A&P 1: Block 3 Flashcards
1
Q
What are the major parts of the brain?
A
Brain stem
Cerebellum
Diencephalon
Cerebrum
2
Q
What are the 3 parts of the brain stem
A
Medulla oblongata
Pons
Midbrain
3
Q
Cerebellum aka?
A
little brain
4
Q
Diencephalon comprised of what 2 things?
A
Thalamus
Hypothalamus
5
Q
What is the largest part of the brain?
How is it supported?
A
Cerebrum
Supported on diencephalon and brain stem
6
Q
What are the 3 layers of the meninges
A
Dura mater
Arachnoid mater
Pia mater
7
Q
Cranial dura mater has _ layers
Spinal dura mater has _layers
A
Cranial: 2
Spinal: 1
8
Q
What are the two layers of the cranial dura mater?
Which one is continuous w/ spinal meninges?
A
External periosteal layer
Internal miningeal layer- continuous w/ spinal dura mater
9
Q
The 2 layers of cranial dura mater are fused together except for where?
A
Separate to enclose dural venous sinuses that drain blood from brain->internal jugular vein
10
Q
What are the 3 extensions of the dura mater?
A
Falx cerebri: separates hemispheres of CEREBRUM
Falx cerebeli: separates hemispheres of CEREBELLUM
Tentorium cerebelli: separates cerebrum from cerebellum
11
Q
Neurons synthesize ATP almost exclusively from ____
A
glucose
12
Q
How is the BBB disrupted?
A
Trauma
Toxins
Inflammation
13
Q
What parts of the brain lack the BBB
A
Pineal gland
Pituitary gland
Hypothalamus (median eminence of hypothalamus)
14
Q
What area senses toxins in the blood?
Where is it located?
A
Area postrema
4th ventricle in medulla
15
Q
What area of the brain controls vomiting
A
Area postrema
4th ventricle in medulla
16
Q
What two structures form the BBB
A
Tight junctions of endothelial cells in capillaries
Astrocyte foot processes
17
Q
What substances cross the BBB by active transport?
A
Water soluble (glucose)
18
Q
What substances cross BBB very slowly?
A
Creatine
Urea
Most ions
19
Q
What substances can not cross the BBB at all?
A
Proteins
Antibiotic drugs
20
Q
What substances cross the BBB easily?
A
O2
CO2
Alcohol
Most anesthetic agents
21
Q
Major functions of CSF
A
Protection- chemical/physical
Carries O2, glucose and chemicals to neurons and neuroglia
22
Q
CSF circulates between what layers of mater?
A
Between Arachnoid and Pia
23
Q
How many ventricles does the brain have?
A
4 Lateral Septum pellucidum 3rd- narrow cavity surrounded by R/L halves of thalamus 4th- between brain stem and cerebellum
24
Q
CSF contributes to brain homeostasis in what 3 ways?
A
Mechanical protection- jolting and floats
Chemical- optimal ionic composition
Medium for nutrient/waste exchange
25
Where is CSF produced?
Choroid plexuses in walls of each lateral ventricles
| Capillary network covered w/ ependymal cells
26
How does CSF flow into 3rd brain ventricle?
two openings called
| Interventricular foramina
27
How does CSF flow into 4th ventricle?
Through cerebral aqueduct
28
How does CSF enter the subarachnoid space?
3 openings in roof of 4th ventricle
Median aperture
Two lateral apertures
29
How is CSF reabsorbed into the blood?
Arachnoid villi
| Reabsorbed as fast as it's secreted
30
Define hydrocephalus
Excess CSF in brain
31
How does hydrocephalus occur in adults?
Head injury
Meningitis
Subarachnoid hemorrhage
32
How is hydrocephalus often treated?
Shunt placement
33
How are PTs with obstructive hydrocephalus treated?
Third ventriculostomy
| Hole is made in floor of 3rd ventricle so CSF can bypass obstruction
34
What formation extend throughout the brain stem?
Reticular formation composed of gray and white matter
35
What functions does the medulla oblongata control?
Breathing
HR
BP
Reflexes of cough, swallow, vomit
36
Where does the medulla oblongata begin?
Foramen magnum
37
Define ascending/descending tracts of the medulla oblongata
Ascending- sensory
| Descending- motor
38
What type of matter make up the ascending and descending tracts of the medulla oblongata?
White
39
Define pyramids of the medulla oblongata
Bulges of white matter on anterior
Largest motor tracts pass from cerebrum to spinal cord
Pyramids represent the corticospinal tracts
40
Define decussation of pyramids
Axons of L pyramid cross to R side, vice versa
41
Define medullary nuceli
| What are the 6 medullary nuclei
Masses of gray matter where neurons from synapses w/ one another to control vital body functions
Cardiovascular center- HR rate/force, vessel diameter
Medullary rhythmicity- basic rhythm of breathing
Deglutition center- swallowing bolus
Gustatory nucleus- input from taste buds to brain
Cochlear nuclei- auditory input
Vestibular nuclei- equilibrium pathway
42
Define Olive and their function
Lateral to each pyramid
| Inferior olivary nucleus relays impulses to cerebellum from cerebral cortex, red nucleus and spinal proprioceptors
43
Define Posterior nuclei and its function
R/L gracile nucleus and cuneate nucleus make posterior medulla
Associated w/ sensations of touch, conscious proprioception and vibration
44
Where do first-order sensory neurons have their cell bodies?
Dorsal roots of spinal cord
45
Where are second-order neurons located?
Posterior nucleus of medulla
46
Define medial lemniscus
Band of white matter in thalamus of second order neurons
47
Where does the medial lemniscus run through?
Medulla
Pons
Midbrain
48
What do the tracts and columns of the posterior medial lemniscus form?
Posterior column-medial lemniscus pathway
49
S/Sx of injury to medulla site?
Paralysis/loss of sensation on opposite side of body
| Irregular breathing/HR rhythm
50
Pons consists of which nuclei?
Both, sensory and motor
51
What type of relay signals does the pontine nuclei relay?
Voluntary movements from cerebral cortex origin to cerebellum
52
How does the Pons help the medulla w/ breathing?
Pons contains pneumotaxic and apneustic area which work in conjunction w/ medullary rhythmic area
53
What comprises the respiratory center
bilateral clusters in medulla and pons
| Comprised of rhythmic, pneumotaxic and apneustic areas
54
Medullary rhythmic area control which specific parts of respiration?
