ANS Flashcards
Definition of autonomic nervous system
Involved in regulating internal environment of the body.
Has motor and sensory components
Definition of sensory fibres
Travel with motor fibres, cell bodies in posterior root ganglia, or in sensory ganglia of cranial nerve
Definition of motor fibres
Innervates smooth muscle and glands, modulate activity of ANS
Definition of sympathetic trunk
Pair of bundle nerve fibres that run from tp base of the skull to the sacrum
Purpose of the autonomic nervous system
Involved in regulating the internal environment of body
Have motor, sensory components
Location and what do sensory fibres travel with
Travel mainly with motor fibres as mixed fibres
Cell bodies in posterior root ganglia (sensory fibres of spinal nerves, sensory ganglia of cranial nerves
Function of motor fibres
Innervate smooth muscle, glands
Modulate activity of GIT, SAN
Has 2 neurons in series
Principle divisions of motor part of ANS
Sympathetic
Parasympathetic
Where does the sympathetic nervous system arise
T1-L2
Distribution of sympathetic nervous system
All parts of body wall and viscera
Function of sympathetic nervous system
Moderate visceral functions, HR, peristalsis, sweating
Pre and post ganglionic fibres in the sympathetic nervous system
Short myelinated preganglionic fibres
Long unmyelinated postganglionic fibres
Sympathetic divisions of the ANS, ganglia
Sympathetic paired chain ganglia
Collateral unpaired ganglia
Adrenal paired medullae
What effect does the sympathetic paired chain ganglia have?
Visceral effectors in thoracic cavity, head, body wall and limbs
What effect does the collateral unpaired ganglia have?
Visceral effectors in abdominopelvic cavity
What effect does the adrenal paired medullae have?
Organs and systems throughout body, through neurotransmitters in blood
What is the sympathetic trunk?
Pair of uncle nerve fibres, run from base of skull to sacrum
Effects of sympathetic stimulation on motor responses
Staring eyes Cold clammy skin Dry mouth Hair standing on end Sinking pit in stomach
Effects of sympathetic stimulation on sensory fibres
Regulation of visceral activity
Only pain is conscious
Referred pain as brain’s map of SNS does not match actual location of pain
Where does the parasympathetic nervous system arise
Cranio-sacral
Cranial nerves III, VII, IX, X
S2-S4
Distribution of parasympathetic nervous system
Head and trunk only
Function of parasympathetic nervous system
Regulating normal functions of organs it supplies
Pre and post ganglionic fibres in the parasympathetic nervous system
Long myelinated preganglionic fibres
Short unmyelinated postganglionic fibres
Locations of the preganglionic neurons in the Para NS
S2-S4
Brain stem
What ganglia does S2-S4 pass through?
Intramural ganglia through pelvic nerves
What ganglia does the brain stem pass through?
Intramural ganglia through NX
What does the intramural ganglia from the pelvic nerves affect?
Visceral organs in lower abdominopelvic cavity
What does the intramural ganglia from NX nerves affect?
Visceral organs of head, neck, thoracic cavity, and most of abdominal cavity
What does the thalamus affect?
Emotions
Sensory input
What does the hypothalamus affect?
Sympathetic, parasympathetic
What parts of the brain is affected by the hypothalamus
Pons
Medulla oblongata
Function of the pons
Higher levels of respiratory control
Function of the medulla oblongata
Processing centers for complex visceral reflexes (S and P)
What does the medulla oblongata control
Spinal cord T1-L2
Sympathetic visceral reflexes
Sacral spinal cord
Parasympathetic visceral reflexes and motor neurons
What are the effects of medulla oblongata control
Cardiac centers Vasomotor centers Swallowing center Coughing center Respiratory rhythmicity center
