VET 400 Pain Pathway and A/P

Pain is classified into 2 categories. They are?

Physiologic and Pathologic

Physiologic pain is?

The bodies protective mechanism to avoid tissue injury

Pathologic pain is?

Pain that arises from tissues injury and inflammation or damage to nervous system

Physiologic pain is also called?

Adaptive

Pathologic pain is also called?

Maladaptive

Acute pain is?

physiologic pain arising from sudden stimulus

Ex of acute pain inlcude?

surgery, trauma, inflammation for diseases like pancreatitis

Chronic pain is?

Pathologic pain that persists beyond the time normally associated with tissue injury

Ex. of chronic pain include?

Cancer, osteoarthritis

Acute pain is divided into?

Nociceptive and neuropathic

Nociceptive pain is?

damage to normal peripheral tissues

Neuropathic pain is?

Pain resulting from damage to CNS or peripheral nerves

Ex. of nociceptive pain is?

burn or cut on hand

Ex. of neuropathic pain is?

Phantom pains in amputated limb

Transduction is?

Injury causes afferent nerve to convert stimuli into electrical energy

— nerves carry info to the CNS/brain

afferent

Transduction can be inhibited by?

local anesthetics, opioids, or NSAIDs

Transmission is?

Pain signal travels to dorsal horn of spinal cord (CNS)a

The 3 nerve fibers involved in transmission are?

A-Delta, C, and A-Beta

A-Delta nerve fibers involve?

sharp, stabbing pain

C (slow) nerve fibers involve?

dull, throbbing pain

A-Beta fiber involve?

Tactile sense —> know you are touching table

Transmission can be inhibited by?

local anesthetics and alpha 2 adrenergic agonist

Modulation is?

Where spinal cord decides if it needs to increase or decrease pain signal before telling the brain

Modulation can be inhibited by?

Local anesthetics, alpha 2 adrenergic agonist, opioids, NSAIDs, Dissociatives

Perception is?

Brain’s response to pain and how it perceives that pain

When do animals “feel” pain?

When pain signal has reached the brain

Neuroma is?

abnormal nerve regeneration that results from it not healing appropriately and causes tissue to spit out chemical and electrical signal which causes pain

Most common site for a neuroma is?

The tail

How does pain become chronic?

have initial stimulation —> prolonged stimulation ( b/c no pain management/length of recovery) —> body becomes used to pain —> modifies NS (neuroplasticity)

Signs of pain in animals includes?

Change in personality, abnormal vocalization, change in facial expression, teeth grinding, licking/biting/scratching pain area, change in posture/ambulation

What are the 3 C’s of the nervous system?

Communication, Coordination, and COntrol

Communication involves?

Transmission of electrical and chemical info

What does the nervous system control?

Manage HR, RR, and muscle movement

The 2 parts of the nervous system are?

Central and peripheral

The CNS includes?

Brain and spinal cord

The function of the CNS is?

To interpret messages from PNS and return instructions

PNS includes?

Cranial nerves, somatic nervous system, and autonomic nervous system

Somatic nervous system (SNS) involves?

spinal nerves

Autonomic nervous system (ANS) is split into?

Sympathetic and parasympathetic

The basic unit of the nervous system is?

Neuron

Sensory neurons have what function?

Carry impulses towards CNS

Associative neurons have what function?

Carry impulses from one neuron to another

Function of motor neurons is?

Carry impulses away from CNS

Which part of the neuron contains the nucleus?

Cell body

Function of the dendrite is?

receive and channel impulses to cell body

The axon is?

Single process that conducts impulses away from cell body

Function of terminal end fibers of a neuron is?

to send impulses to target tissue

Synapses are?

junction between nerve and target tissue

Neurotransmitters are?

Chemicals that pass across synapses to conduct impulses

Functions of autonomic nervous system include?

• Innervate smooth muscle, cardiac muscle, and endocrine glands

• Maintain homeostasis

Sympathetic nervous system is also known as?

Adrenergic or “flight or fight”

The sympathetic nervous system is located?

Ganglion of sympathetic trunk (T1-L3)

Sympathetic nervous system has — preganglionic fibers with — postganglionic fibers

short; long

What are the affects of SNS?

• Increases HR

• Increases RR

• Increases blood flow to muscles

• Decreased GI function

• Pupil dilation

neurotransmitter of SNS for preganglionic synapse is?

Acetylcholine (ACh)

Neurotransmitter of SNS for postganglionic synapse is?

epinephrine or norepinephrin

SNS/adrenergic receptor include?

Alpha 1, Alpha 2, Beta 1, and Beta 2

Alpha 1 receptors are found in?

smooth muscle of blood vessels, GI and urinary tract sphincters, heart and radial dilator muscle of iris

Stimulation of Alpha 1 receptors causes?

• Constriction of arterioles

• Mydriasis (pupil dilation)

• Increased force of heart contractions

• Contraction of GI and urinary sphincters

Alpha 2 receptors are found?

In postganglionic sympathetic nerve endings

Stimulation of alpha 2 receptors causes?

• Inhibition of norepinephrine release in brain

• Sedation, drowsiness, and analgesia

• Dilation of blood vessels —> hypotension

Beta 1 receptors are found in?

Heart and fatty tissues

Stimulation of beta 1 receptors causes?

• Increased heart rate and contractility

• Breakdown of stored fat to fatty acids

Beta 2 receptors are found?

In smooth muscle of lung

Stimulation of beta 2 receptors causes?

• Bronchodilation

• Dilation of skeletal blood vessels

• Relaxation of GI tract

Parasympathetic nervous system (PNS) is also known as?

Cholinergic

PNS is found in?

Brain stem and sacral spinal segments

PNS has — preganglionic fibers with — postganglionic fibers

long; short

Effects of PNS include?

• Bring HR, RR, and blood flow to muscles back to normal levels

• Returns GI function to normal

• Constricts pupils to normal size

Neurotransmitters for both pre- and postganglionic synapses for PNS are?

Acetylcholine (ACh)

Somatic nervous system is divided into?

Sensory (afferent) and Motor (Efferent)