Unit II Flashcards
Neuro & Muscular (155 cards)
1
Q
What are the basic functions of the nervous system?
A
It uses a rapid means of communication to adapt the body to external stimuli and coordinates internal processes
2
Q
Describe the organization of the nervous system.
A
I. CNS- brain & spinal cord
II. PNS- nerves
A. Afferent (input) - sensory
B. Efferent (output) - motor
1. Somatic- voluntary (CNS -> sk. musc)
2. Autonomic- involuntary (sm.& cardiac musc, glands)
a) Sympathetic (fight or flight)
b) Parasympathetic (relax)
3
Q
Define myelinated and unmyelinated axons, include Nodes of Ranvier.
A
- Myelinated axons- has membrane wrapping, fatty insulation (myelin sheath); Schwann cells and Satellite cells; conducts impulses rapidly.
- Nodes or Ranvier- myelin sheath gaps
- Unmyelinated axons- naked axons, conducts impulses more slowly
4
Q
Describe the components of a typical neuron and their functions.
A
- Cell body- contains the nucleus; metabolism and organelles; membrane receives impulses
- Dendrites- receives impulses
- Axon- conducting/ transmission portion of neurons; contains axon terminals with knobs
5
Q
Synapse
A
“Knobs”
Junction between pre-synaptic and post-synaptic neurons
6
Q
Describe the functions of sensory, interneuron, and motor neurons.
A
- Sensory neurons- (afferent neurons) send info from receptors to CNS
- Motor neurons- (efferent neurons) transmit info from CNS to effectors
- Interneurons- located only within the CNS; involved with integration
7
Q
Effectors
A
muscles and glands
8
Q
Describe the formation of a membrane potential. Include force, chemical force, and membrane permeability and movement of ions.
A
There are three electrochemical driving forces:
- The chemical or concentration gradient is caused by the concentration gradient
- The electrical force is the attraction/ repulsion between charges
- Na-K pump maintains the gradients (gate, protein)
9
Q
Repolarization
A
membrane potential returns to resting state; can be caused by increase in potassium ion permeability
10
Q
Discuss the permeability changes for the three phases of the action potential.
A
Phase 1: Depolarization-
Phase 2: Repolarization-
Phase 3: Hyperpolarization-
Resting state-
11
Q
Affarent
A
Sensory input
12
Q
Efferent
A
Motor output
13
Q
Graded potential (location, strength, refractive period, transmission)
A
L: membranes of dendrites and cell body
S: varies depending on stimulus strength
R: absent
T: passive, signal (graded potential) weakens with distance
14
Q
Action potential (location, strength, refractive period, transmission)
A
L: axon hillock, axon
S: all or nothing
R: absolute or relative
T: active, signal stays same strength until the end
15
Q
Membrane potential
A
An unequal distribution of ions between the in/outside of cells causes an unequal charge distribution that produces a membrane potential
16
Q
Steps of synaptic transmission
A
- AP sweeps into synapse “knob”
- Depolarization causes Ca channels to open & Ca rushes into the presynaptic knob
- Ca causes vesicles migration and exocytosis of NT into synapse
- NT diffuses across synapse
- NT attaches to post-syn receptors causing and fast and slow responses (causing graded potential)
- Membrane perm changes cause changes in post-syn memb potential
- Excitatory or inhibitory response
- Removal of NT
17
Q
Fast vs slow responses during synaptic transmission
A
Fast- opens channel gates with the receptor
Slow- activates G protein to open the ion gates
18
Q
Excitatory vs inhibitory synapse
A
Excitatory- firing of pre-syn neuron increases likelihood of firing post-syn neuron: NT & receptors open K+ and Na+ gates and cause small depolarization or EPSP
Inhibitory- firing of pre-syn neuron decreases likelihood of firing post-syn neuron: NT attaches to receptor on post-syn neuron and open K+ gates and Cl- gates, causing a small hyperpolarization or IPSP
19
Q
Summation
A
Additive effect of many EPSPs until threshold is reached, thus creating an AP to fire (or IPSPs causing inhibition)
There are two types which are used simultaneously at synapse.
