Lecture 6: Central Nervous System 2 Flashcards
____ consists of several nuclei located deep within the cerebral white matter
Basal ganglia
____ is associated with a variety of function including motor control cognition , emotions and learning
_____ is associated with functions such as inhibiting muscle tone throughout the body- balance of excitatory and inhibitory inputs to neurons that innervate skeletal muscles
The basal ganglia selects and maintains purposeful _____ while suppressing unwanted pattens of movement
Coordinated slow, sustained ___ especially those related to posture and support
Motor activity
Contractions
______ disease
-caused by the degeneration of dopamine rigid neurons in substantial migration in the midbrain which synapse onto neuron’s in the basal ganglia
-The circuit is important for smooth movement
Parkinson’s
The loss of dopamine results in the characteristic features of Parkinson’s disease :
1 _____
2_____
3_____
Increased muscle tone-rigidity
Tremors
Difficulty initiating and carrying out movement
______ disease
- cased by degeneration of the caudate nucleus
- this loss causes some motor circuits to become overactive resulting in the characteristic features of this disease :
1. Chorea-rapid uncontrolled jerky movements
2. Memory problems
Huntingtons
The ___ is deep in the brain nea the basal ganglia
-serves as “relay station” and synaptic integrating centre for sensory input
- helps direct attention to stimuli of interest
- capable of crude awareness of sensations but cannot distinguish their location or intensity
Thalamus
The ___ is the integrating centre for homeostatic functions .
Brain area most involved in directly regulating internal environment
-Controls body temp+ food intake
- controls thirst and urine output
- controls anterior pituitary hormone secretion
- produces posterior pituitary hormones
Hypothalamus
_________
5 functions :
1. Majority of cranial nerves arise in this area
2. Contains centres that control cardiovascular, respiratory, and digestive function
3. Regulates postural muscle reflexes
4. RAS controls the overall degree of cortical alertness
5. Plays a role in sleep-wake cycle
Brain stem
______ associated with functions:
- optic
- olfactory
-oculomotor and trochlear
- facial
-vestibulocochlear
‘-glossopharyngeal
Cranial nerves
________
- important in integration of Moro to output and sensory perception
- important in balance and planning of movement
Three functionally distinct parts:
1. ________
2.________
3._______
Cerebellum
Vestibullocerebellum
Spinocerebellum
Cerebrocerebellum
Parts of Cerebellum :
1. ______ - balance and eye movement
2. ______- enhances muscle tone and coordinates skilled movements
3. _____- plans and initiates voluntary activity and stores procedural memories
Vestibulocerebellum
Spinocerebellum
Cerebrocerebellum
Brain networks :
- the ____ activating system
- the ___ system
Reticular
Limbic
__________
-Behavioural state system - diffuse modulators system
-Neurons originate in this network and project to various areas in the brain
- influences attention, motivation, wakefulness, memory, motor control, mood, and metabolic homeostasis
- controls levels of consciousness and sleep-wake cycles
- controls overall degree oof cortical alertness
Reticular activating system
Reticular activating system :
-__________ state system - diffuse modulators system
-Neurons originate in this network and project to various areas in the brain
- influences attention, motivation, wakefulness, memory, motor control, mood, and metabolic homeostasis
- controls levels of ________ and sleep-wake cycles
- controls overall degree of _____ alertness
Behavioural
Consciousness
Cortical
____________ depress synaptic transmission in the reticular formation
Blocking ascending pathways between the reticular formation and the ____________ creates a state of unconsciousness
General anaesthetics
Cerebral cortex
_________ system surrounds the brain stem and is not a separate structure
- complex interacting network is associated with emotions, basic survival, sociosexual behaviour , motivation and learning
- it is an interconnected ring of forebrain structures
- includes portions of cerebral lobes, the basal nuclei, thalamus and hypothalamus
- utilizes neurotransmitters norepinephrine, dopamine, and serotonin
- depression is associated with defects in this systems neurotransmitters
The Limbic system is a interconnected ring of ______ structures
Forebrain
_____ is associated with defects in Limbic system neurotransmitters
Depression
Limbic system functions:
- _____: subjective feelings/moods and the physical responses associated with these feelings
- _____: aimed at survival and perpetuation of the species
-______: directing behaviour toward goals
-_______: acquiring knowledge or skills as a result of experience and/or instruction
-_____: storage of acquired knowledge for later use
Emotion
Behavioural patterns
Motivation
Learning
Memory
Cortical structures of Limbic system
-_____
-_____
-_____
Medial prefrontal cortex
Cingulate cortex
Medial temporal lobes
Which cortical structure of the Limbic structure ?
