Autonomic nervous system

Autonomic nervous system

Viscera are innervated by the autonomic nervous system.

Subdivision: sympathetic, parasympathetic
Double innervations of the viscera, effects are opposite.

Parasympathetic neurons location

in the brainstem and in the sacral segments of the spinal cord.

Sympathetic neurons location

in the thoraco-lumbal segments of the spinal cord.

sympathetic innervation

regulated by the pressor center: vasoconstriction in the resistance vessels and venules → redistribution

sympathetic cholinergic fibers

skeletal muscle vessels

parasympathetic cholinergic fibres

corpus cavernosum

Hypothalamic centers

• Hunger and satiety centers → food intake
• Thirst center
• Thermoregulatory center
• Neurons regulating hormone release

Limbic cortex

• Regulates the autonomic, hormonal and somatic responses.
• memory → learning

Conditioned reflex/response

• result of the combination of two separated stimuli
• result of the learning procedure
• it requires constant confirmation/repeat
• without confirmation it ceases
• biological role: adaptaion to the environment

Unconditioned reflex

• automatic response develops in the presence of the adequate stimulus
• genetically encoded program
• patellar reflex