Lecture 1 Flashcards
1
Q
What are the systems in charge of maintaining homeostasis?
A
nervous system and endocrine system
2
Q
What is the nervous system responsible for?
A
behaviours
memories
movements
3
Q
What are the 3 basic functions of the nervous system?
A
- sensing changes w/ sensory receptors
- interpreting and remembering those changes
- reacting to those changes w/ effectors
4
Q
What does the nervous system use to react w/ changes w/ effectors?
A
Muscular contractions
Glandular secretions
5
Q
What output is the nervous system always going to put out?
A
motor
6
Q
What makes up the PNS?
A
- 12 cranial nerves
- 31 spinal nerves
- enteric plexuses in small intestine
- sensory receptors in skin
(ganglia & nerve plexuses)
7
Q
What makes up the CNS?
A
- brain
- spinal cord
8
Q
What are the pathways called that travel into the CNS?
A
afferent - sensory
9
Q
What are the pathways that travel out of the CNS?
A
efferent - motor
10
Q
Where does the constant feedback loop of the nervous system begin and end?
A
in the PNS
11
Q
What are the two subdivisions of the nervous system?
A
CNS and PNS
12
Q
What does the afferent or sensory division transmit?
A
impulses from peripheral organs to the CNS
13
Q
What does the efferent division transmit?
A
impulses from CNS to peripheral organs to cause an effect or action
14
Q
What are the divisions of the efferent/motor division?
A
somatic nervous system
autonomic nervous system
15
Q
What is the role of the Somatic nervous system ?
A
supply motor impulses to the skeletal muscles - voluntary control
16
Q
What is the role of the Autonomic NS?
A
supplies motor impulses to cardiac muscle, smooth muscle, and glands
17
Q
What is another name for the ANS?
A
visceral motor
18
Q
What are the divisions of the ANS?
A
sympathetic, parasympathetic, and enteric divisions
19
Q
What division governs the function of the GI tract?
A
enteric nervous system
20
Q
what are the divisions of the Peripheral NS?
A
afferent (sensory)
efferent (motor)
21
Q
What are the 3 sensory sense divisions?
A
somatic
special
visceral
22
Q
What are somatic senses?
A
general sensation (ex., touch, temperature, tickle, itch, pressure, pain, proprioception, vibration)
23
Q
What are the special senses?
A
sight, smell, taste, hearing, balance
24
Q
What are the visceral senses?
A
pain, stretch of organ wall, blood pressure, pH of fluids within lumen, osmolarity of fluids
25
What senses are you not aware of?
visceral
26
What is somatic motor?
voluntary control of skeletal muscle (either ON or OFF: contracting or not)
27
What is autonomic motor?
involuntary control of smooth & cardiac muscle
28
Any muscle innervated by autonomic motor signal will either be sympathetic mode or parasympathetic mode, which means?
they will never be OFF
29
What are the major divisions of the brain?
cerebrum
diencephalon
cerebellum
brainstem
30
What are the components if the brainstem?
midbrain
pons
medulla oblongata
31
What higher mental activities is the CNS involved in?
learning, memory, and reasoning
32
What does the CNS process?
incoming sensory and outgoing motor messages
33
What is gray matter comprised of?
nerve cell bodies
bundles of unmyelinated nerve fibres
non-neuronal supportive cells, the glial cells or neuroglia
34
What comprises the white matter?
bundles of myelinated nerve fibres known as tracts or fasciculi (singular, fasciculus)
35
The nervous tissue in the CNS is organized as?
gray and white matter
36
the gray matter forms an H-shaped inner core surrounded by white matter in which anatomical structure?
spinal cord
37
a thin outer shell of gray matter, the cortex, covers the core of the white matter in which anatomical structure?
brain
38
A cluster of nerve cell bodies embedded within the CNS is called a?
nucleus
39
aggregation of nerve cell bodies outside the CNS is called?
ganglion
40
When is the primitive brain in place?
by week 3
41
What are the 3 primary vesicles?
