Chapter 16: The Autonomic Nervous System

Muscarinic; produces longer lasting effects by coupling G-protein receptors

@ cholinergic neuromuscular or neuroglandular junctions that are stimulated by a mushroom toxin; how does it produce longer lasting effects?

ACh

All parasympathetic use what neurotransmitter?

Alpha-2; has a inhibitory effect on the cell

Alpha receptor that helps coordinate sympathetic and parasympathetic activities and decreases cAMP levels. What kind of effect does it have on the cell?

Enteric nervous system (ENS); extensive network in digestive tract walls of roughly 100 million neurons; complex visceral reflexes coordinated locally

Briefly describe the 3rd division of the autonomic nervous system

1. Secondary memory 2. Tertiary memory

Components of long term memory 1. May take you longer to retrieve but you will remember this information for a long time 2. Something you will never forget like your name

Parasympathetic innervation dominates under resting conditions; crisis accelerates heart rate by stimulating the sympathetic innervation and inhibiting parasympathetic innervation

Describe how the heart receives dual innervation

Craniosacral (2 parts) Cranial: mesencephalon, pons, medulla oblongata (brainstem) associated with cranial nerves III, VII, IX, X Sacral: later gray horns of spinal segments S2-S4 nerve X

Describe how the parasympathetic division is organized

Supports digestion and nutrient absorption by cells

Describe the activation of the parasympathetic system

very short post-ganglionic fibers that release neurotransmitters into the bloodstream (not at synapse); they function as hormones to affect target cells throughout body

Describe the adrenal medullae

1. Increased Neurotransmitter release: frequently active synapse increases neurotransmitter storage, releasing more and having a greater effect on postsynaptic neuron 2. Facilitation at synapse: frequently active synapse begins continuously releasing neurotransmitter, bringing membrane closer to depolarization 3. Formation of additional synaptic connections: Axon tips can branch and form additional synapses on postsynaptic neuron. So presynaptic neuron has greater effect on postsynaptic neuron.

How are memories made/ stored? (3 steps)

Different receptor types; if it binds to inhibitory receptor it will inhibit stimulus

How does one neurotransmitter (Norepinephrine) have different effects? Inhibitory on some organs and excretory on others?

1. Can only increase activity 2. Can increase or decrease activity

In regards to autonomic tone what happens to activity when 1. A nerve is inactive under normal conditions 2. If a nerve maintains a background level of activity

Preganglionic neurons and ganglionic neurons

In the sympathetic division what is involved in using energy and increasing metabolic rate?

They are located near the spinal cord; Preganglionic fibers (release NE at neuroeffector junctions) release ACH stimulating ganglionic fibers

In the sympathetic division where are ganglia located ? What stimulates them?

Lateral gray horns of spinal segments T1 - L2

In the sympathetic division where are preganglionic neurons located ?

Cholinergic (ACh) sympathetic terminals; stimulates sweat gland secretion and dilates blood vessels

Innervates sweat glands of skin and blood vessels of skeletal muscles and brain. What does this stimulate?

Short term memory

Memory where you can retrieve information quickly and that will not stay very long

Alpha-1; has an excitatory effect on target cell

More common type of alpha receptor that increases intracellular calcium. What type of effect does it have on the target cell?

1. cerebral cortex: interacts with other parts of brain 2. conscious and unconscious information processing 3.Not part of programmed wiring of brain, can adjust over time.

Name 3 things needed for higher order functions

sympathetic synapses closer to the spinal cord and have short pre ganglionic neuron and longer post ganglionic fiber (ACh, nonephinephrine, epinephrine) parasympathetic synapses closes to the effector organ (ACh only)

Name anatomical differences between sympathetic and parasympathetic nervous system

1. stimulates visceral activity 2. conserves energy 3. promotes sedentary activity 4.decreased metabolic rate, heart rate and blood pressure 5.increased salivary and digestive glands secretion 6.increased mortility and blood flow in digestive tract 7. urination and defection stimulation

Name functions of the parasympathetic division of the ANS?

Thoracolumbar

Name the location of sympathetic division

Sympathetic and Parasympathetic Nervous Systems; 2 divisions can work together or separately

Name the two division of the Autonomic Nervous System? How do these two systems work in relation to one another?

alpha (NE preference) and beta receptors; E binds equally to A and B. They activate enzymes on the inside of the cell membrane via G proteins

Name the two types of adrenergic membrane receptors that Norepinephrine (NE) and Epinephrine (E) act on? How do they activate enzymes on the inside of the cell membrane?

Vagus Nerve (X) Innervates: neck, thoracic, abdominopelvic cavity Ex: large intestine

Nerve that carries 75% of parasympathetic outflow? Innervates? Ex?

