Transcript Comparative Vertebrate Physiology

Human Anatomy and
Physiology
Autonomic nervous system
ANS organization
SNS - ANS comparison
SNS - ANS comparisons
Character
SNS
ANS
Neurons
Always stimulatory Stimulatory and inhibitory
Ganglia
Absent
Present
Neurotransmitter
Ach
Ach and epinephrine
Organ stimulation Voluntary
Involuntary
ANS organization

Parasympathetic



Cranial, S2 & S4
Ganglia close to organ
Sympathetic



T1 - L2
Ganglia far from organ
paravertebral
Effects of divisions
Naming nerves of the ANS



All preganglionic are cholinergic (Ach)
Postganglionic neurons of parasympathetic are
cholinergic (Ach)
Postganglionic neurons of sympathetic are
adrenergic (norepinepherine)
Cholinergic receptors


Receptors that bind Ach
Types: Nicotinic receptors


Location
 Postganglionic neurons (symp. & parasymp.)
 Adrenal medulla cells
 Skeletal muscle cells
Effect: always stimulatory
Cholinergic receptors


Types: Muscarinic receptors
Location



All parasympathetic target organs
Some sympathetic target organs (i.e., sweat glands)
Effect: inhibitory or stimulatory
Adrenergic receptors



Receptors that bind norepinephrine
Classes: alpha and beta
Alpha - generally stimulatory


Except for digestion
Beta - generally inhibitory

Except for heart
ANS control