Brain Structure Flashcards
Physical Note cards share the same info as this one
1
Q
Q - Which of the following UMN signs is also known as the Babinski reflex?
A. Clonus
B. Hypertonia
C. Extensor Plantar Response
D. Hyperreflexia
A
C. Extensor Plantar Response.
2
Q
True or false: Skeletal muscles are controlled by lower motor neurons.
A
True.
3
Q
Which of the following is NOT a function of the reticular formation?
A. Autonomic Functions
B. Higher functions of the nervous system
C. Memory
D. Sleep/wakefulness cycle regulation
A
C. Memory is the major function of the hippocampus
4
Q
With patients diagnosed with Alzheimer’s disease, what is one notable macroscopic characteristic of their brain structure?
A
The presence of increased deterioration of grey matter. Therefore these individuals will suffer from lots of memory problems and daily living functions. The severity of either will be dependent on the severity of the diagnosis.
5
Q
Why is hydrocephalus more common in children than in adults?
A
Due to the lack of fusion of cranial bones yet, the dysregulation of CSF can cause the meninges to swell up instead of down (seen in adults). This can be a fatal disease without treatment.
6
Q
Surgical separate of the corpus callosum is the diagnosis of:
A. Disconcord Sign
B. Discontingency Syndrome
C. Connection Sign
D. Disconnection Syndrome
A
Disconnection Syndrome - is the disagreement in what the left and right side of the body are perceiving
7
Q
True or false 20% of children and adults are diagnosed with dyslexia.
A
False, Up to 15 % of children and adults are diagnosed with dyslexia
8
Q
True or false: Strokes tend to be on one side of the brain, hence why the signs of a stroke always occurs on the opposite side of the brain
A
True. it is very rare to have two strokes in both the right and the left.
9
Q
Why would the sign of pain as a result of moving the head closer to the chest result in pain be included in the meningitis?
A
This stretch also stretches the meninges, which will cause some pain if there is swelling and infection.
10
Q
An athlete checks into the ER and complains of a headache after bumping his head after he was tackled during practice. He noted that his helmet fell off during this incident as well. What signs should you be looking for? What is his potential diagnosis?
A
Signs involving a concussion such as vomiting, confusion, blurriness, delayed in responses and drowsiness.
11
Q
Compare and contrast the difference between a seizure and stroke.
A
Both are disorders of the brain. A stroke or cerebrovascular accident, occurs when blood supply is cut from the brain, leading to lack of oxygen. A seizure occurs when an electrical signal becomes out of control leading into more or less an electrical “brain storm”
12
Q
Meningitis is the inflammation of the meninges as a result of infection leading to swelling. What is a danger of meningitis?
A
This can increase the pressure on the brain. This increase in pressure can exert enough force that can lead to brain injuries, necrosis or death.
13
Q
In which layer of the meninges does CSF flow through?
A
CSF flows in between the two layers of dura mater.
14
Q
What is unique about the dura mater in the brain, but not seen in the spinal cord?
A
The Dura mater has 2 layers in the brain, while the spinal cord has only one layer
15
Q
From most exterior to interior, name the different meninges of the brain.
A
Dura mater => Arachnoid mater => Pia Mater
16
Q
A patient is flown in from a severe car crash and upon closer examination, you discover necrosis (death of most or all of cells/tissue due to injury, dx or lack of blood supply) of the medulla oblongata. What are you expectations?
A
The individual is more likely than not, to die. Medulla oblongata is the house of many basic, but vital functions - heart and lung regulation, reticular formations in medulla oblongata has many ANS functions
17
Q
What are the functions of the Metencephalon?
A
The metencephalon specializes into the pons and medulla oblongata.
Pons: links the inferior portions of the brain to the higher, medulla to the thalamus and cerebellum to other parts of the brain and spinal cord
Medulla Oblongata: Controls heart and lung functions as well as monitor the oxygen levels.
18
Q
As you cross the road, you see some movements at the corner of your eye and reflexively turn your head in that direction. What neural tube structure is responsible for maintaining this motion?
A
The mesencephalon, it is responsible for the reflexive somatic motor responses generated in the region
19
Q
On a hike in the mountains, you and Juan are walking a long a trail as the sun is setting. As you both hear a noise, both of you reflexively turn your heads towards the direction? Which neural tube structure is responsible for this action?
A
The mesencephalon, it is responsible for the reflexive somatic motor responses generated in the region
20
Q
What functions are of the mesencephalon responsible for maintaining?
A
The mesencephalon or the midbrain is responsible for
- Processing visual/auditory data
- Reflexive somatic motor responses
- Maintains consciousness
21
Q
The Diencephalon diverges interutero and produces what structures of the brain?
A
Di - Pair, therefore 2 thalami => Thalamus and hypothalamus + pineal gland
22
Q
Through many studies over the year, scientists have discovered that many people taking a placebo melatonin are able to sleep. What does this confirm?
A
This confirms the hypothesis/idea that many normal people out there don’t need melatonin in order to sleep as their body may be creating sufficient amounts.`
23
Q
Which structure of the neural tube is responsible for maintaining sleep through the expression of melatonin?
A
The Diencephalon’s Pineal gland regulates sleep through the neurotransmitter, melatonin.
24
Q
The most posterior structure arising from the diencephalon is the….
A. Thalamus
B. Hypothalamus
C. Pineal Gland
D. Pons
A
C. Pineal Gland
25
What functions does the diencephalon and the mesencephalon share in common.
Both share the control of reflexive, subconscious skeletal muscle movement and role in consciousness through the Hypothalamus (diencephalon, altering state through circadian) and the midbrain (mesencephalon) maintaining it.
