Lecture 6

Question 1

Comparisons of SNS and ANS

1. Which is voluntary?
2. How many neurons in each pathway?
3. Which has ganglia involved?
4. What kind of sensory input?
5. What kind of motor output?
6. What are the axons like?

Answer 1

1. SNS is conscious
2. SNS has single neuron pathways, ANS has two neurons
3. ANS has ganglia involved
4. SNS gets general and special senses, ANS gets visceral senses
5. SNS goes to skeletal muscle, ANS goes to cardiac, smooth, and glands
6. SNS has thick myelinated axons, ANS has thin occasionally myelinated axons

Question 2

Autonomic Plexuses

1. What do ANS plexi consist of?
2. How do sympathetic and parasympathetic plexi relate?
3. What do plexi provide?
4. Where are cell bodies housed?

Answer 2

1. Collections of sympathetic postganglionic axons and parasympathetic preganglionic acons
2. Close to one another but don’t interact/synapse
3. complex innervation to target organs
4. Only in brain or pelvis

Question 3

Autonomic Plexuses

1. Cardiac plexus: sympathetic vs parasympathetic activity
2. Pulmonary plexus: symp vs para activity

Answer 3

1. Symp: increases HR and blood volume, Para: decreases HR
2. symp: bronchodilation, Para: bronchoconstriction and increased secretion from mucous glands

Question 4

Autonomic Plexuses

1. Abdominal aortic plexus: consists of what?
2. Abdominal aortic plexus: function?

Answer 4

1. Consists of the celiac plexus, superior mesenteric plexus, and inferior mesenteric plexus
2. autonomic control of digestion

Question 5

Autonomic Plexuses

1. Esophageal plexus: para axons control what?
2. Hypogastric plexus: function

Answer 5

1. Swallowing reflex
2. Autonomic control of urinary and reproductive function

Question 6

Neurotransmitters and Receptors

1. Two NTs in the ANS

Answer 6

1. ACh and NE

Question 7

Neurotransmitters

1. Which parasympathetic axons release ACh?
2. What is a cholinergic axon?

Answer 7

1. Both the preganglionic and postganglionic axons
2. An axon that releases ACh

Question 8

Neurotransmitters

1. Which axon(s) in the sympathetic division releases Ach?
2. Which axon(s) in the sympathetic division release NE?
3. What does adrenergic mean?

Answer 8

1. Only the preganglionic axons
2. Most of the postganglionic axons
3. An axon that releases adrenergic

Question 9

See and label drawing of parasympathetic pathway #1

Question 10

See and label drawing of sympathetic pathway on sheet. #2

Question 11

Dual Innervation

1. Which ANS divisions innervate most visceral effectors?
2. What is meant by visceral effector?
3. How do both ANS divisions relate on organs?
4. How is this regulated?

Answer 11

1. Both divisions innervate
2. Organs
3. Often have opposite effects
4. Either division can up-regulate or down-regulate.

Question 12

Autonic Reflexes

1. What sorts of mechanisms does the ANS use to maintain homeostasis?
2. What is a classic autonomic reflex?

Answer 12

1. smooth muscle contraction, cardiac muscle contraction, secretion by glands. These are all mediated via reflex arcs
2. Reduction of blood pressure

Question 13

Autonomic Reflex Example: Micturation

1. How does this occur?
2. What is this an example of?

Answer 13

1. A sensory neuron in the bladder senses the presence of urine. The nerve impulse goes to the psinal cord for processing in an integration center. A motor impulse goes back to the bladder to contract the bladder and relax the internal sphinctor.
2. Autonomic reflex

Question 14

CNS Control of Autonomic Function

1. What brain structures have a role?
2. What is the integration and command center for autonomic functions?
3. What are its jobs?

Answer 14

1. Cerebrum, hypothalamus, brainstem, spinal cord.
2. Hypothalamus
3. Communicates with para and symp, communicates with other CNS regions.

Question 15

CNS Control of Autonomic Function

1. Cerebrum interaction
2. Hypothalamus function
3. Brainstem function
4. Spinal cord function

Answer 15

1. Conscious activities in the cerebrum affect hypothalamus control of ANS
2. Integration and CC for autonomic functions
3. Contains major ANS reflex center
4. Contains ANS reflex centers for defecation and urination

Question 16

Organization and Anatomy of the Sympathetic Division

1. More or less complex than parasympathetic?
2. Where are preganglionic neuron cell bodies housed?
3. What pathway do preganglionic sympathetic axons take?

Answer 16

1. Much more complex
2. Lateral horn of T1- L2 portions of spinal cord
3. They follow somatic motor neuron axons to exit the spinal cord and first enter the anterior roots, then the T1 - L2 spinal nerves. They will remain with the spinal nerve for ahosrt distance

Question 17

Organization and Anatomy of the Sympathetic Division

1. What section do T1-T4 cell bodies do?
2. What section do T5-T9 do?
3. What section do T11 - L2 do?

Answer 17

1. Head, heart, lungs, foregut
2. Midgut
3. Remainder of gut into pelvic organs

Question 18

Left and Right Sympathetic Trunks

1. Location relative to paired spinal nerves?
2. Location relative to vertebral column?
3. What does it look like and what is each portion?