Nicotonic

On ganglion cells of both sympathetic and parasympathetic. ACH causes excitation of ganglionic neuron on chemically gated channels; stimulated by nicotine

1. brain stem and lateral portion of anterior gray horns of S2-S4; release ACh stimulating ganglionic neurons 2. near the target organ 3. Postganglionic fibers release ACh @ neuroeffector junctions

Parasympathetic location of the following: 1. Preganglionic neurons? 2. Ganglion? 3. Target organs

Somatic Nervous System (SNS)

Part of the nervous system that operates under conscious and unconscious control; controls skeletal muscles; it seldom affects long term survival

Autonomic Nervous System

Part of the nervous system that operates with conscious instruction; controls vital systems and coordinates vital system functions: cardiovascular, respiratory, digestive, urinary or reproductive

Nitroxidergic synapses; produces vasodilation and increased blood flow

Releases nitric oxide as neurotransmitter; neurons innervate smooth muscles in the walls of blood vessels in skeletal muscles and in the brain. What does it produce?

Beta receptors; they are stimulated by increasing intracellular cAMP levels

Type of receptor that affects membranes in many organs (blood vessels of skeletal muscles, lungs, heart and liver) that triggers metabolic changes in target cells; how is it stimulated?

a. Beta-1 b. Beta- 2 c. Beta-3 Lipolysis

Types of Beta receptors: a. increase metabolic activity b. relaxation of smooth muscles along the respiratory tract c. breakdown of triglycerides in adipocytes

Skeletal Muscles

What are the target organs of the autonomic nervous system ?

Nicotine and Muscarinic

What are the two types of parasympathetic neurotransmitter receptors?

Compounds that enhance serotonin cause hallucinations (Ex: LSD) Blocking serotonin causes depression, blocking its breakdown used as antidepressants (Ex: Prozac)

What do compounds that enhance serotonin cause? What does blocking serotonin cause?

Exhilaration

What do drugs that stimulate Norepinephrine (NE) cause?

Varicosities that are scattered across the cell surface that are filled with neurotransmitter vesicles

What do ganglionic neurons release neurotransmitters from?

Release norepinephrine called adrenergic

What do most sympathetic ganglion release? What is this called?

effectors in body wall, thoracic cavity, head and limbs

What do neurons in ganglia control?

They release ACh and are called Cholinergic synapses

What do preganglionic neurons release? What are they called?

Reduces metabolic rate and promotes digestion

What does the parasympathetic division reduce?

Heightened mental alertness Increased metabolic rate Reduced digestive and urinary functions Energy reserves activated Increased respiratory rates Respiratory Passageways dilate Increased heart rate and blood pressure Sweat glands activated

What happens when their is increased sympathetic activity in this division of the autonomic nervous system? (8 things)

Inherited depression

What is caused by defective Norepinephrine (NE) synthesis?

Rest and Digest

What is the parasympathetic division also called?

Schizophrenia (Parkinsons)

What is the result of having excessive dopamine?

Tracts between the amygdala and hypothalamus

What links memory to emotion

Visceral Reflexes Ex: When light is shone into 1 eye the pupil in BOTH eyes constrict (consensual light reflex)

What regulated autonomic function? Example?

Amphetamines

What stimulates dopamine secretion?

The fight or flight response; sweaty palms; nausea; sweaty palms (are all part of the activation of the sympathetic nervous system

What system in your body is activated when you are anxious or nervous ?

Amygdala and hippocampus

What two parts of the limbic system are essential to memory consolidation?

During exertion, stress or emergency; increases alertness, metabolic rate and muscular abilities

When is the sympathetic division activated ? What does this increase?

Fight or flight

When is the sympathetic division also called?

Dual innervation; ex: heart, digestive tract & lungs

When sympathetic and parasympathetic divisions can innervate the same organ and have the opposite effect. Provide an example

Vasovagal response

When the parasympathetic nervous system goes into overdrive; when you faint

In the cerebral cortex in appropriate association areas

Where are long term memories stored?

They join in bundles called autonomic plexuses; Ex: cardiac plexus and pulmonary plexus

Where do parasympathetic nerves join? Provide an example.

1. Sympathetic Chain Ganglia 2. Collateral Ganglia 3. Adrenal Medullae

Where do ventral root nerves carry myelinated preganglionic fibers to? 1. near vertebral column 2. abdominopelvic viscera receive innervation 3. preganglionic fibers synapse on neuroendocrine cells and secrete hormones into the blood

Originates in the brain stem or sacral region of the spinal cord; synapses in ganglia close to (or within) target organs

Where does the parasympathetic division originate? Synapse?

out of the ventral root; they send post ganglionic nerves to visceral organs in the thoracic cavity

Where does the preganglionic nerve travel? What is the job of these nerves?

Craniosacral

Where is the parasympathetic division located ?

Autonomic Tone

autonomic neurons showing resting levels of spontaneous activity

Preganglionic fibers

fibers that are long

Postganglionic

fibers that are short

serotonin

neurotransmitter that affects sensory interpretation

Collateral Ganglia

structure that is anterior to vertebral bodies and that contain ganglionic neurons that innervate tissues and organs in the abdominopelvic cavity