Exam 2 Lecture 2 Somatosensation Flashcards
What is somatosensation?
Sensation that occurs over the entire body
- Skin and subQ tissue
- Muscles and tendons
- Joints
What two other types of sensation?
- Visceral sensation (from internal organs)
- Special sensation (all located in the head, hearing, smell, taste)
What is the role of sensation?
- Provides information to the CNS regarding the:
- External environment (touch, temp, sound)
- Internal environment (pain, nausea, joint position)
What three things do you need for sensation?
- Sensory receptor (stimulus –> action potential)
- Sensory pathway (transmits sensory nerve impulse to CNS)
- Ability to perceive the sensation (occurs in the cerebral cortex)
Do all sensations reach a conscious level of perception?
NO
What are some physical examples of somatosensory receptors?
- Free nerve endings
- Hair receptor
- Muscle spindle
- Golgi tendon organ
What are the 4 different types of somatosensory receptors and what do they detect?
- Tactile - detect mechanical stimuli (touch)
- Thermoreceptors - detect changes in temperature
- Nociceptors - detect stimuli that damage (or could damage) cells (burn, freeze, crush, compression, pointy object, etc)
- Proprioceptors - detect muscle stretch or contraction, joint position or movement
Where are tactile receptors located?
In the subQ tissue of the skin
What are 4 types of tactile receptors and what do they detect?
- Meissner’s corpuscle: 2-point discriminative touch (fine touch)
- Merkel’s disk: touch (light or crude)
- Pacinian corpuscle: deep pressure and vibration
- Ruffini ending: stretching of the skin
Where are thermoreceptors located?
SubQ tissue of the skin
Where are nociceptors located?
Everywhere EXCEPT the brain
What are the 4 types of nociceptors?
- Mechanical - crushing, poking, pinching (sharp pain)
- Hot - detect burning (over 50 C)
- Cold - detect freezing (under 10 C)
- Polymodal - detect inflammation (dull, achy pain)
What do thermoreceptors specifically detect?
Temperature changes (not absolute temperatures) between 10-50 C
Where are proprioceptors located?
Musculoskeletal system
What specifically do proprioceptors detect?
- Position and movement of muscles, tendons, joint capsules, ligaments
- Used to guide movement
