A&p I. Chapter 16. Sensory, Motor, And Integrative Systems

Front 1

Sensation

Back 1

conscious and subconscious awareness of changes in internal or external environment (CNS)

Front 2

Perception

Back 2

conscious awareness & interpretation of sensation ( Cortex)

Front 3

Sensory Modality

Back 3

Each unique type of sensation; touch, pain, vision, hearing, etc

Front 4

General senses

Back 4

Somatic senses, Visceral senses

Front 5

Somatic senses

Back 5

from bodys walls

Front 6

Visceral senses

Back 6

are sensations from internal organs

Front 7

Special senses

Back 7

smell, taste, hearing, vision & balance

Front 8

Sensory receptor

Back 8

demonstrate selectivity, they respond of one type of stimuli

Front 9

Events occurring within a sensation

Back 9

1. Stimulation of the receptor

2. Transduction (conversion) of stimulus into a graded potential
a. Vary in amplitude and are not propagated

3. When graded potential reaches threshold action potential is generated

4. Integration of sensory input by the CNS

Front 10

Free nerve endings

Back 10

Bare dendrites
Pain, temp, tickle, itch & light touch

Front 11

Encapsulated nerve endings

Back 11

Dendrites enclosed in CT capsule
Pressure, vibration& deep touch

Front 12

Separate sensory cells

Back 12

• Specialized cells that respond to stimuli
• Vision, taste, hearing, balance

Front 13

Generator potentials

Back 13

Found in free and encapsulated nerve endings & olfactory receptors

• If large enough, its generated action potential in a 1st order neuron

Front 14

Receptor potentials

Back 14

- found in all special senses except olfaction
• cells release neurotransmitter molecules

Front 15

Exteroceptors

Back 15

• Near surface of body
• Receive external stimuli
• Hearing, vision, smell, taste, pressure, pain, vibration & temp

Front 16

Interoceptors

Back 16

• Monitors internal environment (BV or viscera)
• Usually not conscious except for pain or pressure

Front 17

Proprioceptors

Back 17

• Muscle, tendon, joint & internal ear
• Senses body position & movement
• Awareness of body position in space

Front 18

Photoreceptors-

Back 18

Light
 

Front 19

Chemoreceptors -

Back 19

Chemicals/molecules
• Taste, smell & changes in body fluid chemistry (dehydration)

Front 20

Osmoreceptors

Back 20

Monitor H20 Levels

Front 21

Nocioceptors-

Back 21

Unconsiuous. Detect tissue damage ( &thus (may) register pain)

Front 22

Thermoreceptors

Back 22

Temperature

Front 23

Mecanoreceptors

Back 23

Detect pressure, stretch, touch, vibration, proprioception, hearing, equilibrium & Blood Pressure

Front 24

Adaptation of Sensory Receptors

Back 24

• Decrease in sensitivity of a receptor to a long lasting stimuli

- Bad smells disappear
- Hit water starts to feel only warm

Front 25

Slowly adapting receptors

Back 25

• ( pain, blood chemistry.. (dehydration) , body position) continue Action Potentials as long as stimulus persists

Front 26

Rapidly adapting receptors

Back 26

(smell, pressure, touch)
- Adapt quickly for detecting stimulus changes

Front 27

Somatic sensations

Back 27

Stimulation of sensory receptors in skin, subcutaneous layer, mucous membranes, muscles, tendons, joints (& inner ear)

Most receptors - tip of tongue, fingers & lips

Front 28

Touch

Back 28

crude touch - ability to only perceive s/t has touched skin

fine (discriminating) touch gives location & texture

Front 29

Pressure

Back 29

sustained sensation over a large area

Front 30

Vibration

Back 30

rapidly repetitive signals

Front 31

Itching

Back 31

chem stimulation of free nerve endings by bradykinins (chemicals) often because of a local inflammatory response

Front 32

Tickle

Back 32

stimulation of free nerve endings only by someone else

Front 33

Rapidly Adapting

Back 33

1.) Corpuscle of touch)
2.) Hair root plexus

Front 34

Slowly Adapting

Back 34

3.) Type I cutaneous mechanoreceptors (fine touch)