prosencephalon (forebrain)
mesencephalon (midbrain)
rhombencephalon (hindbrain)
42
What are the divisions of the prosencephalon ?
telencephalon (cerebral hemispheres)
diencephalon (thalamus, hypothalamus, and epithalamus)
43
What are the divisions of the rhombencephalon?
metencephalon (pons, cerebellum)
myelencephalon (medulla)
44
What is matter made up of?
neurons
45
What are components of neurons?
dendrites, cell body, axon, axon terminal
46
Where do signals synapse?
in gray matter
47
Where do signals travel?
in white matter
48
What are the 2 cells of nervous tissue?
neuroglia
neurons
49
Which cell supports cells of the nervous system?
neuroglia
50
Which cells nourish and clean up after neurons?
neuroglia
51
T/F: Neuroglia send signals throughout the body, and neurons help them send these signals
False, vice versa
52
Where are neuroglia found?
primarily in gray matter
53
Where does synapsing occur between cells?
gray matter
54
Where can you find gray matter?
cerebral cortex
cortical nuceli/diencephalon
grey horns of spinal cord
55
where does information processing/passing of signals occur?
gray matter
56
where do signals travel from one location to another within the CNS?
white matter
57
Where can you find white matter?
- any are we find axons
cerebral tracts (corpus callosum)
white columns of spinal cord
spinal pathways
peripheral nerves
58
What is nucleus?
gray matter in CNS
59
What is ganglion?
gray matter in PNS
60
What is white matter in CNS called?
tracts and/or fasciculus
61
What is white matter outside of CNS called?
nerve
62
What does the cerebrum consist of?
outer cerebral cortex
internal region of cerebral white matter
nuclei deep within white matter
63
What comprises left and right cerebral hemispheres within the anterior and middle cranial fossae?
cerebrum
64
What separates the two hemispheres?
longitudinal fissure
65
What are the 4 main lobes of the cerebral hemisphere?
frontal
parietal
occipital
temporal
66
What is the small hidden portion deep to the lateral sulcus in the cerebral hemisphere?
insula (insular lobe, insular cortex)
67
What is the primary role of the frontal lobe?
motor impulses
cognition, control of voluntary movement, motor production of speech (expressive language)
Special Sensation: Smell
68
What is the primary role of the parietal lobe?
recieve general sensory stimuli
processes sensory information
General sensations: pain, pressure, temperature, touch, tickle, and vibration
Special Sensations: taste
69
What is the primary role of the temporal lobe?
processes memories
Special Sensation: auditory information
70
What is the primary role of the occipital lobe?
primarily responsible for processing visual sensation (special sensation)
71
What is the primary role of the insula?
taste impulses
72
What are the folds/bumps in the cerebral hemisphere called?
gyri
73
What are the furrows/indentations in the cerebral hemisphere called?
sulci
74
What are the 3 main sulci in each cerebal hemisphere?
central sulcus
lateral sulcus
parieto-occipital sulcus
75
What does the central sulcus separate?
frontal lobe from parietal lobe
76
Where is the lateral sulcus, what does it separate?
superior boundary of temporal lobe
separates it from frontal & parietal lobes
77
What does the parieto-occipital sulcus separate?
parietal lobe from occipital lobe
78
What is the outermost layer of the brain?
cerebral cortex
79
What is associated with high level processing and functioning?
cerebral cortex
80
What is the cerebral cortex divided into?
right & left hemispheres
81
What is a fissure?
deep sulcus
82
What fissure divides cerebral cortex hemispheres?
longitudinal fissure
83
What are the clusters of nuclei within white matter called?
basal ganglia (nuclei)
84
What forms the cerebral cortex?
gray matter
85
What are the main components of basal ganglia?
caudate and lenticular (putamen and globus pallidus) nuclei
86
What are caudate and lenticular (putamen and globus pallidus) nuclei involved in?
