Integration of the nervous system

Question 1

Sensation v. Perception

Answer 1

Sensation - process initiated by stimuli

Perception - conscious awareness of those sensations

Question 2

General senses - 2 groups

Answer 2

receptors distributed over a large part of the body
Somatic - sensory info about body and environment
Visceral - provide information about various internal organs; consistent of pain and pressure

Question 3

Special senses

Answer 3

localized to specific organs that have specialized receptors (smell taste sight hearing balance)

Question 4

3 criteria that classify sensory receptors

Answer 4

1) type of stimulus detected
2) location in the body
3) receptor structure

Question 5

Mechanorecetors

Answer 5

respond to mechanical force (compression, behding, stretchign of cells)
Sesnes that use mecanoreceptors include touch, pressure, proprioception, hearing, balance

Question 6

Chemoreceptors

Answer 6

Respond to chemicals

Smell and taste

Question 7

Thermo receptors

Answer 7

respond to changes in temperature

Question 8

Photoreceptors

Answer 8

respond to light, necessry for vision

Question 9

Nociceptors

Answer 9

Pain receptors, respond to extreme mechanical, chemical, and thermal stimuli

Question 10

Location classification of sensory receptors (3)

Answer 10

Cutaneous - skin > external env
visceroreceptors - viscera/ organs > internal env.
Proprioceptors - joints, tendons, and other connective tissue > body position, movement, and stretch/ force of muscle contractions

Question 11

Free nerve endings

Answer 11

simplest and most common sensory receptors
unspecialized neuronal branches
widely distributed in body; epithelial and connective tissues

Question 12

What does the cold receptor do?

Answer 12

increases rate of action potential production
FUN FACT // menthol also activates the cold recptor
10-15x more numerous than warm receptors

Question 13

What does the warm receptor do?

Answer 13

increase rate of action potnetial production as skin temperature increases

Question 14

3rd type of temperature receptor // responsible for extreme cold or heat, a type of pain receptor

Answer 14

Pain receptor

25 - 35 c is comfortable!

Question 15

Merkel disk

Answer 15

flattened expansions at end of axons

Ligh touch and superficial pressure

Question 16

Hair follicle receptor

Answer 16

wrapped around hair follicles

light touch, responds to very slight bending of the hair

Question 17

Pacinian corpuscle

Answer 17

Multi-layered onion-shaped capsule w/ single central nerve process
deep cutaneous pressure, vibration, prioprioception

Question 18

Meissner corpuscle

Answer 18

Several branches of single axon w/ specialized Schwann cells
Two-point discrimination (paperclip exercise)
More numerous in some areas of the body (tongue, hands) than others

Question 19

Ruffini end organ

Answer 19

branching axon

continuous touch or pressure

Question 20

Muscle spindle

Answer 20

3-10 striated muscle fibers enclosed by loose counties; Muscle tone

Question 21

Golgi tendon organ

Answer 21

proprioception associated with stretch fo tendon; muscle contraction

Question 22

Receptor potential

Answer 22

The potential produced after a receptor was stimulated

If large enough, it turns into an action potential and is propagated toward the CNS

Question 23

Primary receptors v secondary receptors

Answer 23

Primary - sensory receptor cells that conduct action potentials in response to the receptor potential (most sensory neurons)
Secondary - no axons, produce receptor potentials (hearing and taste)

Question 24

Adaptation

Answer 24

decreased sensitivity to a continued stimulus

Question 25

Tonic receptors

Answer 25

Generate action potentials as long as a stimulus is applied // slow adaption

Question 26

Phasic receptors

Answer 26

adapt rapidly; sensitive to changes in stimuli

Question 27

Ascending spinal pathways

Answer 27

How sensory information is transmeitted via action potential to the brain
Names - first half gives origin and second half termination

Question 28

Anterolateral System

Answer 28

Conveys cutaneous sensory info to the brain

Question 29

3 tracts of anterolateral system

Answer 29

spinothalamic tract = perception of pain, temp, touch, pressure, tickle, itch
spinoreticular tract - pain and touch to other parts of the brain, where info not consciously perceived
Spinomesencephalic tract

Question 30

How does the spinothalamic tract transmit sensory signals from peripheral receptors to the cerebral cortex?

Answer 30

Primary neurons - sensory receptor to the spinal cord
Secondary neurons - spinal cord to the brain, crossing contralaterally
Tertiary neurons thalamus to the somatic sensory cortex

Question 31

3 major ascending spinal pathways?

Answer 31

Anterolateral
Dorsal-Column/ Medial lemniscal
Spinocerebellar

Question 32

Dorsal-Column/Medial Lemniscal System

Answer 32

Responsible for perceiving
- 2 point discrimination
- proprioception
pressure
vibration

Question 33

2 tracts of the dorsal-column/medial lemniscal system

Answer 33

1) Fasciculus gracilis > sensations above midthorax

Fasciculus cuneatus > sensations below mid throax

Question 34

Trigeminothalamic Tract

Answer 34

Facial equivalent of the ascending nerve tracts

Question 35

Spinocerebellar Tracts

Answer 35

Proprioceptive information to cerebellum > monitor movements and compare them with intended movements

Question 36

Posterior spinocerebellar tract

Answer 36

The upper part of the body in thoracic and upper lumbar regions

Question 37

Anterior spinocerebellar tract

Answer 37

Carries info from lower trunk and lower limbs