20
Q
Temporal vs spacial summation
A
Temporal- domino effect, volley of impulses along one knob
Spatial- different knobs carry impulses
21
Q
Synthesis and degradation of ACh
A
Synthesis:
acetyl CoA + choline —-choline acetyltransferase(CAT)—> ACh
Degradation: ACh—-acetylcholinesterase (aChE)—->acetic acid and choline
22
Q
Synthesis and degradation of NE.
A
Synthesis:
L Dopa –> dopamine –> norepinephrine
Degradation:
- Monoamine oxidase (MAO) in the membrane of the axonal terminals
- Catechol-o-methyltransferase (COMT) on the post-synaptic membrane
- Catecholamines are absorbed (uptake) back into the knobs (reabsorbed and repackaged)
23
Q
ECF
A
more Na and Cl
24
Q
ICF
A
more K and neg. charged proteins
25
Impulses
changes in membrane potentials
26
Depolarization
membrane potential becomes less negative; can be caused by increase in sodium ion permeability
27
Hyperpolarization
membrane potential becomes more polarized or more negative; can be caused by an increase in chloride or potassium permeability
28
five ways drugs can influence the nervous system. Give examples
1. Mimic NT (nicotine/muscarine mimic ACh)
2. Alters the release of NT (Amphetamines increase release of dopamine and NE)
3. Influences the receptor site (Botox blocks receptor site of ACh)
4. Influences the removal of NT (Cocaine reduces uptake of NE)
5. Influences ion channels or gates (Apamin blocks K channels)
29
fcn of blood brain barrier and its importance
Blood supply to the CNS;
Prevents the brain from potential injury from toxins;;
Capillary membranes are permeable to hydrophobic molecules;
Impermeable to hydrophilic molecules unless transport mechanisms are present
30
functions of the spinal cord
- Reflexes (automatic)
- Ascending (sensory) and descending (motor) tracts
- Descending or motor pathways
31
MEDULLA OBLONGATA
```
Vital centers
Respiration
Cardiovascular
Non-vital centers
Swallowing
Sneezing
Coughing
```
32
PONS
Respiration
33
MIDBRAIN
- Eye movements
- Auditory reflexes
- Visual reflexes
34
CEREBELLUM
- Motor coordination and balance
| - Provides feedback to motor systems
35
LEFT CEREBRAL HEMISPHERE
-Language centers
-Verbal skills
-Numerical skills
-Wernicke’s area
Written and spoken language comprehension
-Broca’s area
Muscles of speech
-“Rational brain”
-Stroke to left side can cause anxiety, depression, worry
36
RIGHT CEREBRAL HEMISPHERE
- Recognition of visual patterns
- Expression
- Recognition of emotions
- Artistic abilities
- Stroke to right side can result in patients that are more indifferent and/or blissful
37
PARIETAL LOBE
Primary sensory area
Receives input from receptors
Sensory homunculus
38
OCCIPITAL LOBE
vision
39
TEMPORAL LOBE
- vision
- hearing
- Wernicke's area for language
40
BASAL NUCLEI (Basal ganglia)
Fine motor coordination
Parkinson’s disease
Amygdala
Hippocampus
41
THALAMUS
It is a sensory relay station to cortex, hypothalamus, etc.
42
HYPOTHALAMUS
```
Body temperature
Thirst
Appetite
Sexual activity
Pituitary gland
Autonomic nerves
```
43
LIMBIC SYSTEM
Functional area that is diffused throughout the brain and includes the hypothalamus, thalamus, fornix, basal ganglia, and cingulate gyrus of cortex.
-Emotions (pleasure & punishment)
-Emotional behavior
-Face recognition
44
RETICULAR ACTIVITY SYSTEM (RAS)
Spread throughout the brain and includes: pons, medulla, thalamus, hypothalamus, and influences the cortex and cerebellum.