coordination of motor function
87
T/F: Gray matter is located deep in the cortex
False, white matter
88
What are the 3 groups of nerve bundles in the white matter of the cerebrum?
association
comissural
projectional
89
What do association fibres join?
different parts of the same cerebral hemisphere
90
What do commissural fibres connect?
different gyri of one hemisphere to the corresponding gyri of the other hemisphere
91
What is the most extensive commissural fibre bundle located at the bottom of the longitudinal fissure?
corpus callosum
92
What do projectional fibres include?
ascending (sensory) and descending (motor) fibres connecting the cortex to the lower centers of the CNS
93
What type of fibre is the internal capsule?
projectional fibres
94
What is the thick band of white matter between caudate nucleus and putamen (two of the nuclei of the basal ganglia) anteriorly, thalamus and globus pallidus (one of the basal ganglia) posteriorly?
internal capsule
95
What is the role of basal ganglia?
ensuring coordinated meaningful movement
helps sift out signals that are useless
96
What are the 3 major areas in each cerebral hemisphere?
primary sensory areas
primary motor area
association areas (sensory and motor)
97
What are in each cerebral hemisphere exhibits characteristic receptor selectivity, which means that only a specific type of stimulus can stimulate the receptor to produce its receptor potential?
primary sensory areas
98
From the receptor in we follow a course of peripheral nerve (either cranial or spinal), which will convey the impulse into?
appropriate pathway (tract)
99
What do pathways generally tend to make synapses in with relation to primary senses?
thalamic nuclei
100
The thalamus only gets a crude perception of the signal received, it can’t determine the exact location or shape; therefore?
must forward the incoming signals toward the appropriate cortical area of the cerebrum
101
Where does final analysis and interpretation happen in primary sensory areas?
cerebral cortex
102
What are visual pathway signals perceived as in the cerebral cortex?
images
103
What are auditory pathway signals perceived as in the cerebral cortex?
sounds or words
104
T/F: In the cerebral cortex any tactile sensation would be interpreted fully
True
105
What do primary sensory areas respond to?
sensory signals
106
What does the primary motor area do?
generates outgoing motor signals
107
What do association areas do?
integrate sensory and motor
108
From the receptor --> A course of peripheral nerve (either cranial or spinal) --> A pathway (Tract) --> Thalamus (crude sensation --> Appropriate cortical area for the perception of the sense
primary sensory areas
109
Where is the primary somatosensory area located?
postcentral gyrus
110
Where is the postcentral gyrus located?
over medial and lateral surface of cerebral hemisphere
111
Human-like creature illustrates different parts of the human body having different spatial presentations on the cortex
homunculus - cortical mapping
112
Where is the primary visual area located?
in occipital lobe
113
Where is the primary auditory area located?
upper portion of temporal lobe
114
Where is the primary gustatory (taste) area located?
in insula (insular lobe)
115
Where is the primary olfactory area located?
medial aspect of temporal lobe
116
How is the primary somatosensory area divided?
based on concentration of sensory receptors
117
T/F: Primary somatosensory area on right recieves all sensory info from left side
true
118
What area controls (creates impulses) that travel along the corticospinal tract (pathway) and feed spinal nerves, or the corticobulbar tract (pathway), providing stimuli to the nuclei of cranial nerves?
primary motor
119
Where do the primary motor pathways start?
from the pyramidal cells in the precentral gyrus located in the frontal lobe (the corticospinal tract is also called the pyramidal tract because of its origin form the pyramidal cells).
