Autonomic Nervous System (Doc Martinez) Flashcards
- Visceral Motor System (new term): provides motor control of the viscera
- Vegetative Nervous System (old term)
- Homeostasis
- Regulatory
- Essentially motor
Autonomic Nervous System
2 means of control in the body
Nervous Control - fasting acting, short duration (eg. baroreceptors in the heart in BP maintenance)
Humeral Control - slower acting, long duration (eg. RAAS in BP maintenance)
FUNCTIONS OF ANS
- Maintain constant internal environment or homeostasis: issue commands that leads to compensatory actions
- Regarded as part of the motor system
- Appropriate coordinated response to external stimuli (e.g. helps regulate pupil size in response to different intensities of ambient light, helping the visual system to operate over large range of light intensities)
• FIGHT OR FLIGHT: response to threatening activities
- Mediates visceral reflexes (e.g. gastrocolic reflex, where stomach distention triggers peristalsis in the intestines) and provides sensory information to the CNS for the state of our viscera.
- Activation of autonomic receptors evoke sensory experiences (e.g. pain, hunger, thirst, nausea and sense of visceral distention)
Maintain constant internal environment or homeostasis: issue commands that leads to compensatory actions
- Effectors: smooth muscles, cardiac muscles and glands
- Autonomic fibers in peripheral nerves are accompanied by visceral after end fibers originating from visceral sensory receptors in the viscera.
- Receptors triggers reflexes and evokes sensory experiences such as pain, hunger, thirst, nausea and sense of visceral distention.
Regarded as part of the motor system
PNS
SOMATIC NS
AUTONOMIC NS
12 Cranial Nerves
- OLFACTORY
- OPTIC
- OCULOMOTOR
- TROCHLEAR
- TRIGEMINAL
- ABDUCENS
- FACIAL
- ACOUSTIC
- GLOSSOPHARYNGEAL
- VAGUS
- SPINAL ACCESSORY
- HYPOGLOSSAL
Cranial Nerves involved in ANS
- OCCULOMOTOR
- FACIAL
- GLOSSOPHARYNGEAL
- VAGUS
SPINAL NERVES
Cervical
Thoracic
Lumbar
Sacral
Reflex Arc
Afferent
Integrating
-
REFLEX ARC
- Sensory Receptors (+)-AP
- AFFERENT Nerve
- CENTER
- EFFERENT Nerve
- EFFECTOR Cell
-
Somatic Nerve
Cell body within the CNS
First Neuron
Pre-ganglionic neuron
Cell body is located outside in CNS (Autonomic)
Second neuron
Post ganglionic neuron
ANS junction
Neuroeffector Junction
Nerve Fibers
Somatic (conscious/ voluntary) motor
Autonomic (subconscious/ involuntary) homeostasis
Somatic Nerve
SOMATIC AFF - Sensory
Somatic eff - effectorcell
Visceral Aff-
Visceral Eff- effe
Cerebral coortex
SNS center
ANS Center
Hypothalamus,
Central Components of ANS
- Hypothalamus
2. Limbic System
It release hormone and regulates body temperature
Hypothalamus
It is involved with the emotion and visceral behaviors like feeding, drinking, thermoregulation, reproduction, defense and aggression
Limbic System:
SNS
ONE WAY Acetylcholine (Receptors: N1 and MEP) Center, NMJ Interruption: Complete paralysis - atrophy Excitation (contraction) Neurons: ALPHA-MOTOR NEURONS (myelinated rapid) SKELETAL MUSCLE SYNTHESIS: axon terminal
ANS
TWO NEURON PATHWAY Norepinephrine and Ach Sites of inhibition: Center, peripheral ganglion, NEJ Automaticity Response: Excitatory/ inhibitory Pregangiolonic - myelinated B Post ganglionic - MYELINATED C Effector: Visceral Beads of varicosities