______ - executive function: decision making, control of emotion and impulses
Medial prefrontal cortex
Which cortical structure of the Limbic structure ?
______- motivation , drive, mood:
Decreased activity correlates with depression
Cingulate
Which cortical structure of the Limbic structure ?
______- episodic memory formation of recent event sequences
Medial temporal lobes
Decrease activity in What cortical structure of the limbic structure is correlated with depression ?
Cingulate
Medial prefrontal cortex
Cingulate cortex
Medial temporal lobes
Which type of structures do these belong to in the limbic system ?
Cortical structures
______ stuctures of the limbic system include:
- hippocampus
- hypothalamus
-amygdala
Subcortical
Subcortical structures of limbic system :
1____
2____
3____
Hippocampus
Hypothalamus
Amygdala
Subcortical structures of limbic system
_____-(within medial temporal lobes)
episodic memory formation, context and location
_____- homeostasis and basic drives: food, water, sex, aggression
______- involved in fear and affective learning
- activation causes anxiety
Hippocampus
Hypothalamus
Amygdala
Which Subcortical structure of limbic system is within the medial temporal lobe ?
Hippocampus
_____ is the acquisition of knowledge or skills as a consequence of experience, instruction or both
Learning
It is widely believed that rewards and punishments are integral parts of many types of ______
Learning
_____ is the storage of acquired knowledge for later recall
Memory
Memory is the storage of acquired knowledge for later recall:
_____: seconds to hours
_____: days to years
_____: temporarily holds and interrelates various pieces of information relevant to a current mental task
Short term
Long term
Working memory
A _______ is a neural change responsible for retention or storage of knowledge. These traces are present across multiple regions of the brain
Memory trace
________memory - important for remembering facts and events- involved hippocampus
Declarative memory
(“What” memories of people, places etc)
Declarative
____ memory : the leading of new motor skills - involves cerebellum
Procedural
(“How to “ memories)
Procedural memories
Procedural memory involves which brain structure ?
Cerebellum
Consolidation of short-term declarative memory into long-term memory is the function of the _______, occurs largely during sleep
Medial temporal lobe
Consolidation of short-term declarative memory into long term memory requires _____ leading to protein synthesis and synaptic changes
Gene activation
____ - term memory : involves transient changes in synaptic activity
Short
____ -term memory: involves formation of new. Permanent synaptic connections
Long
_______- decreased responsiveness to a receptive and indifferent stimulus
_______- increased responsiveness to mild stimuli following a noxious stimuli
Both involve changes in ______ and ____
Habituation
Sensitization
Ion channels, currents
_________ is important for initial storage into long term memory
Long term potentiation (LTP)
Concept that _____ temporarily holds and interrelates various pieces of information that are relevant to a current mental task
Working memory
_____ memory is critical for ability to reason, plan and make judgements
Takes place within ______
Working
Prefrontal cortex
______ disease :
-Characterized by short-term memory loss in early stages
-followed eventually by loss of long-term memory
- confusion, disorientation, personality changes
-loss of ability to read, write, calculate
- language ability and speech also impaired
Brain alterations :______ and _______
Alzheimer’s
Neurofibrillary tangles , amyloid plaques
Characteristic los of cholinergic neurons in the basal forebrain- cells that project to to____
Hippocampus
________ neurons: neurons that use acetylcholine as their neurotransmitter
Cholinergic
______ is localized in one hemisphere - left hemisphere (95^ of right handlers , 60%-70% of left handers)
Language
______ area : speaking ability
- damage results in an inability to send the proper commands to the motor cortex to form the words.
