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Flashcards in Unit 1 Phys Deck (449):
1

study of structure and the physical relationships between body parts

anatomy

2

example of anatomy

how a muscle attaches to the skeleton

3

study of living organisms perform vital functions

physiology

4

example of physiology

how a muscle contracts and the force it exerts

5

there is a close link between

structure and function

6

(blanks) at each level determines structure and function of higher levels

organization

7

organization of the human body

cellular--> tissue --> organ --> organ system--> organism

8

molecular interactions--> cell

cellular

9

example of cellular level

protein filaments

10

group of cells--> specific function

tissue

11

example of tissue level

coordinated contractions

12

> or equal to 2 tissues--> specific function

organ and organ system

13

example of organ

pump blood

14

example of organ system level

circulate blood through vessels

15

for life to continue, precise internal body conditions must be (BLANK)

maintained regardless of external conditions

16

homeostasis

existence of a relatively stable internal environment

17

the principal function of regulatory systems is to maintain

homeostasis

18

characteristics of homeostasis

-not a static process (dynamic equilibrium)
-requires energy
-conditions maintained via feedback systems

19

autoregulation (intrinsic regulation)

cell/tissue/organ adjusts to change in environment

20

extrinsic regulation

nervous system or endocrine system (adjust many simultaneously)

21

nervous system regulation characteristics

fast; short duration

22

nervous system

electrical communication via nerve tissue

23

endocrine system regulation characteristics

slow; long duration

24

endocrine system

chemical communication via bloodstream

25

homeostatic regulatory mechanisms require 3 parts

1) receptor
2) control center
3) effector

26

receptor

sensor sensitive to stimulus

27

control center

receives information from receptor and sends out commands

28

effector

responds to commands from control center

29

negative feedback

drives system toward set point

30

can a set point change?

yes

31

positive feedback

drives system away from set point

32

individual variability in set points

genetic factors, age, gender, general health, environment

33

3 types of membrane transport

1) diffusion
2) carrier mediated transport
3) vesicular transport

34

diffusion

passive, movement from high [solute] to low [solute] concentration gradient

35

what types of molecules for diffusion?

lipid soluble or small molecules

36

dissolved gases, lipid-soluble drugs, water through membrane

simple diffusion

37

water, ions through channel protein

channel mediated diffusion

38

special case of diffusion

osmosis

39

osmosis

diffusion of water across a selectively permeable membrane

40

water moves from (blank) to (blank) for osmosis

high [water] to low [water]

41

force with which water moves into that solution as a result of its solute concentration

osmotic pressure

42

what does hydrostatic pressure oppose

osmotic pressure

43

hypotonic looks like

cell full

44

hypertonic looks like

cell shrunken

45

some pediatricians recommend using a 10% salt solution as a nasal spray to relieve congestion in infants with stuffy noses. what effect would such a solution have on the cells lining the nasal cavity, and why?

cells will lose water because this is a hypertonic solution

46

carrier mediated transport

-requires specialized integral membrane proteins
-bind specific molecules
-can be regulated

47

facilitated diffusion

-passive transportation
-molecules too large for simple diffusion
-[high] to [low]

48

types of carrier mediated transport

1) facilitated diffusion
2) active transport

49

active transport

-movement of solutes against [gradient] (REQUIRE ENERGY ATP)
-some move multiple ions

50

example of facilitated diffusion

glucose

51

example of active transport

ion pumps

52

primary active transport

transport using ATP

53

what is an example of countertransport

sodium potassium exchange pump

54

secondary active transport

passive transport that uses ATP to regain homeostasis

55

vesicular transport

requires energy and the material moves in vesicles (bulk)

56

endocytosis

material enters cell

57

exocytosis

material exits cell

58

what material leaves with exocytosis

secretory products, waste

59

nervous system

-all neural tissue in the body
-directs immediate response to stimuli
-coordinates the activities of other organ systems

