Use the diagrams in the book to enhance comprehension of these concepts.

There are 2 control systems in the body

Nervous System (NS)	Endocrine System
Electrical signal	Chemical signal - hormones
Very fast	Slow
Short duration response	Long lived, complex, sustained response
Response to stimulus	Growth, maintenance, development
Respond to stimulus	Homeostasis - often part of the 'NS's response to some stiumulus

This chapter deals with the Nervous System.

What is the function of the NS?
Function: sense external and internal environmental conditions and respond to those conditions.

The neuron is the functional unit of the nervous system. There are two basic types of neuron:

Sensory neuron - responsible for detecting a condition, and transmitting the
     information that a specific condition exists

Motor neuron - responsible for transmitting the command information to the tissues
     that will produce the actual response to a specific condition.

EXAMPLE: you step on a tack.  A pain sensory neuron detects the 'wound' and transmits that information to the Central NS.   The CNS processes that info and sends the 'response' command down the motor neuron to the muscle tissues, commanding them to 'move the foot'.

Detect sensations and regulate and control movements, physiological processes, and intellectual functions. FAST communication between systems

The NS is divided into two main parts:

CNS - the brain and spinal cord; in the dorsal cavity
PNS - the nerves that come off the CNS.  Sensory nerve endings, dendrites, ganglia,
             axons, and presynaptic terminals
       is divided into two main parts:

Afferent (Sensory) carries information about sensations to the CNS

Efferent (motor) carries response (command) away from the CNS to the responding
     organ. The term ‘motor’ in this situation means any type of mechanical response:
          moving a muscle, producing secretions from a gland, tears, etc.)

   The Efferent is divided into two main parts:

Somatic Nervous System (SNS) - VOLUNTARY control of skeletal
     muscles; running and fighting. The things you do CONSCIOUSLY

Autonomic NS (ANS) - INVOLUNTARY –controls most other body parts.
      Controls those functions that you do NOT have to think about.

     The ANS is divided into two parts:

Sympathetic NS - Fight or Flight – STRESS response. Noradrenaline (AKA norepinephrine) and adrenaline (AKA epinephrine). This is a response to an EXTERNAL threat, a condition that will cause IMMEDIATE lethal consequences – so the organism either has to run away (flight) or - as a last resort – fight. All the energy of the organism is directed to these two responses – which organ systems are directly needed? Muscles - for running or fighting. Energy is shunted to the muscles and AWAY from the digestive, endocrine and reproductive systems. Ideally an organism would only spend 5% or less of its lifetime in this response.

Parasympathetic NS – Feed or Breed – RELAXATION response. This is a response to internal body conditions: metabolism, homeostasis, growth and development, etc. All the energy of the organism is directed toward maintaining homeostasis and reproduction. Energy and nutrients (blood flow) is directed toward the Digestive, Endocrine and Reproductive systems and away from the muscles. Ideally, an organism would spend 95% or more of its lifetime in this response.

NOTE: Both the Sympathetic and Parasympathetic responses maintain blood flow (transport of nutrients, O2) to the vital organs (heart, lungs and NS).

 

Draw and label a neuron - include the function of each part.

dendritic nerve endings - detect a condition (a 'stimulus')
dendrite - transmit the info that a condition has been detected
soma - process the info from the dendritic NE
axon hillock - produces an AP that causes a response to the 'stimulus'
axon - transmits the 'response' AP (command) to the responding tissues
presynaptic terminal, synaptic knob - Release the Neurotransmitter which transfers
     the signal (command; response) from the neuron to the responding tissue

Which part is found in the cerebral cortex?
   The SOMA.
Which parts form the nerve tracts?
   The dendrites and axons
Which parts 'detect' a condition or stimulus?
Which parts actually pass the signal to the 'responding tissues'?

What is released from the synaptic knob?

The Synapse is the actual transfer of the signal across the synaptic cleft.  The synapse occurs when the neurotransmitter is released from the presynaptic knob, diffuses across the synaptic cleft, binds to the post synaptic membrane and causes the 'response'.

