Pain helps as to known that there is a problem or damaged to our organs or our mind and we need very attension for seeking a medical advices or to learn from the pain.

1. 2-12-2019

2. • Definition: Pain is an unpleasant and emotional experience
associated with or without actual tissue damage.
• Character of pain:
• Sharp, pricking, electrical, dull ache, shooting, cutting,
stabbing.
• Pain in some condition leads crying and fainting.
• The Duration of Pain may be:
1- Acute pain:
• Is a sharp pain of short duration with easily identified cause.
• Localized in a small area before spreading to neighboring
areas.
• Usually it is treated by medications.
2- Chronic pain:
• Is the intermittent or constant pain with different intensities.
• It lasts for longer periods.
• It is somewhat difficult to treat chronic pain and it needs
professional expert care.

4. Advantages of PAIN:
1. Gives as warning signals.
2. Also tells as how the severity of tissue
injured.
3. Prevents further tissue damage by causing
reflexes from the source of events.
4. Enables as to rest and immobile or minimize
the activity.
5. Pain leads as to seek a mediciation.

5. Dual pathways for transmission of pain signals into
the central nervous system
• According to pain sensation we divide it’s components into
2 type:
1- Fast pain:
• First sensation when stimuli are applied (0.1 second).
• It’s bright, sharp, and localized pain sensation.
• It’s receptors are free nerve endings.
• Afferent nerve fibers is Aδ type fibers (secrete glutamate).
2- Slow Pain:
• Second to fast pain (1 second or more).
• It’s dull, diffuse, and unpleasant pain.
• It’s receptors also are free nerve endings.
• Afferent nerve fiber is C type fiber (secrete substance P).

7. Causes of pain:
• Three Types of Stimuli Excite Pain Receptors:
1. Mechanical.
2. Thermal.
3. Chemical.
• Fast pain is elicited by the mechanical and thermal
stimuli.
• Slow pain can be elicited by all three types.
• Some of the chemicals that excite the chemical type of pain
are bradykinin, serotonin, histamine, potassium ions,
acids, acetylcholine, and proteolytic enzymes.
• In addition, prostaglandins and substance P enhance the
sensitivity of pain endings but do not directly excite them.

8. Non - adapting Nature of Pain
Receptors:
• Pain receptors adept very little or not at all in
contrast to other sensory receptors of the body.
• Hyperalgesia: increase in sensitivity of the pain
receptors.
• This condition excitation of pain fibers becomes
progressively greater, especially for slow-aching-
nauseous pain, as the pain stimulus continues.
• For this reason the pain failure to adapt because
it allows the pain to keep the person apprised of
a tissue-damaging stimulus as long as it persists.

9. NOCICEPTION
• Nocioception: is a complex sequence of actions
between tissue damage and the perception of pain.
• Its includes:
1. Transduction: Translation of a (chemical) pain
stimulus into electrical activity on nerve level.
2. Transmission: Guidance of the pain – information
through the nervous system.
3. Modulation: Modification of the nociceptive
transmission through a number of humoral and
neural effects.
4. Perception: Observing the pain in a conscious way.

12. Effects of pain:
• Sympathetic responses:
1. Pallor.
2. Increased blood pressure.
3. Increased pulse.
4. Increased respiration.
5. Skeletal muscle tension.
6. Diaphoresis.
• Parasympathetic responses:
1. Decreased blood pressure.
2. Decreased pulse.
3. Nausea & vomiting.
4. Weakness.
5. Pallor.
6. Loss of consciousness.

13. • As we know we have different structure and region to our body
so pain that are transmitted to brain area are different for
example:
1. Pathway from skin and deeper structures:
• Receptors of pain sensation are the free nerve endings.
2. Pathway from face:
• carried by trigeminal nerve.
3. Pathway from viscera:
• Pain sensation from thoracic and abdominal viscera is
transmitted by sympathetic (thoracolumbar) nerves.
• Pain from esophagus, trachea and pharynx is carried by vagus
and glossopharyngeal nerves.
4. Pathway from pelvic region:
• Pain sensation from deeper structures of pelvic region is
conveyed by sacral parasympathetic nerves.

14. • Pain from viscera is
unpleasant.
• It is poorly localized.
• „Causes Of Visceral Pain:
1. Ischemia
2. Chemical Stimuli
3. Spasm and Overdistention
of Hollow Organs.
VISCERAL PAIN:

16. REFERRED PAIN:
• Referred pain: is the pain that is perceived at a site adjacent to
or away from the site of origin.
• Deep pain and some visceral pain are referred to other areas.
• But, superficial pain is not referred.
• Examples of referred pain
1. Cardiac pain is felt at inner part of left arm and left Shoulder.
2. Pain in ovary is referred to umbilicus.
3. Pain from testis is felt in abdomen.
4. Pain in diaphragm is referred to shoulder.
5. Pain in gallbladder is referred to epigastric region.
6. Renal pain is referred to loin.
• MECHANISM OF REFERRED PAIN:
• dermatomal rule, pain is referred to a structure, which is
developed from the same dermatome.

19. ANALGESIA SYSTEM:
• Analgesia system means the pain control
system.
• Body has its own analgesia system in brain,
which provides a short-term relief from pain.
• It is also called endogenous analgesic system.

20. • Analgesia system has got its own pathway through which it
blocks the synaptic transmission of pain sensation in spinal
cord and thus attenuates the experience of pain.
• In fact analgesic drugs such as opioids act through this
system and provide a controlled pain relief.
• There are 2 condition by which pain is reduced or
blocked:
1- Brain sends a substances that control the gate of pain.
2- Other techniques (rubbing, massage techniques,
application of ice packs, acupuncture and electrical
analgesia) that the person used.
• All these techniques relieve pain by stimulating the release
of endogenous pain relievers (opioid peptides), which close
the gate and block the pain signals.

21. Gate control system:

22. Analgesia system of the brain and spinal cord,
showing (1) inhibition of incoming pain signals
at the cord level and (2) presence of
enkephalin-secreting neurons that suppress
pain signals in both the cord and the brain
stem.

23. rubbing, massage techniques, application of ice
packs, acupuncture and electrical analgesia