PL7 ANS 1 Flashcards
(21 cards)
What are the three main divisions of the autonomic nervous system (ANS)?
The three main divisions of the ANS are the sympathetic nervous system, parasympathetic nervous system, and enteric nervous system.
Which tissues and organs are controlled by the autonomic nervous system?
The ANS controls smooth muscles, cardiac muscles, and glands.
How does the autonomic nervous system interact with the somatic nervous system?
The ANS regulates involuntary functions, while the somatic nervous system controls voluntary movements.
What is the origin of the sympathetic nervous system, and how do its fibers differ in length?
The sympathetic nervous system originates from the thoracolumbar region, and its fibers are short preganglionic and long postganglionic.
Describe the origin and fiber arrangement of the parasympathetic nervous system.
The parasympathetic nervous system originates from the craniosacral region, with long preganglionic and short postganglionic fibers.
What neurotransmitters are released by preganglionic and postganglionic neurons in the sympathetic division?
Preganglionic neurons release acetylcholine, while postganglionic neurons primarily release norepinephrine.
Why are sweat glands an exception in the sympathetic division in terms of neurotransmitter release?
Sweat glands are an exception because they release acetylcholine instead of norepinephrine.
What are the main types of cholinergic receptors, and where are they located?
The main types of cholinergic receptors are nicotinic receptors (located in ganglia) and muscarinic receptors (located in target organs).
List the adrenergic receptors and their respective locations.
Adrenergic receptors include alpha-1 (vascular smooth muscle), alpha-2 (presynaptic neurons), beta-1 (heart), and beta-2 (bronchial smooth muscle).
What is the primary difference in neurotransmitter use between the sympathetic and parasympathetic divisions?
The sympathetic division primarily uses norepinephrine, while the parasympathetic division primarily uses acetylcholine.
How are norepinephrine and epinephrine synthesized, and how are they removed from tissues?
Norepinephrine and epinephrine are synthesized from tyrosine and are removed from tissues by reuptake into neurons or by enzymatic degradation.
What are the primary effects of sympathetic stimulation on heart rate, pupil size, and digestive processes?
Sympathetic stimulation increases heart rate, dilates pupils, and inhibits digestive processes.
What are the primary effects of parasympathetic stimulation on the same processes?
Parasympathetic stimulation decreases heart rate, constricts pupils, and stimulates digestive processes.
What does the term ‘non-adrenergic non-cholinergic (NANC)’ system refer to?
The NANC system refers to neurons that do not use adrenergic or cholinergic neurotransmitters.
List some neurotransmitters involved in the NANC system and their functions.
Neurotransmitters involved in the NANC system include nitric oxide (vasodilation) and vasoactive intestinal peptide (regulates gut motility).
How do NANC neurons contribute to gastrointestinal regulation?
NANC neurons modulate gastrointestinal motility and secretion through various neurotransmitters.
What is the role of the adrenal medulla in the sympathetic division?
The adrenal medulla releases epinephrine and norepinephrine into the bloodstream, enhancing the sympathetic response.
What is the significance of co-storage and co-release of neurotransmitters in the ANS?
Co-storage and co-release allow for more complex signaling and modulation of responses in the ANS.
Explain the concept of ganglia in the ANS and its functional importance.
Ganglia are clusters of neuronal cell bodies that act as relay points in the ANS, facilitating communication between the CNS and target organs.
How do myelinated and non-myelinated fibers differ in the ANS, and where are they found?
Myelinated fibers are found in preganglionic neurons and conduct impulses faster, while non-myelinated fibers are found in postganglionic neurons and conduct impulses slower.