What is the synapse?
  It is the intercellular communication between the neuron and the next cell.

Neurons can be classified according to Function, Structure

Function: Sensory and Motor neurons.

Sensory (afferent) Dendrites form the AFFERENT nerve tracts that carry information about
   the body or its environment to the CNS.

Exteroceptors - sensory nerve endings that sense conditions OUTSIDE the body: temperature, light, touch, pressure, etc.

Interoceptors - sensory nerve endings that sense conditions INSIDE the body: temperature, light, touch, pressure, chemicals such as pH, CO2 and O2 concentrations, ion and electrolyte concentrations etc.

Proprioceptors – sensory nerve ending that sense the position of body parts relative to each other. The muscle or joint ‘sense that allows you to walk and juggle at the same time.  People with superb proprioception are athletic.

Motor (efferent) – axons form the nerve tracts for the SNS and the ANS.

Structure (Shape): Unipolar, bipolar, and multipolar.

Unipolar - 1 (one - uni) branch attached to the soma
Bipolar - 2 (two - bi) branches attached to the soma. One dendrite coming in, one
        axon exiting the soma
Multipolar - many (multi- many) branches attached to the soma.  Many dendrites entering,
       one axon exiting the soma.

Nissl bodies (free ribosomes) and Rough ER are GRAY in color and are massed in the soma of the neuron – gives the soma a gray color – hence the term ‘gray matter’ for the brain.

What causes the cortex of the cerebrum to be a gray color?
If a NS structure is gray – what would you expect to find in that area?
What is the function of the soma?)

The neuroglia support and protect the neurons. There are several types of neuroglia. List them and name the function of each type.

Astrocyte – in CNS, have cell extensions that cover the surface of the capillaries in the CNS.   Forms part of the blood brain barrier that controls the movement of things from the blood into the CNS.

What is the blood brain barrier?
How does it protect the nervous system?
Why is it a ‘good thing’?
What is the structure of the capillary wall?
  A simple squamous epithelium
How does this added layer of CM affect movement of ions, molecules, nutrients, wastes, toxins etc out of the capillaries and into the CNS?
   The astrocytes ADD a second layer of cells to the outside of the capillary, which means that anything that diffuse OUT of the blood must now pass through 4 layers of Cell Membrane.  Diffusion is LESS efficient.

Microglia - a phagocyte in the CNS

What type cell is this?
   WBC
Where did it come from?
   Produced in the bone marrow, migrated to CNS
What is its function?

Ependymal cells – in the CNS, Epithelial tissue lining the Central Canal Spinal cord and Ventricles.

Produce Cerebrospinal Fluid (CSF).
Where are they found?
What do they produce?
What kind of tissue is this?
How are nutrients and wastes transported through the CNS?
What is CSF?

Oligodendrocytes – two types

Satellite cells -  in the CNS, protect the Soma of neurons in the CNS (in much the same way that Schwann cells protect the axons in the PNS). The neuroglia have cell extensions that cover the surface of the soma, forming a barrier of CM. Anything external to the CMs of the oligodendrocytes must pass through this barrier before getting to the cm of the soma.

Schwann cells in the PNS, protect the Axons of motor nerves (efferent NS). The Schwann cells have cell extensions that wrap around the axon sort of like a tortilla is wrapped around a burrito. This ‘wrapping’ forms multiple layers of Cell Membrane containing myelin – this forms the myelin sheath. Anything that is external to the myelin sheath must pass through MANY layers of CM and myelin to get to the axon. It is a very effective protective barrier.
In addition, Schwann cells produce SALTATORY conduction of the AP.

Describe Continuous transmission of AP vs. Saltatory conduction of AP

The Action Potential is produced and moves along the axon in two ways:
     Continuous - in a domino-like wave, moving along the CM as each adjacent Na channel opens
     Saltatory - in axons wrapped in Schwann cells, the AP jumps from one Node of Ranvier to
           the next Node of Ranvier.