60

nervous system basic functional unit

neuron

61

central nervous system

control center

62

central nervous system consists of

-brain
-spinal cord

63

-complex integrative functions
-voluntary and involuntary

brain

64

-relays information to/from brain
-less complex integrative functions
-many simple involuntary activities

spinal cord

65

peripheral nervous system

links CNS with other systems and sense organs

66

enteric nervous system

walls of digestive tract

67

functional divisions of the PNS

afferent division and efferent division

68

afferent division

brings sensory info to the CNS from receptors in peripheral tissues and organs

69

efferent division

carries motor commands from the CNS to effectors

70

somatic nervous system

-controls skeletal muscle contractions

71

somatic nervous system consists of

voluntary and involuntary

72

autonomic nervous system

-regulation of smooth muscle, cardiac muscle, glandular secretions at subconscious level

73

autonomic nervous system consists of

sympathetic and parasympathetic

74

negative feedback reduces

distance from set point

75

examples of positive feedback

bleeding and childbirth

76

plasma membrane has

passive and active transport

77

plasma membrane is

selectively permeable

78

channel mediated example

LEAK channels always open

79

what are specific to particular ions

LEAK channels

80

rate of diffusion can

change by changing number of channels

81

what is critical to water balance in cells

solute concentration

82

describes effects of a solution on a cell

tonicity

83

isotonic

does not create a net flow of water into or out of cell

84

hypotonic concentrations

solute concentration outside < inside
water concentration outside > inside

85

hypotonic net movement of water

into cell

86

hypertonic concentration

water concentration inside > outside

87

hypertonic net movement of water

out of cell

88

saline

0.9% NaCl for dehydration

89

carrier mediated transport can be used for

regulation # of proteins and other molecules

90

pinocytosis

cell drinking, fluid

91

phagocytosis

cell eating

92

two key types of regulation

extrinsic and intrinsic (auto)

93

afferens

to bring to

94

effero

to bring out

95

types of transport

-diffusion, carrier mediated, vesicular

96

two functional divisions of the peripheral nervous system are the afferent and efferent divisions. what are their respective functions?

sensory input to the CNS; carries motor commands to muscles or glands

97

nervous system anatomical divisions

central, peripheral, enteric

98

functional divisions of PNS

afferent and efferent

99

efferent splits into

somatic and autonomic (sympathetic and parasympathetic)

100

neurons cell body

soma...nucleus, cytoskeleton, mitochondria, RER

101

neurons dendrites

extend from cell body

102

neurons axon

cytoplasmic process capable of propagating electrical impulse

103

specialized site where neuron communicates with another cell

synapse

104

presynaptic cell

sends

105

postsynaptic cell

receives

106

synaptic vesicles

contain neurotransmitters

107

synaptic cleft

separates pre- and post synaptic membranes

108

how do neurons communicate with each other

synapse

109

neurotransmitters, enzymes, lysosomes along axon

axoplasmic transport

110

cell body to synaptic terminal

anterograde

111

-synaptic terminal to cell body
-route for viral infection

retrograde

112

rabies bite

virus in peripheral tissues

113

steps of rabies

-virus infects muscle cells--multiplies
-virus enters synaptic terminals--retrograde transport
-CNS: symptoms

114

rabies problems

-hydrophobia (saliva glands)
-heightened aggression

115

cell bodies in peripheral sensory ganglia

sensory (afferent) neurons, collection neuron PNS

116

sensory (afferent) neurons location

between sensory receptor and CNS

117

sensory receptors

processes of specialized sensory neurons, or cells monitored by sensory neurons

118

what are the types of receptors

interoceptors, exteroceptors, proprioceptors

119

Somatic =

skeletal

120

multipolar neurons are found as

motor and interneurons

121

motor (efferent) neurons receive

instructions from CNS

122

somatic motor neurons

skeletal muscle

123

somatic motor neurons characteristics

-cell body in CNS and concious control

124

visceral motor neurons

other peripheral effectors through second set of VMN

125

interneurons are

most numerous type

126

interneurons location

brain and spinal cord between sensory and motor neurons

127

interneurons functions

involved in higher functions, distribution of sensory information, coordination of motor activity

