Autonomic Nervous System (Lec 22) Flashcards
Structural difference between somatic nervous system and autonomic nervous system
SNS
- conscious control of motor output
- 1 neuron peripheral motor pathway
- perception of sensory input: yes
ANS
- independent - no concious
- 2 neuron peripheral motor pathway
- perception of sensory input: no
Functional difference between somatic nervous system and autonomic nervous system
SNS
Sensory input: external environment
Motor output: skeletal muscle
ANS
Sensory input: internal environment
Motor output: internal organs
Anatomy of Autonomic nerve pathways
Consists of 2 neurons
- preganglionic (myelinated) and postganglionic (unmyelinated) meet in synapse in autonomic ganglion
-
Physiological effects related to the sympathetic divisions of ANS
Fight or flight response to danger to mobilize body for action
- increases heart rate
- increases respiratory rate
- releases glucose
- dilates pupils
- reduces other processes to focus energy on danger (digestion)
Physiological effects related to the parasympathetic divisions of ANS
Utilized in ordinary situations (rest & digest)
- slows heart rate
- decreasing respiration if rate
- stimulates digestion
- stores glucose
ANS divisions
- sympathetic
- parasympathetic
What is the output of the sympathetic nervous system called
Thoracolumbar outflow
Sympathetic nervous system: The postganglionic neurons originate in peripheral ganglia in 2 locations
- Sympathetic chain ganglia
- lie along vertebral column
- output - viscera above diaphragm
- Prevertebral ganglia
- lie within abdominal cavity
- output - viscera below diaphragm
Pathways for sympathetic postganglionic neurons after sympathetic chain (trunk)
- postganglionic - spinal nerves - skin of body
- postganglionic - parietal nerves - skin of face & viscera of head
- postganglionic - sympathetic nerves - viscera of thoracic cavity
- preganglionic go through sympathetic trunk (chain) - relay to postganglionic in prevertebral ganglia - viscera of abdominal/pelvic cavity
Sympathetic nervous system: postganglionic neurons that originate in the __________ transmit signals to viscera above the diaphragm
sympathetic trunk ganglia
Sympathetic nervous system: postganglionic neurons that originate in the __________ transmit signals to viscera below the diaphragm
Prevertebral ganglia
What is the output of parasympathetic nervous system
Craniosacral outflow
Postganglionic neurons of parasympathetic nervous system originate in ________
Terminal ganglia
Located within/close to visceral organs
Cranial nerves that have autonomic motor functions (parasympathetic axons contained within)
CN III, CN VII, CN IX, CN X
Sympathetic NS: Preganglionic neurons arise from _________ spinal cord (exit spinal cord via spinal nerves)
T1-L2
Parasympathetic NS: Preganglionic neurons arise from _______ and ______ of spinal cord
Brain stem (for viscera above pelvic cavity) S2 - S4 (within pelvic cavity)
(exit brainstem via cranial nerve, exit spinal cord via spinal nerves)
What regulates the balance between the physiological effects of the competing parasympathetic and sympathetic nervous system
Hypothalamus
