Flashcards in this deck (69)

• What are the 'five senses'?

  • Sight
  • Hearing
  • Taste
  • Smell
  • Touch
  senses basics
• Which senses are 'general'?

  • Touch
  • Pain
  • Pressure
  • Body position
  general senses
• Which senses are 'special'?

  • Sight
  • Hearing
  • Taste
  • Smell
  special senses
• Do 'general' and 'special' senses have specialized organs?

  • General: No
  • Special: Yes
  organs senses
• How does receptor/structural complexity differ?

  • General: Simple
  • Special: Complex / Specialized
  complexity senses
• How do the pathway types differ between 'general' and 'special' senses?

  • General: 'Labeled lines' (simple pathway)
  • Special: Complex pathway
  pathway senses
• What are the main types of general sense receptors?

  • Thermoreceptors
  • Chemoceptors
  • Nociceptors
  • Mechanoreceptors
  receptors general
• What stimulus do thermoreceptors detect?

  • Change in temperature
  thermoreceptors stimulus
• Where are thermoreceptors located?

  • Dermis
  • Skeletal muscle
  • Hypothalamus
  thermoreceptors location
• What stimulus do chemoceptors detect?

  • Change in chemical concentrations
  chemoceptors stimulus
• Where are chemoceptors located?

  • Medulla
  • Heart
  • Arteries near heart
  chemoceptors location
• What stimulus do nociceptors detect?

  • Pain
  nociceptors stimulus
• Where are nociceptors located?

  • Epidermis
  nociceptors location
• What stimulus do mechanoreceptors detect?

  • Touch
  mechanoreceptors stimulus
• Where are mechanoreceptors located?

  • Multiple locations
  mechanoreceptors location
• What are the types of mechanoreceptors?

  • Baroreceptors
  • Proprioreceptors
  • Tactile receptors
  mechanoreceptors types
• What stimulus do baroreceptors detect?

  • Pressure
  baroreceptors stimulus
• Where are baroreceptors located?

  • Blood vessels
  • Lungs
  baroreceptors location
• What stimulus do proprioreceptors detect?

  • Changes in body position
  proprioreceptors stimulus
• Where are proprioreceptors located?

  • Muscles (muscle spindle)
  • Tendons (Golgi tendon organ)
  proprioreceptors location
• What stimulus do tactile receptors detect?

  • Touch
  tactile stimulus
• Where are tactile receptors located?

  • Skin
  tactile location
• What is a phasic receptor?

  • Sends signal to CNS only when stimulated
  • Stimulus intensity is frequency coded
  sensory phasic receptors
• What is a tonic receptor?

  • 'Always on' — constantly sending signals
  • Stimulation turns signals off
  sensory tonic receptors
• Give an example of a tonic receptor.

  • Nociceptor (pain receptor)
  nociception tonic
• How is stimulus intensity encoded by phasic receptors?

  • Frequency coded
  sensory coding
• What does this oscilloscope image illustrate?

  

  • Neuronal firing patterns change with stimulus intensity
  • Responses shown for increasing mechanical stimuli (brush, probe, forceps)
  oscilloscope lab sensory
• Can the brain distinguish true from false sensations?

  • No — the brain cannot tell the difference between true and false sensations
  • Examples: mechanical stimulation of photoreceptors; referred pain
  perception sensory
• What question does the text pose about receptor types?

  • What could be the advantages of either type of sensory coding?
  concept sensory
• What are 'unencapsulated tactile receptors'?

  • Specialized for fine perception of touch
  sensory skin
• Which receptors are examples of unencapsulated tactile receptors?

  • Free nerve endings
  • Root-hair plexus
  • Tactile discs (Merkel cells)
  receptors touch
• What is the location/function of 'free nerve endings'?

  • Project through the epidermis
  • Detect general touch and pain (as shown in diagram)
  free_nerve_endings epidermis
• What does the 'root-hair plexus' detect?

  • Detects movement of hair
  hair mechanoreceptor
• How are 'tactile discs' stimulated and where are they located?

  • Stimulated via association with Merkel cells
  • Located in stratum basale of the epidermis
  merkel tactile
• Name other receptors shown in the diagram (besides unencapsulated types).

  • Tactile corpuscle
  • Lamellated corpuscle
  • Ruffini corpuscle
  • Sensory nerve
  diagram receptors
• Refer to the diagram: which unencapsulated receptor projects through the epidermis?