Inspiration area
| Expiratory area
55
Pneumotaxic and apneustic areas control what specific parts of respiration?
transition between inhalation and exhalation
Pneumotaxic turns off inspiratory area before lungs become full
Apneustic prolongs inhalation by stimulating inspiratory area
56
Vestibulocochlear nerve has nuclei in which two parts of the brain stem?
Pons and medulla
Vestibular branch: sensory axons ending in vestibular nuclei in pons (some enter cerebellum via inferior cerebellar peduncle
Cochlear: sensory axons end in nuclei in medulla oblongata
Axons of motor neurons in both branches project from pons to hair cell sin semicircular and spiral organ
57
Midbrain is also termed what?
Mesenchephalon
58
Function of the midbrain?
| What kind of tracts are here?
```
Connects pons to diencephalon
Both types (like medulla and pons)
```
59
Function of cerebral peduncles
Corticospinal
Corticobulbar
Corticopontine
60
Define tectum
roof
| two pairs of elevations called corpora quadrigemina
61
Define corpora quadrigemina
Superior/inferior colliculi (little hills)
Superior: reflex centers for visual reflexes and visual tracking of moving objects
Inferior: auditory reflex centers
62
What are the two visual reflexes in the Superior Colliculi
| What do these two reflexes account for in one action?
Pupillary reflex: adjusts size of pupil
Accommodation reflex: shape of lens for close/distant vision
Involuntary turning of head when an object is seen out of the corner of an eye
63
Function of inferior colliculi
Relay auditory impulse from ear to thalamus
64
What reflex is located in the inferior colliculi
Startle reflex, involuntary head turning in response to a loud/unexpected noise
65
What are the two nuclei of the midbrain and what are their functions?
Substantia nigra: releases dopamine, subconscious muscle movements
Red nuclei: rich blood and iron containing pigment. Cerebellum and cerebral cortex synapses merge here to coordinate muscular movements
66
Loss of what midbrain nuclei is associated with Parkinson's disease?
Substantia nigra
67
What muscle movements does the Red Nuclei control?
Babies crawling
| Arm movement during walking (large muscles of shoulders and arms)
68
What spinal tract originates in the red nucleus?
| Where does this tract end?
Rubrospinal tract
| Superior thoracic region which is why this tract doesn't have impact in lower limb movement
69
Define reticular formation
Small clusters of neuronal cell bodies along with bundles of myelinated axons
70
Reticular formation comprises of what kinds of neurons?
Sensory
| Motor
71
Main function of descending neurons from reticular formation?
Regulate muscle tone
72
What is the function of the reticular activating system?
Maintain consciousness and participate in awakening from sleep
73
What is the central constricted area of the cerebellum
Vermis
74
What are the lateral lobes of the cerebellum called?
Hemispheres
75
What are the ridges/convolutions of the cerebellum called?
Folia
76
The cerebellar cortex is what color matter?
Gray
77
The white matter of the cerebral cortex forms what structure?
arbor vitae (tree of life)
78
Function of the cerebellar peduncles
White matter axons that conduct impulses between cerebellum and rest of the brain
79
Difference between Cerebral Peduncles and Cerebellar Peduncles
Cerebral: anterior, cerebrum->spine
Cerebellar: posterior, cerebellum->brain
80
What part of the brain regulates posture and balance?
Cerebellum
81
What is the main function of the cerebellum?
Evaluate how well movements are carried out and sending feedback to motor areas
82
Function of the Anterior and Posterior lobes of the cerebellum
Unconscious refinements of skeletal muscle movements
83
What is the function of the floculonodular lobe of the cerebellum
Equilibrium and balance
84
Define ataxia
| What causes this?
```
Inability to coordinate muscle movements
Infection
Injury
Disease
Degenerative changes
```
85
Diencephalon comprises what 4 structures
Thalamus
Hypothalamus
Epithalamus
Subthalamus
86
Diencephalon surrounds what ventricle?
| How far does it extend?
Third
| Stem to cerebrum
87
How are the two halves of the thalamus connected?
Across the third ventricle by bridge of gray matter- intermediate mass
88
Function of the thalamus
Main relay station for most sensory impulses reaching the cerebral cortex from the spine, stem and midbrain
Regulation of autonomic activities and maintenance of consciousness
89
What is the Internal Capsule
Thick band of white matter
| Separates thalamus and caudate nucleus from lentiform nucleus
90
Function of the hypothalamus
Regulator of homeostasis
Regulates the pituitary
"Bosses boss"
```
Control of autonomic NS
Hormone production
Emotion/behavior
Eating/drinking regulation
Body temp
Cardiac rhythms
States of consciousness
```
91
Function of the mammillary bodies
Relay stations for reflexes related to sense of smell
92
What are some of the important parameters interpreted by the hypothalamus?
Glucose
Osmotic pressure
Blood temp
Hormones
93
What comprises f the epithalamus?
| What do those structures do?
Habenular nuclei and pineal gland
Habenular: olfaction, emotional responses to odors
Pineal: secretes melatonin
94
Function of the subthalamus
Works with other structures to control body movement
95
Define gyrus
folds within the brain
96
Define sulcus
Shallow grooves in between gyri
97
Define fissure
| Which ones are more prominent?
Deeper grooves in between gyri
| Longitudinal- separates brain into R/L hemisphere
98
When/how are gyri and fissures formed?
During embryonic development when gray matter of cortex enlarges faster than the deeper white matter
99
How do the R and L hemisphere communicate?
Commissure called Corpus Callosum, the largest fiber bundle in the brain
100
What are the 4 lobes of the brain?
Frontal
Parietal
Temporal
Occipital
101
What separates the frontal lobe from the parietal lobe?
Central sulcus
102
What separates the frontal and temporal lobes?
Lateral cerebral sulcus
103
What separates the parietal lobe from the occipital lobe?
Pariteo-occipital sulcus
104
What are the 3 tracts in the cerebral white matter?
Association tract: myelinated fibers for impulses between gyri in same hemisphere
Commissural tract: myelinated fibers for impulses from gyri to gyri in opposite hemispheres(corpus callosum)
Projection tract: myelinated fibers for impulses from cerebrum to lower CNS (thalamus, stem, cord) OR from them up to CNS(internal capsule)
105
What are the 3 important commissural tracts?
Corpus callosum
Anterior commissure
Posterior commissure
106
What are the 3 nuclei within each cerebral hemisphere?
Globus pallidus
Putamen
Caudate nucleus
107
What comprises the lentiform nucleus?
