Lecture 25 (Autonomic Nervous System)

Question 1

Autonomic nervous system (ANS)

Answer 1

• visceral motor (involuntary)
• conducts impulses from CNS to cardiac muscles, smooth muscles and glands

Question 2

Somatic

Answer 2

• Voluntary
• Innervation of skeletal muscle
• Single efferent neuron from CNS to muscle
• Always excitatory
• Controlled by cerebrum

Question 3

Autonomic

Answer 3

• Involuntary
• Innervation of smooth and cardiac muscle, glands
• 2 efferent neurons from CNS to effector
• Both excitatory and inhibitory
• Controlled by homeostatic centers in the brain, hypothalamus and brainstem

Question 4

Sympathetic

Answer 4

Prepares body for emergency (fight or flight)

Question 5

Parasympathetic

Answer 5

Non-emergency (rest and digest)

Question 6

Sympathetic preganglionic neurons

Answer 6

• thoraco-lumber (T1-L2) origin
• close to the spinal cord
• each pregang. neuron synapses with many postganglionic neurons
• axons also project to adrenal gland, synapse on chromaffin cells in adrenal medulla

Question 7

Parasympathetic preganglionic neurons

Answer 7

• located in brainstem and sacral spinal cord
• very close to or in wall of visceral organs

Question 8

Control of ANS

Answer 8

• Hypothalamus regulates activity, and projects to reticular nuclei center for execution of specific ANS pathways
• Cortex van influence activity of hypothalamus