128

neuroglia are found in

cns and pns

129

central nervous system contains (BLANK) cells

-astrocytes, ependymal, oligodendrocytes, and microglia

130

peripheral nervous system contains (BLANK) cells

-satellite cells and schwann cells

131

surround all axons in PNS; responsible for myelination of peripheral axons; participate in repair process after injury

Schwann

132

mylinate

schwann and oligodendrocytes

133

myelinated CNS axons; provide structural framework

oligodendrocytes

134

membrane potential

plasma membrane slightly negative inside

135

plasma membrane characteristics

-differences in permeability to various ions

136

plasma membrane type of transport

active

137

resting potential

undisturbed cell
-10 mV to -100 mV (neg)

138

passive forces include

chemical and electrical gradients

139

concentration gradient

chemical

140

pos and neg ions held apart, resting potential

electrical

141

sodium outside or inside

outside

142

potassium outside or inside

inside

143

membrane potential = charge

inside vs outside

144

fat membrane potential number

-40

145

thyroid membrane potential number

-50

146

neurons membrane potential number

-70

147

skeletal muscle membrane potential number

-85

148

cardiac membrane potential number

-90

149

how much membrane restricts ion movement (current)

resistance

150

change resistance by

opening and closing ion channels

151

sum of chemical and electrical forces acting on a specific ion across the plasma membrane

electrochemical gradient

152

-chemical gradient moves out of cell
-attracted to neg charge inside cell

potassium ions

153

equilibrium potential (no net movement) of potassium

-90 mV

154

-chemical gradient moves into cell
-attracted to neg charge inside cell

sodium ions

155

equilibrium potential (no net movement) of sodium

+66 mV

156

important characteristic of sodium ion

permeability low, pumped out

157

remove Na+ and recapture K+

active forces

158

active forces involve

sodium potassium ATPase
-3Na+ for every 2 K+
-balances diffusion

159

cells are dynamic so

membrane potential changes

160

passive channels

leak, always open and permeability can change

161

active channels

gated, open or close in response to stimuli

162

graded potentials characteristic

-gated channels open, membrane potential shifts

163

graded potentials movement of ions

parallel to membrane- local current

164

degree of depolarization

decreases with distance

165

graded potentials do what

triggers specific cell functions

166

change in membrane potential consists of

depolarization, depolarization, and hyperpolarization

167

Na+ voltage gated channels has 3 states

open (activated)
closed (capable of opening)
closed (inactivated)

168

how large depolarized area is depends on

strength of stimulus and area stimulated

169

depolarization

shift to more + potential

170

repolarization

restoration of normal resting potential after depolarization

171

hyperpolarizaton

shift to more negative potential

172

what effect would a chemical that blocks voltage-gated Na+ channels have on a neuron's ability to depolarize?

decrease/unable to depolarize because flow of sodium is what causes depolarization so this can't occur if it is blocked

173

what effect would decreasing the concentration of extracellular K+ ions have on the membrane potential of a neuron?

cause hyperpolarization

174

remove K+ it

increases the chemical gradient and more K+ will move out of cell through leak channels

175

mechanically gated ion channel opens in response to

distortion of the membrane

176

voltage gated ion channel response to

changes in the membrane potential

177

example of what happens with Na+ voltage gated ion channel

-resting potential of -70mV, closed
- at -60 opens
-at +30 inactivated

178

chemically gated channel example

ligand gated, opens in response to presence of ACh (ligand) at binding site

179

Fugu puffer fish example

-tetrodotoxin is found in liver and skin
-binds voltage gated sodium channels
-paralyzed but remain conscious
-toxin produced by bacteria so non-toxic fugu can be produced

180

propagated changes in the membrane potential that affect an entire excitable membrane

action potential

181

chain reaction

-initial segment to synaptic terminals

182

threshold of action potential

all or none

183

generation of action potentials step 1

1) depolarization to threshold (-70 mv to -60)