Globus pallidus
| Putamen
108
What comprises the Corpus striatum?
Globus pallidus
Putamen
Caudate nucleus
109
What does the internal capsule separate?
| Where is it located?
Caudate nucleus of basal ganglia and the thalamus separated from lentiform nucleus of the basal ganglia
Lateral to the thalamus
110
What does the lentiform nucleus consist of?
Putamen and globus pallidus
111
What does the basal ganglia help regulate?
Initiation and termination of movement
Controls inconscient (unconcious) contractions
Muscle tone
Action selection- decision when several possible behaviors to execute at a given time
112
What are the two movement disorders the basal ganglia is involved with?
Parkinsons- melanin-pigment dopamine producing neurons degenerate
Huntingtons- damage to corpus striatum
113
Damage to basal ganglia causes what three signs?
| Damage to the basal ganglia has also been associated to what two conditions?
tremors
stiffness
involuntary movements
OCD and ADHD
114
Define limbic system
Emotional brain
| Emotions, pain, pleasure, docility, affection and anger
115
The cerebral structures of the limbic system encircle what part of the brain?
Upper part of brain stem
116
What are the main components of the limbic system?
```
Hippocampus
Anygdala
Limbic lobe
Dentate gyrus
Cingulate gyrus
Hypothalamus mammillary bodies
Anterior/medial nuclei of thalamus
Olfactory bulbs
Fornix
```
117
Function of the hippocampus
Converting new info to long-term memories
118
Function of the amygdala
Behavior patterns- docile, rage, presence/absence of fear/aggression and restlessness
119
Function and location of Cingulate gyrus
Superior to corpus callosum
Limbic system- emotion formation, learning and memory
Coordinates sensory input with emotions, regulates aggression and mediates emotional response to pain
120
Function and location of Fornix
Band of nerve fibers extending from hippocampus to mamillary body of hypothalamus, forming arch over thalamus
Carries signals from hippocampus to hypothalamus, transfer of info from mammillary body of limbic system to hippocampus
121
Hippocampus is critical for the formation of what two types of memories?
Autobiographical
| Fact
122
What happens when the hippocampus is damages?
Anterograde amnesia- loss/inability to form new memories while preserving old memories
123
What part of the brain is termed the "executive suite" of the NS?
Cerebral cortex
124
What is the function of the cerebral cortex?
Allows us to communicate, perceive, remember, understand, appreciate, and initiate voluntary movements.
Seat of consiousness
125
What kind of matter comprises the cerebral cortex?
Gray matter only
Neuron cell bodies, dendrites, unmyelinated axons plus glia and blood vessels
NO fiber tracts
126
What are the 3 generalizations of the cerebral cortex?
Contralateral concerning
Symmetrical hemispheres in size, not function
No functional area of the cortex acts alone
127
What are the 3 general areas of the cerebral cortex?
Sensory- receive/interpret sensory impulses
Motor- initiate movement
Association- communicate w/ motor cortex and other association areas (analyze, recognize and act on sensory inputs)
128
Define Primary sensory areas
receive nerve impulses from sensory neurons without prior filtering/analysis
129
Define Primary motor areas
originators of voluntary muscular contractions
130
Define Association area
includes cortical areas that do not have word "primary" in their name. Receive input from primary areas, integrate sensory experiences to generate meaningful recognition/awareness
131
Where does speech originate from in the brain?
Broca's area
| Planning and production takes place, impulses sent to premotor regions that control muscles of larynx, pharynx and mouth
132
Function of Wernicke's Area
Interprets meaning of speech by recognizing words
133
Define Aphasia
Inability to use or comprehend words
134
Where are Broca and Wernicke's area located?
L cerebral hemisphere, regardless if R or L handed
135
What causes Non-Fluent Aphasia
Damage to Broca's area
| Know what they want to say but can not speak it
136
What causes Fluent Aphasia?
Damage to Wernicke's area
Faulty understanding of spoken or written words
Words put together but no combined meaning (word salad)
```
Word deafness (inability to understand spoken words)
Word blindness(inability to understand written words)
```
137
L hemisphere has greater control of what functions?
Language
Math
Logic
138
R hemisphere has greater control of what functions?
Visual-spacial
Intuition
Emotion
Ar/music appreciation
139
Define hemispheric lateralization
functional asymmetry of R/L hemisphere control
140
Sequence of events in Alzheimers
```
Difficulty remembering recent events
Confusion/forgetful- repeating questions or getting lost in familiar areas
Disorientation and loss of memories
Loss ability to read, walk, eat, talk
Death attributed to complications
```
141
What 3 findings in autopsy of Alzheimers
Loss of neurons that secrete Ach
Destruction of neurons in nucleus basalis (hallmark)
Beta-amyloid plaques- protein deposits outside of neurons
Neurofibrillary tangles- abnormal bundles of protein filaments inside neurons
142
Define concussion
brain injury characteried by abrupt/temporary loss of consciousness, vision disturbances, equilibrium problems
MOST COMMON brain injury
143
Define contusion
Bruising of the brain from trauma
144
Define free radical
charged molecule w/ unpaired valence e-
145
Define hematoma
localized pool of blood, clotted
146
Define hypoxia
O2 deprivation
147
Define Ischemia
localized reduction of blood flow
148
Define laceration
Tear of the brain, bleeding follows
149
Define necrosis/necrotic
Pathologic death of living tissue
150
Define cerebrovascular accident
Loss of brain function characterized by abrupt onset of neurological symptoms due to destruction of brain tissue
Common cause: intracerebral hemorrhage, emboli and atherosclerosis of cerebral arteries
AKA stroke
151
Define Transient Ischemic Attack
temporary cerebral dysfunction caused by impaired blood to brain
152
Define brain tumor
Abnormal growth of tissue in brain
153
Define ADHD
Learning disorder characterized by poor or short attention span
Hyperactivity
Age inappropriate impulsiveness
154
Define agnosia
inability to recognize significance of sensory stimuli
155
Define apraxia
inability to carry out purposeful movements in absence of paralysis
156
Define lethargy
Functional sluggishness
157
Define Reyes Syndrome
Potentially fatal
Brain and liver involvement after viral infection (chicken pox or influenza) usually in teens/kids who have taken aspirin
158
Define stupor
unresponsiveness from PT w/ only brief arousal after vigorous and repeated stimulation
159
What are the two cranial nerves that only contain sensory neurons?
