympathetic division, along with the beta receptors. The nicotinic receptors and the muscarinic receptors used by the parasympathetic division are both responsive to acetylcholine. The two receptors used by the parasympathetic division are the muscarinic and nicotinic receptors. There are two types of receptors in the postsynaptic neuron used by the parasympathetic division: nicotinic and muscarinic. The nicotinic receptor subtype is located on all the ganglionic neurons. Upon exposure to the neurotransmitter, acetylcholine, these receptors lead to excitation of either the ganglionic neuron or the muscle fiber. Muscarinic receptors are located at cholinergic neuroeffector junctions (small narrow synaptic clefts). Once stimulated, these are longer-acting than nicotinic receptors.

7 Question No. 7 of 10 A 67-year-old male patient is diagnosed with a disease that causes almost constant activity of the sympathetic innervation to his heart. Based on this information, which of the following would be correct? Question #07 A. The nicotinic receptors located in the patient s heart would be constantly stimulated by the sympathetic division of the autonomic nervous system. B. The activation of the beta receptors located in this patient s heart would lead to a constant decrease in his heart rate. C. The activation of the beta receptors located in this patient s heart would lead to a constant increase in his heart rate. D. The constant sympathetic innervation activity would lead to a constant constriction of his coronary blood vessels. E. The coronary blood vessels in this patient s heart would not be impacted by this disease, as the sympathetic innervation of the heart does not affect the coronary blood vessels. The innervation of the patient s heart would involve the activation of beta receptors. B. Incorrect! The constant activation of the sympathetic innervation would lead to an increased heart rate. C. Correct! The activation of the beta receptors located in this patient s heart would lead to a constant increase in his heart rate. Sympathetic nerve fiber activation would cause coronary blood vessel dilation. Sympathetic nerve fiber activation would cause coronary blood vessel dilation. Heart: the activation of sympathetic innervation of the heart increases the heart rate and strength of contraction. The coronary blood vessels of the heart are dilated as part of this activation.

8 Question No. 8 of 10 Both the sympathetic and parasympathetic divisions of the autonomic nervous system innervate the stomach and the intestine. Which of the following statements about the sympathetic innervation of the stomach and intestines is correct? Question #08 A. The activation of sympathetic innervation of the stomach would lead to an increase in the motility and the tone. B. The activation of sympathetic innervation of the stomach would lead to a decrease in the motility and the tone. C. Activation of the sympathetic nerve fibers to the intestines would lead to an increase in motility and tone. D. The sympathetic innervation of the stomach and intestines promote digestion and absorption. E. The sympathetic innervation utilizes the pterygopalatine ganglia. Activation of the sympathetic innervation of the stomach would lead to a decrease in the motility and tone. B. Correct! The activation of sympathetic innervation of the stomach would lead to a decrease in the motility and the tone. Activation of the sympathetic nerve fibers to the intestines would lead to a decrease in motility and tone. The sympathetic innervation of the stomach and intestines would slow down digestion and absorption, to support the fight-or-flight response. The sympathetic innervation utilizes the celiac and superior mesenteric ganglia.

9 Question No. 9 of 10 The autonomic nervous system contains unique plexuses; these plexuses are located in the thoracic, abdominal and pelvic cavities. Which of the following statements about the autonomic plexuses is correct? Question #09 A. The autonomic fibers that enter the thoracic cavity intersect at the cardiac and pulmonary plexuses. B. The esophageal plexus contains the descending branches of the pelvic nerves. C. The autonomic plexuses contain either parasympathetic or sympathetic fibers but never both. D. The autonomic plexuses include: cardiac plexus, pulmonary plexus and the abdominal plexus. E. None of the answers are correct. A. Correct! The autonomic fibers that enter the thoracic cavity intersect at the cardiac and pulmonary plexuses. B. Incorrect! The esophageal plexus contains the descending branches of the vagus nerve. The autonomic plexuses contain both parasympathetic and sympathetic fibers. The autonomic plexuses include: pulmonary, esophagus, celiac, inferior mesenteric and the hypogastric plexus. One of the answers is correct. Within the abdominopelvic cavities, both the parasympathetic and sympathetic fibers mix in special plexuses: cardiac, pulmonary, esophagus, celiac, inferior mesenteric and the hypogastric plexus. The cardiac and pulmonary plexuses contain both parasympathetic and sympathetic fibers, which are interconnected. The parasympathetic preganglionic fibers of the vagus nerve follow the path of the esophagus into the abdominal cavity to arrive at the celiac plexus. The inferior mesenteric plexus is associated with the celiac plexus. The hypogastric plexus is located at the level of the wings of the ilium bones of the hip.

10 Question No. 10 of 10 The control of the autonomic nervous system involves different brain regions that communicate with each other to process all the sensory information and execute the correct responses. Which of the following statements about the control of the autonomic nervous system is correct? Question #10 A. The thalamus is the control center of the autonomic nervous system. B. The cerebral cortex and the limbic system can influence the autonomic nervous system. C. The sympathetic division is controlled by the posterior and lateral thalamus. D. The limbic system can influence the parasympathetic division but not the sympathetic division. E. The cerebral cortex has no influence or control on the autonomic nervous system. The hypothalamus is the control center for the autonomic nervous system. B. Correct! The cerebral cortex and the limbic system can influence the autonomic nervous system. The sympathetic division is controlled by the posterior and lateral hypothalamus. The limbic system can influence the parasympathetic and the sympathetic system through the hypothalamus. The cerebral cortex communicates at a subconscious level with both the hypothalamus and the pons, and it can dramatically influence the autonomic nervous system. Centers in the brain stem control the parasympathetic and sympathetic nerve fibers. Within the brain stem are processing centers for the autonomic nervous system. The processing centers in the brain stem are in communication with the control center in the hypothalamus. The control of the autonomic nervous system can be divided as follows: (1) sympathetic division is controlled from the posterior and lateral hypothalamus, and (2) the parasympathetic division is controlled from portions of the anterior and medial hypothalamus. The functions of the autonomic nervous system can be impacted by the cerebral cortex, and the limbic system through emotions. The hypothalamus can be influenced by higher centers, such as the cerebral cortex and the limbic system, to modify the actions of the autonomic nervous system.