general senses

3 types of sensory receptors

1. exteroreceptors

2. interoceptors

3. proprioceptors

which sensory receptor are aka visceroreceptors, and respond to stimuli arising within the body.

they are found in the internal visceral organs and include stretch receptors, chemoreceptors, and more.

interoceptors

which sensory receptor is sensitive to stimuli in the external environment, and are typically found close to the body surface.

include simple cutaneous receptors in the skin and the highly specialized receptors of the special senses

exteroceptors

which sensory receptor respond to internal stimuli but are restricted to skeletal muscles, tendons, joints, ligaments, and CT coverings bones and muscles.

they provide info about body movements and position by monitoring the amount of stretch of those structures

proprioceptors

2 types of GENERAL sensory receptors

• unencapsulated tactile receptors

• encapsulated tactile receptors

3 structures that are part of the unencapsulated tactile receptors:

1. tactile disc

2. free nerve ending

3. root hair plexus

6 structures that are a part of the encapsulated tactile receptors:

1. tactile corpuscles

2. end bulb

3. bulbous corpuscles

4. lamellar corpuscles

5. muscle spindles

6. tendon organs

____ is the process by which ENVIRONMENTAL STIMULI change into nerve impulses that are related to the CNS.

transduction

receptor physiology:

1. ___= awareness of the stimulus

2. ___= conscious interpretation of the stimulus

These both occur IN THE BRAIN!

1. sensation

2. perception

nerve impulses from cutaneous receptors are related to the primary ____, where stimuli from different body regions form a body map.

somatosensory cortex

1. each location on the body is represented by a specific ___ area.

2. it is the ___ organization that allows us to know EXACTLY where a sensation comes from on the body.

3. further interpretation of the sensory info occurs in the ____________.

1. cortical

2. cortical

3. somatosensory association cortex

Two-point discrimination:

1. a stimulus must be applied to a sensory neuron’s ____- the area served by that neuron.

2. the two point discrimination test is used to determine a crude map of density tactile receptors in the various regions of the skin. in general, areas that have the greatest density of tactile receptors have a heightened ability to “feel”. these areas correspond to areas that receive the greatest motor interaction, thus, they are also typically areas of ______ control.

3. on the basis of of this info, which areas of the body do you predict will have the greatest sensory receptors?

1. receptive field

2. fine motor control

3. finger tips, lips, face, tongue

1. ________ is the brain’s ability to determine which portion of the skin has been touched.

2. in general, the ____ the receptive field of the sensory neurons serving the area, the ____ the brain’s ability to detect the location of the stimulus.

1. tactile localization

2. smaller, greater

when a stimulus is applied for a prolonged period of time without movement, the rate of the receptor discharge slows, an conscious awareness of the stimulus decline or is lost until some type of stimulus change occurs. this phenomenon is called

adaptation

_____ demonstrate limited adaptation. in response to a constant stimulus, these continuously generate nerve signals and only slowly decrease the number related to the CNS.

tonic receptors

examples of tonic receptors include sensory receptors within the ___ that determine head position and ________ in the muscles and joints that provide info of where your body is in space.

inner ear

proprioceptors

all ___ receptor are tonic receptors

pain

______ exhibit rapid adaptation to a constant stimulus. they generate nerve signals only in response to new (or changing) stimulus and quickly decrease the number of nerve signals related to the CNS

phasic receptors

examples of phasic receptors include the deep pressure receptors that sense the increased pressure when we first sit down in a chair - we immediately sense this. but soon, don’t you start to not feel the pressure of the chair you’re sitting on? what’s another example?

correct;

when you place sunglasses on your head or nose, the phasic receptors quickly phase out

tonic receptors vs phasic receptors:

1. ___receptors - sensitivity to stimulus remain relatively constant

2. ___receptors - sensitivity to stimulus quickly diminished ; rapid adaptation

1. tonic

2. phasic

1. _______ are densely distributed in the skin, and they adapt very little, if at all.

2. this lack of adaptability is due to the ____ function of the receptors.

3. ____ is a sensory experience in which pain is perceived as arising in one area of the body whim in fact another remote area is receiving the painful stimulus.

1. pain

2. protective

3. referred pain