-Alertness
45
Face recognition
- Visual input → cortex (lobes)
| - Amygdala → limbic system for emotional input
46
Natural smile
Visual cortex recognizes face →
Sent to limbic center →
To basal nuclei →
To muscles
47
Artificial (forced) smile
Auditory input → higher brain centers (temporal lobe) →
Frontal lobe → muscles
Different responses
48
Reflexes
Rapid (and unconscious) response to changes in the internal or external environment needed to maintain homeostasis
49
integrated CNS fxn of REFLEXES
- Controlled by spinal cord and brain
- Monosynaptic or polysynaptic
- Somatic or autonomic
- Innate or learned
50
REFLEX ARC
The neural pathway over which impulses travel during a reflex. The components of a reflex arc include:
1. Receptor – site of stimulus
2. Sensory neuron – transmits the afferent impulse to the CNS
3. Integration center – either monosynaptic or polysynaptic region within the CNS
4. Motor neuron – conducts efferent impulses from the integration center to an effector
5. Effector – muscle fiber or gland that responds to the efferent impulse
51
STRETCH REFLEX
-Reflex contraction of a muscle when an attached tendon is pulled.
-Monosynaptic.
52
WITHDRAWL REFLEX
Withdrawal reflexes move a body part away from a stimulus such as pain or pressure.
53
VOLUNTARY MOTOR CONTROL
1. idea
2. program
3. execution
4. feedback
54
LANGUAGE
motor cortex
- broca's area
- Wernicke's area
55
WERNICKE'S AREA
Comprehension
| Auditory and Visual
56
BROCA'S AREA
Language expression
Speak and write words
Syntax – the arrangement of words and phrases to create well-formed sentences in a language
57
different types of memory and their locations within the brain.
- immediate
- working
- long-term
58
Development of synaptic circuits are activated by
an experience or thought
59
immediate memory
fraction of seconds to seconds
60
working memory
- seconds to days
- takes place in prefrontal cortex
- enables us to keep a thought in order to make plans
- dopamine receptors help regulate
61
long term memory
- days to years
- requires hippocampus to convert short term to long term
- stores memory in the associative cortex for future retrieval
62
Discuss learning and the factors that can enhance or decrease memory.
```
-RAS
Attention and focus on an area of a sensory world
-THALAMUS
Multiple senses for more memories
-AMYGDALA & LIMBIC SYSTEM
Emotional memory and consolidates learning
-MESO-LIMBIC SYSTEM
Learning should be pleasurable
Drugs activate, but also degenerates the pathway
-HYPOTHALAMUS
Stress reducing learning
-SUPRACHIASMATIC NUCLEUS
```
63
MEMORY AND SLEEP
-NON-REM SLEEP
Rebuilds memories and pathways
-REM SLEEP
Consolidation of memories
64
pain
Pain receptors create neurocircuit in the brain
65
SOMATOSENSORY SYSTEM
Touch
66
PROPRIOCEPTION
Muscle and tendon stretch
67
SPECIAL SENSORY SYSTEMS
1. Eyes
2. Ears
3. Olfactory
4. Taste
68
Describe how the CNS interprets stimulus strength and duration.
- Higher frequency of A.P.
| - Recruitment of neighboring receptors (increased volley of impulses, weakens with distance)
69
types of sensory modalities
- photoreceptors
- thermoreceptors
- mechanoreceptors
- mechanoreceptors
70
photoreceptors
rod and cone cells are sensitive to photons of light
71
chemoreceptors
activated by odors, various foods, and within body fluids
72
osmoreceptors
type of chemoreceptor which receives changes in osmotic concentration
73
thermoreceptors
monitor temperature changes
74
mechanoreceptors
activated by pressure, stretch, or distension. perceive stimuli (touch, muscle tension, hearing)
75
3 types of mechanoreceptors
Baroreceptors – monitor BP
Proprioceptors – tension
Auditory receptors – sound
76
Nociceptors
monitor pain from tissue damage (can be thermoreceptors or mechanoreceptors)
77
features of the autonomic system
- involuntary
- regulated by hypothal, pons, medulla, spinal cord
- cardiac and smooth muscles
- glands
78
autonomic neurons
Pre-ganglionic neuron -> ganglion -> post-ganglionic neuron
