Autonomic Nervous System- Sensory and Autonomic

Question 1

What is the autonomic nervous system?

Answer 1

[A nervous system dedicated to homeostasis, a constant internal environment; there are three divisions: parasympathetic, sympathetic and enteric. An important regulator is the hypothalamus which is influenced by the amygdala which is influenced by several prefrontal cortical areas. The hypothalamus also has plenty of sensors for regulating output. In days of yore, the autonomic nervous system was viewed as strictly ‘motor’, but now various texts refer to some visceral sensors in the context of autonomics]

Question 2

What brain area is a major controller of the autonomic nervous system?

Answer 2

[ Hypothalamus.

Question 3

Where are the pre-ganglionic sympathetic neurons?

Answer 3

[They form the intermediolateral cell column in the spinal cord, extending from levels T1 to L2.

Question 4

Where are the pre-ganglionic parasympathetic neurons?

Answer 4

[In cranial nerves III (nu Edinger-Westphal), VII (Superior salivatory nu), IX (inferior salivatory nu), X (dorsal vagal nu), and in at sacral levels, S2-S4.

Question 5

What are white and gray rami?

Answer 5

[Axons coming into (white, pre-ganglionic) and out of (gray, post-ganglionic) the sympathetic chain.

Question 6

What are the primary neurotransmitters of the autonomic nervous system?

Answer 6

[Acetylcholine (ACh) and norepinephrine (NE). Among parasympathetics, both the pre- and post- use ACh. Among sympathetics, the pre- is ACh, the post is NE (epinephrine in the adrenal medulla). An important exception among sympathetics is innervation of sweat glands: post- is ACh.

Question 7

What does vagal stimulation of the spleen do?

Answer 7

[It suppresses the immune response, blocks cytokine production. It is thought that such a ‘reflex’ may be important in preventing toxic shock.

Question 8

Identify the 4 pre-ganglionic parasympathetic nuclei of the brainstem?

Answer 8

[Nu Edinger Westhphal (III), superior salivatory nu (VII), inferior salivatory nu (IX), dorsal motor nu of Vagus (X)]

Question 9

Identify the two brainstem nuclei associated with fine touch and proprioception of the body?

Answer 9

[nu gracilis, nu cuneatus]

Question 10

Nerves of the brachial plexus (C5-8, T1) innervate nu cuneatus, but not nu gracilis?

Answer 10

[true]