Broca’s
_____ area: language comprehension
- damage results in an inability to attach meaning to words or choose the appropriate words
Wernicke’s
Language disorders :
______- is a defect in language processing caused by dysfunction of the dominant cerebral hemisphere
____- defects in mechanical aspect of speech
____- difficulty in learning to read because of inappropriate interpretation of words. Due to developmental abnormalities in connections between the visual and language area of the cortex
Aphasia
Speech impediments
Dyslexia
Which language disorder is Due to developmental abnormalities in connections between the visual and language area of the cortex
Dyslexia
Electrical activity patterns define ___ states
Arousal
Electrical activity in neurons can be measured by ____
EEG’S
EEG’S:
Surface electrodes placed on the scalp can detect ______ of the cortical neurons in the region under the electrode
Depolarizations
Depolarizations of the cortical neurons represents _____________ and _________ in cell bodies of the cortical layers
Excitatory post synaptic potentials (EPSP) and inhibitory post synaptic potentials (IPSP)
In wake states - neurons are firing but not always in a coordinated fashion
This desynchronization may be a result of ascending signals coming from the _________
Reticular activating system RAS
EEG is often used as a clinical tool in diagnosis of _____ dysfunction
Cerebral
____- shows distinctively abnormal traces on EEG.
- seizures occur when collections of neurons undergo synchronous action potential that produce stereotypical, involuntary spasms and alterations in behaviour
- neuronal excitability coupled with comprised inhibitory activity or prolonged activation of excitatory transmitters
Epilepsy
__________
- electro cerebral silence - flat EEG
-needs to be coupled with other stringent criteria
Legal determination of death
EEG is also used to distinguish various stages of ____
Sleep
The ____ rhythm in the EEG is 8-13 Hz: index of cortical activity.
- present in adult who is awake but relaxed with eyes closed
- amplitude is negatively correlated with cortical activity
Alpha
_____ rhythm in the EEG is 13-30 Hz: decreased synchronization with cortical activity
- individuals who are alert and attentive to external stimuli or exert specific mental effort
Beta
States of consciousness include
1___
2____
3____
Maximum alertness, wakefulness, sleep
_______ depends on sensory input that stimulates the RAS and subsequently the activity levels of the CNS as a whole
Maximum alertness
________: normal cyclic variation in awareness
Sleep-wake cycle
Sleep is an ___ process. Brains overall activity is not reduced during sleep
Active
2 types of sale characterized by different EEG patterns and different behaviours:
-_______sleep : delta -wave , non rapid eye movementn NREM
-_____sleep : rapid eye movement , REM
Slow-wave sleep
Paradoxical
Slow wave sleep occurs in 4 stages- each displaying a ____ frequency but ____ amplitude EEG wave
Lower, higher
At onset of sleep upon move through the stages from _______ sleep (1) to ___ sleep (4) in a 35-45 min period
Ten i reveres through the same stages in the same amount of time
Light , deep
A short period of ____ sleep occurs at the end of each slow-wave cycle
REM
Sleep stages :
Stage ___: drowsiness and drifting in and out of consciousness
1
Sleepers move through stages 2-3-4 and then back through the stages, rather than returning to stage 1 sleepers enter ___ sleep
It is a ___minute cycle
REM
90
Time in ____ stage increases whereas Tim win stages ___ and ___ decreases over the cycles
REM
3 and 4
Main functions of sleep include :
1.__ - defence from predation
2.__- healing, growth, immune function
3.___ - underlie consolidation of long-term memory in cortex
Conservation of energy
Restorative function for brain/body
Cerebral changes