26
All of the following are functions of the hypothalamus except…
A. Maintenance of consciousness
B. Circadian Rhythm
C. Feeding and Thirst Centers
D. Communication with the pituitary gland
A. Maintenance of consciousness. All other functions are of the hypothalamus. Including subconscious skeletal muscle control
27
Explain the importance of CSF in the brain
The health of CSF directly impacts the health of the brain. CSF regulates gases, wastes and nutrients coming in and out as well as act as a protective mechanism in protecting the brain
28
True or False: Bundles of Axons are called tracts of nerves in the central nervous system
False. Bundles of axons are named differently based on the location. PNS - nerves and CNS - Tracts
courses.lumenlearning
29
Upper motor neurons are exclusively considered in which peripheral nervous system?
The Somatic Nervous system. The ultimately control voluntary muscular movement.
30
As axons of the upper motor neurons run from the cerebral cortex down, they form tracts within the brain. What are the different tracts called? What are their beginning points and their final points?
Upper Motor Neuron Divisions of tracts are named based on their origin and destination.
1. Corticospinal Tract - UMN from cerebral cortex -> LMN in spinal cord
2. Corticobulbar Tract - UMN from Cerebral Cortex -> LMN in the brainstem
31
Nerves Branching from the brainstem are:
A. Cervical Nerves
B. Cranial Nerves
C. Spinal Nerves
D. Cerebral Nerves
B. Cranial Nerves. The brainstem is a portion of the brain (Remember cranial n. ≠ cervical n.)
32
True or False: Lower Motor Neurons in the spinal cord are as likely as lower motor neurons in the brainstem to innervate skeletal muscle of the head and neck.
False. Lower Motor Neurons in the spinal cord tend to innervate the trunk and limb muscles. Lower motor n. in the brainstem tend to innervate the head and neck
33
Somas of the Upper Motor Neurons are from
A. Cerebral cortex
B. Cerebellular Cortex
C. Ganglias
D. Tracts
A. Cerebral Cortex. Upper Motor n. send axons to the spinal cord or brainstem to synapse to lower motor neurons
34
Where in the CNS does Corticospinal tracts cross in order to reach their respective lower motor neuron?
Tracts cross over at the area in which the brainstem becomes the spinal cord.
Fact: Most axons of the corticospinal tract travel down (side of the brain then crossover to travel on to the other side of the body)
35
Regardless of dysfunction in the pathway, whether the upper motor n or the lower motor n. the ultimate phenotype shared by both is
A. Skeletal muscular weakness
B. Fasciculation
C. Clonus
D. Hyperreflexia
A. Skeletal Muscle Weakness
36
True or False: Dysfunction in the upper motor neuron can cause skeletal m. weakness (a shared phenotype with lower motor n dysfunction). However, UMN signs do not necessarily have to occur with weakness to be diagnosed with UMN
True. UMN signs can occur with or without weakness. They are sufficient enough for a diagnosis. This is not true of diagnosis with LMN dysfunction. In this disorder/syndrome, weakness must occur with lower motor signs.
37
Name the 4 signs of UMN signs
Hyperreflexia
Clonus
Hypertonia
Extensor Plantar response
38
The Mechanism of Hyperrefleixa due to UMN dysfunction is much unknown. What is one theory as to why this sign occurs? How does the role of UMN play a role?
It is assumed that without stimulus from the UMN, the LMN becomes hyper sensitive. W/NL stimulus, an overreaction will occur.
39
What is Clonus? How is this similar to fasciculation (seen LMN dysfunction) How are they different?
Clonus is the rhythmic contraction of the antagonist m. of our focus m.
Clonus is similar to fasciculation, as they are involuntary contractions, but differ on specific m.
40
Distinguish between dorsiflexions of the foot and plantar flexion.
These terms are used to describe the ankle's movements.
Dorsiflexion is pulling the toes to the ankle, and plantar flexion is moving the toes away from the ankle
41
How are the different sets of movements:
A. Dorsiflexion & Plantar flexion
B. Extension & Flexion
Relate or differ to one another
A. These are the terms used to descrie the ankle's movements when the angle of the shin and foot decrease - Dorsiflex and Increase in angle - plantar flex
(But! They are intertwined with B too. Plantar flexion - extension of the ankle and Dorsiflexion - flexion of the ankle)
42
You ask you patient to relax and then you grab their foot. In a swift motion, you move the limb away. Almost immediately, the limb starts to rhythmically move back and forth in an automatic manner. What is causing this action? What is the final diagnosis?
The antagonistic m. is causing the limb to contract back and forth rhythmically
Dx: Clonus
43
The UMN syndrome, Clonus, is characterized as the rhythmic contraction of an antagonistic m. when the m. of focus is rapidly stretched causing a repetitive contraction of both the m. of focus & antagonistic m. What is the likely reason why/mechanism of this diagnosis?
Hyperreflexia maybe the cause.
NL - pulling of 1 m causes its neighboring , to also be stretched.
ABNL - The small stretch in neighboring m. would result in m. reflex in which they quickly contract => our m of focus to stretch => reflex => stretch of neighboring m.
44
Differentiate bt hypertonia and hypotonia which Sx belongs to which syndrome?
Hypertonia - Increase in tone of a m. when atttempting to relax m. Causes most likely due to hyperreflexia. No really through of understanding why
Hypotonia - Decrease in Tone of m. When attempting to relax m. Cause most likely due to LMN injuries in which afferent or efferent n lacks communication
45
Describe how hyperreflexia of a muscle is a cause of hypertonia in this case. Is it similar to the mech seen in clonus
In attempting to relax the m, they move the supersensitive m. This causes the m. to automatically reflex => increase in tone and resistance
Clonus involves neighboring m. Hypertonia looks within the focus m. only
46
True or False: The abnormal, extensor plantar response, the UMN Sx is the plantar flexion of the ankle as the foot feels a scrape/pressure by the doctor.
False. This is the extension of the toes! Extension of the toes ≠ extension of the ankles
47
What is the normal reflex of your toes as you feel pressure under your foot?
