PNS

Question 1

Perception

Answer 1

conscious interpretation of the stimuli involved in sensation

Question 2

Senstation

Answer 2

awareness of changes in external and internal env

Question 3

what are the 3 levels of neural integration

Answer 3

perceptual level (processing in cortical sensory centres)
circuit level (processing in ascending pathways)
receptor level (sensory reception and transmittion to CNS)

Question 4

receptor level processing

Answer 4

-stimulus match receptor
-stimulus w/in receptive field
-transduction of stimulus to graded potential
+generator potential in general receptors
+receptor potential for special senses receptors
+reach threshold - AP

Question 5

Adaptation @ receptor level

1) what level of processing
2) what is
3) what happens
4) phasic vs tonic receptors

Answer 5

• receptor level of processing
  2) change in sensitivity to a stimuli due to constant stim
  3) receptor membranes become less respnsive
• receptor potentials dec in freq or stop
  4) Phasic receptors (fast acting) send sig at begin or end of stim (P, touch, smell)
• tonic receptors (adapt slow or not at all) - (nociceptors or proprioceptors)

Question 6

processing at circuit level

Answer 6

pathways of 3 neurons send sensory information to appropriate cortical locations

Question 7

Processing at perceptual level: perceptual detection

Answer 7

ability to detect a stimulus

Question 8

Processing at perceptual level: Magnitude estimation

Answer 8

intensity encoded as frequency of impulses

Question 9

Processing at perceptual level: spatial discrimination

Answer 9

ID site or pattern of stim

Question 10

Processing at perceptual level: Feature abstraction

Answer 10

ID more complex aspects and stimulus properties (velvet)

Question 11

Processing at perceptual level: quality discrimination

Answer 11

ID submodalitites of stimulus (sweet vs sour tastes)

Question 12

Processing at perceptual level: pattern recog

Answer 12

recog familiar or sig patterns in stimulus

Question 13

Perception of pain

-2 fibres and what release

Answer 13

• thinly myelinated Adelta fibres release glutamate

- unmyelinated C fibres release glutamate and Substance P

Question 14

Pain modulation (Gate contro theory)

Answer 14

nonpainful inputs (alphaB) inhibit pain transmission (unmyelinated C)
\+activation of nonpainful touch receptor increases activation of inhibitory interneuron, dec pain sig going to brain

Question 15

Descending pain control

Answer 15

• pain impulses inhibited endogenous opioids (norepinephrine and epinephrine)
• descending fibres from cortex and hypothalamus release inhibitory NTs that supress pain
• NE and E release from periaqueductal grey matter

Question 16

How treat pharntom limb pain

Answer 16

epidural anesthesia

Question 17

Hyperalgesia

Answer 17

• refers to pain amplication
  -caused by long lasting/intense pain
  -chronic pain and phantom limb pain
  +modulated NDMA receptors (allow spinal chord to learn excess pain) [why early pain mngmnet important]

Question 18

Visceral

1) how, feel, why visceral pain

Answer 18

1) stimulation of visceral organ receptors
+feel aching knawing or burning
+tissue stretch, ischemia, chems, muscle spasms

Question 19

Referred pain

Answer 19

pain coming from one body area perceived as coming from another

• EX. body learn when spec spinal cord seg activate usually skin, when smthing below skin hurt body think skin.
• why feel heart attack in arm

Question 20

Nerve fibres

Answer 20

nerves in PNS

Question 21

Can mature neurons divide

Answer 21

mature neurons are amitotic

Question 22

if the soma of a neuron is intact can it’s axon regrow

Answer 22

yes

Question 23

what is involved in axonal regrowth (soma intact)

Answer 23

Macrophages - clear debris
Schwann cells - tube to tell where axon go
axons - form new axons

Question 24

CNS fibre regeneration

Answer 24

INHIBITS CNS FIBRE REGEN
CNS oligodendrocytes bear growth-inhibiting proteins
astrocytes form scar tissue

Question 25

4 steps to nerve fibre regen

Answer 25

1) axon fragmented at injury site 2) macrophages clear out debris distal to axon 3) axon sprouts grow through regeneration tube formed by schwann cells 4) Axon regenerates and myelin sheath forms

Question 26

how many pairs of mixed spinal nerves

Answer 26

31 pairs

Question 27

spinal nerves

Answer 27

``` Cervical Nerves: C1-C8 Thoracic nerves: T1-T12 Lumbar nerves: L1-L5 Sacral nerves: S1-S5 Coccygeal nerves Co1 ```

Question 28

Dermatome

Answer 28

- area of skin innervated innervated by cutaneous branches of a single spinal nerve - most overlap - used to det spinal cord dmg

Question 29

what spinal nerve dosent innervate skin (no dermatome)

Answer 29

C1

Question 30

Innervation of joints: hiltons law

Answer 30

any nerve serving a muscle that produces movement at a joint also also innervates the joint and the skin over the joint

Question 31

Spinal nerve roots

Answer 31

cord -> rootlets -> root - >spinal nerve -> rami

Question 32

Each spinal nerve branches into how many rami

Answer 32

4 mixed rami

Question 33

what are the 4 mixed rami of a spinal nerve

Answer 33

1) meningeal branch: to spinal meninges and BVs 2) Dorsal ramus: posterior to the body trunk 3) ventral ramus form plexuses except in T2-T12 +T2 to T12 act as intercostal nerves to muscles the ribs, anterolaterla thorax, abdomen 4) Rami communicantes: autonomic pathways (join to ventral rami in thoracic region)

Question 34

why ventral rami -> plexus

Answer 34

Fibres from various ventral rami crisscross +each resulting branch has fibres from several spinal nerves +fibres from ea ventral ramus travel to the target by different routes RESULT: each muscle has nerve supply from more than one spinal nerve BENEFIT: DMG one spinal segment/root wont cause complete paralysis of any limb or muscle REDUNDANCY

Question 35

damage above c345

Answer 35

info no flow, dmg to C1 C2 lethal (diaphragm no work)

Question 36

dmg to c345

Answer 36

able breathe, not move | -c345 keeps diaphragm alive through phrenic nerve in cervicle plexus

Question 37

cervicle plexus

Answer 37

innervates skin and muscles of the ear, neck, back of head, and shoulder

Question 38

What forms the brachial plexus

Answer 38

ventral rami C5-C8 + T1 | -gives rise to nerves that innervate upper limb and pectoral girdle

Question 39

lumbar plexus

Answer 39

thigh, abdominal wall, psoas muscles - obturator nerve - through obturator foramento innervate adductor muscles - Femoral nerve - innervates anterior thigh muscles and skin of the medial/anterior thigh and medial leg

Question 40

Sacral plexus

Answer 40

buttocks, pelvic structures, perineum -pudenal nerve - skin and muscles of the perineum -sciatic nerve - longest thickest nerve of body, +Innervates hamstrings, adductor magnus, & most muscles in leg & foot +Composed of tibial & common fibular nerves

Question 41

Muscle spindles

Answer 41

3-10 short intrafusal muscle fibres in a CT capsule | intrafusal muscle fibres are non contractile in central regions (no myofiliments)