Question

Differentiate between sympathetic and parasympathetic nervous system with reference to:
a. Pre and post ganglionic nerve fibres.
b. Effect on heart beat.
Give reason – All spinal nerves are of mixed type.

Hint:

Sympathetic prepares for "fight or flight"; parasympathetic promotes "rest and digest"; mixed nerves have dual roles.

Answer 1

i. Differentiation:

Feature	Sympathetic	Parasympathetic
Pre and Post Ganglionic Fibres	Short pre-ganglionic, long post-ganglionic	Long pre-ganglionic, short post-ganglionic
Effect on Heart Beat	Increases heart rate	Decreases heart rate

ii. Reason: Spinal nerves are mixed because they contain both sensory (afferent) and motor (efferent) fibres, carrying sensory signals to the spinal cord and motor signals to muscles/glands.
Answer: i. Sympathetic has short pre-ganglionic, increases heart rate; parasympathetic has long pre-ganglionic, decreases heart rate; ii. Spinal nerves carry both sensory and motor fibres.