120
What are the largest areas of the homunculus on the precentral gyrus devoted to?
motor signals for the muscles of hands, muscles of facial expression and muscles that functionally belong to the vocal apparatus (the areas that initiate fine movements)
121
What does injury to the precentral gyrus of the left side result in?
motor paralysis of the contralateral (ride) side of the body
122
Where is the precentral gyrus?
over medial and later cerebral surfaces
123
What does the part of the precentral gyrus that extends itself to the medial surface produce?
motor signals for muscles of the leg and foot
124
What supplies the part of the precentral gyrus that extends itself to the medial surface?
anterior cerebral artery
125
What would an isolated cerebrovascular accident of the part of the precentral gyrus that extends itself to the medial surface produce?
motor weakness of the leg and foot muscles
126
What does the area of the precentral gyrus located on the lateral surface produce?
motor signals for the rest of the body
127
What is the precentral gyrus located infront of?
central sulcus
128
Involved in conscious control of precise, skilled, voluntary movements
primary motor area
129
Where does the primary motor area receive input from?
premotor area & supplementary motor areas
sensory cortex, thalamus, basal ganglia, and cerebellum
130
Motor control to different parts of the body comes from the appropriate part of the primary motor area as outlined by the?
homunculus
131
Where is the premotor area located in?
frontal lobe in front of precentral gyrus
132
serves as a space where the patterns of movement are stored
premotor area
133
Learned and several times performed movement is stored as an algorithm into this gyrus
premotor area
134
Where is algorithm that was previously learned and mastered imported to from the premotor area?
precentral (primary motor) gyrus
135
Where is the frontal eye field?
in front of premotor area of front lobe
136
What controls the voluntary, synchronized movement of eyeballs?
frontal eye field
137
Left-sided center of the frontal eye field forces both eyes to move to the __, and the right-sided center moves them to the __
right; left
138
What happens if one of the two frontal eye fields is injured?
the other side center dominates and forces eyes to “look into the side of injury.”
139
Where is the Broca's area located?
inferior to frontal gyrus of frontal lobe, just anterior to inferior part of precentral gyrus
140
Which side is Broca's area almost always on?
left side
141
What is the Broca's area responsible for?
generating motor signals for the vocal apparatus
142
What occurs when there is an injury in the Broca's area?
Broca or motor aphasia, where the patient understands the speech but cannot speak
143
Where is Wernicke area located?
around the posterior end of the lateral sulcus (loops around the end of the sulcus) in the left temporoparietal junction
144
What is Wernicke area critical for?
understanding of language
145
What would damage to Wernicke's area cause?
receptive/sensory/ Wernicke’s aphasia
- empty, fluent speech and a loss of speech comprehension
146
What connects Broca's and Wenicke's area?
arcuate fasciculus
147
What is damage to the arcuate fasciculus cause?
conduction aphasia
- Can comprehend and articulate
- Difficulty repeating heard speech
148
Where are the association areas located?
adjacent to the primary areas
149
What connects the primary areas to the association areas?
association fibres
150
What do association areas enable?
enable sharing of different signals by an entire cerebral hemisphere to create a comprehensive perception of objects or things that surround us or come into contact with the surface of our bodies
151
Where is the somatosensory association area located?
behind primary somatosensory area in parietal lobe
152
What is the somatosensory association area responsible for?
integrates and interprets general sensations, such as shape, texture, and weight
compares objects by their shapes and interprets the position of body parts relative to the rest of the body
stores that information in long-term memory
153
What does a lesion in the somatosensory association area result in?
astereognosis (astereognosia) or the inability to recognize an object placed in the hand
154
Where is the visual association area?
surrounds the primary visual area in the occipital lobe
155
What is the visual association area responsible for?
meaning and interpretation to what we see
156
Where is the auditory association area located?
adjacent to the primary auditory area on the lateral surface of the superior temporal gyrus
157
What is the auditory association area responsible for?
enables us to interpret the sounds we hear and give them meaning
158
Where is the common integrative area located?
among the sensory, visual, and auditory association areas
159
What is the common integrative area responsible for?
integrates signals it receives from primary areas --> redirects those signals into other parts of the brain, where it generally creates thoughts and ideas that we understand and then voluntarily look for the most appropriate responses
160
Receives somatic sensory signals from and controls muscles on right side of body + spoken & written language - Right or left hemisphere functions?
left
161
Recieves somatic sensory signals from and controls muscles on left side of body - right or left hemisphere function?
right
162
Where is the diencephalon located?