Schwann cells form a myelin sheath around the axons, with Nodes of Ranvier, small 'gaps', between adjacent Schwann cells.. This sheath causes the Action Potential to ‘jump’ along the axon from Node of Ranvier to the Next Node of Ranvier – in a very RAPID form of electrical signal transmission. This is 10X faster than normal AP transmission.

Which of these neuroglia are found in the CNS and which in the PNS?

Cerebrum - The LARGE brain. Processes intellectual, conscious thought. 
        There are 2 hemispheres:
                Right (creative, spatial info)
                Left (Logical, math, etc)

Cortex - gray matter, OUTER layer of the Cerebrum
        What makes it GRAY?
        What is the function of the soma?
       Therefore, what process occurs in the Cortex?

Medulla - made of dendrites and axons, INNER region of the Cerebrum
       What is the function of Dendrites and Axons?
 

Each Hemisphere is divided into 5 Lobes:

Frontal - deep to the frontal bone
Parietal - deep to the parietal bone
Occipital - deep to the occipital bone
Temporal - deep to the temporal bone
Insula (5th lobe) - deep to the Temporal lobe, deep inside the Lateral fissure.

The cerebrum is divided into these lobes based on Surface Landmarks:
Longitudinal fissure - landmark that separates the two hemispheres
Lateral fissure - landmark that separates the Temporal lobe from the rest of the cerebrum.
Define a fissure, sulcus, and gyrus.
Central sulcus - separates the Frontal Lobe from the Parietal Lobe
Precentral Gyrus - on Frontal Lobe, just anterior to the Central Sulcus, contains the
       Premotor Cortex, processes motor information, i.e.. RESPONSEs
Postcentral Gyrus - on the Parietal Lobe, just posterior to the Central Sulcus, contains the
       Sensory Cortex, processes stimulus information, i.e. SENSORY info

Cingulate gyrus - Deep in the Longitudinal Fissure, superior to the Corpus Callosum,
        responsible for feelings of satiation (satisfaction) with sex and feeding.

Corpus Callosum - just internal to the Longitudinal Fissure, superior to the Diencephalon,
        axons that connect the two hemispheres. The largest of the Cortical Connections, it is the major
        communication pathway between cerebral hemispheres..

Diencephalon - the ventricle (cavity) at the top of the Brain Stem, filled with CSF,

Thalamus - the WALL of the Diencephalon, A relay center, it relays info between
          different parts of the Cerebrum.

Hypothalamus – the FLOOR of the Diencephalon, this CONNECTS the NS with the endocrine
       system. It coordinates the control mechanisms of the NS and Endocrine system. The
       Hypothalamus secretes neurohormones, which are taken to the pituitary and cause it to
        produce hormones.

Where are the thalamus and hypothalamus located?
  What are the functions of the thalamus and hypothalamus?
    How are the hypothalamus and pituitary connected?
      What are neurohormones and what do they control?

Cerebellum - the LITTLE brain. Inferior to the Occipital Lobe and Posterior to the Brain Stem.
         Responsible for 'reflex' memories - things you do by 'learned' movements (reflex): walk and
           chew gum at the same time; juggle, ride a bike, skate, etc.
      Proprioception is an important 'sense' that allows you to automatically maintain posture
         and balance..

Brain stem – inferior to the cerebrum, anterior to the Cerebellum, superior to the Spinal Cord.
       Connects the Spinal Cord to the Cerebrum and Cerebellum
       Contains many of the VITAL function ANS control centers: cardiac, respiratory, etc. Even
           slight damage or injury to the brain stem is often fatal – that’s why professional assassins
           hit the brain stem.

Three Parts:
    Midbrain
    Pons
    Medulla oblongata

Why is the brain stem so important to life?
What does 'vital' mean?