1 and 2
160
What cranial nerve is predominantly sensory?
7 vestibulocochlear
161
What are the 3 sensory nerves?
1 2 7
162
What are the cranial nerves that are called motor nerves?
3 4 6 12
163
Since cranial nerves can be exclusively motor, so the general principle is that the sensory functions of the motor nerves is ?
Proprioception of muscles
164
What are the mixed nerves?
5 7 9 10
165
What 2 cranial nerves innervate a single muscle only?
4- superior oblique
| 6- lateral rectus
166
All motor cranial nerves have neurons that innervate _____ muscles
somatic (skeletal)
167
What motor cranial nerves also have autonomic motor axons?? What part of the NS do these axons belong to and what is their function?
3 7 9 10
| PNS, innervate glands, smooth and cardiac muscles
168
What does in-situ mean?
as they are "in place"
169
How do olfactory axon receptors reach into the brain?
Through the cribiform plate of the ethmoid bone
170
What is the loss of smell called?
Anosmia
171
How are impulses conveyed from the eye?
Rods/cones to bipolar cells to ganglion cells in retina
172
What is the sequence of anatomical structures behind the eye?
Axons of ganglion to optic nerves to optic chiasm to optic tract
173
What movements does CN 3 control?
Ciliary muscles in lens
Sphincter pupillae (iris)
Levator palpebrae
174
What are the unique facts of CN 4
Smallest CN
| Only nerve to arise from posterior aspect of brainstem
175
What muscle does CN 4 control and what type of movement does the allow?
Superior oblique
| Inferior and lateral
176
Having a PT follow a moving object w/ eyes tests which of the CN?
3 4 6
177
What is the origin and unique fact of CN 5?
Pons
| Largest CN
178
What does CN 5 provide?
Sensory to face, head and anterior 2/3 of tongue
Mastication
179
What are the two roots of CN 5
Smallest- motor, mastication
| Largest- sensory, ophthalmic, maxillary and mandibular nerves (dermatome)
180
Which nerve is targeted by dentists for procedures?
Maxillary nerve of CN 5
181
What CN is tested with the corneal reflex?
Ophthalmic nerve of CN 5
182
What does CN 6 control and what type of movement does this allow?
Lateral rectus muscle
| abduction away from midline
183
What does CN 7 control?
Somatic: Facial expression, Stylohyoid, Posterior belly of digastric, Stapedius muscle
PNS: lacrimal, nasal and saliva glands, taste of anterior 2/3 of tongue
184
What are the branches of CN 7
```
Temporal
Zygomatic
Buccal
Mandibular
Cervical
```
185
What are the two functions of CN 8
Vestibular- equilibrium
| Cochlear- hearing impulses
186
What function does CN 9 provide?
Sensory to posterior 1/3 of tongue for taste and sensation
Baroreceptors in carotid sinus
Chemoreceptors in carotid bodies
Motor fibers to parotid gland
187
Having PT open mouth, protrude tongue and say AAHHH tests what CNs?
9 and 10
188
Functions of CN 10
```
Sensory:
taste
touch
pain
temp
proprioception of epiglottis and pharynx
BP
O2/CO2
```
Somatic:
swallow
cough
voice production
Autonomic:
GI contract/relax
Slowing heart rate
Digestive fluid secretion
189
Hyperactivity of what nerve can lead to stomach ulcers/GURD? How is this fixed?
```
CN 10, vagus
Selective vagotomy (r/l gastric nerve severed)
```
190
Where does CN 11 originate from?
Both brain stem and spinal cord
Called spinal accessory
Only CN w/ spinal cord component
191
What functions does CN 11 control?
Swallowing
| Trapezius/sternocleidomastoid usage
192
Function of CN 12
Innervate all intrinsic and extrinsic tongue muscles, EXCEPT palatoglossus, during speech and swallowing
193
What muscles are used for protruding the tongue?
Genioglossi muscles
194
Where does the spinal cord begin and end?
Continuation of medulla oblongata
| Ends as the Conus Medullaris between L1 and L2
195
What is the singular term for meninges?
Meninx
196
What are the 3 meninges of the spinal cord?
Dura mater
Arachnoid mater
Pia Mater
197
How far does the spine's dura mater extend?
Sac from foramen magnum to second sacral vertebrae
198
Where does the epidural space exist?
| What does it contain?
Between dura mater and wall of vertebral canal
| Fat and CT
199
Where is the subdural space?
| What does it contain?
Between dura mater and arachnoid mater
| Contains interstitial fluid
200
Where is the subarachnoid space?
| What is it filled with?
Between arachnoid and pia mater
| Filled w/ CSF
201
What does the pia mater contain?
Blood vessels for O2 and nutrient supply
202
What protects the spinal cord from sudden displacement and suspends it within it's dural sheath?
Denticulate ligaments- membranous extensions of pia mater that fuse w/ arachnoid mater and inner surface of dura mater
203
How is the arachnoid mater connected to the pia mater?
Arachnoid trabeculae
204
What is the conus medullaris
Where the spine tapers into a conical shape
| Occurs inferior to lumbar enlargement at L1/L2
205
How does the spinal cord get anchored to the coccyx
Filum terminale
| Extension of pia mater from conus medullaris to the coccyx
206
Define cauda equina
| How far does it extend
horse's tail
Fine strands of nerves that branch from column and are before leaving the column
Lumbar
Sacral
Coccygeal
207
Where is a spinal tap done?
L3/L4 or L4/L5
| Into subarachnoid space
208
What are the reasons for doing a spinal tap?
```
Withdraw CSF
Introduce ABX
Introduce contrast
Introduce anesthetics
Administer chemo
Measure CSF pressure
```
209
How many axon bundles connect each spinal nerve?
2 bundles connect each nerve to a cord segment
210
When in the spine, bundles are called ____ and axons are called ____
```
bundles= roots
axons= rootlets
```
211
What are the two spinal roots
Posterior (dorsal)
| Anterior (ventral)
212
What are the posterior/anterior roots containing?
Post root ganglion- sensory
| Anterior root and rootlets- motor neurons
213
What shape does the gray matter in the spinal cord make?
H for butterfly, surrounded by white matter
| Gray commissure forms crossbar of the H
214
What are the make up of the parts of the gray H in the spinal cord?
Anterior horns- somatic motor neurons and motor nuclei for skeletal muscle contraction
Posterior horns- Somatic and autonomic sensory nuclei
215
The central canal within the spinal cord extends how far?