4.) Type II cutaneous mechanoreceptors (stretching)

Front 35

Corpuscle of touch

Back 35

Encapsulated receptor in dermal papillae of hairless skin (hands, eyelids, tongue, genitals)

Fine (Discriminative) touch and pressure- Rapidly adapting
 
 

Front 36

Hair root plexus

Back 36

Rapidly touch receptors in hairy skin

Free nerve endings wrapped around hair follicles, detect hair movement

Front 37

Type I cutaneous mechanoreceptor

Back 37

Flattened dendrite touches Merkel cells of stratum basaleFree nerve endings for Fine Touch & Pressure, Slow Adapting
25% of receptors in fingertips, hands, lips, external genetalia.

 

Front 38

Type II cutaneous mechanoreceptor

Back 38

Encapsulated receptors deep in dermis ( and hands/soles), ligaments, & tendons to detect stretching in fingers/limbsSlow Adapting

Front 39

Pressure Receptors

Back 39

Pressure is a sustained sensation felt over wider area than touch.. Involve:
1.) Corpuscle of Touch
2.) Type I mechanorecpetors
3.) Lamellated Corpuscles

Front 40

Lamellated corpuscle

Back 40

Onion like encapsulated dendrite, found in dermis, subcutaneous layer, mucous & serous membrane, joints, tendons, muscles, periosteum, mammary glands, & certain viscera.. Sense pressure

Front 41

Thermal sensations

Back 41

Free nerve endings with 1mm diameter receptive fields on the skin surfaceCold receptors, Warm receptors

Front 42

Pain Sensations. Noceiceptors

Back 42

= pain receptors

• Free nerve endings- in every tissue except brain
• Tissue injury releases chemicals such as K+ kinins or prostaglandins that stimulate nociceptors

Little adaptation

Front 43

Fast Pain

Back 43

acute

Front 44

Slow Pain

Back 44

(chronic) - aching or throbbing pain

Front 45

Phantom pain -- Phantom limb sensations

Back 45

cells in cortex still active

Front 46

Superficial somatic pain

Back 46

skin

Front 47

Deep somatic pain

Back 47

muscle, tendons, joints and fascia

Front 48

Visceral pain

Back 48

organs

Front 49

Referred pain- Visceral pain

Back 49

felt just deep to the skin over affected organ OR far away from the organ

• Skin area & organ are served by the same Spinal Cord level
• Heart attack- is felt in skin along left arm since are both supplied by T1-T5

Front 50

Pain Relief

Back 50

• Aspirin and ibuprofen block formation of prostaglandins that stimulate nonciceptors

• Novocain/Lidocaine blocks Action Potentials along pain fibers

• Morphine decreased the perception of pain in the brain

Front 51

Proprioceptive or Kinestetic Sense

Back 51

Awareness of body position and movement.

Proprioceptors adapt only slightly

Sensory information is sent to cerebellum and cerebral cortex

Front 52

Muscle spindles

Back 52

a proprioceptor but also monitor muscle length and participate in stretch reflexes ( contraction)

 

Front 53

Golgi Tendon organs

Back 53

- A proprioceptor, but also monitor change un muscle force

• Too much force in tendon a sensory signals to CNS cause muscle’s relaxation

• Found at junction of tendon & muscle

Front 54

Joint Kinesthetic receptors

Back 54

• Signal joint position/movement
• Type II mechanoreceptors
- found in joint capsule
• Lamellated corpuscles
- found in CT around joint (“widely distributed”)

Front 55

1st order neurons

Back 55

conduct AP from somatic receptors TO spinal cord ( cell body in DRG) OR from cranial nerves to brain stem.

Front 56

2nd order neurons

Back 56

conduct APs from spinal cord OR brainstem to opposite side of thalamus-- decussates.

Front 57

3rd order neurons

Back 57

in thalamus; conduct APs from thalamus to primary somatosensory cortex.

 

Front 58

Somatic sensory map of cerebral cortex

Back 58

• Relative size of corical areas:
- Proportional to # of sensory receptors & thus to sensitivity of each body part

• Can be modified
- Can learn Braille & will have larger area representing fingertips