لخّصلي

Nervous system: • ANS regulates everyday requirements of vital body functions without conscious participation of mind (involuntary) Sympathetic and parasympathetic divisions typically function in opposition to each other. But this opposition is better termed complementary in nature rather than antagonistic. The sympathetic division typically functions in actions requiring quick responses. • The parasympathetic division functions with actions that do not require immediate reaction. • Consider sympathetic as "fight or flight" and parasympathetic as "rest and digest Prepares body for physical action (Fight or Flight): – Increased heart rate – Increased blood pressure – Redistribution of blood flow - ↑ flow to skeletal muscle, ↓ flow to skin and organs – ↓ GI activity – Dilation of pupils and bronchioles – ↑ blood glucose Opposite effects to SNS • Prepares the body for feeding and digestion – Slows heart rate – Lowers blood pressure – Promotes GI secretions – Stimulates GI movement – Constricts the pupil – Empties bladder and rectum Acetylcholine is the neurotransmitter for parasympathetic division, act on muscarinic and nicotinic receptors. • Noradrenaline is the neurotransmitter for sympathetic division, act on adrenoceptors

Nervous system:
• ANS regulates everyday
requirements of vital
body functions without
conscious participation
of mind (involuntary)
Sympathetic and parasympathetic divisions
typically function in opposition to each
other. But this opposition is better termed
complementary in nature rather than
antagonistic. The sympathetic division
typically functions in actions
requiring quick responses.
• The parasympathetic division
functions with actions that do
not require immediate reaction.
• Consider sympathetic as "fight
or flight" and parasympathetic
as "rest and digest
Prepares body for physical action (Fight or
Flight):
– Increased heart rate
– Increased blood pressure
– Redistribution of blood flow - ↑ flow to skeletal
muscle, ↓ flow to skin and organs
– ↓ GI activity
– Dilation of pupils and bronchioles
– ↑ blood glucose
Opposite effects to SNS
• Prepares the body for feeding and digestion
– Slows heart rate
– Lowers blood pressure
– Promotes GI secretions
– Stimulates GI movement
– Constricts the pupil
– Empties bladder and rectum
Acetylcholine is the neurotransmitter for
parasympathetic division, act on muscarinic
and nicotinic receptors.
• Noradrenaline is the neurotransmitter for
sympathetic division, act on adrenoceptors