between the cerebral hemispheres and the midbrain
163
What does the diencephalon include?
thalami and all other structures surrounding the third ventricle, such as the hypothalamus and epithalamus
164
What do the lateral walls of the diencephalon form?
epithalamus superiorly
thalamus centrally
subthalamus & hypothalamus inferiorly
165
What does the thalamus consist of?
group of nuclei - mostly sensory
166
What does the thalamus play a crucial role in?
many brain functions, serving as a processing and distribution centre, relaying and regulating information from the outside world and the internal milieu to the cerebral cortex and sustaining cortico-thalamo-cortical communication
167
What activities does the thalamus involve?
consciousness
sleep
attention
memory
sensory & motor functions
168
Where does the thalamus relay all senses (except smell) to?
certain sensory areas of the cerebral hemisphere
169
Where is the hypothalamus located?
inferior and medial to thalamus
170
What does the hypothalamus function as?
center of the autonomic nervous system
171
What does the hypothalamus control?
emotion
body temperature
eating
drinking etc.
172
What does the hypothalamus regulate?
the function of the major components of the endocrine system through the pituitary gland
173
Where is the epithalamus located?
posterior and superior to thalamus
174
What does the epithalamus consist of?
pineal gland
175
What does the pineal gland do?
regulates the circadian rhythm and distribution of pigment melanin in the skin
176
Where is the cerebellum?
contained within the posterior cranial fossa, underneath the tentorium cerebelli, behind the medulla and pons from which is separated by the fourth ventricle
177
What connects the two cerebellar hemispheres?
vermis (worm-like structure)
178
What joins the cerebellum with the brainstem?
cerebellar peduncles: 3 bilaterally paired major fibre tracts
179
What is the function of the superior cerebellar peduncles?
carry axons that connect the cerebellum to the red nucleus of midbrain & thalamus
180
What is the function of the middle cerebellar peduncles?
connect pontine nuclei of the pons to the cerebellum
181
What is the function of the inferior cerebellar peduncles?
carry bundles of axons travelling b/w medulla and cerebellum, such as spinocerebellar tracts
182
What does the gray matter form in the cerebellum?
cerebellar cortex
183
What is located in the white matter of the cerebellum?
deep cerebellar nuclei
184
What are the deep cerebellar nuclei in the cerebellum?
fastigial, globose & emboliform (interposed), and dentate
185
What are the folds of the cerebellar cortex on the surface of the cerebellum called?
folia
186
What is the primary function of the cerebellum?
coordination of voluntary movements and maintaining posture and balance
187
T/F: Brainstem is made up of only white matter
False, white and gray
188
What is the brainstem composed of?
medulla oblongata (inferior)
pons
midbrain (superior)
189
What are the major functions of the brainstem?
1. It acts as a passageway for all ascending and descending tracts between the cerebrum and spinal cord - some paths may synapse there
2. It contains the nuclei of the cranial nerves III to XII.
3. It regulates the automatic behaviours required for survival, such as respiration.
190
What does the midbrain connect?
pons inferiorly and the diencephalon superiorly
191
Where does CN III emerge from?
cerebral peduncles
192
The anterior aspect of the midbrain presents two columns, what are they?
cerebral peduncles
193
What do the cerebral peduncles contain?
descending tracts: corticospinal & corticobulbar tracts (crus cerebri)
194
On the posterior aspect of the midbrain, there are four elevations known as?
superior and inferior colliculi (singular, colliculus)
195
What is the function of the nuclei deep in the colliculi of the midbrain?
relay center for the visual and auditory reflexes, respectively
196
What are the ascending tracts of the midbrain composed of?
white matter
197
Where are the ascending tracts of the midbrain?
behind crus cerebri
198
What cranial nerves are associated with the nuclei embedded within the white matter of the midbrain?