184

generation of action potentials step 2

2) activation of sodium channels and rapid depolarization (-60 to 10 mv)

185

generation of action potentials step 3

3) inactivation of sodium channels and activation of potassium channels (10-30)

186

during generation of action potentials step 3

electrical and chemical gradients favor movement of K+ out of cell

187

generation of action potentials step 4

4) return to normal permeability (30 to -90mv) with hyper polarization

188

membrane will not respond normally to additional depolarizing stimuli

refractory period

189

cannot respond at all during

absolute refractory period

190

another AP can occur if sufficient depolarization during

relative refractory period

191

"message" is relayed from one location to another in series of repeated steps

action potential propagation

192

continuous propagation

unmyelinated axons (1m/sec)

193

saltatory propagation

-myelinated axon
-only nodes depolarize
-faster, less energy

194

node =

exposed axon

195

action potential jumps along nodes and is

less energy

196

large diameter (4-20um), myelinated

type A fibers

197

axon groups

type A, B, C fibers

198

-up to 120 m/sec
-sensory info (position, balance, touch, pressure)
-motor neurons to skeletal muscles

type A fibers

199

smaller (2-4um), myelinated

type B fibers

200

-ave 18 m/s

type B fibers

201

small (< 2um), unmyleinated

type C fibers

202

-1m/s
-temp, pain, touch
-instructions to smooth muscles, glands

type C fibers

203

what would happen if the myelin was removed in axon groups?

lack coordination between input and output
-ex) multiple sclerosis, progressive loss of myelin across neurons (axons)

204

message transfer to another cell

synaptic activity

205

gap junctions link pre and postsynaptic membranes

electrical synapses

206

local currents affect other cell, not common

electrical synapses

207

dynamic, may be modified

chemical synapses

208

communication in one direction

chemical synapses

209

neurotransmitters classified based on effects

chemical synapses, excitatory vs inhibitory

210

cause depolarization

excitatory

211

cause hyperpolarization

inhibitory

212

depends on properties of the receptor (not neurotransmitter)

chemical synapses

213

neurotransmitters

chemicals released by presynaptic neurons into synaptic cleft

214

widespread, best studied neurotransmitter

acetylcholine (ACh)

215

cholinergic synapses

release ACh

216

cholinergic synapses

-all neuromuscular junctions (skeletal muscle)
-many synapses in CNS, all neuron-neuron synapses in PNS
-all parasympathetic junctions

217

ACh is found in

synaptic vesicles

218

events at a cholinergic synapse

-action potential arrives at axon terminal
-voltage gated Ca++ channels open
-ACh binds to receptors
-AChE breaks down ACh

219

voltage gated Ca++ channels open

-trigger exocytosis
-Ca++ rapidly removed by active transport

220

ACh binds to receptors

-graded potential
-action potential if threshold reached

221

AChE breaks down ACh

-choline absorbed into axon terminal
-acetate metabolized

222

synaptic delay

0.2 to 0.5 msec leads to more synapses, longer propagation time and fatigue can occur

223

adrenergic synapses in brain, ANS
-depolarizing inhibits hyper polarization

norepinephrine (NE)- noradrenaline

224

-learning, mood, attention
-inhibatory (fine control of movements)
-excitatory

dopamine CNS

225

lack of inhibitory neurons is characteristic of

parkinsons

226

-mood, appetite, sleep, muscle contraction
-inadequate production (SIDS< OCD< DEPRESSION)

serotonin (CNS and GI tract)

227

-inhibitory, brain

gamma aminobutyric acid (GABA)

228

SNDRI

reuptake inhibitor

229

SNDRA

releasing agent (change amt)

230

picrotoxin

blocks receptor

231

alter rate of neurotransmitter release or change response

neuromodulators

232

slow action on multiple neurons

neuromodulators

233

affect many neurons in a wider area (no one target cell)

neuromodulators

234

activity of receptor determines cell response to

neurotransmitter and neuromodulator action

235

neurotransmitter and neuromodulator action (direct)

