Week 9 Ch. 48 Flashcards
Somatic senses classification (3)
Mechanoreceptive
Thermorecepive
Pain sense
Exteroreceptive sensation
surface of body
Proprioceptive sensation
physical state: position, tendon, muscle, pressure, equilibirum
Visceral sensation
internal organs
Deep sensations
faciae, muscles, bones
(deep pressure, main and vibrations)
Mechanoreceptors detect
Touch, pressure, vibration
Free nerve ending receptor (what they detect and location)
Location: Skin and many tissues
Detect: touch and pressure
Meissner’s corpuscles receptor (location and characteristics)
Location: Nonhairy parts of skin
Characteristics: elongated and encapsulated, large, myelinated, many. branching nerve filaments, adapt after stimulation
Expanded tip receptor (location and characteristics)
Location: hair parts of skin
Characteristics: strong initial signal, partially adapt and transmit a weaker signal
Merkel’s disks form
Iggo dome receptor
Merkel’s discs receptor (Location, Characteristics and role)
Location: underside of skin epithelium
Role: Localizes sensations and determines texture
Characteristics: creates bump, extremely sensitive receptor
Hair end-organ receptor (Location and role)
Location: entwines base of a hair
Role: detects movement of objects on body surface at initial contact
Ruffini’s ending receptor ( location and role)
Location: Deep layers of skin and join capsules
Role: adopt slowly, continues states of tissue deformation
Pacinian Corpuscles (Location, role, characteristics)
Location: beneath skin and facial tissue
Role: rapid local compression of tissues
Characteristics: quickly adapt to tissue vibrations or changes to mechanical state of tissues
Type Abeta (Ab) nerve fibers characteristics
Fast (large and myelinated)
detect precise localization, intensity, rapid changes
(think marker on finger tip in lab)
Small Type A gamma nerve characteristics and what they detect
Detect pressure, a little slower. Location not precise
(think back of neck with marker point lab)
Type C fibers speed and what they detect
unmyelinated, slow
Poorly localized, detect touch and tickle
Vibration sensation - what receptors are involved?
-all tactile receptors
-Pacinian corpuscles detect high frequency
-Meissner’s corpuscles detect low frequency
Tickle and itch sensation - what receptors are involved?
-highly sensitive free nerve endings (in superficial layers of skin)
-Transmitted by type C
What are the 2 sensory pathways?
- Dorsal column aka Medial Lemniscal
- Anterolateral column
Dorsal column speed
fast - large diameter, heavily myelinated