Lecture 16

Question 1

What are the four forms of nervous system input (afferent division)?

Answer 1

1. endocrine
2. somatic sensory
3. visceral sensory
4. special sensory

Question 2

What are the three forms of nervous system output (efferent division)?

Answer 2

1. somatic motor
2. autonomic motor (sympathetic, parasympathetic, and enteric)
3. endocrine

Question 3

TRUE or FALSE - most of somatic motor control is conscious

Answer 3

FALSE - most of it unconscious and is controlled automatically

Question 4

What levels of the spinal cord are sympathetic system output?

Answer 4

Thoracic to lumbar

Question 5

What levels of the spinal cord are parasympathetic output?

Answer 5

Cervical and sacral regions. Mostly, the 10th cranial nerve (vagus)

Question 6

What does the vagus nerve control?

Answer 6

multiple elements within the viscera

Question 7

TRUE or FALSE - many organs have dual intervention of both sympathetic and parasympathetic NS

Answer 7

TRUE

Question 8

Where does viscera efferent enter?

Answer 8

The dorsal root

Question 9

What systems act together in the gut?

Answer 9

for sympathetic, parasympathetic and enteric NS

Question 10

What is role of the parasympathetic system?

Answer 10

rest, digest and propagate

Question 11

What is the role of the sympathetic system?

Answer 11

fight or flight

Question 12

TRUE or FALSE - only one system is active as a time

Answer 12

FALSE - both systems are always active

Question 13

What are the target organs of the sympathetic nervous system?

Answer 13

It is widely distributed to salivary glands, eyes, skin, viscera and muscles

Question 14

What is the structure of the sympathetic nervous system?

Answer 14

First synapse in the paravertebral and prevertebral ganglia, post-ganglionic fibres innervate organs.

Question 15

What are the neurotransmitters used in the sympathetic nervous system?

Answer 15

Ach onto post synaptic neuron, norepinephrine onto target tissue

Question 16

What does the adrenal medulla do?

Answer 16

release E and EN into circulation and NOT onto target tissue

Question 17

What target tissue is the exception to being transmitted NE?

Answer 17

Sweat glands, they are transmitted Ach

Question 18

What are the target organs of the parasympathetic nervous system?

Answer 18

It is distributed less widely, and mainly to the viscera, salivary glands, and eyes.

Question 19

What is the structure of the parasympathetic NS?

Answer 19

The first synapse is in or near the target organ. it has long pre-ganglionic fibres, and short post ganglionic fibres.

Question 20

What neurotransmitter is used in the parasympathetic NS?

Answer 20

Ach

Question 21

What type of receptors does Ach bind to?

Answer 21

in the somatic NS, sympathetic NS and post ganglionic fiber in the parasympathetic NS - a nicotinic AchR.
in parasympathetic target organs, it is muscarinic AchR

Question 22

What type of receptors do NE and E bind to?

Answer 22

several types of alpha and beta adrenergic receptors

Question 23

What is the enteric nervous system?

Answer 23

It is the multi-layered ‘brain’ in the gut.

Question 24

What are the characteristics of the ENS?

Answer 24

• contains about as many neurons as the spinal cord throughout the GI tract
• responds to local chemical and mechanical stimulation
• regulates motility, secretion, and endocrine singling through local reflexes

Question 25

TRUE or FALSE - is ENS activity completely independent ?

Answer 25

False - it is autonomous, but it heavily influenced by para- and sympathetic NS inputs

Question 26

What neurotransmitter inhibits smooth muscle contraction in the ENS

Answer 26

VIP

Question 27

Are there inhibitory motor neurons in all muscles?

Answer 27

No, this is unique to the gut.

Question 28

What does a local excitatory reflex induce in the gut?

Answer 28

Contraction (oral)

Question 29

What does a local inhibitory reflex induce in the gut?

Answer 29

relaxation (anal)