Limbic system – function is the basic survival instincts: food/water acquisition, reproduction- smell pheromones. It consist of a ring of structures around the brain stem: cingulate gyrus, diencephalon, hypothalamus, thalamus, and several basal nuclei.

The Primitive brain is the part of the brain that is similar to the brain of amphibians and reptiles. It consists of the Limbic system, the brainstem and the cerebellum.
The FUNCTION of the primitive brain is basic survival responses.

NOTE: the Limbic System is part of the Primitive Brain.  This area is responsible for
    basic survival - i.e. those functions/responses that are controlled by the ANS!

The Cranial Nerves are part of the PNS that originate from the brain stem.

There are 12 pair of Cranial Nerves. Some carry sensory info, some carry motor info, and
     some carry both.  They have numeric names - but ROMAN numerals: I,II, III, IV, V...
      IX, X, XI, and XII.  They also have alpabetical names: Olfactory, Optic, Vagus, etc. 
Four, III, VII, IX, and X, are parasympathetic.

How many are there?
How are they named?
What are their names?
List them and whether each is sensory or motor – what does this mean?
Which are Parasympathetic?
What is the function of the Parasympathetic NS?
Describe the important things about the Vagus nerve.

Vagus Nerve - CN # X
   - Parasympathetic
   - Has branches that innervate (control) many organs in the Ventral Cavity: Heart, Small intestine, Large intestine, etc.
   - DAMAGE to the Vagus can have lethal consequences - it can shut down the heart.

Damage to which cranial nerve can result in death?

Spinal cord - carries sensory info from the dendritic nerve endings to the cerebrum, carries motor responses from the cerebrum to the motor (effector) organs/tissues, and processes some 'reflex' info.

Surface anatomy:

Cervical enlargement – location where nerves that innervate the upper extremities originate
Lumbar enlargement – location where nerves that innervate the lower extremities originate.
Conus medularis – what vertebrae is near this point?  The Spinal cord ENDS about L2,
        before the sacrum. i.e. it does NOT extend all the way to the bottom of the vertebral
        column.
Filum terminale - a 'ligament' that connects the bottom of the spinal cord to the coccyx.
Cauda equina - literally the 'horse tail'.  the mass of peripheral nerves that exit the spinal cord
     from the lumbar enlargement.
Epidural space - the 'space' external to the dura mater, commonly mentioned with respect to
     the area around the cauda equina and/or conus medularis.

There are 31 pairs of spinal nerves that exit the spinal cord.  Each nerve is named for the vertebra next to it's exit point.  Spinal nerve C1 exits the spinal cord near vertebra C1, S1 exits near the vertebra Sacrum 1, and so on.

What are the spinal nerves?
How many are there?
How are they named – to what does the name of each spinal nerve relate?
Which ones are parasympathetic?
   S2, S3, S4  (sacral)
Relate the spinal nerves to the ‘dermatomes’.
   A dermatome is a MAP of the body's skin surface that shows which area is 'controlled' by the which spinal nerve.  Doctors stick a sharp point into areas of skin to see where a patient can 'feel' the stick.  This a diagnostic tool that tells the MD which cranial or spinal nerves are functioning.

Why is it important to know that some cranial and spinal nerves are sympathetic and others
    are parasympathetic?
The sympathetic and parasympathetic nervous systems cause OPPOSITE responses in the
     body. Knowing the response, can be a diagnostic tool for assessing the CAUSE.

CSF is located in the Central Canal and Ventricles of the CNS. 
The function of the CSF is to
    - carry nutrients to the cells of the CNS
    - carry waste products away from the CNS
    - cushion the CNS from hard impacts to the head . 

Ependymal cells pull plasma, the fluid of the vascular system, out of the capillaries (through the Blood Brain Barrier), and secrete this fluid (containing nutrients: glucose, O2, etc) into the Central Canal and Ventricles.  The CSF flows flows outward, from the ventricles into the interstitial spaces around the nervous tissue cess.  It then flows into the subarachnoid space and through arachnoid granulations into the cerebral sinuses.  The cerebral sinuses are part of the venous blood vessels and return fluids (blood and CSF) to the vascular system.