Continuous w/ 4th ventricle of medulla oblongata of the brain
216
What do the lateral gray horns of the spinal column contain?
Cell bodies of autonomic motor neurons for regulation activity of smooth and cardiac muscles and glands
217
Where/how far down are gray horns present in the spine?
Only in thoracic and upper lumber
| T1-L3 and S2-4
218
What is the overall functional aspect of the spinal cord gray matter?
Receives and integrates incoming/outgoing information
219
What are the purposes of the cervical and lumbar enlargements?
Accommodate nerves to/from upper and lower limbs
220
What are the S/Sx of polio onset?
Fever
Stiff neck/back
Severe headache
Deep muscle pain/weakness
221
How does the Polio virus effect the body?
| How can this cause death?
Destroys cell bodies of motor neuron in anterior horns of spinal cord and nuclei of cranial nerves
Respiratory/heart failure
222
The anterior/posterior gray horns of the spine divide the white matter into what 3 broad columns?
Anterior
Posterior
Lateral
223
What are bundles of myelinated axons called?
tracts
| Common origin or destination and carry similar info
224
Spinal nerves and nerves branching from it are a part of what nervous system?
PNS
225
What connects the CNS to PNS?
Spinal nerves (31 pairs)
226
Where does the first cervical pair of spinal nerves emerge from?
Between occipital bone and atlas
| All other emerge from intervertebral foramina
227
How are spinal nerves named?
```
C1-8
T1-12
L1-5
S1-5
Co1
```
228
Most spinal nerves exit the cord where with what exception?
Inferior to the vertebra of the same number
| C1- exits superior to atlas
229
Spinal cord growth occurs until what age?
4-5y/o
230
How do spinal nerves emerge, join and extend?
Emerge from dorsal/ventral surfaces of cord
Converge to form dorsal/vetral roots
Nerve roots unite at points of exit from vertebral canal to form spinal nerve
Spinal nerve splits into dorsal/ventral primary ramus
231
What are the layers of CT coverings in the spinal nerves?
Endoneurium- individual axon covering
Perineurium- covers fascicles
Epineurium covers entire nerve
232
Define ramus
Branches of nerves after passing through intervertebral foramen
233
The ___ are the terminal branches of the spinal nerves
Rami
234
The posterior ramus innervates what parts of the body?
| Anterior ramus?
Post: Deep muscles and skin of dorsal surface of the trunk
Ant: muscles and structures of upper/lower limbs, skin of lateral and ventral surfaces of trunk
235
What is the function of the meningeal branch of each spinal nerve?
Reenters the vertebral canal to supply vertebrae and structures
236
What is the function of the rami communicantes
Contribute to trunk ganglia of autonomic NS
237
Define plexus
| What region of the spine does not have a plexus?
Network of axons of paired anterior rami
| Thoracic
238
What composes the intercostal nerves?
Anterior rami of T2-12
239
Anterior rami of thoracic nerves connect/supply where?
Intercostal muscles
Abdominal muscles
Skin above previously mentioned muscles
240
Posterior rami of the intercostal nerves supply what/where?
Deep back muscles and skin posterior to thorax
241
Plexuses contain what types of neurons?
Motor and sensory
242
Plexus roots come from where?
| What forms trunks of plexuses?
Roots- arise from spinal cord
| Trunks- formed by union of roots (only in brachial plexus)
243
What are the 3 trunks plexuses in the brachial plexus?
| How are they further subdivided?
Superior
Middle
Inferior
Anterior and posterior
244
Function of the cervical plexus?
Supplies skin and muscles of head, neck, superior shoulders/chest and diaphragm
245
Where do the phrenic nerves arise from?
| What do they supply?
Cervical plexuses
| Supply motor fibers of diaphragm
246
What does the brachial plexus supply?
Shoulder and upper limbs
247
Where does the radial nerve arise and what is it's function?
Brachial plexus
| Supplies muscles to posterior arm/forearm
248
How do you know if the radial nerve is injured?
| How does this occur?
Wrist drop- inability to extend wrist and fingers
| Can occur from improperly administered IM injection in deltoid or from cast applied too tightly on mid-humerus
249
What does the lumbar plexus supply?
Anterolateral abdominal wall
External genitals
Lower limbs
250
What does the sacral plexus supply?
Buttocks
Perineum
Lower limbs
251
What happens during sciatic nerve injury?
Largest nerve in the body
2 nerves connected by CT arising from sacral plexus
Injury causes sciatica- pain down buttock to posterior and lateral leg and foot
252
What does the sciatic nerve supply?
Muscles of leg, foot and toes
253
What types of injuries can cause sciatica?
Disc herniation
Dislocated hip
Pregnancy
Improperly administered IM injection
254
Define cutaneous sensations
Sensation that arises in skin
| Includes tactile sensations (touch, pressure, vibration, ticking) thermal (warm, cold) and pain sensations
255
What are the two maps of conveying cutaneous sensations towards the CNS?
Dermatomes
Peripheral nerve fields (cutaneous nerves)
Map difference due to plexuses
256
Adjacent dermatomes typically overlap except for where?
Axial line
257
What causes shingles?
Acute infection of PNS caused by herpes zoster virus (chicken pox)
258
Where does shingles remain dormant in the body?
| Where does it travel when it emerges?
Posterior root ganglion
| Along sensory neurons by fast axonal transport
259
What are the two principal functions of the spinal cord in maintenance of homeostasis?
Nerve impulse propagation
| Information integration
260
What does gray and white matter doe with impulses during homeostasis maintenance?
Gray- receives and integrates incoming/outgoing info
White- carry sensory impulses towards brain and motor impulses away from brain
261
How are tracts named?
By 3 things:
the position within the white matter
Beginning and end
Extension, direction of flow
262
Define discriminative touch
Ability to feel exactly what part of the body is being touched
263
Define 2 point discrimination
Ability to distinguish between touch of two different points on skin that are close together
264
Motor output to skeletal muscles travels down the cord in what two types of descending pathways
Direct
| Indirect
265
Define direct pathways
What do they carry
What tracts are included?
Originate in cerebral cortex
Precise, voluntary movement of skeletal muscles
Includes lateral corticospinal, anterior corticospinal and corticobulbar tracts
266
Define indirect pathways
Originate in brain stem or part of brain with autonomic control
Coordinate movement w/ visual stimuli, maintain skeletal tone and contraction of postural muscles, regulate tone in response to head movements
```
Includes:
Rubrospinal
Tectospinal
Vestibulospinal
Lateral reticulospinal
Medial reticulospinal tracts
```
267
Define reflex
fast, involuntary, unplanned sequence of actions in response to stimuli
268
What are the 2 types of reflexes
Innate (inborn)
| learned
269
The type of a reflex is based on the site of integration, what are the two sites?