NL - Flexion of the Toes (towards the foot, toes down)
ABNL - Babinski Sign (Fanning of Toes)
48
What mechanism induces the Babinski Sign?
Unknown Mechanism. Babinski Sign AKA Extensor Plantar Response (Toes Fanning)
49
Identify the sensory information that are precise touch sense.
Touch - Somatosensory Information
Information Type - Position, Vibration & Fine touch
50
Different types of somatosensory information tends to travel in different pathways. Of the two, what type of information travels in less precise tracts. What is the other pathway?
Less Precise - Pain, Temperature, Gross Touch
The other pathway of somatosensory is precise touch
51
True or False: Somatosensory information of the head including both precise and less precise somatosensory information travel in the spinal nerves to send signals about is surrounding area
False. Information of the head and neck tends to travel through cranial n.
52
Differentiate the difference between gross touch motor and gross touch in terms of sensation and perception
Gross motor - motion involving large skeletal m. due to contraction as a unit.
Gross Touch - more general afferent sensation
53
Compare and Contrast fine touch and gross touch. What are the alternative names for these senses?
Fine Touch - Discriminate touch. Detailed, localized information of touch
Gross Touch - Non-discriminate touch. Crude, overall general feeling or touch. No differentiation
54
Resting your hand on Juan's stomach, it starts to growl from hunger. This vibration travels up your hand and... Describe its travel up the PNS and the CNS
Vibration along, with discriminatory touch, pressure, and proprioception travel the lemniscal pathway (precise pathway). The lemniscal tracts stay on the same side and cross in the medulla. To achieve contralateral perception (these information tend to be seen up higher on the spinal cord the other somatosensory info from spinothalamic pathway)
55
Information such as pain, temperature, & gross touch travel in
A. Spinothalamic pathway
B. Spinomedulla pathway
C. Lemniscal Pathway
D. Levinsky Pathway
A. Spinothalamic Pathway. After entering the spinal cord, it crosses over immediately in the spinal cord to achieve contralateral perception
56
Somatosensory Information such as pain enters the left side of the spinal cord. Illustrate this pathway for spinothalamic tracts
Information in the spinothalamic pathways cross over in the spinal cord and travels up the same side of the cerebral cortex
57
Somatosensroy information coming in from the head and neck travel to the cerebral cortex through cranial n. Differentiate the travel between the lemniscal and spinothalamic pathway
Spinothalamic tracts (Px, temp, and gross touch) travels down first before it ascends
Lemniscal Tracts (position, Vibration, and fine touch). There is no large dip in these seen in the spinothalamic tracts
58
Once information has been relayed to the thalamus, what occurs to the signal after?
Information then, is dispersed to their associated cortex or additional processings
59
In a traumatic car accident, you patient injures their right cerebral hemisphere. What do you expect their somatic sensation and perception will be?
The left side of his body and face will experience a lost of perception or abnormal perception. The right side of his body and face should still experience normal sensation and perception of somatosensory
60
Anatomically, where is the cerebellum? How can the cerebellum be further divided?
The cerebellum is inferior to the cerebrum and posterior to the pons and medulla. It can be further divided into the right and left cerebellular hemispheres
61
The function of the cerebellum
A. Initiates motor
B. Plan out motor and muscle movements
C. Coordinates motor independently
D. Corrects Movements
D. Cerebellum corrects motor to smooth out the motion and make the motion as intended. The cerebellum is unable to achieve this indpd and requires many other structures
62
You have to write an essay and plan to type it out. What structure in the brain allows this intention? What structure in the brain allows you to physically commit to it?
Primary motor cortex - allows planning a movement out
Cerebellum - allows motion to occur
63
True or False: Very little work has to be done from the cerebellum to revise a motion as the motion is planned by the cerebral cortex initially
False. Correction from the cerebellum occur frequently and almost all actions undergo revision
64
Once an UMN has synapsed onto a LMN and a motion is initiated, this movement is relayed back to the cerebellum for correction. How is this information relayed? How does the cerebellum process this incoming information?
he body's motion is sensed and relayed by proprioceptors and therefore position of the body is sent to the cerebellum. There cerebellum weights the intended outcome from the primary cortex and actual motion. This is stimulated when there is a difference/conflict between the two.
65
True or False: Somatosensory information ascending to the cerebellum to give information about muscle movement, reaches consciousness
False. This information does not reach consciousness. It only goes to the cerebellum. but info from the cerebellum does ascend to the cerebral cortex after it sends to the thalamus first, but not always
66
How is the cerebellum able to compare the planned motion and the actual motion?
It receives axons from the upper motor n. from the primary motor cortex AND it receives axons from the proprioceptors from the m.
67
Explain the role of an UMN in relaying a message. Where are they located?
UMN are located in the CNS. These neurons send motor signal from the cerebral cortex to the spinal cord to the brain stem and play a role in controlling lower motor n. and their activities
68
Before an action can begin, the motor plan must be established. Meaning the primary motor cortex creates and plans the action. What aspects are created in this plan?
1. Type of m. involved in motion
2. Number of m. involved
3. Intensity of contraction
4. Duration of Contraction
69
Once the primary cortex has created a motor plan, where does it send its axons to? Describe the travel.
The UMN is sending axons through the cerebellum, past the brainstem and crosses over in the brainstem and differentiates as the corticospinal or corticobulbar tracts
70
Information from the proprioception delivering information about the position of muscles to the cerebellum.
A. Crosses over in the brainstem
B. Crosses over in the Spinal Cord
C. Crosses over in the thalamus
D. Stays on the same side to the cerebellum
D. Stays on the same side as it ascends to the cerebellum. It the crosses at the brainstem as the action travels from the cerebellum to the thalamus
71
After the cerebellum has processed the somatosensory information coming in where does it send its signal? Depict the conscious route.
After the cerebellum sends signals to the thalamus, the nuclei can also send conscious input to the frontal cortex. Here is can adjust its activity of the UMN.
