Acupuncture Points: An Overview

• This covers general considerations about acupuncture points
• This is an introduction to acupuncture by Luís Resende in 2024

Why Learn Acupuncture Points and Channels?

• There are 361 classic acupuncture points
• 309 of these are located near peripheral nerves
• 286 are located near vessels, often clustered with small nerves

Access Points: Neuromodulation

• Neuromodulation is how acupuncture impacts the nervous system via sensory nerve stimulation to change pain perception
• This happens through several mechanisms:
  • Endorphin release acts as a natural painkiller
  • The Gate Control Theory blocks pain signals in the spinal cord
  • Autonomic Nervous System Regulation balances the sympathetic and parasympathetic systems

Fascial Treatment

• Fascia is the connective tissue network around muscles and organs
• Acupuncture can impact fascia by:
  • Releasing tension and adhesions by stimulating fibroblasts and increasing flexibility
  • Improving blood flow to enhance oxygen and nutrient delivery
  • Modifying pain perception and reducing myofascial pain and stiffness

Neuromodulation

• Neuromodulation modifies synaptic activity to alter functional connectivity within the nervous system
• This involves interactions between nerves, glia, and the neurological microenvironment
• Evidence for Neuromodulation:
  • Nerve stimulation leads to neurological changes
  • Nerves are associated with acupuncture points
  • Acupuncture points map to the nervous system shown in both human and non-human animal studies

Fascial Treatment

• Fascial Treatment is a method of muscle and fascia manipulation resulting in whole-body action
• It indirectly influences the nervous system and blood circulation.
• Evidence:
  • Mechanical studies show changes in connective tissue due to needle action
  • Treatment of trigger points and dry needling
  • Osteopathy and massage therapy have scientific support.

Considerations

• Structure-function relationship of channels and points
• Target tissues in acupuncture
• Comparative anatomy
• Clinical Applications of Acupuncture Points
• Combination of points and fundamentals

Structure-Function Relationship of Channels and Points

• Learn which nerves, vessels, and myofascia are related to acupuncture channels and points
• Relate the physiological effects of each point through the structure-function link

What Determines an Acupuncture Channel?

• Nerves(peripheral nerves, spinal cord)
• Vessels (superficial and deep)
• Myofascial cleavage planes (fascial divisions) which create natural pathways that separate and connect muscles, organs, and tissues

Neural Acupuncture Unit (NAU)

• The Neural Acupuncture Unit (NAU) explains acupuncture point function via multiple structures
• Nerves (sensory and motor pathways)
• Blood vessels (microcirculation changes)
• Fascia and connective tissue (mechanical and electrical properties)
• Immune cells (modulation of inflammation)
• Stimulating nerves, increasing blood flow, and reducing inflammation.

Definition of Acupuncture Point

• Acupuncture points are neurovascular intersections where nerves and blood vessels meet
• 10 key features
• Neural Acupuncture Unit (NAU) - explains how acupuncture works at a general level involving nerves, vessels, fascia, and immune cells
• Acupuncture Field - describes the area around a point that is also affected by stimulation
• Acupuncture Nodal Sites - major convergence points where multiple acupuncture effects are amplified.

Acupuncture Field

• The acupuncture field is a broader area around an acupuncture point
• It also responds to stimulation because acupuncture is not limited to a single location, it spreads into nearby tissues
• Needling LI4 on the hand can relieve pain in the entire arm or face due to the related meridian pathway

Acupuncture Nodal Sites

• Acupuncture nodal sites are key anatomical locations where acupuncture effects converge
• They converge due to a high concentration of nerve endings (neuromodulation effects), blood vessels (circulation changes), and fascial connections(mechanical signal transmission)
• GV20 (Baihui) at the top of the head is a nodal site affecting brain circulation, mood, and autonomic nervous system regulation.

Neurais Acupuncture Units - NAU

• NAU includes free nerve endings, Merkel disc ending, Meissner's corpuscle, Ruffini's corpuscle, Pacinian corpuscle, Muscle spindles, Cutaneous afferent nerve, Lymph vessel, Vein, Artery and arterioles, Nerve and branches.

Acupuncture Field

• The term 'acupuncture field' is more appropriate than 'acupuncture points'

Acupuncture Nodal Sites C

• Compact arrangements of small blood vessels, lymphatic vessels, and nerves, with relationships between other anatomical structures
• They are used to influence circulation and induce physiological equilibrium reactions and have clinical importance

Acupuncture Nodal Sites areas

• Thoracic and pelvic limbs: Located along blood, lymphatic, and nerve pathways.
• Trunk Nodal: Sites aligned with levels of segmental innervation located where spinal nerves and blood vessels penetrate fascia
• Head and face: Located near cranial nerves and cranial cervical nerves, besides major blood and lymphatic pathways

Nodal Site Functions

• Acupuncture nodal sites are strategic locations to maximize therapeutic effects by targeting nerve, vascular, and lymphatic networks
• Their anatomical placement allows practitioners to modulate circulation, neuromuscular activity, and physiological balance effectively.

