Exam 3 Chapter 15 Flashcards
Which fibers in the motor division of the PNS are not myelinated?
Postganglionic axons of the sympathetic and parasympathetic divisions
As you are driving home from school, a car suddenly swerves toward you, forcing you to hit the brakes quickly. You feel your heart pump, and you begin to sweat a bit. Which division of ANS has been activated?
Sympathetic division (fight or flight)
Where are the sympathetic ganglia located? Where are most parasympathetic ganglia located?
sympathetic ganglia: near spinal cord and vertebral column
parasympathetic ganglia: in or near target organ
What is the result of vagal stimulation of the heart?
decreases heart rate
What is the result of vagal stimulation of the small intestine?
increases motility and secretion
What is the result of vagal stimulation of the salivary gland?
stimulates secretion
Why are white rami communicantes located only on sympathetic trunk ganglia between T1 and L2, and gray rami communicantes branch off each sympathetic trunk ganglion?
White: carry preganglionic outflow from the thoracic and lumbar regions of the cord into the sympathetic trunk
Gray: postganglionic fibers that exit off the sympathetic trunk onto a spinal nerve at each level of the sympathetic trunk (innervate blood vessels, sweat glands, arrector pili)
What is the general effect of sympathetic innervation to the abdominal organs?
decreases activity of the glands and muscles of the digestive system
Which region of the CNS is the main control center for the ANS?
hypothalamus
What is part of the ANS?
- two-neuron motor chains
- preganglionic cell bodies of the CNS
- presence of postganglionic cell bodies in ganglia
Which division of the ANS has short preganglionic axons and long postganglionic axons?
sympathetic
Which division of the ANS has intramural ganglia?
parasympathetic
Which division of the ANS has craniosacral outflow?
parasympathetic
Which division of the ANS has adrenergic fibers?
sympathetic
Which division of the ANS has cervical ganglia of the sympathetic trunk?
sympathetic
Which division of the ANS has optic and ciliary ganglia?
parasympathetic
Which division of the ANS has more widespread response?
sympathetic
Which division of the ANS increases heart rate, respiratory rate, and blood pressure?
sympathetic
Which division of the ANS increases motility of stomach and secretion of lacrimal and salivary glands?
parasympathetic
Which division of the ANS innervates blood vessels?
sympathetic
Which division of the ANS is most active when you are lolling in a hammock?
parasympathetic
Which division of the ANS is most active when you are running in the Boston marathon?
sympathetic
Which division of the ANS has gray rami communicantes?
sympathetic
Which division of the ANS has synapse in celiac ganglion?
sympathetic
Which division of the ANS relates to fear response induced by the amygdaloid body?
sympathetic
Which nerve innervates most of the organs of the abdomen and the thorax?
vagus nerve
What kind of cell bodies do collateral ganglia contain?
postganglionic sympathetic
How is the ANS controlled?
little control by cerebrum, major control by hypothalamus and amygdaloid body and
major control by spinal and peripheral reflexes
What kind of axons does the white rami communicantes contain?
preganglionic sympathetic
What are collateral sympathetic ganglia involed with?
Innervation of the abdominal organs
Describe the anatomical relationship of the white and gray rami communicantes to a spinal nerve, and to the dorsal and ventral rami.
White: connect spinal nerves to sympathetic chain ganglia & emerge from spinal nerve’s ventral root
- found from T1 to L2 spinal levels
Gray: connect sympathetic chain ganglia to spinal nerves & emerges from spinal nerve’s dorsal root
- found at every spinal level
Why are gray rami communicantes gray?
nonmyelinated nerve fibers
LACK OF MYELIN
How do the somatic motor and visceral motor pathways differ anatomically and functionally?
Somatic: originates from CNS motor neurons and directly innervates skeletal muscles (only 1 neuron)
Visceral: involves preganglionic and postganglionic neurons and controls involuntary functions of internal organs (2 neuron pathway: CNS to ganglion to effector)