Spinal- gray matter
| Cranial- brain stem
270
Somatic reflexes involve contraction of ___ muscles compared to a visceral reflex what involves what type of muscles
Skeletal
| Smooth, cardiac and glands
271
Dermatomes are only associated with what sense?
sensory
272
Reflex arc aka ?
Reflex circuit
273
What are the five functional components of the reflex arcs?
```
Sensory receptor
Sensory neuron
Integrating center
Motor neuron
Effector
```
274
Sensory receptor responds to a specific stimulus by producing what?
Graded potential called generator (receptor) potential
275
The integrating center is comprised of what type of matter?
Gray spinal cord matter
276
Define monosynaptic arc
integrating center of one synapse between sensory neuron and motor neuron, simplest refelx
277
What type of reflex arc is the stretch reflex (patellar reflex)
What is the opposite reflex?
Monosynaptic, ipsilateral
| Polysynaptic, interneuron of reciprocal innervation
278
Define Westphal's Sign
Correlation of the absence or decrease of patellar reflex/knee jerk
Sign of receptor damage or lesion of dorsal column of spinal cod or cerebellum
Lesion on motor cortex of pyramid tracts
Motor impulse transmission in femoral nerve
279
What kind of reflex is the tendon reflex?
Polysynaptic, ipsilateral reflex
280
Where are tension receptors located?
Golgi tendon organs located in tendons at the MSJ of skeletal muscles
281
What are the 3 phases of the tendon reflex?
Tendon stretches and activates tension receptors
Inhibitory neuron stimulated
Motor neuron is hyperpolarized and muscle relaxes
282
Stretch reflex involves muscle spindles which are ________ located in ___ muscles
proprioceptors
| skeletal
283
Tendon reflex involves ____ organs which are located where?
tendon
| tendons at the junction of the tendon and the muscle
284
What does the tendon reflex prevent
Application of excessive force to muscle/tendon by causing relaxation
285
What does the stretch reflex prevent?
Prevents over stretching of a muscle by causing contraction
286
Define flexor (withdrawal) reflex
Ipsilateral
| Protective withdrawal reflex that moves a limb to avoid pain (aka nociceptive withdrawal reflex)
287
Stretch reflex is ____innvervation
reciprocal
288
Define crossed extensor reflex
Contralateral
Maintains balance during flexor reflex by causing synchronized extension of joints of one limb and flexion of joints in the opposite limb
289
Example sequence of events fo flexor (withdrawal) reflex
Pain fibers send signal to spine
Interneurons branch to different spine segments
Motor fibers in several segments activated
Multiple muscle groups activated to lift foot
290
Example sequence of events during crossed extensor reflex
Lifting R foot req's extension of L leg to maintain balance
Pain signals cross to opposite side of spinal cord
Contralateral extensors stimulated by interneurons to hold up body weight
Reciprocal innervation occurs
291
Define reciprocal innervation
when extensors contract,
| flexors relax
292
Define Babinski sign
Dorsiflexion of great toe w/ or w/out fanning of other toes
293
When is Babinski's sign normal and abnormal
Normal- Children under 18mon due to incomplete myelination of fibers in corticospinal tract
Abnormal- present after 18mon
Indicates interruption of corticospinal tract due to lesion
294
What is a "normal" Babinski response after 18mon of age?
Curling of toes
295
Define Clasp Knife reflex
Stretch reflex w/ rapid decrease in resistance when attempting to flex joint
Characteristic response of upper motor neuron lesion, indicating damage to a pyramidal tract
Spastic limb resists passive motion then suddenly gives way
296
What happens to muscles with presence of an upper motor neuron lesion
Muscle tonus increased
Resistance of muscle to stretch increase
With enough applied force, limb resistance suddenly decreases
297
Hyperactive reflexes suggest ?
| Decreased reflexes are found ?
CNS disease
Damage to relevant spine segments
Muscle diseases
NMJ diseases
Loss of sensation
298
Define monoplegia
Paralysis of one limb only
299
Define diplegia
Paralysis of both upper/lower limbs
300
Define paraplegia
Paralysis of both lower limbs
301
Define hemiplegia
Paralysis of both upper limbs, trunk and lower limb on one body side
302
Define hemisection
Partial transection of spinal cord on either side
303
Define areflexia
loss of reflex function
304
Define myelitis
inflammation of spinal cord
305
Define myelography
CT or Xray of spine taken after injection of radiopaque dye to diagnose tumors/herniations
306
Define neuralgia
attacks of pain along entire/branch of sensory nerve
307
Define neuritis
inflammation of one or several nerves
308
Define parasthesia
Abnormal sensation resulting from disorder of sensory nerve
309
Most input to ANS comes from what type of receptors?
Interoceptors
Chemoreceptors
Mechanoreptors
310
How does the ANS regulate visceral activities?
Excite or inhibit activities of effector tissues
311
What is the difference between skeletal and ANS tissues?
Unlike skeletal, ANS tissues have intrinsic function that enables them to continue to operate with damaged nerve supply
312
ANS motor pathways consists of __ motor neurons in series
2
313
Define ANS pre-ganglionic neuron
First neuron with cell body in CNS and myelinated axon extending from CNS to autonomic ganglion
2nd- cell body in ganglion, unmelinated axon extends from ganglion to effector= post-ganglionic neuron
314
All pre ganglionic neurons are
| All post ganglionic neuron are
myelinated
| unmyelinated
315
Somatic motor neurons only release ___
| Autonomic motor neurons release ___ or ____
AcH
| AcH or NorEpi
316
What are the two parts of the motor part of the ANS
Sympathetic
| Parasympathetic
317
What does it mean for an organ to have dual innervation
Receive impulses from both para/symp
318
Autonomic motor pathways consist of what two neurons?
Preganglionic
| Postganglionic
319
Where are preganglionic neuron cell body's located?
| Where do their axons exist?
Body: Brain and Spinal cord
Axon: CNS in cranial or spinal nerves
320
Where do preganglionic nuerons convey impulses to/from?
