Tri B - Autonomic Nervous System Flashcards
What is controlled by the Somatic and Autonomic nervous systems?
Somatic –> voluntary control of skeletal muscle
Autonomic –> reflex control of smooth muscle
Describe a Reflex Arc
Input –> Central Relay –> Output
Where do reflex arcs receive input from?
Temperature receptors
Pain receptors
Chemoreceptors
Baroreceptors
What are the 2 divisions of the Autonomic nervous system?
Sympathetic nervous system
Parasympathetic nervous system
Where do Sympathetic nerve fibres leave the spinal cord and what is this called?
Leave at thoracic and lumbar levels
–> thoracolumbar
Where do Parasympathetic nerve fibres leave the spinal cord and what is this called?
Leave at cervical and sacral levels
–> Craniosacral
What is dual innervation?
Both divisions of the ANS supply the same organs
Describe Autonomic Ganglion
Collection of nerve cell bodies in ANS; where synapses between 2 neurones occur
Describe the differences and similarities between neurotransmitters used at synapses
Both divisions use Acetylcholine at ganglion synapse
Parasympathetic uses Acetylcholine at target organ
Sympathetic uses Noradrenaline at target organ
Describe the adrenal medulla
Middle portion of adrenal gland
Acts as a combo of sympathetic ganglion and a gland
Secretes adrenaline and noradrenaline
Describe the energy usage of the divisions of the ANS
Sympathetic –> generally energy expanding
Parasympathetic –> generally energy conserving
Name and describe the 2 types of Noradrenaline receptors
Alpha and beta
Produce different effects when noradrenaline binds
Name and describe the 2 types of Acetylcholine receptors
Nicotinic - also respond to nicotine
Muscarinic - also responds to muscarine
Why does it matter about different receptor types?
Different drugs can block or activate different recptors
What activities is the Parasympathetic nervous system involved in?
‘Rest and digest’
Salivation, Lacrimation, Urination, Digestion, Defaecation
Decreased heart rate, airway diameter, pupil size