Remember the Neuromuscular junction from the last chapter?
There are neuroneural junctions, neuroglandular junctions, etc.

Describe the Action Potential, and Resting Membrane Potential

These are PROTEINs.
What are the 4 shapes of proteins?
  What characteristic does the shape of a protein mean to homeostasis?
     What is the specific function of each channel?
Will a Na+ channel allow a Ca++ to pass through, or vice versa?
  Why not?

How does the storage of Ca++ in bones affect nerve signal transmission, muscle contraction and blood clotting?
  Ca++ stored in hydroxyapatite serves as a source of ions to maintain blood Ca++ concentrations. 
   Ca++ in the extracellular fluid is important for nerve signal transmission, muscle contraction, and
       blood clotting.
How does this affect homeostasis?
  The hormones, Calcitonin and PTH maintain a negative feedback control of blood Ca++ concentration.
Where is the Ca++ located prior to depolarization of the CM around the presynaptic knob?
  It is extracellular
Where is Ca++ AFTER depolarization of the CM around the presynaptic knob?
   Intracellular

Describe a cell whose membrane is ‘polarized’.
- The extracellular electrical charge (in mV) is different than the intracellular electrical charge. 
- The charge OUTSIDE the CM is different than the charge INSIDE the CM.
     What significance does this have for the cell?
      It is the RMP.
       The charge difference is -70 mV.  The extracellular charge is 70 mV different than the
          intracellular charge.
      How does ‘polarized’ help a cell respond to a stimulus?
         The RMP means there is a LARGE difference in electrical charge - a BIG, STEEP gradient
           of electrical charges and ions that WANT to diffuse.
          There is tremendous POTENTIAL for diffusion to occur.  If ANY thing opens the channels in
            the CM, an AP will result.
        Where are the ions?
           Na+ is extracellular
           K+ is intracellular
     What is the Na/K pump?
        An active transport process that throws 3 Na+ out of the cell and pulls 2 K+ into the cell. 
        Maintains the RMP.
      What is the condition of the proteins in the CM when the cell is ‘polarized’?
         The Na and K CHANNEL proteins (ligand and voltage gated) are CLOSED - the CM is
            doing its job the Na/K pump is maintaining the RMP.

Describe a cell whose membrane is ‘depolarizing’.

    What significance does this have for the cell?
       Some external condition is causing the Na+ channels to open - the cell is responding to
         its external environment. The electrical charge difference is decreasing - toward 0, equilibrium.  
         If it decreases to -35 mV (threshold), the cell will be stimulated and produce a response.
    Why is the cell ‘depolarizing’?
        The Na+ channels are open, Na+ is diffusing into the cell, which puts MORE (+) charges inside
          the cell.
    What has changed about the CM that permits the CM to depolarize?
        It is more permeable to Na+.  The Na+ channels are open.
    What is the condition of the proteins in the CM when the cell is ‘depolarizing’?

   The cell has 'responded', it was stimulated/excited and produced a response 
NOW:
      The gated channels are closed,
      The Na/K pump is pumping 3 Na+ out and 2 K+ into the cell. 
      The electrical charge difference is being re-built.
       The RMP is being re-established, 
Describe this in terms of AP, threshold, and RMP.
    The electrical potential (charge difference) is increasing.  It is going from 0 (equilibrium)
       toward -70 mV, the RMP.   When it is exceeds the threshold (-35 mV), the voltage-gated
       channels close, and the Na/K pump is able to restore Na++ outside and K+ inside.
What is the condition of the proteins in the CM when the cell is ‘repolarizing’?
  The gated channels are 'closed'.

Hypopolarize - a cell membrane that is closer to the threshold than normal.  A stimulus is more
    likely to cause and AP.
Hyperpolarize - a cell membrane that is FARTHER away from the threshold than normal.  Requires
    a much large stimulus than normal to reach the threshold and cause an AP.

