Unit 2

Question 1

What does the Somatic Nervous system control?

Answer 1

Voluntary movements of skeletal muscles

Question 2

How many neurons does the Somatic NS use to transmit signals from CNS to effector?

Answer 2

ONE

Question 3

What Neurotransmitter does the Somatic NS release at the neuromuscular junction?

Answer 3

Acetylcholine

Question 4

What is the target response of the SNS?

Answer 4

Can only be excitatory. ALL or Nothing response if threshold is reached (muscle contraction).

Question 5

What does the Autonomic Nervous system control?

Answer 5

Involuntary functions of smooth muscle, cardiac muscle, and glands

Question 6

How many neurons does the Autonomic NS use to transmit signals from CNS to effector?

Answer 6

2 Neuron chain: Preganglionic neuron (originates in the CNS –spinal cord or brainstem)
and Postganglionic neuron (connects to effector organ)

Question 7

What Neurotransmitters are utilized at junctions?

Answer 7

1. Acetylcholine MOSTLY
   -pre/post ganglionic junction of parasympathetic NS
   -post ganglionic/effector organ junction of parasympathetic
   -pre/post ganglionic junction of sympathetic NS
2. Norepinephrine
   -post ganglionic/effector organ in sympathetic NS

Question 8

What is the target response of the ANS?

Answer 8

Can be either excitatory or inhibitory, depending on organ and receptor type

-ex: often parasympathetic division will indicate decreased function of certain glands (rest & digest) whereas sympathetic division (fight or flight) will amp up production of some

Question 9

Give examples of how the sympathetic vs parasympathetic division impacts the following organ systems:

1. Heart
2. Lungs
3. Digestive system
4. Pupils
5. Urinary bladder

Answer 9

Sympathetic:
1. Increases heart rate
2. Dilates bronchi (increased airflow)
3. Inhibits digestion and decreases peristalsis
4. Dilates pupils (see better in dark)
5. Relaxes the bladder, inhibiting urination

Parasympathetic:
1. Decreases HR
2. Constricts bronchi (reduces airflow)
3. Stimulates digestion and increases peristalsis
4. Constricts pupils (allows less light)
5. Promotes bladder contraction for urination

Question 10

Length of preganglionic VS postganglionic neurons in SYMPATHETIC DIVISION:

Answer 10

Pre-ganglionic Neurons: SHORT

Post-ganglionic Neurons: LONG

**broad effect. forking sound the alarm everywhere messily it doesn’t matter how.

Question 11

Length of preganglionic VS postganglionic neurons in PARASYMPATHETIC DIVISION:

Answer 11

Preganglionic neurons:
LONG

Postganglionic neurons: SHORT

**More localized effect. Body is calmer so it can wind down in a more organized put-together way.

Question 12

Neurotransmitter at preganglionic synapse for both divisions?

Answer 12

Acetylcholine

Question 13

Neurotransmitter at postganglionic synapse for both divisions?

Answer 13

sympathetic: Norepinephrine

parasympathetic: Acetylcholine

Question 14

Define dual innervation:

Answer 14

Most organs in the body receive input from both the parasympathetic and sympathetic divisions
–and they typically have opposing effects on the same organ

Question 15

Give an example of dual innervation for the heart:

Answer 15

The sympathetic division increases the heart rate, while the parasympathetic division decreases it.

Question 16

What is the function of dual innervation?

Answer 16

It allows for precise control of the body’s involuntary functions, maintaining homeostasis by balancing the activities of both divisions

Question 17

What is an autonomic plexus?

Answer 17

A network of nerve fibers that contain both sympathetic and parasympathetic fibers.

They serve organs and glands

Question 18

True or false:
Plexuses carry both afferent (sensory) and efferent (motor) fibers that modulate organ function?

Answer 18

TRUE!

**imagine a self-regulating machine. Requires both sensory feedback and motor response.

Question 19

What are the 5 autonomic pleuxes for the purpose of this class?

Answer 19

1. Cardiac plexus
2. Esophageal plexus
3. Pulmonary plexus
4. Abdominal aortic plexuses
   a) Celiac plexus
   b) Superior mesenteric plexus
   c) Inferior mesenteric plexus
5. Hypogastric plexus

Question 20

What does the cardiac plexus influence?

Answer 20

The heart. It controls heart rate, force of contraction, and the diameter of coronary arteries

Question 21

What does the esophageal plexus influence?

Answer 21

The esophagus. Regulates the smooth muscle contractions involved in swallowing and controlling the movement of food down the esophagus.

Question 22

What does the pulmonary plexus influence?

Answer 22

The lungs and bronchi. It controls the airway diameter and secretion of mucus in the respiratory passages

Question 23

What is the abdominal plexus?

Answer 23

Consists of several interconnected plexuses surrounding the abdominal aorta, that influence various abdominal organs, including digestive system, kidneys, and reproductive organs.

Question 24

What does the celiac plexus influence?

Answer 24

Stomach, liver, pancreas, spleen, kidneys, and parts of intestines. Regulates digestive processes and visceral functions.