72
After the cerebellum has processed the somatosensory information coming in where does it send its signals? Depict the reflexive route
Signal sent to the red nucleus in the thalamus. Red nucleus sends input to the lower motor n. through the rubrospinal tract to directly change /adjust skeletal m. activity.
73
The function of the cerebellum as a whole differs from the anatomical position. Differentiate the function seen in the middle and lateral bodies of the cerebellum
Lateral bodies coordinate m. movement with limbs (especially when they are used individually
Middle segment coordinates the muscle movement of the trunk and core
74
How does the cerebellum play a role in the head and neck?
1. Ocular Motion
| 2. Coordinate m. involved in speech. Ex: Enunciating
75
During a motor accident, your patient's family is saying that he has had a lot of problems enunciating words. What portion of his nervous system may he have damaged?
His Cerebellum or Broca's area, both contribute to speech and damage to either can cause difficulty. Patient is able to understand words and phrases (Wernicke's area). However his motor, the act of responding back is uncoordinated. (this action is governed by the cerebellum and initiated by Broca's area)
76
What is the brainstem's anatomical relationship to cranial and spinal nerves?
Most Cranial n comes out of the brainstem (therefore they are attrached to the brainstem!)
Spinal n are not so anatomically related to the brainstem, however signals that have to reach the spinal nerves do cross over or travel at the brainstem in tracts
77
The reticular formation of the brainstem plays many roles. What are its particular functions as it sends axons to the cerebrum?
It is involved in higher functions such as emotions, cognition, and consciousness
78
What is the difference between the reticular formation and the reticular activating system?
Reticular Formation - Bundle of nuclei scattered in the brainstem in the brainstem that regulates many ANS functions
Reticular Activating System - sys that regulates arousal and sleep-wake transitions (this is a small part of the reticular formation)
79
Because the brainstem serves as a connection/bridge of the brain to the spinal cord, how does the structure and its content differ inferiorly and superiorly?
Inferiorly - medulla oblongata shares many similarities of the spinal cord: Grey matter on the inside and while without
Superior to Pons and Midbrains, grey and white matter is more scattered which is similarly seen in the brain
80
Two big tracts run through the brainstem as it carries information from the periphery to the central nervous system. What info do they carry? How are they differ?
These tracts carry motor and somatosensory information
Both look very similar to their travels, to and from the brain
81
The reticular formation of the brainstem play many roles. What are its particular functions as it sends out axons to the periphery?
It plays a role in Automatic regulation such as digestion, respiration and blood circulation. These function are more holistic and focused on the body as a whole
82
Describe the relationship of most cranial n to the brainstem.
The brainstem houses the somas of the cranial n. alongside the reticular formation, therefore the grey matter in the brainstem is often related to a cranial n. (the brainstem therefore receives sensory info and sends motor info to the head and neck)
83
Structures deep to the cerebral cortex are all called what? What type of matter exists deep to the cerebral cortex
Under the grey matter, cerebral cortex is the subcortical cerebrum. There is a blend of both while grey matter is dispersed in this portion of the cerebrum
84
True or False: Upon a closer look at the brain in a cross section, you can see that the white matter is connected and indifferentiable. Therefore, axons are undistinguished
False. To the naked eye, its undifferentiated. However, these axons can be traced to different regions and each pathway has a specific tract name.
85
An individual suffers from disturbances of balance and coordination. This most likely is caused by a lesion in the
A. Corpus Callosum
B. Thalamus
C. Cerebellum
D. Frontal Lobe
Cerebellum. The cerebellum plays a significant role in coordination
86
Which of the following sensory pathways does not synapse at the thalamus before entering the appropriate cortical region?
A. Vision
B. Audition
C. Taste
D. Smell
D. Smell
87
What is the corticospinal tract? Describe its travel within the central nervous system.
These upper motor neurons descending from the primary cortex dow to the spinal cord It travels with the internal capsule in the brain (The tract of axons running from superior of the brain to inferior in a v shape) then crosses over in the brain stem
88
True or False: The corpus callosum is a tract of axons connecting the right and left cerebral hemisphere
True! This is how the corpus callosum allows communication of the left and right brain
89
What structure is separated by the internal capsule? How does this affect its function?
The internal capsule divides the somas of the basal ganglia, creating 2 distinct nuclei grey matter regions. However, they still function as a whole unit. This separation doesn't affect the function
90
The Basal Ganglia differentiates from the telencephalon just like the cerebrum. How does this determine its functions?
The basal ganglia shares many functions seen in the cerebrum, especially the frontal lobe:
1. Motor function (but no upper motor neuron
2. Cognition
3. Emotions
91
What specific roles in motor does the basal ganglia have?
Much of its role in motor control is unknown. However, it is assumed that the basal ganglia is linked to the motor initiation and executive movements by facilitating desired movements and inhibiting unwanted/competing motions
92
What structures specialize from the diencephalon in utero? What are their functions?
Di - 2 therefore 2 thalamus
Thalamus - Processes and relays all/most sensory information to their correct destination for further processing. Also involved in processing cognition, emotion and consciousness
Hypothalamus - Regulator of the pituitary gland and therefore the endocrine system. Also involved in processing cognition emotion and consciousness
Pineal Gland
93
True or False: Most or all of prosencephalon structures have a role in regulation and function of emotion, consciousness, and cognition
True!
Telencephalon - All cerebrum, basal ganglia, and limbic system does all 3 functions
Diencephalon - Both the thalamus and hypothalamus has role in all 3
94
Compare and contrast ridges, grooves, and fissures of a cerebral cortex
All three are present on the cerebrum
gyri/gyrus (single) - ridges or elevated clefts AKA mountain top
Sulci/sulcus (single) - groove - depression AKA valley
Deep groove/deep valley
95
Describe the specific location in the brain in which visual information is processed.
