Innervation Flashcards
What is the role of the sympathetic nervous system?
Mobilizes body systems to respond to acute environmental stressors
What physiological changes occur due to sympathetic activation?
Accelerates heart and respiration rates, dilates pupils, reduces blood flow to less essential organs
What hormones are involved in the sympathetic response?
Epinephrine (adrenaline) and norepinephrine (noradrenaline)
Where are epinephrine and norepinephrine produced?
Produced by the adrenal medulla; norepinephrine is also produced by most sympathetic neurons
What is the primary function of the parasympathetic nervous system?
Lowers heart rate and promotes ‘rest-and-digest’ activities
How many neurons are involved in the sympathetic and parasympathetic pathways?
Two neurons act as intermediates: preganglionic and postganglionic neurons
Where do preganglionic neurons synapse in the parasympathetic system?
On ganglia near or on the target organ
How do the lengths of preganglionic fibers differ between sympathetic and parasympathetic systems?
Preganglionic fibers are shorter in the sympathetic system and longer in the parasympathetic system
What is the sympathetic trunk?
A chain of ganglia near the spinal cord extending from the base of the skull to the coccyx
What neurotransmitter do postganglionic sympathetic fibers primarily rely on?
Norepinephrine
What neurotransmitter is primarily used by preganglionic and postganglionic fibers in the parasympathetic system?
Acetylcholine
Fill in the blank: The parasympathetic response is often referred to as the _______ response.
rest-and-digest
True or False: The sympathetic nervous system increases blood flow to organ systems that are essential during acute stress.
False