  • Free nerve endings

  
  visual diagram
• What type of skin receptor is the Ruffini corpuscle?

  • Encapsulated skin receptor
  receptors skin ruffini
• What is the primary function of the Ruffini corpuscle?

  • Detects tension/change in shape of skin
  function mechanoreceptor ruffini
• Which structures surround or compose the Ruffini corpuscle?

  • Collagen fibers
  • Sensory nerve fiber
  • Capsule
  • Dendrites
  structure anatomy ruffini
• What part of the skin would this receptor be located in?

  • Not specified in the provided text
  location skin ruffini
• What is a tactile (Meissner's) corpuscle?

  • Encapsulated mechanoreceptor in skin
  • Involved in light touch/pressure detection
  tactile meissner receptors
• How is a tactile corpuscle encapsulated?

  • Encapsulated by Schwann cells
  tactile schwann structure
• Where are tactile corpuscles located?

  • Dermal papillae (just below the epidermis)
  tactile dermis location
• Are tactile corpuscles phasic or tonic?

  • Phasic (rapidly adapting)
  tactile physiology
• What stimulus are tactile corpuscles sensitive to?

  • Pressure/light touch
  tactile sensation
• What is a lamellated (Pacinian) corpuscle?

  • Encapsulated mechanoreceptor in skin
  • Sensitive to deep pressure and vibration
  lamellated pacinian receptors
• How is a lamellated corpuscle encapsulated?

  • Encapsulated by Schwann cells
  lamellated schwann structure
• Where are lamellated corpuscles found?

  • Deep dermis (deeper than dermal papillae)
  lamellated dermis location
• Are lamellated corpuscles phasic or tonic?

  • Phasic (rapidly adapting)
  lamellated physiology
• What are key structural features of a lamellated corpuscle?

  • Concentric lamellae of collagen fibers separated by fluid
  • Contains a central dendritic process and accessory cells (specialized fibroblasts)
  lamellated structure fibers
• What is a general sense?

  • Pathway: simple ('labeled lines')
  • Complexity: simple
  • Specialized organs: no
  general senses
• What is a special sense?

  • Pathway: complex
  • Complexity: specialized
  • Specialized organs: yes
  special senses
• What does a 'simple' pathway mean for general senses?

  • Referred to as 'labeled lines'
  pathway general
• Do general senses use specialized organs?

  • No
  general organs
• Do special senses use specialized organs?

  • Yes
  special organs
• What are examples of general senses?

  • Touch
  • Pain
  • Pressure
  • Body position
  general examples
• What are examples of special senses?

  • Sight
  • Hearing
  • Taste
  • Smell
  special examples
• What is the 'labeled lines' principle in somatic sensation?

  • Simple pathways for general senses
  • Single sensory receptor → one chain of neurons → one cortical area
  • Brain can identify exactly which receptor was stimulated
  neuroscience sensory
• Which modalities use the dorsal column-medial lemniscus pathway?

  • Fine touch
  • Proprioception
  • Vibration
  anatomy pathways
• Which modalities use the spinothalamic pathway?

  • Pain
  • Temperature
  • Coarse touch
  anatomy pathways
• Where do fine touch, vibration and proprioception pathways cross the midline?

  • They cross the midline in the medulla
  neuroanatomy decussation
• Where do pain, temperature and coarse touch pathways cross the midline?

  • They cross the midline in the spinal cord
  neuroanatomy decussation
• Where do somatic sensory pathways synapse before reaching cortex?

  • They synapse in the thalamus
  physiology thalamus
• Where are somatic sensations perceived in the brain?

  • In the primary somatic sensory cortex
  cortex sensory
• What are the 'orders' of neurons in somatic sensory pathways?

  • First-order neuron
  • Second-order neuron
  • Third-order neuron
  neurons pathways
• What is a receptive field?

  • The specific region of the body monitored by a single sensory receptor
  sensory receptivefield
• What does a large receptive field cause?

  • Coarse detection; nearby stimuli may be perceived as a single point
  receptivefield detection
• What does a small receptive field and dense neuron arrangement cause?

  • Finer detection; ability to perceive two closely spaced points separately
  receptivefield detection
• What is the 'labeled line' principle in sensory pathways?

  • Each sensory neuron follows a specific 'labeled line' to a single neuron in the CNS
  labeledline neuroscience