Unit 1 Phys Flashcards
1
Q
study of structure and the physical relationships between body parts
A
anatomy
2
Q
example of anatomy
A
how a muscle attaches to the skeleton
3
Q
study of living organisms perform vital functions
A
physiology
4
Q
example of physiology
A
how a muscle contracts and the force it exerts
5
Q
there is a close link between
A
structure and function
6
Q
(blanks) at each level determines structure and function of higher levels
A
organization
7
Q
organization of the human body
A
cellular–> tissue –> organ –> organ system–> organism
8
Q
molecular interactions–> cell
A
cellular
9
Q
example of cellular level
A
protein filaments
10
Q
group of cells–> specific function
A
tissue
11
Q
example of tissue level
A
coordinated contractions
12
Q
> or equal to 2 tissues–> specific function
A
organ and organ system
13
Q
example of organ
A
pump blood
14
Q
example of organ system level
A
circulate blood through vessels
15
Q
for life to continue, precise internal body conditions must be (BLANK)
A
maintained regardless of external conditions
16
Q
homeostasis
A
existence of a relatively stable internal environment
17
Q
the principal function of regulatory systems is to maintain
A
homeostasis
18
Q
characteristics of homeostasis
A
- not a static process (dynamic equilibrium)
- requires energy
- conditions maintained via feedback systems
19
Q
autoregulation (intrinsic regulation)
A
cell/tissue/organ adjusts to change in environment
20
Q
extrinsic regulation
A
nervous system or endocrine system (adjust many simultaneously)
21
Q
nervous system regulation characteristics
A
fast; short duration
22
Q
nervous system
A
electrical communication via nerve tissue
23
Q
endocrine system regulation characteristics
A
slow; long duration
24
Q
endocrine system
A
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