-direct effect on membrane potential (open or close gated ion channels)

236

neurotransmitter and neuromodulator action (indirect)

-indirect effect on membrane potential (work through second messenger cAMP)

237

lipid soluble gases

bind to enzymes

238

Homeostasis and fever

Homeostasis acts to change the set point of body temperature and fevers are actually a useful response because heat creates a hostile environment for invaders

239

Net effect on membrane potential occurs in

Axon hillock

240

Axon hillock functions

-integrates excitatory and inhibitory stimuli
-initial segment —> action potential

241

Excitatory postsynaptic potential (EPSP)

Graded depolarization

242

EPSP open chemically gated (BLANK) channels

Na+

243

Inhibitory postsynaptic potential (IPSP)

Graded hyperpolarization

244

IPSP open chemically gated (BLANK) channels

K+

245

Summation

Effects of all graded potentials

246

Temporal

Stimuli in rapid succession at single synapse

247

Spatial

Simultaneous stimuli at different locations

248

Facilitation

Membrane potential shifted closer to threshold

249

Neurotransmitters include

Excitatory and inhibitory

250

Axon hillock

Mechanically and chemically graded potentials

251

Initial segment of neuron

Voltage gated channels participating in action potential

252

EPSP, (BLANK) MV and function

0.5 MV, sufficient depolarization causes action potential

253

Summation takes place at

Axon hillock

254

When does summation occur?

Depolarization enough for action potential signal

255

Stimuli in rapid succession at single synapse

Temporal

256

Simultaneous stimuli at different locations

Spatial

257

Facilitation

Membrane potential shifted closer to threshold

258

Farther from threshold

Inhibition

259

Different ways information processing takes place at neuron

Presynaptic inhibition and facilitation

260

Reduces the amount of neurotransmitter released

Presynaptic inhibition

261

Increases the amount of neurotransmitter released

Presynaptic facilitation

262

Key question regarding signaling?

Enough depolarization at axon hillock to generate signal?

263

Frequency of action potentials can change (BLANK)

Message

264

Greater depolarization of axon hillock results in (BLANK)

Higher frequency of action potentials

265

What limits action potential within given neuron?

Absolute refractory period limits # action potentials generated

266

Neuronal pods

20 billion interneurons- organized into functional groups in CNS

267

Few thousand pools

-limited number of inputs and outputs
-excitatory and inhibitory neurons
-may be diffuse or localized

268

Functional characteristics of neuronal pods

-divergence
-convergence
-serial processing
-parallel processing
-reverberation

269

Usual info sent to many parts of brain (posture and response)

Divergence

270

Motor neuron subject to conscious and subconscious control

Convergence

271

One part of brain to another

Serial processing

272

Many responses simultaneously

Parallel processing

273

Response sustained consciousness and normal breathing activities

Reverberation

274

Information processing occurs at level of

Neuron and groups of neurons

275

Complex neural processing occurs in

Spinal cord and brain

276

Simple neural processing occurs in

PNS and spinal cord

277

What is in charge of reflexes?

Simple neural processing

278

Rapid, automatic responses to specific stimuli with little variability

Reflexes

279

Reflex arc

Pathway of single reflex

280

Steps of reflex arc

1) activation of receptor
2) activation of sensory neuron
3) information processing by interneuron
4) activation of motor neuron
5) response of effector

281

Reflex generally (BLANK)

Generally removes or opposes the original stimulus

282

Reflex is a positive or negative feedback system

Negative feedback

283

Receptor

Specialized cell and sensory neuron

284

Steps of reflex arc from in class

1) receptor
2) sensory neuron activated
3) sensory neuron —> NT
4) motor neuron activated
5) motor neuron releases NT (neurotransmitters)

285

Sensory neuron —> NT

Interneuron activated, multiple inputs

286

Motor neuron releases NT

Stimulate effector

287

Classification of reflexes

-development
-response
-complexity of circuit
-processing site

288

Development classification

Innate (genetic) and acquired (learned)

