Lecture 3- Sensory receptors Flashcards
(20 cards)
5 types of receptors
Somatic and visceral Proprioceptors Chemoreceptors Audioreceptors Photoreceptors
Classification criteria
Origin of stimulus (interoreceptors vs exteroreceptors) Stimulus detected Structural complexity (encapsulated vs unencapsulated)
Unencapsulated receptors of skin
Merkel cells
Free nerve endings
Root hair plexus
Encapsulated receptors of skin
Meissner’s corpuscles
Pacinian corpuscles
Krause end bulbs
Ruffini corpuscles
Proprioceptors
Muscle spindles
Golgi tendon organs
Joint kinesthetic organ
Muscle spindles
Detect distention in surrounding extrafusal muscle fibers
Concentric layers of flattened cells with interstitial fluid and intrafusal muscle fibers
Encapsulated by modified perimysium
Golgi tendon organ
Encapsulated
Encloses sensory axons and collagen bundles
At myotendinous junction
Detects changes in tension in contracting muscles and inhibit motor nerve activity if tension becomes excessive
Joint kinesthetic receptors
Monitor stretch in articular capsule of synovial joints receptor subtypes Pacinian corpuscles Ruffini corpuscles Free nerve endings Tendon organs
Merkel cells
Sustained light touch and object texture
Free nerve endings
Temperature, pain, itching, tactile receptor
Root hair plexus
Detects hair movement
Meissner corpuscles
Light touch and low frequency touch
Pacinian corpuscles
Course touch, pressure and vibrations
Bowel and bladder too
Krause end bulbs
Low frequency vibrations
Ruffini corpuscles
Stretch or torque of skin
Proprioceptors
In striated muscles and myotendinous junctions Respond to position and movement Muscle spindles Golgi tendon organs Joint kinesthetic receptors
Muscle spindles
Stretch detectors in muscle fascicles
Encapsulated by modified perimysium with concentric layers of flattened cells, containing interstitial fluid and a few thin intrafusal fibers
Detect distension of surrounding extrafusal muscle fibers and relays info to spinal cord
Gogli tendon organ
Encapsulated structures that enclose sensory axons penetrating among the collagen bundles at the myotendinous junction
Detect changes in tension produced by muscle contraction and act to inhibit motor nerve activity
Joint kinesthetic receptors
Proprioceptors that monitor stretch in the articular capsules that enclose synovial joints
Contains 4 receptor types
- Lamellar corpuscles
- Ruffini corpuscles
- Free nerve endings
- Receptors resembling golgi tendon organs
Provide info on joint position and motion
Ganglion definition
Collection of cell bodies of the CNS