Target Tissues in Acupuncture

• Skin (mechanoreceptors)
• Fascia (Fibroblasts, collagen fibers, extracellular matrix)
• Muscles and tendons (Muscle spindles, Golgi tendon organs)
• Nervi vasorum (nerves of the vessels) and autonomic nervous system

Classification of NAU Based on Mechanoreceptors (Zhang, 2002)

• Skin NAU contains relatively dense and concentrated skin receptors
• Muscle spindle is when an acupuncture needle is inserted and a large portion of the inserted needle body is surrounded by muscle fibers
• Tendon Organs is when Tendon organs, Ruffini and Pacinian corpuscles dominate NAUs

Local Sensations During Acupuncture - NAU

• Aching, soreness, or warmth involves cutaneous-receptor-rich NAUs with a predominance of nociceptors as a biochemical reaction affecting Aδ and C fibers
• Numbness, heaviness involve Muscule Spindle as a biophysical reaction affecting Aβ and Aδ fibers

Comparative Anatomy

• Vertebral formulas
• Absence or presence of digits
• Presence of tail
• Absence of the gallbladder (horse)
• Biped vs. Quadruped
• Skin surface
• Fur, hair, scales, feathers, etc...
• Cranial sutures (ossified or not)
• Access to certain points (easy??)

Clinical Applications of Acupoints

• Consider the functions of structures influenced by acupuncture
• What are the local, regional and systemic ramifications of peripheral nerve or connective tissue stimulation?
• How do these effects benefit patients?

Combination of Points and Fundamentals

• Rarely use isolated points
• How to carry out a treatment protocol that acts on the central, peripheral and autonomic nervous system?
• What determines the selection of acupuncture points related to myofascial and connective tissue dysfunction?
• What points can work together to promote the desired neuromodulation?
• What is the rational for including certain points?

Acupoints Features

• Cranial sutures
• Foramina
• Nerve size
• Depth (superficial may have higher sensitivity)
• Fascia
• Sensitive connective tissue structures
• Fiber complexity
• Neurovascular component
• Bifurcations
• Trigger Points
• Electrical Properties
• Histological properties
• Specificity

Cranial Sutures

• Near or in the cranial sutures (high innervation)
• Ossified or not?
• Governor's Vessel Channel e.g. GV20
• Nerve fibers that emerge from the dura mater, along the suture lines

Foramina

• Foramina are small openings within bones that transmit nerves and blood vessels
• Located in bony areas from which nerves emerge
• Cranial nerves may emerge from these sites such as infraorbital nerve, mental nerve, supraorbital nerve

Nerve Size

• Most important points are near large peripheral nerves. Electrical signals travel faster down the nerve. Tend to become sensitive more quickly.

Depth of Nerves

• Cutaneous innervation is more superficial and easier to elicit tenderness
• Deeper nerves control autonomic functions

4. Depth of Nerves

• There are four types of acupuncture points according to the tissues that penetrate the nerves
  • Type I (motor): Nerves enter through the muscles
  • Type II: Where the nerves intersect the dorsal and ventral midlines
  • Type III: the superficial nerves branch off
  • Type IV: The nerves penetrate the tendons
• Thoracic limb: With many points in the forearm and hand region than in the arm
• Pelvic limb: More points in the leg and foot area than in the thigh

Fascia

• Located in areas where nerves travel through the outer layers of the body and ascend to the surface
• From the deep fascia to the outer layers of the skin

Sensitive Connect Tissue Structures

• A high percentage of the points appear to align with the intermuscular or nonmuscular septa and connective tissue planes
• Ligaments, tendons, retinaculum, joint capsules, and fascial laminae, that gather sensory data on pressure, pain, and stretch

Fiber complexity

• Greater fiber complexity translates to greater neuromodulatory diversity within the targeted point

Neurovascular Component

• Together the neurovascular bundles that comprise arteries and veins that accompany the nerve
• These points have high impact on autonomic regulation

Bifurcations

• Found in branching zones of nerves
• Distal part of the limbs
• Baxie points linked w/nerve bifurcation zones

Trigger Points

• Points tender when palpated - usually within skeletal muscle w/a hypersensitive nodule in tight bands of tissue
• Painful and can cause: Referred pain with motor dysfunction, prolonged tension, vascular alterations and autonomic phenomena

Electrical Properties

• High conductance, organized field patterns, and electric potential differences
• Release of immune mediators, in particular, nitric oxide, local noradrenaline, tumor-related factors, histamine and serotonia contribute to electrical properties

Histological Properties

• Higher concentration of structural materials, such as connective tissue, afferent nerve endings, veins, arteries, lymphatic vessels, and glands

Specificity

• Stimulation of PC6 generates a strong afferent input to areas of the brain, which regulates the vestibular system
• Acupuncture stimulates the afferent fibers which increase gastric contractions
• Acupuncture stimulates primarily the spinal nerves, resulting in gastric relation

Ways to Group Acupuncture Points

Grouping locations using key features such as :

• Peripheral nerves: Location along major nerves
• Regions: Elbows and knees as reference
• Acupuncture Channels: Points belonging to a select channel
• Point combinations: e.g. LI 15 & TH14 for shoulder pain