From CNS to autonomic ganglia
321
What is the first and secondary motor motor neuron
First: preganglionic neuron
Second: postganglionic
322
Where are postganglionic neuron body and dendrite located?
Body and dendrite located in autonomic ganglion
323
Where do postganglionic neurons relay impulses to/from
From autonomic ganglia to visceral effectors
324
Preganglionic neurons of the sympathetic division have their cell bodies located where?
Lateral gray horns of the 12 thoracic and first 2 lumbar segments
325
Preganglionic neurons of the parasympathetic division have their cell bodies located where?
Nuclei of CN 3 7 9 10
| Lateral gray horns of 2-4 sacral segments
326
Sympathetic ganglia are the sites of synapses between what two neurons
Between sympathetic pre and postganglion neurons
327
What are the two major types of sympathetic ganglia
Sympathetic trunk ganglia
| Prevertebral ganglia
328
Sypathetic trunk ganglia are aka?
Vertebral Chain Ganglia
| Paravertebral Ganglia
329
Sympathetic trunk preganglionic axons are how long?
Short
| Same as prevertebral axons
330
Sympathetic trunk postganglionic axons mostly innervate organs above _____
Diaphragm
331
Sympathetic trunk postganglionic axons are how long?
Fairly long
| Same as preganglionic axons
332
Prevertebral ganglia are ___ to the vertebral column and lie close to ______
anterior
| large abdominal arteries
333
Prevertebral postganglionic axons mostly innervate organs below ____
Diaphragm
334
What are the 5 major prevertebral ganglia
```
Celiac
Superior mesenteric
Inferior mesenteric
Aorticorenal
Renal
```
335
Most terminal ganglia of parasympathetic ganglia are located close to or within where?
Wall of visceral organ
336
Parasympathetic preganglionic axons are typically ____ and postganglionic axons are _____
Long
| Short
337
Parasympathetic ganglia of the head have what four specific names?
Ciliary
Pterygopalatine
Submandibular
Otic
338
Parasympathetic spanchnic nerves extend to _____
viscera
339
How and where do axons of parasympathetic neurons extend to parasympathetic postganglionic neurons in terminal ganglia?
Colon walls
Bladder
Reproductive organs
Via splanchnic nerves
340
Sympathetic preganglionic neurons arriving at sympathetic trunk ganglia connect w/ postganglionic neurons by what 4 ways?
Synapsing in first ganglion it reaches
A/descending before synapsing
Continuing to prevertebral ganglion and synapsing
Extend to chromaffin cells of adrenal meudllae
341
Parasympathetic ganglia are often called ___ ganglia
Terminal
342
Define divergent projection pattern and what does this phenomenon explain
Sympathetic pregangionic fibers w/ many axon collaterals that synapse with 20 or more postganglionic neurons
Explains why sympathetic responses affect most of body simultaneously
343
Postganglionic axons of the sympathetic division usually terminate where?
In several effectors after leaving ganglia
344
Parasympathetic preganglionic neurons have ___ axon collaterals while sympathetic preganglionic fibers have ___ axon collaterals
Symp. Pre- many
| Para. Pre- few
345
What explains why parasympathetic responses are localized to a single effector?
Few axon collaterals and synapse with limited postganglionic neurons in the same visceral effector
346
Where do parasympathetic postganglion axons terminate?
Same effector after leaving ganglia
347
What two systems for to make an autonomic plexus?
Symp and Parasymp NS
348
Where are autonomic plexuses present?
Thorax- cardiac/pulmonayr
Abdomen- celicac, sup/inf mesenteric
Pelvis- hypogastric and renal
Lie along major arteries
349
Visceral afferent fibers are commonly present where?
Autonomic plexuses
350
Characteristics of cardiac plexus
Base of heart surrounding large blood vessels that emerge from heart
Contributed by BOTH pre and post ganglionic parasym. nerves
351
Characteristics of pulmonary plexus
Posterior to lungs
Symp= bronchi dilation
Para= constriction and secretion
352
Characteristics of celiac plexus
AKA solar plexus
Largest autonomic plexus surrounding celiac and superior mesenteric arteries
Located at last thoracic/first lumbar vertebrae
353
Characteristics of Sup/Inf mesenteric plexus
Sup- small and large intestine
| Inf- large intestine
354
Characteristics of hypogastric plexus
Supplies pelvic viscera- bladder and genitals
355
Characteristics of renal plexus
Supplies renal arteries in kidneys and ureters
356
Where are sympathetic preganglionic neurons located?
Lateral horns of all thoracic and first 2 or 3 lumbar vertebrae
357
How do the myelinated axons of the symp. preganglions enter an adjoining paravertebral ganglion
Through white ramus communicans
358
Where does sympathetic outflow only occur?
All of thoracic and first 2 lumbar vertebrae
359
Describe cervical ganglia
Symp preganglion fibers serving head and neck
Emerge from T1-6 and synapse w/ postganglion nerves in cervical ganglia (superior, middle and inferior cervical ganglion)
360
Where do superior cervical ganglion postganglionic sympathetic fiber supply?
Head
Heart
Sweat, salivary, pineal, lacrimal glands
Eye smooth muscle
Heart
Facial vessels
361
What region receives the most of the sympathetic preganglionic axons
Thoracic
362
What do thoracic postganglia fibers supply?
```
Heart
Lungs
Bronchi
Sweat glands
Blood vessels
Arrectores muscles
```
363
Axons leave sympathetic trunk in 4 ways
Enter spinal nerves
Cephalic periarterial nerves
Sympathetic nerves
Splanchnic nerves
364
How do unmyelinated postganglionic axons connect to ganglia of sympathetic trunk to spinal nerves
gray ramus communications
365
Gray ramus communications are associated with all ______ nerves
Spinal
| White only associated with thoracic and first 3 lumbar
366
Where do cephalic periarterial nerves supply sympathetic innervation to?
Skin of the face(sweat, vessels, arrectores pilorum muscles)
| Visceral effectors of head (eye muscles, lacrimal/pineal/salivary glands, nasal mucosa)
367
Postganglionic neurons form sympathetic nerves that extend to visceral effector in thoracic cavity to provide ?
Heart
Sup, middle, inf cervical ganglia
1-4th thoracic ganglia
Lung/bronchi smooth muscles
368
What happens to the sympathetic preganglionic neurons that pass through the trunk without terminating?
For splanchnic nerves that generally extend to prevertebral ganglia
369
Postganglionic neurons of the greater splanchnic nerve supply ?