This is the most posterior cortex in the primary visual cortex of the occipital lobe. The opposite side of the brain processes the info from its opposite eye
96
Differentiate where somatosensory information is processed from motor information
It is processed in the parietal lobe in the primary somatosensory cortex while motor info is processed in the frontal lobe in the primary motor cortex
97
Name the lobes of the cerebrum
Frontal, parietal, temporal, ad occipital lobes (these are the anatomical divisions of the cerebrum)
98
How is the cerebrum functionally divided?
Cerebrum - divided into the primary and association cortices
Primary cortices - process the basic sensory information
Association Cortices - are involved in complex processings and function of different types of info
99
A ballet dancer is planning on trying a new move. She maps out her steps and performs it flawlessly in her attempt. What functional cortex is required for each part of this scenario?
Primary motor cortex (AKA precentral gyrus) - performing the new dance, a basic function.
Association motor cortex (AKA premotor cortex or non-primary motor cortex) - planning the movement
Both are located within the motor cortex
100
How do other association cortices achieve higher processing to perform more complex motor and sensory functions?
These cortices and integrate them with other types of information, such as somatosensory & visual, visual & motor, motor & somatosensory
101
What is the outcome of association cortex integration of different types of information?
It produces higher functions of the nervous system such as cognition, emotion, and consciousness
102
Language is one aspect of life considered to be a part of cognition thanks to the cerebrum. In most people, what portions of the brain perform language
The left cerebral hemisphere where the frontal & temporal lobes meet and where parietal meets temporal.
103
True or False: Occasionally, an individual will have the language centers on the right side of the brain rather than on the left side of the brain. However, no one can ever have it on both cerebrum.
False. Some people can have the language centers on both sides of the cerebrum or on the right side only
104
Like the language centers in the brain, the attention centers' location ....
Tends to be the one side of the cerebrum as well. However, it tends to be on the right side inside of the left.
Like the language centers it can also be on the opposite side or in both sides in some individual
105
True or False: The attention centers tend to be in the right hemisphere of most indv, meaning there are no center on the left
False. While the centers tends to be on the right, the left hemisphere still plays a small role in attention centers focus on the right side of the body while the right hemisphere attends to both sides of the body.
106
Define how the brain performs attention
The frontal lobe/specifically the prefrontal cortex taking notice of the body and environment
107
Neurotransmitters are the basic units of action in a synapse. Differentiate the actions between glutamate and glycine in the central nervous system. What are their roles in the peripheral nervous system?
Both are commonly used in the CNS and rarely in the PNS. Therefore, both have little to no role in the PNS
Glutamate - An excitatory ntsr
Glycine - an inhibitory ntsr
108
Compare and Contrast gamma amihobutyric acid and glycine
Both are inhibitory ntsr of the CNS. However GABA predominantly is active in the brain, while gylcine is more common in the spinal cord
109
Certain areas of the brain send axons diffusely to many regions in the brain in order to elicit a function. What higher functions require the inputs of many structures (that is not seen in other functions like visual and motor).
Cognition, Emotion, and Consciousness
110
What structures are involved with the reticular activating system?
The reticular activating system denotes the part of the brainstem reticular formation and parts of the thalamus which performs the role in maintaining behavioral arousal, consciousness, and motivation.
111
Explain the importance of CSF in the brain.
The health of CSF directly impacts the health of the brain. CSF regulates gases, wastes and nutrients coming in and out.
112
What is the relation of the choroid plexus and ependymal cells?
The choroid plexus is a group of modified ependymal cells surrounding a bundle of capillaries produce and maintain the CSF
113
True or false. The olfactory tracts are the only nerves that don’t cross to produce contralateral control.
False, the Olfactory tracts are the only nerves that don’t go to the thalamus to be relayed. Auditory information is the only sensation that doesn’t cross to produce contralateral control
114
Describe the olfactory tracts’ travel.
The olfactory tracts (many axons) travel up through the temporal lobes to synapse onto the olfactory cortex.
115
Why would increase in DA onto the Basal Ganglia produce jerky movements commonly seen Parkinson’s?
There are many theories surrounding the production of jerky movements when the basal ganglia is inhibited or damaged.
1. It is hypothesized that the basal ganglia inhibits these jerky movements. Therefore when it is inhibited these jerky motions will be produced.
2. Indirect Pathway: theory is that basal ganglia suppresses the opposing muscles of the motion of desired.
3. Lastly, the direct/indirect model: the basal ganglia is thought to suppress the thalamus, which would communicate to the motor cortex to inhibit their motion. The basal ganglia suppresses their actions
116
True or false. The basal ganglia is inhibited by GABA. This inhibition is seen very commonly in Parkinson’s leading to jerky, rather than smooth coordinated movements.
False. The basal ganglia is inhibited by the dopamine from the substantia nigra (wiki) while it secretes GABA when it is active. Everything else is true
117
Both the basal nuclei and the primary motor cortex have a role in motor functions and originate from the cerebrum. How is the basal nuclei different from the primary motor cortex?
The Basal nuclei helps maintain learned movements (rather than initiating it - primary motor cortex)
118
How did the clinical case of Henry Molaison, a patient with epilepsy who underwent limbic resection, demonstrate memories had “addresses”?
The Dogma of memories was that they were stored in different parts of the brain, therefore they had different “addresses”. After his surgery, he was unable to remember people however he was able to remember the house he moved to after his surgery. As spatial memory is different from factual long term memories, process of storing and consolidation must be different along with location.
119
Henry Molaison underwent memory lost after the surgical removal of several structures of the limbic system including his hippocampus and amygdala. As a result, what important function was he unable to do?
HM was unable to form long term memories although he was able to remember everything up until that point of surgery. This solidified that the hippocampus consolidated new memories.
120
How is the hippocampus an example of plasticity?
The hippocampus reinforces information into long term memory by enhancing the connections through change. This is neuroplasticity, the ability for the CNS to change
121
What system is the hippocampus a part of?