Describe the role of neurotransmitters on nerve signal transmission at the synapse

Neurotransmitters are chemicals that conduct the command across the synaptic cleft from the neuron to the next cell.  There are two main types of neurotransmitters:

Excitatory - generate an AP in the post synaptic cell membrane (depolarize) or
     hypopolarize the post synaptic cell membrane. 
  Excites = CAUSE a response.
Inhibitory - push the post synaptic membrane potential AWAY from the
     threshold - HYPERpolarize it and make it less likely to respond to a stimulus.
   Inhibit = STOPS a response

There are many different neurotransmitters - but all transfer the command from one cell to the next.

Acetylcholine - the neurotransmitter for the PARASympathetic Nervous System;
     The RELAXATION response.
      Cholinergic receptors on post synaptic cell membrane 'receive' ACh.

The MonoAmines -
    NorEpinephrine - THE neurotransmitter for the Sympathetic Nervous System
          The STRESS response.
          Also called NorAdrenaline.
          Adrenergic (from adrenaline) receptors on post synaptic cell membrane bind NorEpi.

    Dopamine - (parkinson's disease)
     Serotonin - (depression)

Nitric oxide
Amino acids - GAMA, GABA
Opioids - beta endorphins, enkaphalins - block pain
  Substance P (enhances pain)

NOTE: Acetylcholine and Norepinephrine are the neurotransmitters for the ANS.

What is the function of the neurotransmitters?
Where are they located?
What structure releases neurotransmitters? (see the description of the neuron, above)
To what do adrenergic receptors respond?
To what do cholinergic receptors respond?
Why are these receptors called 'adrenergic' or 'cholinergic'?
How are acetylcholine and norepinephrine related to the ANS?
How is the synapse related the neurotransmitter?
What is the function of Acetylcholinesterase?
What is the function of Mono Amine Oxidase?
What is the function of MAO Inhibitors?  (monoamine oxidase inhibitors)

List the 5 parts and the function of each part.  View the following as an arc on it's side: NE, dendrite,
    CNS, axon, and presynaptic knob.

   sensory nerve ending (dendritic NE)  senses condition/stimulus
       dendrite - carries sensory info to the CNS
            CNS (processes sensory info, produces motor command AP)
        axon - carries motor command AP to the motor tissues
   synapticl knob

Which are the ‘general’ senses and which are the special senses?
Why are the special senses called ‘special’?  (see the next section - Special Senses)

Referred Pain - pain caused by one body part, but SENSED (felt) in a different body part. 
      Pain in the left shoulder and arm - is REFERRED pain.  We recognize this as a signal of
         a heart attack.
      Look at the diagram in your book: pain in
             shoulder signals what?
             lower back ?  etc?

What is referred pain?
How do we use it as a diagnostic tool? God, nature, your body did NOT develop referred pain so that we would have a diagnostic tool – the pain is merely your body’s way of telling that some problem exists that requires immediate, voluntary response. We, as conscious, intelligent beings have learned to recognize the source of referred pain and to voluntarily, consciously treat that source.

Chronic Pain - pain that is felt for long durations of time.  Over time, a pain 'memory' may
       develop and when the Cause disappears, the 'memory' may keep the sensation of pain
       alive.

What is chronic pain?
How can an injury cause chronic pain?

How can a ‘memory’ for pain be created? If a pain is constant for a long period of time, the NS can form a ‘memory trace’ for that pain which persists even after the original cause of the pain has been treated.

Phantom Pain - pain 'sensed' in a body part that is no longer attached to the body.

What is phantom pain? Amputees often feel pain in the body part that has been lost – phantom pain.

List the sensations detected by the following types of sensory nerve endings: baroreceptors, mechanoreceptors, nociceptors, thermoreceptors. and chemoreceptors.