What does the lesser splanchnic nerve supply?
```
Liver
Stomach
Spleen
Small intestine
Kidney
```
Lesser: Small intestine and colon
370
What does the lumbar splanchnic nerve innervate?
Colon
Rectum
Genitals
Bladder
371
Where are paraymp. pregang. neuron cell bodies found?
Nuclei in brain stem
| Lateral horns of 2-4 sacral segments
372
What does the parasympathetic outflow consist of?
Preganglionic axons from brain stem in 4 cranial nerves
373
What does the sacral parasympathetic outflow consist of?
Preganglionic axons in anterior roots of the 2-4 sacral spinal nerves
374
How do aparasymp. pregang. neuron axons end?
Myelinated and end in terminal ganglia near the organ they innervate
375
Where doe the ciliary ganglia associate with?
CN3
376
What does the pterygopalatine ganglia associate with?
CN 7
377
What does the submandibular ganglia associate with?
CN 7
378
What does the otic ganglia associate with?
CN 9
379
80% of total craniosacral outflow is carried by what axons?
Preganglionic axons part of CN 10
380
What forms the pelvic splanchnic nerves
Preganglionic neurons of sacral parasympathetic outflow
381
Autonomic neurons are classified into what two groups based on what?
Neurotransmitter released
Cholinergic- releases ACh
Adrenergic- norepi (aka noradrenalin)
382
Cholinergic neurons includes what neurons?
All para/sympathetic preganglionic neurons
All Parasympathetic prostaglandin nuerons
Symp. postgang. that innervate sweat glands
Somatic nervous system motor neurons
383
Sympathetic postgangleon neurons release
norepi
384
Sympathetic sweat glands that innervate sweat glands releases ?
ACh
385
Adrenergic neurons are most ____ _____ neurons
sympathetic postganglionic neurons
386
Receptors for neurotransmitters are what type of proteins?
Integral membrane proteins located in plasma membrane of post-synaptic neuron/effector cell
387
All cholinergic receptor bind to ____
ACh
388
What are the two types of cholinergic receptors?
Nicotinic- nicotine mimics action of ACh by binding to this receptor
Muscarinic- muschroom poison muscarine binds and mimics ACh
No cross activation, both activated by ACh
389
What happens when a nicotinic receptor is activated?
ACh causes depolarization (excitation) of post-synaptic cell
Postganglionic neuron
Skeletal muscle fibers
390
What happens when muscarinic receptors are activated?
Depolarization and sometime hyperpolarization (inhibition)
Smooth muscle sphincters of GI tract- relax
ACh in eye sphincters- contraction
391
Activation of muscarinic receptors causes ____ syndrome
```
Defecation
Urination
Miosis
Bronchoconstriction
Emesis
Lacrimation
Salivation
```
392
All adrenergic receptors bind to ____ and _____
norepi
| epi
393
How are adrenergic receptors activated?
Norepi- symp. postgang neuron
| Epi- hormones in blood by adrenal medulla
394
What are the two types of adrenergic receptors?
Alpha (1, 2)
| Beta (1, 2)
395
Activation of subscript 1 receptors (a1 and b1) is what type of response?
What is activation by subscript 2?
```
1= excitatory
2= inhibitory
```
396
Where is B3 receptors found?
Only in cells of brown adipose tissue where activation causes thermogenesis
397
When/how does norepi activity end?
Reuptake
| Enzyme incativation: COMT or MAO
398
How/why does norepi effects remainin action longer?
linger in synaptic cleft longer than ACh
399
Define agonist
substance that binds to receptor and triggers a response
400
Define antagonist
binds to receptor and blocks receptor from activation by agonist
401
Define partial agonist
activates receptor but does not cause physiological change
402
Where are B1 receptors found?
Heart
403
Why are Beta blockers used?
Adrenergic blockers that attach to B1 receptors
404
Where are A1 receptors located?
blood vessels of all sympathetic target organs EXCEPT heart
405
What happens when adrenalin binds w/ A1 receptors?
Vessels and visceral sphincters contract
| Pupils dilate
406
When/why are alpha blockers used?
Block A1 receptors, relaxing muscles that constrict vessles
407
Define autonomic tone
| What regulates it
balance between sympathetic and parasympathetic activity
| Regulated by hypothalamus
408
What are some structures that receive ONLY sympathetic innervation?
```
Sweat glands
Adrenal glands
Arrector muscles
Kidneys
Spleen
Blood vessels
```
409
Why is the sympathetic division called the E division?
Exercise
Excitement
Emergency
Embarrassment
410
Sympathetic activation has what impact on metabolic processes?
Constrict abdominal viscera
| Glycogenolysis
411
What is the acronym to sum up the parasympathetic responses?
```
SLUDD
Salivation
Lacrimation
Urination
Digestion
Defecation
```
412
Overall components of an autonomic reflex arc are the same as _________
```
Somatic reflex arc
Sensory receptor
Sensory neuron
Integrating center
Motor Neuron
Effector
```
413
Where is the receptor in an autonomic reflex?
Distal end of a sensory neuron
414
Autonomic sensory receptors are generally what type of receptor?
Interoceptor
415
Cell bodies of visceral sensory organs are located where?
Sensory ganglia of associated cranial nerves or in dorsal root ganglia of spinal cord
416
What is the main integrating center for most autonomic reflexes?
Hypothalamus and brain stem
| Some in spinal cord
417
What are the two motor neurons that connect the CNS to an effector?
Pregang.: From CNS to autonomic ganglion, myelinated
| Postgang: from ganglion to effector, unmelinated
418
What are the 3 effectors in an autonomic reflex?
Smooth muscle
Cardiac muscle
Glands
419
Define Raynaud disease
digits become ischemic after exposure to cold or with emotional stress
Due to excessive sympathetic stimulation of smooth muscles in the arterioles
420
Effect of atropine?
Anticholinergic that blocks parasympathetic effects
```
Suppresses salivation and respiratory secretions
Dilutes pupils (mydriatic agent)
Antidote to inactivate acetylcholinesterase
```
421
Effect of Neostigmine
anticholinesterase druge
Inhibits AChesterase allowing ACh to accumulate in synapse
Treatment of myasthenia gravis
422
Function of Trycyclic antidepressants
Antidepressants that help relieve depression
Prolongs activity of Norepi on postsynaptic membrane
Brand names Elavil and Sinequan
423
What are MAO inhibitors
Monoamine oxidase
Inactivates norepi
Relieve depression