289

Response classification

Somatic and visceral

290

Somatic

Control skeletal muscle contractions and include superficial and stretch reflexes

291

Visceral

Control actions of smooth and cardiac muscle and glands

292

Complexity of circuit classification

Monosynaptic and polysnaptic

293

Monosynaptic

One synapse, 2 neurons

294

Polysynaptic

Multiple synapses (2 to several hundred)

295

Processing site classification

Signal reflexes and cranial reflexes

296

Processing in spinal cord

Spinal reflexes

297

Processing in brain

Cranial reflexes

298

Sensory neuron synapses directly on motor neuron

Monosynaptic

299

Example of monosynaptic

Stretch reflex (incl., patellar, postural)

300

Stretch reflex

Stimulus is increasing muscle length
-counteracts stimulus, reduces chance of damage

301

Sensory receptors

Muscle spindles

302

Stretching (BLANK) frequency of action potentials

Increases

303

Compressing (BLANK) frequency of action potentials

Decreases

304

Type A fibers are

Fastest, similar to monosynaptic

305

Polysynaptic

Complex responses

306

Polysynaptic characteristics

-involve pools of interneurons
-involve reciprocal inhibition
-have reverberating circuits
-cooperate to produce coordinated response

307

What can affect reflexes

Higher centers

308

Higher centers

-descending pathways from brain modify motor patterns
-facilitate or inhibit

309

Polysynaptic examples

-withdrawal reflex and crossed extensor reflex

310

Withdrawal reflex

-flexors contract, extensos relax
-reciprocal inhibition
-versatile in response

311

Crossed extensor reflex

-motor response also on side opposite to stimulus
-complements flexor reflex

312

Reciprocal inhibition

Overrides stretch reflex

313

Receptors, sensory neurons, sensory pathways =

Afferent division

314

Receptive field

Area monitored by single receptor (neuron)

315

Sensory receptors

-specificity
-receptive field
-labeled line
-adaptation

316

One type of stimulus

Specificity

317

Identifies type of stimulus

Labeled line to CNS

318

Reduction in sensitivity

Adaptation

319

All information is conveyed in form of

Action potentials

320

Specificity example

Free nerve endings

321

Free nerve endings

Dendrites of sensory neurons

322

Free nerve endings purpose

Pain —> tissue damage, chemicals and extreme temps

323

How does brain determine different senses?

Has to do with labeled lines

324

Labeled line

Link between peripheral receptor and cortical neuron

325

How does labeled line work ?

Each line (group of neurons) carries info about one type of stimulus

326

Example of labeled lines

Rubbing eyes, brain interprets light

327

Where line arrives in sensory cortex determines

Perceived location

328

Labeled line key things

-strength of signal, duration, variation of stimulus- frequency and pattern of action potentials

329

Adaptation

Constant stimulus

330

Peripheral adaptation

Receptors activity changes

331

Temperature receptors are

Fast adapting

332

Pain receptors are

Slowadapting

333

Central adaptation

Pathway to CNS where sensory neuron is still active

334

Example of central adaptation

Smell

335

Example of peripheral adaptation

Temperature and pain receptors

336

Adaptors (BLANK) or (BLANK) receptor sensitivity or signal transmission

Facilitate or inhibit

337

General sensory receptors

Throughout body and are relatively simple

338

Classify general sensory receptors

By nature of stimulus

339

Most processing occurs along

Sensory pathways

340

Visceral

Fewer pain, temp, touch receptors and no proprioceptors

341

Nociceptors

Pain

342

Where do nociceptors occur?

