The Somatic Senses Flashcards
What are the 7 types of somatic sense?
• Pain,
• Temperature,
• Proprioception,
• Vibration,
• Light pressure/ touch,
• Deep pressure/ stretch,
• Two-point discrimination
Nociceptors: ..?.. receptors that only respond to ..?.. caused by intense ..?.. (e.g., chilli powder in the eyes), ..?.. (e.g., pinching, crushing) or ..?.. (heat and cold) stimulation
Pain; tissue damage; chemical; mechanical; thermal
The role of inflammatory mediators (e.g., cytokines) in mediating the nociceptor response
- ..?.. are ..?.. mediators formed by the action of ..?.. (PLA2), cyclooxygenase (COX) and ..?.., which converts ..?.. into various prostanoids. The prostanoids serve pivotal functions in ..?.. at the site of …?.. and at the level of the ..?… The spinal prostanoids are important in ..?.. pain, and probably also in ..?.. pain and in the early phase of ..?.. induced pain.
- At the ..?.., the responsiveness of pain receptors is enhanced by the presence of ..?… These prostaglandins are formed in response to ..?… This means that the receptors will respond to a ..?.. stimulus than before they were ..?… A number of ..?.. compounds (e.g., ..?.., serotonin) may be responsible for the actual ..?.. sensation.
- ..?.. acid is one of the chemicals released during ..?… It is then metabolized into ..?.. (and ..?..). The action of the prostaglandins is mediated through a ..?.., protein ..?.. cascade. The prostaglandins block the ..?.. efflux released from ..?.. following ..?.., which results in additional ..?… This makes the nociceptors more ..?… ..?.. is an effective pain killer because it blocks the ..?.. of ..?.. to ..?…
- Tissue damage stimulates the ..?.. to release ..?.. to the surrounding ..?… Histamine ..?.. the ..?…
- prostanoids; lipid; phospholipase A2; prostanoid synthases; arachidonic acid; pain signalling; inflammation; spinal cord; spinal; inflammation-induced; postoperative; nerve injury
- periphery; prostaglandins; tissue trauma; lesser; before; sensitised; endogenous; histamine; pain
- arachidonic; tissue damage; prostaglandins; cytokines; G protein; kinase A; potassium; nociceptors; damage; depolarisation; sensitive; aspirin; conversion; arachidonic acid; prostaglandin
- mast cells; histamine; area; excites; nociceptors
How nociceptors differ from other sensory receptors in terms of threshold for stimulation and rate of adaptation
- Substance ..?..: transmits information about ..?.. from ..?.. nociceptors to ..?.. neurons within the ..?.. within ..?.. tracts up to the ..?..
- Nociceptor stimulation threshold is ..?.. than for other sensory receptors.
- Nociceptors adaptation: This adaptation varies in terms of ..?.. (most showing a ..?.. response rate with ..?.., a few showing ..?.. increases in ..?.. during ..?..) and ..?.. (most adapt ..?.., fewer more slowly).
- ‘Windup’: Following an injury, ..?.. cells are bombarded by ..?.. originating from ..?.. receptors. Over a period of time, the ..?.. of these cells ..?… This process of increasing ..?.. of ..?.. cells is called ..?..
- P; tissue damage; peripheral; second order; spinal cord; spine-thalamic; CNS
- higher
- direction; declining; time; short-term; firing rate; stimulation; time; rapidly
- dorsal horn; stimuli; pain; receptive field; increases; central sensitisation; dorsal horn; windup
A-delta fibres (smallest ..?.. fibres) convey ..?.., ..?.. pain
myelinated; sharp; localised
C-fibres (small, ..?.. that carries signal more ..?..) convey ..?.., ..?.. pain with poor ..?..
Non-myelinated; slowly; burning; throbbing; localisation
The neurotransmitters and neuromodulators involved, including endogenous opioids, noradrenaline and serotonin
- The midbrain’s ..?.. area has inputs from the ..?.., the ..?.. and the ..?.. cortex. From it ..?.. axons ..?.. to end in synaptic contact with ..?.. situated in the ..?..
- They release endogenous ..?.. which close the ‘..?..’ by ..?.. the release of ..?… There are also opioid ..?. and non-opioid ..?.. descending mechanisms, which are capable of ..?.. upward transmission of ..?.. generated impulses.
- In these ways the spinal ..?.. are ..?.. to inhibit ..?.. transmission cells responsible for projecting ..?. information received.
- periaqueductal grey; thalamus; hypothalamus; frontal; serotoninergic; descend; enkephalinergic interneurons; dorsal horn
- opiate neuromodulators; pain gate; inhibiting; substance P; serotoninergic; noradrenergic; blocking; pain
- interneurons; activated; dorsal horn; nociceptor
The effects of descending inhibitory pain pathways on spino-thalamic tract firing
Gate theory of pain modulation: ..?.. input ..?.. the “gates” to ..?.. input, which prevents ..?.. sensation from traveling to the..?… Therefore, stimulation by ..?.. input is able to ..?.. pain. Pre-synaptic ..?.. of ..?.. information produced by ..?.. stimulation to ..?.. the pain stimulus at the ..?…
Non-painful; closes; painful; pain; CNS; non-noxious; suppress; inhibition; pain; mechanical; inhibit; interneuron
Pain ..?.. and ..?.. are not simply determined by the ..?.. of the ..?.. stimulus, but ‘..?..’ cognitive activities can influence perceived ..?.. and ..?..
Intensity; unpleasantness; magnitude; painful; higher; intensity; unpleasantness
Corneal reflex:
- Afferent - ..?..
- Efferent – ..?..
- ophthalmic division of trigeminal (V) nerve
- facial (VII) nerve
Gag reflex:
- Afferent – ..?..
- Efferent – ..?..
- glossopharyngeal (IX) nerve
- vagus (X) nerves
Name the ascending (sensory) pathways
- dorsal column pathways
- anterolateral pathways (spinothalamic)
- spino- cerebellar pathways
Dorsal column pathways
- Mediate input from a ..?.. type of ..?.. receptor that can be ..?.. precisely on ..?.. (such as ..?.. touch) and is consciously ..?..
- Form tracts in the ..?..
- Signals travel via the ..?.. to the ..?.. cortex
- single; sensory; localised; body surface; discriminative; interpreted
- dorsal white column
- thalamus; somatosensory
Anterolateral pathways (spinothalamic)
- Receive input from many ..?.. types of ..?.. receptors and make ..?.. synapses in the ..?.. and is consciously ..?..
- ..?.. order fibres ..?.. over in the ..?..
- Signals travel via the ..?.. to the ..?.. cortex
- Primarily transmit impulses for ..?.. and ..?.. that is not easily ..?.., but also for ..?.. touch and ..?..
- different; sensory; multiple; brain stem; interpreted
- second; cross; spinal cord
- thalamus; somatosensory
- pain; temperature; localised; coarse; pressure
Spino-cerebellar pathways
- Consists of ..?.. and ..?.. tracts
- Conveys information about ..?.. or ..?.. stretch to the ..?.., which is then used to ..?.. skeletal muscle activity
- Do not contribute to ..?..
- ventral; dorsal
- muscle; tendon; cerebellum; coordinate
- conscious sensation