A. Limbic System
B. Olfactory System
C. Reticular Formation
D. Auditory System
A. The hippocampus is part of the Limbic System. It works in consolidation of memories via long term synaptic potentiation as well as regulation of emotions
122
The hippocampus is embedded in the:
A. Midbrain
B. Temporal lobe
C. Frontal lobe
D. Cingulate Gyrus
B. Temporal Lobe. The hippocampus is embedded in the temporal lobe.
123
How does the cingulate gyrus help contribute to the limbic system?
As part of the frontal lobe protruding inferiorly to cover the corpus callosum, it plays a big role in regulation, decision making, language expression and autonomic motor functions for emotions. (thoughtco)
124
Given the role of the amygdala, if an organism like a zebra’s amygdala was impaired, what would the organism’s actions be if they were facing a lion?
The Zebra would be unable to associate emotions with a response. Therefore a range of actions would occur from not fleeing while feeling scared, to approaching the lion without any development of an emotion. Overall, the organism won’t have a proper response to their feelings
125
What is the purpose of the limbic system?
The limbic system plays a crucial role in processing and developing emotions of the organism as well as storing memories and memory retrieval
126
For your epileptic patient, you plan to surgically separate the corpus callosum in order to prevent her grand mal seizures. What can minimize the effect of the left brain not communicating with the right brain?
The anterior commissure, a band of tissues in the most anterior portion of the brain allows some form of communication between certain parts of the two hemispheres. Therefore the severity of a split corpus callosum will vary from person to person
127
The corpus callosum is undeniably the bundle of cells that allows the left hemisphere to communicate with the right hemisphere. With a patient who has had these tissues cut, can they determine the pencil they are holding in their left hand?
Pencil in left hand - all information processed goes to the right side and is able to cross over before it reaches the right hemisphere. After processing in the right hemisphere, information is unable to travel to the left side (area of speech and language comprehension) therefore the person is unable to identify the pencil.
128
The corpus callosum is undeniably the bundle of cells that allows the left hemisphere to communicate with the right hemisphere. With a patient who has had these tissues cut, can they determine the pencil they are holding in their right hand?
Pencil in the right hand, able to detect the object with information coming from the right side. Left brain is able to interpret what they are touching and unable to name and comprehend (because the crossover of the somatosensory information is at the pons, visual is at the chiasm) both are not part of the corpus callosum.
129
Much like many of the association areas of the brain, how is the visual association area similar to them?
The visual association area makes sense of the things we are seeing, such as putting letters together and visualizing the object of the word.
130
As a volunteer teacher, you are demonstrating how to visualize words in your head. One student in particular can’t picture any words, such as apple, even as they see the letter. What portion of the brain may be dysfunctioning?
The visual association cortex may be abnormally functioning. This area allows you to not only see objects, but elicit other visual memories and comprehend what you are seeing.
131
Describe the olfactory cortex’s relationship to the hippocampus. How is smell related to memory
The olfactory cortex is superior to the hippocampus. Therefore as the olfactory tract sends signals up the tract, they bypass the hippocampus in the temporal lobe to synapse without relay to the thalamus. This pathway is why certain smells induce certain memories, because the hippocampus is important in storage of memory.
132
What is the relationship between Wernicke’s area and the auditory association cortex? Are they the same thing?
Both share the role of processing and comprehending sounds. Wernikes is specifically the posterior ⅓ of the auditory association cortex and processes only information about language sounds while the association cortex comprehends more than just language.
133
How is the responsibilities of the primary auditory cortex different from the auditory association cortex?
The primary auditory cortex perceives and processes tones and pitches of the sound waves (hence tonotopic mapping) while the auditory association cortex allows you to make sense of what you are hearing.
134
True or False. Once the vibration sound waves are transduced into electrical impulses, they travel through the acoustic nerve and crosses the brainstem to be processed on their contralateral cortices.
False. This is the only sensory information not crossing to be processed in their contralateral primary auditory cortex. Instead, this information travels straight up to their respective cortices.
135
Upon reviewing some articles about Einstein’s brain, you note that they often quote how large his brain is especially in the parietal/Wernicke’s area. What about this information made him such a unique character?
Imagination and dreaming are often associated with these areas as well. Perhaps this is what allowed him to think beyond the scope of himself to contribute to the world of physics tremendously.
136
Compare and Contrast the difference between aphasia and dyslexia.
When it affects spoken language it is medically described as aphasia; when it affects reading it is called alexia or dyslexia; and when it affects writing it is called agraphia. (springer)
137
Due to underdevelopment intrautero, your ped has always struggled with language comprehension. Today, you want to run a series of tests to see her comprehension and see if diagnosing her with Fluent Aphasia is appropriate. In this test you ask her to sit and ask her to define here. Then you ask her to sit here. What do you expect if she does have this aphasia?
She will be able to sit and define her. However, she will have a hard time stringing what sit here means. Fluent aphasia/receptive aphasia/Wernicke’s aphasia is the inability to grapes spoken words or sentences, however she will be able to still produce speech perfectly well.
138
Why does it make sense that Wernicke’s area is located in the temporal lobe, just a short distance from the auditory pathway?
Speech is processed in Wernicke’s area as it is responsible for comprehension of speech. Therefore while Weirnicke’s area is in the partiental lobe, shares boundaries with the temporal as well. This short distance allows for efficient and effective processing of the language.
139
Contralateral processing is very commonly seen in the body. Compare and contrast the motion and touch of your left hand’s designation as it is processed.
Both information crosses over to the right and is processed in their respective cortices => primary motor cortex and the primary somatosensory cortex respectively. Simultaneous processes allows you to feel and move the same arm at the same time
140
One of your residents asks you for a neuro consultation. The scans demonstrate some trauma to the right cerebral hemisphere near Broca's area. She reports that she is worried about speech impairment. What should your resident be concerned about?