CN III, IV, V
199
What is the red nucleus in white matter of midbrain associated with?
rubrospinal tract as part of the extrapyramidal pathways
200
What is the substantia nigra in white matter of midbrain associated with?
linked to the basal ganglia regulating voluntary movements
201
In the transverse section of the midbrain, the internal structures can be divided into three main areas (relative to the cerebral aqueduct that connects the 3rd ventricle to the 4th ventricle), what are they?
tectum - behind cerebral aqueduct
tegmentum - from cerebral aqueduct to substantia nigra
cerebral penduncle
202
Where is the Periaqueductal Gray Matter (PAG)?
around the cerebral aqueduct
203
What is the Periaqueductal Gray Matter (PAG) a site of?
production of natural painkillers (endorphins and enkephalins)
204
Where is the pons?
cerebellum (posteriorly), medulla oblongata (inferiorly), and midbrain (superiorly)
205
What does the convex anterior surface of the pons carry?
longitudinal sulcus: the basilar sulcus (occupied by the basilar artery)
206
Which cranial nerves emerge from ponto-medullary sulcus?
CN VI, VII, and VIII
207
What cranial nerve appears at anteriolateral surface of pons?
CN V
208
What is the white matter of the pons formed by?
ascending & descending tracts
209
What is the gray matter in the pons organized as?
nuclei embedded in the white matter
210
Some of the nuclei in the gray matter of the pons is related to which CN's?
CN V, VI, VII, and VIII
211
Where are pontine nuclei?
gray matter of pons
212
What is the function of the pontine nuclei in the pons?
a relay center for motor pathways between the cerebrum and cerebellum to coordinate voluntary movements
213
What are the two nuclei within the pons that add more control to the respiration?
pneumotaxic and apneustic area
214
what separates the medulla oblongata from the pons?
transverse sulcus: ponto-medullary sulcus
215
Viewing the medulla oblongata anteriorly, there is an elevation, the pyramid, on either side of the?
median anterior fissure formed by the pyramidal tracts
216
Lateral to the pyramid on the medulla oblongata is a second elevation, the olive, that overlies?
the inferior olivary nucleus
217
What cranial nerves emerge from the anterolateral surface of the medulla oblongata?
CN IX, X, XI, XII
218
What is at the junction of medulla and spinal cord?
decussation of pyramids that deep to that the corticospinal tracts cross each other
219
What is the medulla composed of?
gray and white matter
220
In the superior half of the medulla, how it the gray matter embedded?
within white matter as clusters of nuclei
221
What cranial nerves are the nuclei in the superior half of the medulla associated with?
CN V, VIII, IX, X, XI, & XII
222
What are the major nuclei in the medulla?
inferior olivary nucleus
nucleus gracilis
nucleus cuneatus
223
What is the function of the inferior olivary nucleus?
relay center for proprioceptive information to the cerebellum
224
What is the nucleus gracilis and nucleus cuneatus associated with?
posterior column - medial lemniscus pathway
225
What are the major functional areas in the medulla?
cardiovascular center
respiratory center (medullary rhythmicity area)
centers that control vomiting, coughing, and sneezing
226
The reticular formation is not an individual section of the brain but an?
integral part of the brain stem
227
What is the reticular formation?
collection of nuclei running vertically throughout the brainstem in three columns (the median, medial, and lateral columns)
228
What is the functions of the reticular formation?
control of skeletal muscle, pain modulation, control of autonomic and endocrine systems, circadian rhythms, and consciousness - re-establish homeostasis
229
How does the reticular formation prevent sensory overload as it receives an enormous number of sensory signals?
filter out up to 99% of all incoming sensory signals, preventing them from being consciously perceived
230
Some neurons that fire their impulses into the cerebral cortex create the?
Reticular activating system (RAS)
231
What does the RAS do?
It responds to some stimuli, potentially disrupting a relatively constant flow and unchanged level of intensity of incoming signals
232
the __ __ is involved in regulating our circadian rhythm (internal clock) and sleep-wake cycle, plus it makes its input to the spinal cord (reticulospinal pathway).
reticular formation
233
What system do general anesthetics work to suppress?
RAS
