Lecture 1: Viscerosomatic and Chapman's Reflexes Flashcards
What is a reflex?
Relationship between an input stimulus to body and output action in a muscle or secretory organ
What receptors are found in the upper layers 3 and 4 of the spinal cord gray matter?
Mechanoreceptors
What receptors are found in the upper layers 1 and 5 of the spinal cord gray matter?
A-δ fast pain fibers
What receptors are found in the upper layer 2 of the spinal cord gray matter?
Small c fibers of slow pain
What is found in the lower layers of the spinal cord gray matter?
Interneurons
Motorneuron cell bodies
Where do interneurons receive input from?
Visceral and somatic afferents
What is habituation?
Process of decreasing response of a neural pathway w/ a continuous stimulation
Ex: getting use to a bad smell or not feeling pain for long time
What is sensitization?
Repetitive stimuli that can lead to a growing response until stabilization
-Amplifying of sensations
What is the nociception theory?
Homeostasis between habituation and sensitization between over and under reactions to a stimulus
What is facilitation?
Maintenance of a pool of neurons in a state of sub-threshold excitation
-Less stimulation needs to happen for excitation
What is the current theory regarding nociception?
- Strong stimulus activates nociceptive pathways.
- Impulses travel to spinal and cord and branch.
- Release of peptides in motor neurons
What type of peptides are released in the nociceptive pathway?
- Inflammatory cascade and initiate release of prostaglandins. bradykinins, etc
- Lowers nociceptor thresholds
Inflammation disrupts the balance between what?
Habituation and sensitization
-larger normal motor outputs to autonomic and somatic systems
What is short term excitability?
1-2 seconds of afferent input
90-120 seconds of excitability
What is long term excitability?
Several minutes of afferent input
Hours of excitability
What is fixation?
15-20 minutes of afferent input
Days or weeks of excitability
What can cause permanent excitability?
Death of inhibitory neurons
What is allostasis?
- Long term neural effect of segmental facilitation
- Process by which the body responds to stressors in order to regain homeostasis.
What are some things that can affect allostasis?
Physical stress: somatic and visceral Psychological stress (emotional) CV: HTN, Increased risk for MI Neuro: Depression, anxiety, memory loss, etc Weaker immune system
Describe somatosomatic reflex.
Localized somatic stimuli producing patterns of reflex response in segmentally related somatic structures
Describe somatovisceral reflex.
Localized somatic stimulation producing patterns of reflex response in segmentally related visceral structures
*If finger is injured, can have increase HR and feel sweaty
Describe viscerosomatic reflex.
Localized visceral stimuli producing patterns of reflex response in segmentally related somatic structures
*Somatic pain from visceral nociceptive stimuli
Describe viscerovisceral reflex.
Localized visceral stimuli producing patterns of reflex response in segmentally related visceral structures
*Cramping due to bad food you ate
What is the withdrawal response?
Somatosomatic reflex response: occurs when noxious stimulus is applied to somatic structure
*Quickly withdrawing hand from hot pot
What is the myotatic response?
Somatosomatic reflex response: occurs when stretch receptor is stimulated and stretched muscle receives impulse to fire. Meanwhile, antagonist muscle receives inhibitory muscles
*Active biceps and relax triceps
Describe somatocardiac reflex.
Nociceptive somatic stimuli result in elevation of heart rate and blood pressure
*When in pain, HR increases
Describe somatogastric reflex.
Nociceptive somatic stimuli results in inhibition of peristalsis in the stomach
*When in pain, peristalsis stops
Describe somatoadrenal reflex.
Nociceptive somatic stimuli results in the release of catecholamines from the adrenal medulla.
*When in pain, release of Norepi and epi.
Where are cell bodies located in visceral sensory system?
DRG or Vagal Ganglia
What are Chapman’s points?
Palpable points on the anterior and posterior surfaces of the body that are considered to be reflections of visceral dysfunction/disease
What are the three components of the Chapman’s points?
- Viscerosomatic reflex of both diagnostic and treatment value
- Gangliform contraction that blocks lymphatic drainage and causes SNS dysfunction
- A consistent reproducible series of points both anterior and posterior related to specific organs or conditions`
Where are Chapman’s points located?
- Deep to the skin in the subcutaneous areolar tissue on deep fascia or periosteum
- Paired anterior and posterior points in most cases
How do you treat a Chapman’s point?
- Apply gentle but firm pressure that can cause a disagreeable pain response in patient
- Can alternate between clockwise and counter clockwise
What should the patient feel when you are treating a Chapman’s point?
Pinpoint
Sharp
Non-radiating
*normally unaware of this point
What are some relative contraindications of Chapman’s points?
Fracture
Cancer
Etc.