Cerebral hemorrhage only. Broca’s area tends to be on the left side of the brain for most people therefore speech impairment is often very rare in this case.
141
You’re assessing a scan of your small patient after he had a fight with his brother and bumped his head on the left.. The convolutions in the frontal lobe, near the pterion, are distorted with minor blood and you fear this may mean impairment to its function. What type of dysfunction can occur from this? What was damaged?
The child may suffer from Broca’s Aphasia as the area of injury was to Broca’s area. He will be able to produce words and sentences, but the words maybe uncoordinated or words maybe unclear.
Mnemonic - The word Bro, uses the muscles of the lips and tongue, which is achieved by Broca’s area
142
Compare and contrast the Homunculus maps in the brain.
While both are sensory maps of their own respective sensory information - muscles and touch- they both share similarities in the size of their maps for certain areas. Both have large areas for the lips, hands, jaw and feet
143
True or False: The Homunculus mapping in the brain is exclusively found in the only somatosensory receptors of the body.
False, the homunculus mapping of motor is also found in the brain as well. While somatosensation is mapped onto the primary somatosensory cortex in the parietal lobes, the motor is mapped onto in the primary motor cortex of the frontal lobe.
144
The primary motor cortex is located in which lobe? What are the main responsibilities of this gyrus?
This gyrus is the most posterior segment of the frontal lobe. The primary duties of this cortex is to initiate movement, therefore it develops the motion plan
145
The Frontal Lobe has many functions within the body. In the classical case in which Phineas Gage, a railway worker, gets traumatically injured, a tube of metal shots straight up his eye into his frontal lobe. He undergoes lots of changes as a result of this injury. What portion of the frontal lobe is responsible for maintaining these characteristics Gage had lost. What characteristics are these?
The prefrontal cortex, a gyrus at the most anterior portion of the frontal lobe was injured in this accident. This cortex is important in maintaining not only personality (such as punctuality and goal orientation) but intelligent thought, planning, and sense of consequences and rationalization
146
How is a fissure different from a sulcus? Name examples.
A fissure is a deep groove in the cerebrum and a sulcus is a shallow groove.
147
What are the key components in forming the iconic wrinkle or a convolution in the cerebrum.
A convolution or a wrinkle, is produced as a result of a gyrus and a sulcus or a mountain ridge/top and valley
148
How do these “wrinkles” in the brain change over time?
As the brain grows and others die off, there will be established convolutions within the brain.
149
How are convolutions important in the brain?
Convolutions are wrinkles in the brain. The more convolutions the brain has, the more neural tissue the brain can fit within the skull
150
True or false: At birth, a lot of the baby’s nervous system structures have already formed. Therefore much of development of birth is simply pruning.
False, brain development doesn’t stop after delivery as much of the structures are still developing after birth
151
At birth, how does the anterior portion of the brain of a neonate structurally compare to its former shape in utero? What about the posterior portions of the brain?
The Telencephalon and diencephalon have become a lot bigger in size and the Telencephalon has become almost entirely the cerebrum.
The posterior ends have differentiate as well, but their proportions in mass are still relatively similar to their developmental stages
152
Your mom comes in for her month and a half prenatal visit. Where is her fetus at this stage in its growth?
At 6 weeks the prosencephalon has divided further into telencephalon and diencephalon anteriorly. The Mesencephalon remains the same (this becomes the adult midbrain) and Rhombencephalon has divided into Metencephalon and Myelencephalon.
Mnemonic: ABCs from Mesen - Rhombo: Mes => Met => Mye
153
Your new mom excitedly craves to learn about her growing fetus and wishes to learn the process of fetal development. She is currently about 2 weeks pregnant. What should you tell her about her fetus at this stage? What about at week 3?
The fetus startes out as nothing but a hollow tube of cells called a neural tube. At this point of development, no structures have been differentiated. But it has developed little pocket-liike vesicles within the tube. At week 3, the tube differentiates into 3 different sections called the prosencephalon, mesencephalon, and the rhombencephalon. (draw structure out)
154
Describe the importance of an ependymal cell in the brain.
They create and regulate Cerebral Spinal Fluid which is important in maintaining an electrolytic environment and serves as a nutrient source to neuronal and non-neuronal cells.
155
You are studying a new virus that has the ability to bypass the blood brain barrier. Does this ultimately lead to an infection once the microbe crosses the membrane?
Not necessarily. The brain has many lines of defense. One is the use of microglias as macrophages in which they consume and digest harmful things through a process called phagocytosis.
156
You order an MRI for your patient who suffered some trauma after falling from a stairwell under the influence. He is a reported chronic methamphetamine user. What are your expectations of the blood brain barrier and the cells producing the BBB? What are your concerns if your suspicions are correct?
Psychostimulants such as methamphetamine and MDMA, produce blood brain barriers degeneration. Therefore, you should expect inflammation of the astrocytes producing the BBB. If inflammation is present in the image, you should order a CSF culture. BBB acts as a filter against harmful molecules and infections, therefore a vulnerable BBB increases susceptibility to bacteria and viral infections of the brain. (NHI and Biomedcentral)
157
Both Oligodendrocytes and Schwann Cells have the same function. How do you differentiate between the two?
COPS => CNS - Olgiodendrocytes and PNS - Schwann
| Both function in producing myelin sheaths around a neuron.
158
Neuronal cells are the units transmitting signals in a pathway to and from the brain. Contrast non-neuronal cells.
Glias, or neuroglias are non-neuronal cells in the nervous system (CNS and PNS) that produce no electrical impulses. There are 4 main types you have to know: Astrocytes, Microglial, Ependymal, and Oligodendrocytes.
