Autonomics Flashcards
Flow of information
Afferent-message from ____________ to ____________
Periphery
CNS
Flow of information
Efferent-from _____________ to __________________
CNS
Periphery
Afferents (___________) travel through the _____________ (____________) horn to the _______________ root
Sensory
Posterior
Dorsal
Posterior
Efferents (____________) travel from the ____________ root to the ______________ (_____________) horn
Motor
Anterior
Anterior
Ventral
Basic steps of reflex arc
- Sensory input to CNS
- Response
- Inmate a motor outflow to elicit an action and correct the sensory output
ANS control centers
Hypothalamus
Pons
Medulla
Hypothalamus controls…
Water balance
Temperature
Hunger
Pons controls…
Respiration & cardiac
Vasculature
Medulla controls…
Respiration
Effects of PNS
Plenty of oxygen Heart beating slowly Blood pressure low Digesting food-blood flow to GI Absorbing fuel from GI
Effects of SNS
More oxygen intake and oxygen delivery to muscle
Heart rate increase
Need fuel to run
Conserve energy to non-essential organs for the task
Sympathetic Origin of preganglionic neurons- Location of autonomic ganglia- Length of preganglionic axons- Length of postganglionic axons- Effector organs- Neuroeffector junctions- Neurotransmitter and receptor in ganglion- Neurotransmitter in effector organs- Receptor types in effector organs-
Spinal cord T1-L3 Paravertebral & prevertebral Short Long Smooth muscle, cardiac muscle, glands Diffuse, branching, receptors not concentrated in one region ACh/nicotinic Norepinephrine (except sweat glands) Adrenergic alpa1, alpha2, beta1, beta2
Parasympathetic Origin of preganglionic neurons- Location of autonomic ganglia- Length of preganglionic axons- Length of postganglionic axons- Effector organs- Neuroeffector junctions- Neurotransmitter and receptor in ganglion- Neurotransmitter in effector organs- Receptor types in effector organs-
Nuclei of CN III, VII, IX, and X, spinal cord S2-S4 In or near effector organs Long Short Smooth muscle, cardiac muscle, glands Diffuse, branching, receptors not concentrated in one region ACh/nicotinic ACh Muscarinic
Somatic Origin of preganglionic neurons- Location of autonomic ganglia- Length of preganglionic axons- Length of postganglionic axons- Effector organs- Neuroeffector junctions- Neurotransmitter and receptor in ganglion- Neurotransmitter in effector organs- Receptor types in effector organs-
NA NA NA NA Skeletal muscle -------- NA ACh Nicotinic
Visceral reflexes
Subconscious sensory signal from organs to region of nervous system for coordination, signal sent directly back
Fight or flight response vision receptors
Alpha1-adrenergic receptor activation
-contraction of radial muscle leads to dilation of pupil
Beta-adrenergic receptor activation
-relaxation of ciliary muscle flattens lens
-focus on distant objects
Fight or flight response heart receptors
Increase heart rate & contractility
-beta1 and beta2-adrenergic receptors
Vasodilation & vasoconstriction of appropriate vessels
-norepinephrine activates alpha-adrenergic receptors (alpha1)
-epinephrine activates beta-adrenergic receptors (beta2)
Rule of thumb:
Alpha receptors cause vasoconstriction-contraction of vascular smooth muscle
Beta receptors cause vasodilation-relaxation of vascular smooth muscle
Most smooth muscle of vessels have both alpha and beta adrenergic receptors
- heart, skeletal muscle, lungs, abdominal organs, kidneys
- but some have only alpha receptors-salivary glands, skin
Fight or flight response lungs
Bronchial smooth muscle
-relaxation-bronchodilation
-beta2-adrenergic receptors
Bronchial glands
-alpha1-adrenergic receptors-decrease secretion
-beta2-adrenergic receptors-increase secretion
Fight or flight response gastrointestinal tract
Decrease motility-relaxation
-activation of alpha1/2 and beta2 adrenergic receptors
Constrict sphincters
-activation of alpha1-adrenergic receptors
Decrease secretions
-activation of alpha2-adrenergic receptors
Fight or flight response metabolic
Liver-increased glycogenolysis
-activation of alpha1 and beta2-adrenergic receptors
Adipose tissue-increased lipolysis
-activation of alpha1, beta1, and beta3-adrenergic receptors
PNS Eyes
Relaxation of radial muscle of eye-constrict pupil
Contract ciliary muscles of lens-near vision
PNS heart & vasculature
Decrease heart rate & contractility
Little influence on many vessels
Vasodilation-no muscarinic receptors in abdominal viscera, kidneys & veins
PNS lungs
Bronchial smooth muscle contraction
Gland secretion
PNS gastrointestinal tract
Increased motility -contraction of smooth muscle Relax sphincters Increased secretions Glandular secretions
PNS bladder
Wall-detrusor muscle contraction
Sphincter-relaxes
SNS vs PNS antagonistic
SNS/PNS innervate same cells
Counteract each other
Example: heart
SNS vs PNS complementary
SNS/PNS produce similar effects
Example: salivation
SNS vs PNS cooperative
SNS/PNS produce different effects that work together
Micturition
