Sensory Systems- 7 Flashcards
Why do we need sensory systems.
Maintain Homeostasis
Detect and react to changes in the environment
Protect the body from noxious stimuli.
What sensory systems do we have?
Vestibule-ocular reflex
Somatic sensory/ touch
Gustatory-Salivary Reflex
Smell gag Reflex
Acoustic reflex
Proprioception
Characteristics and location of Thermoreceptors
Activated by extreme temperature >45 <5
Found in Afibres
Location and characteristics of Mechanoreceptors
Activated by intense pressure on skin
Found in AFibres
Characteristics and Location of Polymodals
Activated by high intensity mechanical, chemical and thermal.
Found in C-Fibres
Is pain always at the site of injury
No for example myocardial infarction and visceral pain
What neuronal pathways are involved in pain transmission
- Transduction
- Transmission
- Relay
- Integration and Interpretation
- Modulation
What are primary Afferent Neurons
A special class of neurons with their cell bodies in the dorsal root ganglia- the nociceptors.
C or A fibres conduct relatively slowly
What is first pain?
Relatively fast AS fibres mediate a sharp first pain, myelinated
What is second pain
Relatively slow C fibres mediate a delayed, longer lasting second pain- unmyelinated.
How do pathways project to the brain
Via the spinothalamic tracts- descending in inhibition and perception
What is acute pain
Nociceptive pain- activation of AS and C fibres
Related to actual or potential tissue injury
Initiates protective reflexes or behaviour
What is the gate theory of pain.
Pain signals can be interrupted in the substantia gelitanosa of the spinal cord which acts as the gate.
Examples of NSAID’s
Aspirin, Ibuprofen
Example of local anaesthetics
Lidocaine