Question 25

What does the superior mesenteric plexus influence?

Answer 25

The small intestine and the first part of the large intestine. Regulates movement of digestive contents through these organs and coordinates secretion and absorption.

Question 26

What does the inferior mesenteric plexus influence?

Answer 26

the lower part of the large intestine and the rectum. Regulates bowel movements and secretions in these organs.

Question 27

What does the hypogastric plexus influence?

Answer 27

Pelvic organs, including bladder, rectum, reproductive organs and parts of the lower digestive tract. Controls urinary, reproductive and rectal functions.

Question 28

Where do the nerve fibers of the parasympathetic nervous system originate?

Answer 28

In both the CRANIAL NERVES of the brainstem and the SACRAL SPINAL CORD segments (S2-S4)

Question 29

What does the term craniosacral refer to in the parasympathetic NS?

Answer 29

The parasympathetic division can also be called the crianiosacral division because of the origin of its nerve fibers. ie: the parasympathetic nerves either come from the cranial or sacral portion of the CNS.

Question 30

True or false: Nerves of the parasympathetic division original from either the cranial-brainstem or sacral -spinal cord region?

Answer 30

TRUE!

Question 31

What is the vagus nerve? Why is it important?

Answer 31

The vagus nerve is responsible for about 75% of all parasympathetic output. And it innervates multiple organs in the thorax and abdomen (heart, lungs, digestive organs, etc.).

Question 32

True/False? The vagus nerve originates in the cranial region.

Answer 32

TRUE!

Question 33

True/false: The pelvic splanchnic nerves originate in the cranial region.

Answer 33

FALSE! The pelvic splanchnic nerves originate in the sacral region of the spinal cord (S2-S4).

Question 34

What is the name of the nerves that represent the "sacral" (S2-S4) portion of the craniosacral (parasympathetic) division?

Answer 34

Pelvic Splanchic Nerves

Question 35

What do the pelvic splanchnic nerves innervate parasympathetic ally?

Answer 35

Pelvic organs and lower abdominal structures: -bladder -rectum -reproductive organs

Question 36

True/False: Sexual arousal is a sympathetic response?

Answer 36

FALSE! Sexual arousal is actually a parasympathetic response. Ex. an erection would be a parasympathetic response. (relaxation and arousal --think pleasant :)))) )

Question 37

What is the roman numeral for the vagus nerve?

Answer 37

Cranial Nerve X

Question 38

Which cranial nerves are involved in the parasympathetic division?

Answer 38

1. III (Oculomotor) 2. VII (Facial) 3. IX (Glossopharyngeal) 4. X (Vagus)

Question 39

How does the Vagus nerve connect to the concept of Plexuses?

Answer 39

Cranial nerve X carries parasympathetic fibers to organs of the thorax and abdomen. -Esophageal Plexus: lower esophagus -Cardiac plexus: heart -Pulmonary plexus: lungs and bronchi -Celiac plexus: foregut -Superior mesenteric plexus: midgut

Question 40

What is the sympathetic chain (AKA sympathetic trunk)?

Answer 40

A series of interconnected ganglia that run parallel to the spinal cord on both sides

Question 41

Compare and contrast white vs grey rami communicantes:

Answer 41

White rc = carry preganglionic sympathetic fibers from spinal nerves TO sympathetic chain Grey rc= carry postganglionic symp. fibers FROM sympathetic chain back to the spinal nerves to be distributed to the proper target organs

Question 42

What does Thorocolumbar refer to?

Answer 42

Refers to the origin of the nerves in the sympathetic division. --they originate in the thoracic as well as lumbar (L1-L2) region of the spinal cord

Question 43

What are the 4 main pathways of the sympathetic division? Hint-- think ASSS

Answer 43

1. Adrenal Medulla Pathway: Stimulates release of epinephrine (adrenaline) and norepinephrine directly into bloodstream 2. Spinal Nerve Pathway: sweat glands, blood vessels, skin 3. Sympathetic Nerve Pathway: Thoracic cavity, heart, lungs, etc. 4. Splanchnic Nerve Pathway: Abdominal and pelvic organs

Question 44

What is referred pain?

Answer 44

The perception of pain in a part of the body that is distant from the actual source of pain.

Question 45

What causes referred pain?

Answer 45

Sensory neurons from dif. party of the body converging onto the same neurons in the spinal cord ex. heart attack may be felt in the left arm or jaw because the nerves from these areas share common pathways with those from the heart.

Question 46

True/False: In the autonomic nervous system, preganglionic fibers are ALWAYS lightly myelinated while postganglionic fibers are ALWAYS unmyelinated

Answer 46

TRUE!

Question 47

True/False: The ANS contains only unmyelinated axons.

Answer 47

FALSE. The ANS contains both lightly myelinated (preganglionic) and unmyelinated (postganglionic) axons

Question 48

An autonomic plexus contains ________ parasympathetic fibers and ___________ sympathetic fibers.

Answer 48

1. preganglionic 2. postganglionic