79
Dual innervations
the process of being innervated by both the sympathetic and parasympathetic nervous system
80
General function of Sympathetic
Fight or flight
81
General function of Parasympathetic
rest and digest
82
Sympathetic
Pre-ganglionic Neuron
Neurotransmitter, Neuron name, Receptors on post-ganglionic dendrites
Acetylcholine
Cholinergic
Nicotinic cholinergic
83
Parasympathetic
Pre-ganglionic Neuron
Neurotransmitter, Neuron name, Receptors on post-ganglionic dendrites
Acetylcholine
Cholinergic
Nicotinic cholinergic
84
Sympathetic
Post-ganglionic Neuron
Neurotransmitter, Neuron name, Receptors on Effector
Norepinephrine
Adrenergic
Alpha or Beta
85
Parasympathetic
Post-ganglionic Neuron
Neurotransmitter, Neuron name, Receptors on Effector
Acetylcholine
Cholinergic
Muscarinic cholinergic
86
Sympathetic
| Receptor types and their loc/fcn
- Nicotinic: dendrites of post gang
- Alpha 1, Alpha 2: smooth muscle, glands: excitatory
- Beta 1: heart: excitatory
- Beta 2: smooth muscle: generally inhibitory
87
Parasympathetic
| Receptor types and their loc/fcn
- Nicotinic: Dendrites of post-ganglionic
- M1: salivary glands and stomach
- M2: heart
- M3: Smooth muscle contration: vasodilation
88
Sym- Heart
B1, speeds rate, increases force of contraction
89
Sym- Blood vessels
a, constriction
| B2, dilation
90
Sym- Pupil
a, dilates
91
Sym- Bronchioles
B2, dilates
92
Sym- Digestive System
B2, slows motility and inhibits secretions
93
Sym- Urinary bladder
B2, relaxes
94
Sym- Uterus
a, relaxes
95
Sym- Reproductive System
B2, orgasm
96
Sym- Adrenal Medulla
nicotinic, releases epi and norepi
97
Para- Heart
M2, Slows rate
98
Para- Blood vessels
----- (no analogy)
99
Para- Pupil
M3, constricts
100
Para- Bronchioles
M3, constricts
101
Para- Digestive System
M1, increases motility and stimulates secretions
102
Para- Urinary bladder
M3, Contracts
103
Para- Uterus
----- (no analogy)
104
Para- Reproductive System
M3, Erection
105
Para- Adrenal Medulla
----- (no analogy)
106
Sym- Salivary glands
a, secretes mucus
107
Para- Salivary glands
M1, secretes serous fluid
108
Somatic- Neurotransmitter
Acetylcholine at neuromuscular junction;
| Cholinergic fibers and nicotinic receptors on muscle membrane
109
Somatic- neuron name
Somatic nerve
110
Function of somatic system
voluntary movement
111
MOTOR UNITS
The somatic nerve and its innervated muscle fibers. One nerve may stimulate a few dozens of muscle fibers.
Finer motor control.
112
NEUROMUSCULAR JUNCTION: motor end plate
a large terminal formation where the axon of a motor neuron establishes contact with a striated muscle fiber.
(“footprint” in the sarcolemma)
113
properties of muscle tissue
1. Excitability
2. Contractility
3. Stretchability
4. Elasticity
114
MYOFILAMENTS
thin and thick filaments made of protein
115
thin filaments
Actin:
- trypomyosin
- troponin
- myosin binding site
116
thick filaments
Myosin:
- tail, head with cross bridges
- actin binding site
- ATP binding site
117
SARCOMERE
a segment of a myofibril, contratile unit, composed of myofilaments
- functional contractile unit (shortening or contraction)
- Z lines – ends of sarcomere
118
MYOFIBRIL
hundreds make up one muscle fiber; contains organelles
119
SARCOLEMMA
– outer plasma membrane which wrap around a budle of myofibrils
120
TRANSVERSE TUBULES
physically attached to sarcolemma
121
SARCOPLASMIC RETICULUM
around myofibril, holy looking, ends are swollen
122
TERMINAL CISTERNAE
storage, contain Ca++
123
TRIADS
2 terminal cisternae and 1 T-tubule, releases Ca++
124
FIBER
Muscle cell
125
TROPONIN
has a calcium binding site
126
TROPOMYOSIN AND TROPONIN
regulate actin and myosin interaction
127
I BAND
(light bands) only thin filaments (isotropic); length changes
128
A BAND
(dark band) length of thick filaments (Anisotropic); length does not change; has an overlap area that includes thin filament
129
Events at a cross bridge cycle
1. release (atp ataches to myosin)