Skin, joints, bones, and blood vessels

343

Nociceptor description

Free nerve endings with large receptive fields

344

Nociceptor characteristics

Temperature extremes, damage, chemicals

345

Nociceptor peripheral adaptation

Little

346

Nociceptors CNS

Facilitation, inhibition in CNS

347

Classification of nociceptor and chemoreceptors

By stimuli

348

Neuromodulators

Production of endorphins

349

Sensory receptors

-specificity
-receptor field
-labeled line
-adaptation
—-peripheral (receptor) or central (CNS)

350

Chemoreceptors characteristics

-water soluble, lipid soluble substances
-adaptation
-pH, CO2 in cerebrospinal fluid, blood

351

Thermoreceptors found

Free nerve endings in dermis, muscles, liver, hypothalamus

352

Thermoreceptors pathway

Same as pain and quickly adapt

353

Chemoreceptors adaptation

Peripheral and possibly central

354

Chemoreceptors info

No info to primary sensory Cortex

355

Pathway for thermoreceptors and nociceptors

Labeled lines

356

Mechanoreceptors stimuli

Distort plasma membranes

357

Types of mechanoreceptors

Tactile, baroreceptors, proprioceptors

358

Mechanoreceptors are

Mechanically gated channels

359

Proprioceptors

Position of joints and muscles, some info is conscious

360

Tactile

Respond to touch, pressure, vibration
-range of receptors specialized to respond to specific stimuli

361

Baroreceptors

-pressure changes in walls of tracts; free nerve endings

362

Somatic sensory pathways

-three major pathways up spinal cord
-information from skin, skeletal muscles

363

Three major pathways up spinal cord

-fine touch, pressure, proprioceptors
-crude touch, pressure, pain, temperature
-proprioceptors to cerebellum

364

Visceral sensory pathways

-interceptors
-not to primary sensory cortex

365

Role of major pathways

Each one caries a particular message

366

Pathway description

Physical pathways created by neurons traveling in a group

367

1st order pathway

Sensory neurons

368

Second order pathway

Interneurons (CNS)

369

3rd order neuron

Thalamus to primary sensory cortex

370

Pathway application to real life

Brain mapping and stimulation
-phantom limb pain

371

Somatic motor system

-controls contractions of skeletal muscles
-three motor pathways
-conscious motor control, subconscious regulation

372

Spinal, cranial reflexes

Rapid, involuntary responses

373

Integrative centers in brain

More complex processing

374

Atuonomic nervous system two main subdivisions

Sympathetic and parasympathetic

375

Role of autonomic ns

Routine homeostatic adjustments

376

Sympathetic definition

Fight or flight
-prepares body for heightened levels of somatic activity

377

Sympathetic regulation

Increase tissue metabolism, alertness
Decrease digestive, urinary activities

378

Parasympathetic definition

Rest and digest
-conserves energy, promotes sedentary activities

379

Parasympathetic nervous system control

Increase digestion, secretion
Decrease energy demand, heart rate

380

Sympathetic activation

Entire division responds

381

Steps of sympathetic activation

1) release of norepinephrine (NE) at peripheral synapses
2) release of NE and epinephrine (E) from adrenal medulla -hormones

382

-affects cells not innervated by sympathetic fibers
-effects last much longer

Release of NE and epinephrine from adrenal medulla

383

Sympathetic neurons

-preganglionic fiber relates ACh
-branching network of telodendria
-varicosities
-many release NE (adrenergic)
-others release ACh
-broken down by enzymes

384

Somatic motor system pathways

1) from primary motor cortex
2-3) from midbrain

385

Pathway from motor cortex

Conscious control

386

Pathway from midbrain

Subconscious control (muscles of trunk and proximal/distal limbs)

387

Sensory homunculus

Size of body part, # of sensory receptors

388

Motor humunculus

Size of body part, # of motor units (amt control)

389

If neuron is more or less likely to fire it is

Facilitated vs inhibited

390

If you prevent inactivation and K+ from opening then...

Depolarization can’t take place, then membrane continues to be depolarized and neurotransmitters continue to be released. A constant stimulation of muscles occurs until neurotransmitters run out. This causes a muscle lock/spasm until paralysis occurs.

391

Change in potential at which voltage gated Na+ channels open

Open at more positive = shift threshold away from resting potential and it is hard to reach

392

3 states of gates

Open (-60)
Close and active (third mem potential)
Closed and inactive (+33)

393

When the membrane potential is reached, what happens?