Nerve tissue requires a great deal of energy.  Glucose is the most common source of energy.
Normally, glucose is broken down via aerobic cellular respiration.

Review Aerobic Cellular Respiration.
List the three steps of aerobic cellular respiration.
Where does each step of aerobic cellular respiration occur?
What is the simple formula for aerobic cellular respiration?

Creatine -PO4
Catabolism of fats and proteins serve as secondary sources of energy.

EEG - electroencephalograph.  A measure of the electrical activity of the nervous system.
Remember, neurons produce APs then return to RMP, then produce another AP while processing information.  These APs and RMPs are a change in electrical activity.  The EEG measures these changes in electrical activity.

Alpha (α) waves - Characteristic of a person who is very relaxed.  Awake, but NOT thinking or active
Beta (β) waves - Characteristic of a person who is in Active thoughts and physical activity
Delta (Δ) waves -  Characteristic of a person who is DEEP asleep, or in a coma
Theta (θ) waves -  Characteristic of children, or a person under lots of stress,

You are able to breath, digest nutrients, grow, develop and maintain metabolic functions and homeostasis without consciously monitoring these activities - the ANS controls them.

Often times, a sick person has a malfunction of the ANS – say High Blood Pressure. He goes to the MD, who then gives the patient a chemical that the patient must consciously ingest to control the BP. The patient now is VOLUNTARILY controlling that condition.

Do you know folks who ‘forget’ to take their meds?
  These folks want their body's ANS to control the homeostasis - but if the ANS is NON-functional, then what happens?
How about diabetes?
   If a diabetic does not take his insulin - his blood sugar fluctuates far outside the normal range, which causes problems.

List the two parts of the ANS.
List the organ systems that are involved in the
   Sympathetic - fight or flight - STRESS - responds to an external threat that is potentially lethal. 
       Uses all possible resources without regard to maintaining homeostasis - the goal is to get out
        of danger!
       Which organ systems are active while fighting?
   Parasympathetic - feed or breed - RELAXATION -
       Maintains homeostasis while the body is at rest.
       Returns the body to homeostasis after the sympathetic has depleted energy and resource stores.
      Which organ systems are active while feeding or breeding?

What is the function of the two main parts of the ANS?
How is the Sympathetic NS indirectly homeostatic?
  The Sympathetic NS uses whatever resources are available to get you away from a perceived, LETHAL condition.  It's whole goal/focus is to keep you alive right now!  All resources are used for fight or flight.
How is the Parasympathetic NS directly homeostic?
  The Parasympathetic NS restores your body to its set points.  It activates tissue repair, digestion to restore nutrients to optimum levels, etc.

Why is it important to know that some cranial and spinal nerves are sympathetic and others are parasympathetic?
   The sympathetic and parasympathetic nervous systems cause OPPOSITE responses in the body.
        Observing the response can be a diagnostic tool for assessing the CAUSE.

What is an adrenergic response?
  It is a response to NorAdrenaline.
Is it sympathetic or parasympathetic?
  Sympathetic
What is the neurotransmitter for adrenergic receptors?
  Noradrenaline

What is a cholinergic response?
  It is a response to Acetylcholine.
Is it sympathetic or parasympathetic?
  Parasympathetic
What is the neurotransmitter for cholinergic receptors.
  Acetylcholine

Refer to the cranial and spinal nerves – which are parasympathetic? By default, the rest must be sympathetic.

Locate the vagus nerve.
  What does it innervate?
     Why is it so important to EMS and emergency room personnel?

What is a ‘plexus’?
A plexus is the joining of adjacent nerves and then splitting again.  The cervical plexus is a network of
spinal nerves C1-C7 that merge and then split.  The brachial plexus feeds into the upper arm.
   Where is the lumbar plexus?
     Where is the sacral plexus?

Some of the receptor proteins on the CM of muscle cells are Beta (β) receptors.
What are β-blockers?
What are calcium channel blockers?
Speculate on how these drugs achieve their function?
Where are calcium channels located?