2.5 - Chemical mediators of the ANS

Medulla oblongata

This is the central location for the autonomic nervous system

Hypothalamus

This is the structure that integrates autonomic functions and receives feedback from the limbic system

SNS

This is the fight or flight response, active constantly to maintain basal homeostasis

PNS

This regulates organ and gland functions during rest and dampens the effects of the SNS

Sensory neuron

This carries signals from the periphery into the CNS

Interneuron

This connects various neurons within the CNS to coordinate signalling

Motor neurons

This carries signals from the CNS to the periphery

Norepinephrine

This is a catecholamine that acts on α1 and β1 receptors

Epinephrine

This is a catecholamine that acts on α1, α2, β1, and β2 receptors

Nicotinic and muscarinic receptors

These are receptor types that receive acetylcholine

M2 receptor

This is a muscarinic receptor found in the heart that decreases SA node firing, AV node contraction, heart rate, contraction strength, and overall cardiac output

M3 receptor

This is a muscarinic receptor found in the lungs that constrics the bronchial muscles, increases lung secretions, and decreases airway diameter

Sympathomimetic drug

This is a drug that mimics the action of the sympathetic nervous system

Direct-acting sympathomimetic

This is a drug that directly mimics the action of NE/E

Indirect-acting sympathomimetic

This is a drug that increases the availability of NE/E

Sympatholytic drug

This is a drug that inhibits the action of the SNS

Parasympathomimetic

This is a drug that mimics the action of the PNS

Direct-acting parasympathomimetic

This is a drug that mimics ACh on a receptor

Indirect-acting parasympathomimetic

This is a drug that increases the availability of ACh

Parasympatholytic

This is a drug that inhibits the action of the PNS