State is changed

394

Membrane potential of states are

Independent of each other

395

Varicosites

Swelling in vessel
-neurotransmitter stored and released

396

Sympathetic neurons simple pathway

Preganglionic fiber, ganglion (ACh), postganglionic, NE/ACh

397

Effects of sympathetic stimulation depends on

Receptors

398

Norepinephrine stimulates

Alpha receptors more than beta receptors

399

Epinephrine stimulates

Both alpha and beta

400

Adrenergic receptors are

G proteins

401

G proteins produce

Second messengers

402

(BLANK) stimulate enzymes on inside of plasma membrane

Alpha receptors

403

Release Ca++ from ER, excitatory effect on target cell

Alpha 1

404

Lowers cAMP levels, inhibits target cell

Alpha 2

405

Trigger changes in metabolic activity of target cell

Beta receptors

406

Increase in metabolic activity, increased heart rate and force

Beta 1

407

Relaxation of smooth muscles of respiratory tract

Beta 2

408

Lipolysis- release fatty acids

Beta 3

409

What cause vasodilation in skeletal muscles, brain

ACh and NO

410

Out of the alpha receptors what are more common

Alpha 1

411

B1

Liver

412

B2

Inhibit

413

B3

Adipose tissues

414

asthma inhaler has to do with

Beta 2

415

ACh and NO cause vasodilation in skeletal muscles, brain

Adrenergic

416

ACh vasodilation

Sweat glands and dilate blood vessels —> muscles and brain

417

NO vasodilation

Blood vessel walls—> dilation

418

How would a drug that stimulates acetylcholine receptors affect the sympathetic nervous system?

Widespread excitatory response, stimulates postganglionic fibers, large/widespread sympathetic response

419

An individual with high blood pressure is given a medication that blocks beta receptors. How could this medication help correct that person’s condition?

B1 blocked which blocks metabolic activity such as an increase in heart rate which will lead to contraction and reduce the heart rate

420

Parasympathetic activation

All parasympathetic neurons release ACh

421

All parasympathetic neurons release ACh

-effects localized and short lived
-narrow synaptic clefts

422

Nicotinic

Skeletal muscles, excitatory, both para and symp

423

Ganglion cells (symp and parasympathetic), somatic neuromuscular

Nicotinic

424

Open chemically Na+ gated channels

Nicotinic

425

Nicotine poisoning

High blood pressure, rapid heart rate

426

Muscarinic

Neuromuscular, neuroglandular

427

Muscarinic G proteins

Excitatory or inhibitory

428

Muscarinic changes permeability to

K+

429

Muscarinic poisoning

Slow heart rate, low blood pressure, constricted respiratory passages

430

Two types of receptors

Nicotinic and muscarinic

431

Sympathetic receptors

Organs and tissues throughout body

432

Parasympathetic receptors

Visceral structures

433

Dual innervation

Innervations from both and usually opposing effects

434

Autonomic tone

Resting level of activity

435

Autonomic tone function

Increase or decrease activity (gives nervous system finer control, input of information)

436

Example of autonomic tone

Heart function

437

Para vs symp autonomic tone

Parasymp dominates when at rest vs symp dominates when crisis

438

Examples of visceral reflexes

Pupils dilate, swallow, urination

439

Visceral reflexes all are

Polysynaptic

440

Describe visceral reflexes

Modified, facilitated, inhibited, integrated by higher centers

441

Long reflexes

Sensory info to CNS

442

Short reflexes

CNS not involved

443

Describe long reflexes characteristics

Processing in CNS and coordinate organ activities

444

Short reflexes

CNS not involved

445

Describe short reflexes

-autonomic ganglion
-localized control

446

Enteric nervous system

-walls of digestive tract
-short reflexes
-controls digestive function without CNS

447

Higher levels of control

Simple and complex reflexes

448

Simple reflexes

Rapid automatic response

449

Complex reflexes

Coordinated by brain
-activity in other portions of brain affect autonomic and somatic function