ANS Flashcards
what does the ANS control?
voluntary or involuntary?
what type of efferent fibers does it use?
what controls the ANS? Which controls it the most?
smooth muscle, cardiac muscle, and glands
Involuntary
GVE
Hypothalamus and brainstem
Hypothalamus controls ANS mostly
where do we find the pneumotaxic control center?
What it the pneumotaxic control center?
Blood pressure control centers can be subdivided by function, what are these?
in the pons
area in brainstem that controls respiration
1) cardiac acceleration and vasoconstriction
2) cardiac slowing
what do you call the higher control centers for the ANS?
supraspinal
There are three main pathways connecting the hypothalamus to the brainstem control centers…what are these (3)?
which of these pathways is bidirectional?
- Mammilotegmental tract - unidirectional
- Dorsal longitudinal fasciculus -unidirectional
- Medial forebrain bundle - bidirectional
the mammilotegmental tract goes from where to where? (structurewise)
what about the dorsal longitudinal fasciculus?
what about the Medial forebrain bundle?
- mammillary bodies to pontine and midbrain reticular formation, and raphe nuclei.
- from medial hypothalamus to brainstem CN’s involved in ANS, reticular formation and continues into spinal cord.
- In one direction: medial hypothalamus, septum, and amygdala, to brainstem CN’s, and spinal cord.
- in the other direction: Neurons in brainstem go to septum, prefrontal cortex, hippocampus,
Differences between ANS and SNS?
SNS: Sensory stimuli are consciously perceived. Motor component: voluntary movement.
ANS: Sensations generally not consciously perceived.
Motor component: smooth and cardiac muscle.
What are the Functional Aspects of the ANS?
- Maintains body homeostasis.
- Sympathetic prepares and mobilizes body for emergency.
- Parasympathetic conserves and stores energy
- Sympathetic and parasympathetic have antagonistic actions
what effect does the Parasympathetic Division?
**remember: SLUDD**
- Salivation
- Lacrimation
- Urination
- Digestion
- Defecation
Also: decreases heart rate, causes pupillary
constriction and bronchioconstriction.
the sympathetic division of the ANS takes care of these actions…
- Pupillary dilation
- Increases in heart rate, blood pressure, etc.
- Dilation of airways
- Constriction/dilation of blood vessels
- Release of glucose from liver
- Inhibition of GI and digestive processes
where does the Enteric Division begin?
what does it do?
- Originates in enteric ganglia and GI tract plexuses.
- Is involved in GI motility.
Parasympathetic includes which cranial nerves?
Sympathetic includes which cranial nerves?
Craniosacral: CN’s 3, 7, 9, 10 and cord segments S2, S3, S4
Thoracolumbar: from T1 to L2 and uses sympathetic
chain
the sympathetic and parasympathetic systems have which, pre-ganglionic or post ganglionic? what is the difference?
What does the SIF contain?
When ACh gets released, what 2 other neurotransmitters get released as well?
both yet sympathetic has interneurons called SIF
SIF contains dopamine
VIP and NO because they are stored with ACh
what is nicotine?
what is its antagonist?
where does nicotine act?
ACh agonist
curare
at neuromuscular junction and postganglionic neurons
what is a muscarine receptor?
what is its antagonist?
where does it act?
ACh receptor agonist
atropine
parasympathetic effectors
what is Isoproterenol?
what is its antagonist?
beta 2 adrenergic agonist receptor
propanolol