2. activation or the cocking of the myosin head (atp binds with myosin and splits into ADP "high energy")
3. binding of myosin to actin
4. sliding or power stroke (myosin head pivots against actin shortening the sarcomere, ADP is released)
5. repeat steps 1-4
130
steps of excitation contration coupling in a skeletal muscle fiber #1-5
1. AP on somatic nerve arrives at neuromuscular junction
2. Ca channels open, Ca triggers exocytosis of ACh
3. ACh diffuses across and binds to receptors on muscle motor end plate
4. Na and K channels open, creates a large depolarization or end plate potential (EPP)
5. EPP migrates to the "true sarcolemma" and triggers an AP
131
steps of excitation contration coupling in a skeletal muscle fiber #5-9
6. AP propragates down sarcolemma into t-tubules by the process of transmission
7. depolarizes the terminal cisternae of S.R. and causes them to open Ca gates/ release stored Ca
8. Ca moves into sarcoplasm/ binds with troponin, causing release of regulatory inhibition on actin
9. Thick/thin filaments slide and sacromeres shorten (contraction, cross bridge cycle)
132
relaxation of skeletal muscle
1. no AP on neuron, muscle sarcolemma, or t-tubules (no EPP)
2. ATP is used to pump Ca back into terminal cisternae
3. Ca unbinds with troponin and inhibits actin's interaction with myosin
4. thus no actin myosin interation, sarcomeres lengthen and muscles relax (no cross bridge cycle)
133
three sources of ATP production
1. CREATINE PHOSPHATE
2. AEROBIC RESPIRATION
3. ANAEROBIC RESPIRATION
134
CREATINE PHOSPHATE
Immediate source of ATP
creatine phosphate + ADP ATP + Creatine
135
AEROBIC RESPIRATION
Myoglobin
Cardiovascular
(slower than anaerobic)
136
ANAEROBIC RESPIRATION
Oxygen debt
due to metabolism of lactic acid to glucose or to carbon dioxide that requires ATP or oxygen directly, the formation of creatine phosphate, and the replenishment of myoglobin.
137
describe the three periods of a muscle twitch
1. LATENT PERIOD
time from stimulus to beginning of contraction
2. CONTRACTION PERIOD
tension develops and muscle shortens
3. RELAXATION PERIOD
tension fades and muscles become relaxed, longest period
138
isotonic contraction
same tension
| sarcomeres shorten, muscle shortens
139
isometric contraction
same length
| sarcomeres shorten, muscles don't shorten because of elasticicy
140
factors affecting force in a SINGLE fiber
1. Frequency (summation/ tetanus)
2. Fiber length
3. Fiber diameter
141
recruitment of motor unites
an increase in strength is determined by the number of motor units recruited, thus the number of fibers recruited for contraction (in whole muscles)
142
asynchronous recruitment
delays muscle fatigue
143
factors that cause muscle fatigue
1. short-term maximal exertion fatigue
(buildup of inorganic phosphates and decrease in Ca release from SR)
2. extended sub-maximal fatigue
(depletion of glycogen and/or fatty acids)
144
hypertrophy
neurological stimulation- muscle builds
145
atrophy
not using muscles- muscle shrinks
146
Slow oxidative
Function:
Fatigue:
Strength:
- posture
- fatigue resistant
- low
147
Fast oxidative
Function:
Fatigue:
Strength:
- Endurance (marathon)
- Fatigue resistant
- Intermediate
148
Fast Glycolytic
Function:
Fatigue:
Strength:
- High intensity (sprinting, weights)
- Fatigable
- High
149
Slow oxidative
Fiber diameter:
Twitch speed:
ATP pathway:
- thin
- slow
- aerobic
150
Fast oxidative
Fiber diameter:
Twitch speed:
ATP pathway:
- thin
- fast
- aerobic
151
Fast Glycolytic
Fiber diameter:
Twitch speed:
ATP pathway:
- thick
- very fast
- anaerobic
152
```
Slow oxidative
Capillary amount:
Myoglobin levels:
Glycogen levels:
Fiber color:
```
- abundant
- high
- low
- dark
153
```
Fast oxidative
Capillary amount:
Myoglobin levels:
Glycogen levels:
Fiber color:
```
- abundant
- high
- low
- dark
154
```
Fast glycolytic
Capillary amount:
Myoglobin levels:
Glycogen levels:
Fiber color:
```
- few
- low
- high
- light
155
fiber types are determined by
genetics and type of training
