Lecture 2 Flashcards
What are the types of somatic sensations?
1) Mechanoreceptive: detect mechanical displacement
2) Thermoreceptive: detect hear and cold (changes in stimulus)
3) Nociceptive: detect pain and tiddue damage
What are the two types of mechanoreceptors?
1) Tactile: touch, pressure, vibration, tickle, itch
2) Proprioception (position): static position and dynamic position (rate of change)
What are the types of tactile receptors?
1) Free nerve endings (Aδ and C)
2) Meissner‘s corpuscles (Aβ)
3) Merkel’s discs (Aβ)
4) Hair end organ
5) Ruffini’s end organ
6) Pacinian corpuscles
7) Golgi tendon apparatus and muscle spindles
8) Iggo dome receptors
What do free nerve endings detect? Where are they found?
Touch and pressure; everywhere in the skin and tissues.
What do Meissner‘s corpuscles detect? Where are they found?
Movement of light objects over skin and low frequency vibrations; hairless skin (glabrous skin), fingertips, and lips down in the epidermis.
Which tactile receptors are encapsulated (rapidly adapting) receptors?
1) Meissner‘s corpuscles
2) Pacinisn corpuscles
3) Merkel’s discs
4) Ruffini’s corpuscles
What do Merkel’s discs detect? Where are they found?
“Steady state” and touch; found on hairy and hairless (glabrous) skin.
Which tactile receptors respond rapidly at first and then slowly adapt?
Merkel’s discs
What do hair end organs detect? Where are they found?
Acts rapidly to detect movement of hair; found around hair shafts.
What do Ruffini’s end organs detect? Where are they found?
Changes in pressure and joints formation; found deep in the dermis
Which tactile receptor is slowly adapting and responds to continual deformation of the skin and joint rotation?
Ruffini’s end organ
What do Pacinian corpuscles detect? Where are they found?
High frequency vibration, pressure, and other rapid changes in the skin; found down in the dermis.
Which tactile receptor is rapidly adapting, stimulated only by rapid movement, and looks like onion rings?
Pacinian corpuscle
Where are golgi tendon apparatus and muscle spindles found?
Skeletal muscles
Which receptors transmit signals in type Aβ nerve fibers at 30-70 m/s?
1) Meissner’s corpuscles
2) Hair receptors
3) Pacinian corpuscles
4) Ruffini’s end organs
Which receptors transmit signals in type Aδ nerve fibers at 5-30m/s and some C at 0.5-2m/s?
Free nerve endings
Why is fine touch transmitted very fast through Aβ or Aα fibers?
Because the faster the rate of transmission, the more critical the information.
Almost all sensory information enters the spinal cord through which roots?
The dorsal roots
What are the two pathways for the transmission of sensory information?
1) Dorsal column-medial lemniscal system
2) Anterolateral (spinothalamic) system
The dorsal column medial lemniscal system’s tract ascends in the:
Dorsal column of the spinal cord and forms medial lemniscus
The dorsal column medial lemniscal system contains ____(small/medium/large) ____(myelinated/unmyelinated) fibers for ____(slow/fast) transmission with which kind of fibers?
Large; myelinated; fast (30-110m/s); Aβ
What is the difference between spatial and temporal?
Spatial: position/space
Temporal: time
What does spatial fidelity mean?
The fibers come from each part of the body and are arranged in a highly organized way.
What does temporal fidelity mean?
Faithfulness