Mnemonic: Glia cells function in Obscuring, Macrophage, set Apart, and CSF => Oligodendrocytes, Microglia, Astrocytes, Ependymal Cells
159
True/False - The dogma for the longest time was that adult brains can’t generate any new brain cells. The ones you have after pruning, are the ones you get
False, Neurogenesis has been studied and spectated for years and there appears to be proof that development of new cells can help enhance cognitive functions. - Dr. Amr Sahay, Harvard
160
A neonate after delivery has a total of 100 billion neurons. Once they develop and reach adulthood, their neuronal amount is only 86 billion. Account the difference
A child undergoes pruning within the nervous system. This process ensures that only necessary neurons for functioning are kept unnecessary neurons are eliminated to increase efficiency and effectiveness of brain functions
161
Which of the following is a major function of the Cerebrum?
A. Coordinate thought and actions
B. Coordinate movement
C. Coordinate Sensory information
D. Coordinate emotions
A. Coordinate thoughts and actions (higher level function such as thinking and planning)
Cerebrum is a synonym for cerebral cortex (not really)
162
True or false: The old brain consists of the brainstem and the cerebellum
False. The old brain consists of more than just these two. Including them, it consists of the brain thalamus, the amygdala, hypothalamus and hippocampus (opentextbc.ca)
163
What is a requirement for functions to reach consciousness? Do the old brain functions seen in humans and in evolutionary distant species, the mouse, meet this criteria?
The cerebral cortex’s processing is required for consciousness. Without this, there is none. The mouse, an animal with small cerebrum, will have basal functions from the old brain without reaching consciousness.
164
The thalamus’s main function is to relay sensory information to the cerebral cortex for higher processings and originates from the prosencephalon/forebrain. Both factors are commonly known as functions and origins of the new brain. Why is the thalamus identified as part of the old brain?
The thalamus is part of the old brain due to the fact that before it developed in other species, it has significant role in other basal functions such as motor, emotion, memory, arousal, and sensorimotor association functions. With the new brain, the thalamus’s functions has been extended to include audition, somatosensation, gustation, etc. (other periphery senses)
165
T/F - All information is relayed to the thalamus for higher processing
False. All except smell passes through the thalamus.
166
Even as you are debating with an extremist student regarding old and new brain. What point about the old brain could he be correct on?
The old brain is a very basic set of structures (composing of the brainstem structures and the cerebellum) that do very basic functions. These simple functions when compared to complex functions like from the cerebral cortex, can be misconstrued into superior versus inferior.
167
As the cerebellum is important in the role of voluntary smooth movements, damage to it would cause what?
Trauma to the cerebellum would produce jerky, uncoordinated movements. This is not only seen in trauma but also in alcohol impaired individuals as well.
168
As your mouse is sleeping, you send an electric signal through a surgically implanted nanoelectrode to its reticular formation. Chart your results.
The mouse should become fully aroused/awake. The reticular formation plays a significant role in the sleep wake cycle and stimulation of it will wake it up.
169
During a CAT scan of your comatosis patients’ cranium, you see very sparse networks of the reticular formation. What dysfunctions are potential? What connecting structure won’t receive its information. Where in the brain is this image being produced?
The reticular formation is important in the sleep wake cycle, especially for arousal. Damage to this area can explain why your patient is in a coma. With damage to this structure in the brainstem, information from the body relaying to the reticular activating system and thalamus won’t be processed by the cerebral cortex. This means your patient won’t sense and process any peripheral sensations.
170
What is the reticular formations’ relationship to the spinal cord?
The reticular formation of the pons acts as a filter of incoming stimuli. It discriminates irrelevant background stimuli
171
The brainstem has many basal functions. What other landmark does it serve?
It serves as the place where nerves and axons cross over to the other side of the brain/body to produce the contralateral sensation/processing/control.
172
The structures deep in the brain are shared with many species and demonstrate crucial to life. As a rule of thumb, what functions are these?
These functions are the basal regulations that include but are not limited to: breathing, heart rate, and sleep.
173
Oftentimes, ideas in science are taken out of textbooks and it takes a life on its own in pop culture. How can you explain to a person challenging you about the human brain as the most superior brain to other species on earth due to its very distinct structure from other organisms like a mouse?
Superior is an opinionated word that does hold its ground in science. Even as the human brain has developed for many years away from other species, the brain is still very similar to brains from other species. Humans have newer developed feature called cerebral cortex placed on top, but everything underneath it is still very similar. Human brains still have very functional and necessary life “old brain” including the midbrain apparatus and limbic systems structure.
174
A neuroscientist wants to increase EEG waves on different sides of the brain as proof of tapping into different hemispheres. He starts to design an experiment in which he will have individuals attempt to focus on one specific task designated for one side of the brain. Such as right handed people will focus on creativity, while left handed people will focus on mathematics. Interpret the results of this experiment. What do you expect?
This experiment as of today is flawed. There is no possible way yet to tap into one hemisphere over the other as people use both sides for many of the same functions. The characteristics/functions coined for each hemisphere is just the partially dominant functions seen with each hemisphere. This does not mean that only one side creates these functions.
175
True or false: The old brain consists of the brainstem and the cerebellum
False. The old brain consists of more than just these two. Including them, it consists of the brain thalamus, the amygdala, hypothalamus and hippocampus (opentextbc.ca)
176
Compare and Contrast the difference between spinothalamic/leminiscal pathways and A-β/A-γ/C Fibers. When are either used?
In general, lemniscal pathway carries proprioception, vibration sense, and fine discriminative touch while the pinothalamic tract and other associated tracts that convey pain, temperature sense, and crude touch.
These describe the pathways of axons travel from the periphery to the central nervous system.
A-β/A-γ/C/A-δ Fibers describe the neuronal axon itself, which are classified in diameter, velocity, and the amount of myelination. They tend to have overlapping of information carried in the pathway, but the difference is that the type of information traveled within these will reach the brain differently. [for instance, temperature is carried by both C and A-δ fibers. But cool temperature carried by the A-δ will reach the brain first because A-δ is myelinated and has a larger diameter than C fibers carrying hot temp info
