ANS overview Flashcards
Describe the structural organization of the central nervous system and peripheral
nervous system
CNS: brain and spinal cord
PNS: cranial and spinal nerves
name the major functional components of the nervous system
Sensory (afferent) and motor (efferent)
The motor can be divided into somatic and visceral motor systems.
compare and contrast somatic and visceral systems
Both have a sensory and motor component. Somatic is associated with voluntary behavior, while the visceral system is unconscious and involuntary. Examples of somatic include skeletal muscle and connective tissues, while the autonomic function is determined by glands, smooth muscle, and cardiac muscle.
describe some functions of the autonomic nervous system
Regulating internal organ function, maintaining homeostasis, innervating organs and tissues, endocrine secretions, etc
Describe the components and the divisions of the autonomic nervous system,
including the sympathetic and parasympathetic divisions.
They dually innervate almost all tissues in the body, with the exception of few tissues. They are physiologic antagonists; SNS is associated with fight or flight, while PSNS is rest and digest. They are both motor (efferent) involuntary systems
Give the alternative names for sympathetic and parasympathetic systems
Sympathetic: thoracolumbar
Parasympathetic: craniosacral
describe the organization of the sympathetic ganglia
There is a sympathetic chain anterior and slightly lateral to the vertebral column. It is a bilateral structure with interconnected ganglia. It is an all-or-none system, as preganglionic fibers synapse on to many postganglionic fibers
What neurotransmitters are involved in the sympathetic nervous system?
Preganglionic fiber: Ach
Postganglionic fiber: NE
What neurotransmitters are involved in the parasympathetic nervous system?
Preganglionic and postganglionic both use Ach
Describe the organization of parasympathetic ganglia
The ganglia are found close to the effector organs. Most ganglia are set up in a 1:1 ratio, meaning one preganglionic fiber per one postganglionic fiber.
Describe the relative lengths of neurons and the neurotransmitters associated
with the sympathetic and parasympathetic divisions of the ANS.
SNS: The preganglionic fiber is short, while the postganglionic fiber is long
PSNS: the preganglionic fiber is long, while the postganglionic fiber is short
what are varicosities?
Long chains of swellings on the post-ganglionic fiber of ANS synapses
Identify and describe the control systems/brain regions for the autonomic nervous system
Brainstem: received visceral sensory information
Hypothalamus: integrative center for the ANS