Answer 18

1. Immediately anterior
2. Immediately lateral
3. String of beads. “Bead” is a ganglion, “string” is axons.

Question 19

Left and Right Sympathetic Trunks

1. Association with each spinal nerve
2. What is different about the Cervical portion of the sympathetic trunk?

Answer 19

1. Approximate association
2. All of the cervical portion is partitioned into only three sympathetic trunk ganglia (instead of 8 like the spinal nerves)

Question 20

White Rami

1. Connect what to what?
2. Which axons do they carry?
3. Whitish appearance is due to
4. Analagous to what?

Answer 20

1. Spinal nerves to each sympathetic trunk
2. Preganglionic sympathetic axons from T1-L2 ONLY
3. Preganglionic axons being myelinated
4. Entrance ramps!

Question 21

Gray Rami

1. Connect what to what?
2. What do they carry where?
3. Grayish appearance?
4. Which spinal nerves do they connect to?
5. Analagous to what?

Answer 21

1. Spinal nerves to each sympathetic trunk
2. Postganglionic sympathetic axons from sympathetic trunk to spinal nerve
3. Unmyelinated
4. ALl spinal nerves
5. Off ramp

Question 22

Splanchnic Nerves

1. Composed of what?
2. Where do they run?
3. Which 5 are we responsible for?

Answer 22

1. Preganglionic SYMPATHETIC axons
2. Anteriorly from the sympathetic trunk to most of the viscera
3. Greater thoracic, lesser thoracic, least thoracic, lumbar, sacral

Question 23

Splanchnic Nerves

1. Where do they terminate?
2. What do they cluster around? How does this relate to their naming?
3. How do sympathetic postganglionic axons relate to these?

Answer 23

1. Prevertebral ganglia
2. Major abdominal arteries. They are named for these arteries
3. They extend away from the ganglionic neurons

Question 24

Types of Prevertebral Ganglia

1. How do they differ from sympathetic trunk ganglia?
2. Location relative to vertebral column.
3. Locateion vertically where?
4. Include which ganglia?

Answer 24

1. Single structures rather than paired
2. Anterior to the vertebral column on the anterior surface of the aorta
3. Abdominopelvic cavity only
4. Celiac, superior mesenteric, inferior mesenteric

Question 25

Sympathetic Pathways 1. What four pathways are there? 2. What part of their pathway do they all share in common?

Answer 25

1. Spinal nerve pathway, postganglionic sympathetic nerve pathway, Splanchnic nerve pathway, adrenal medulla pathway. 2. They all go from the spinal nerve to the white ramus to the sympathetic trunk

Question 26

See pathway slides from 40 to 50 and understand them

Question 27

Fight-or-Flight Function of the ANS 1. How many effectors? 2. What does it cause? 3. What gets activated?

Answer 27

1. One or many 2. Heightened sense of alertness 3. Reticular activation system

Question 28

Parasympathetic Division General 1. AKA 2. Primary concerns 3. Which CNs are involved? 4. Which nerve does everything?

Answer 28

1. Craniosacral division 2. Conserve energy, replenish stores 3. 3, 7, 9, 10 4. Vagas

Question 29

See slide 53 and learn ganglia names

Question 30

Cranial Nerves 1. Name and number the CNs involved 2. Which do the head and which do other things?

Answer 30

1. Oculomotor (3), Facial (7), Glossopharyngeal (9), Vagus (10) 2. The first three do head, the last does everything

Question 31

Oculomotor Nerve 1. Which ganglion? 2. Functions?

Answer 31

1. Ciliary Ganglion 2. Pupil contstriction

Question 32

Facial Nerve 1. Name the ganglia and each function

Answer 32

1. Pterygopalatine - tears, nasal cavity, oral cavity. Submandibular ganglion - submandibular and sublingual glands (saliva)

Question 33

Glossopharyngeal Nerve 1. What ganglion? 2. Activity?

Answer 33

1. Otic ganglion 2. Parotid gland (saliva production)

Question 34

Vagus Nerve 1. What are the ganglia? 2. Effects on heart, respiratory, bronchial passages, esophagus, abdominal viscera

Answer 34

1. Multiple terminal and intramural ganglia 2. Decreases rate, decresases respiration, constricts passages and excites mucous production, promotes swallowing and peristalsis, promotes digestion

Question 35

Caudal Contribution of Parasympathetic System: Via Pelvic Splanchnic Nerves and Sacral Spinal Nerves 1. Aside from the CN portion, Where is the rest of the parasympathetic innervation in the body? 2. What contributes to the formation of the superior and inferior hypogastric plexus? 3. Then where do preganglionic axons travel to?

Answer 35

1. In the sacral region of the spinal cord (S2-S4) 2. Preganglionic parasympathetic axons from neuron cell bodies in the lateral horn 3. To organs where they synapse with ganglia close to or in the walls of the organs

Question 36

Caudal Contribution of Parasympathetic System via Pelvic Splanchnic Nerves 1. First off, what is special about the Pelvic Splanchnic nerve that may seem counterintuitive? 2. What is innervated by the pelvic splanchnic nerve?

Answer 36

1. It has the word :splanchnic" in it but is Parasympathetic and not sympathetic. This is the ONLY one that has splanchnic in it and is not sympathetic 2. Distal portion of large intestine, rectum, reproductive organs, urinary bladder, distal ureters, erection

Question 37

Effects and General Functions of the Parasympathetic Division 1. WHen is it most active? 2. What prevents mass activation (like is seen in the sympathetic division) 3. How are effects spread out?

Answer 37

1. When the body needs to process nutrients and conserve energy 2. Lack of extensive divergence in preganglionic axons 3. Discrete and localized