Week 3 Flashcards
What is the sensation of a mechanical stimulus?
Perceptions of touch, pressure, stretch, flutter/vibration, hearing
What is the sensation for a thermal stimulus?
Perceptions of hot and cold
What is the sensation for a photic stimulus?
Perception of light
What is the sensation for a chemical stimulus?
Perceptions of taste, smell and pain
How many people observe “subjectively”?
Only one person
How many people observe “objectively”?
Two or more people
What is the definition of a stimulus?
An objective, quantitative environmental interaction that is conveyed to the CNS
What is the definition of a sensation?
A subjective, qualitative characterization of a stimulus at the level of consciousness
What are C fibers?
non-myelinated afferent axons
What sensors fall under the caterogy of C fibers?
many pain sensors and warm/cold sensors
What are A-delta fiber?
thinly myelinated, smallest and slowest conducting of the myelinated afferents
What kind of sensation do A-delta fibers respond from?
sharp, quick pain, some crude touch and temperature sensation
What are A-beta fibers?
large, fast, conducting myelinated afferents
Where are there afferents located that belong in the category of A-beta fibers?
Meissners corpuscles, Pacinian corpuscles, Merkel’s discs and hair follicles
True or False: Pseudonipolar neurons are specialized sensory neurons
True
what are somatic sensations?
bodily sensations arising from the external environment
What are visceral sensations?
bodily sensations arising from the internal environment
What is the receptive field?
that region of sensory space(body’s surface or sensory environment) where a stimulus is transduced
What is sensory transduction?
the conversion of physical energy into action potentials
What are proprioceptors?
they are modified muscle cells (myocytes)
What do proprioceptors contribute to and where are they found?
Body position sense and found among normal muscle cells (the junctions between muscles and tendons)
What are nociceptors, where are they located and what do they respond to?
“free” “naked” nerve endings which are sensory receptors for painful stimuli and are present in the skin and respond to tissue damage
What is mechanical nociception?
the detection of mechanical aspects of pinch, stab, cut
What is thermal nociception?
the detection of extreme heat or cold
What is chemical nociception?
the detection of various chemicals released as the result of tissue damage
Many nociceptors are [ ] nociceptors
Polymodal
What is the role of transient receptor potential channels?
playing a role in pain and temperature detection and regulation
What does TRP channels stand for?
transient receptor potential channels
What is hyperalgesia?
abnormally heightened sensitivity to pain
What is peripheral sensitization?
reduction of activation threshold and increased responsiveness of the peripheral ends of nociceptors
What is central sensitization?
increased excitability of neurons in the CNS in response to stimulation, creating abnormal sensation
What does the insula help with?
helps to build an image of the body that’s informed by our internal states
What is the cingulate cortex involved in?
the prefrontal cortical networks that evaluate the conse
What is the dorsal root ganglia?
has the cell bodies of sensory receptor neurons
Where are the dorsal root ganglia located?
peripheral nervous system am send their axonal projections into the central nervous system
State the Bell-Magendie law
The dorsal roots of the spinal cord are sensory and the ventral root are motor
What is a radicle?
a small rootlike part or structure, such as the beginning of a nerve
What does DCML (pathway) stand for?
Dorsal column medial lemniscus pathway
What does the DCML pathway carry?
Carries conscious proprioception, vibration, touch, pressure and discriminative touch
The DCML carries its components from the [ ] to the [ ]
from the [periphery] to the [ cortex]
What are the first order neurons in the DCML pathway?
mechanosensory receptor neurons
True or False: the DCML pathway is the first center somatosensory pathway
True
What does LSTT (pathway) stand for?
lateral spinothalamic tract
The lateral STT is also known as the ..
anterolateral system
What does the LSTT carry?
pain and temperture
The LSTT carries its components from [ ] to the [ ] and runs parallel the what pathway
[periphery] to the [cortex] and runs parallel to the [DCML] pathway
What is the sensation from a Meissner’s Corpuscle?
touch velocity, flutter
What are mechanoreceptors?
type pf somatosensory receptors which relay extracellular stimulus to intracellular signal transduction through mechanically gated ion channels
What is the sensation from a Pacinian Corpuscle?
touch acceleration, vibration
What is the sensation from a merkel cell?
touch intensity, duration, velocity, pressure
What is the sensation from a ruffini Corpuscle?
pressure, vibration, stretch, distension, displacement
What is the sensation from a Peritrichal Receptor?
movement of hairs, direction, velocity
What is the sensation from Neuromuscular spindles?
muscle stretch (dynamic and static)
What is the sensation from golgi tendon organs?
muscle tension
Match the mechanoreceptor to adapting speed
merkel cell [ ]
Meissner’s Corpuscle [ ]
Peritrichal Receptor [ ]
Pacinian Corpuscle [ ]
golgi tendon organs [ ]
ruffini Corpuscle [ ]
Neuromuscular spindles [ ]
[SA]
[RA]
[SA, RA]
[RA]
[ NEITHER]
[SA]
[NEITHER]
Where are Meissner’s Corpuscles?
located mainly at the dermo-epidermal junction, found in the hand, volar forearm, sole of the foot, lips and oral mucosa
Where are pacinian Corpuscles?
located in the hypodrmis of the hand, arm and external genitalia
additionally, in the periosteum, joint capsules, mesentery, pancreas and urinary bladder
Where are merkel cells?
all over the body but greatest density in the hands
Where are ruffini corpuscles?
located in the dermis of the skin of the hands, nail beds, tendon attachments, gingiva and periodontal ligament
Where are Peritrichal receptors?
surround the base and proximal shafts of hairs over the whole body
Fill in:
There are [ ] pairs of spinal nerves, 8 [ ], 12 [ ], [ ] lumbar, 5 [ ], and [ ] coccygeal, making up [ ] nerves in all
[31], [cervical], [thoracic], [5], [sacral] and [1], [62]
What is the dermatome?
the area of skin that is innervated by a single dorsal root of the spinal cord
