Limbic system & Reticular system - Sleep & Arousal Flashcards
What are the three different elements that make up Emotion?
- Cognitive (thinking) component: an appraisal or judgment
*Feeling (subjective) component: what a person experiences privately
action (or, action tendency) . - Component: either an action or, at least, a tendency to an action
What is the Primary Centre of Emotion?
The limbic system in association with the Hypothalamus
What are the types of emotions perceived?
- Rage and fighting
- Placidity and Tameness
- Reward / Satisfaction/ Pleasant reaction
- Punishment/ Aversion / Unpleasant reaction.
- Sexual Drive – Mating and maternal behaviour.
- Fear
- Anxiety
What are the components of the limbic system?
Amygdaloid body
Hippocampus (“seahorse”)
limbic lobe
Cingulate gyus
Parahippocampal gyrus
Hypothalamus
Mamillary bodies
Anterior nucleus of thalamus
Which part of the limbic system provides an emotional component to the learning system?
Amygdala
In which lobe of the brain is the Amygdala located?
Temporal lobe
Which region of the Amygdala is related to the Olfactory cortex?
Corticomedial group
What is the function of the Basolateral group of the Amygdala?
Provides direct input to basal ganglia and motor system.
Fill in the blanks. “ The medial and central nuclei of the Amygdala is connected to the ________.”
Hypothalamus
Fill in the blanks.” Anxiety increases blood flow to __________.”
To the anterior end of the Temporal lobe
Where is the most dominant pleasure area?
Dopaminergic pathway from ventral tegmental area to nucleus accumbens.
Which drug reduces re-uptake of dopamine & serotonin?
Cocaine
What substance increase the release of Dopamine?
Amphetamine
Nicotine
Alcohol
Which nucleus regulates the release of Dopamine in the Nucleus Accumbens and Enkaphalins in Hypothalamus?
Midline Raphe Nuclei
Which nuclei is a source of 5- HT ( Serotonin )?
Midline Raphe Nuclei
Fill in the blanks. “ Stimulation of the ___________ amygdala increases food intake.”
Corticomedial amygdala
Fill in the blanks. “ Stimulation of the __________ amygdala reduces feeding behavior. “
Basolateral amygdala
Stimulation of which nuclear group of the Amygdala results in powerful rage or fear?
Basolateral group
What is the pathology associated with bilateral destruction of the Amygdala?
Kluver-Bucy Syndrome
What are the characteristics of Kluver- Bucy syndrome?
- Hyper-orality (indiscriminate eating or chewing of food and other objects)
- Hyper-sexuality (lack of sexual inhibition)
- Psychic blindness/visual agnosia (lack of object recognition).
- Personality changes (abnormal passivity, fearless)
- Decreased emotionality.
What is the Input to the Hippocampus?
Entorhinal cortex & Contralateral hippocampus
What are the outputs of the Hippocampus?
- To mammillary bodies via fornix
- Contralateral hippocampus
- Also output to amygdala
Damage to which brain region will result in the reduced level of tension & anger ?
Cingulate cortex
Damage to which brain region will result in impaired ability to identify angry expressions (but not happy expressions) ?
Medial Frontal cortex
What is the Ascending Reticular pathway responsible for?
Responsible for arousal of cortex
Fill in the blanks. “ The descending reticular pathway us responsible for ___________.”
Body balance
Through what does the Ascending reticular system receive collateral input from?
I) Long somatic pathway
II) Trigeminal , Olfactory , Auditory and Visual pathway
III) Visceral pathway
Fill in the blanks. “ Deactivation of the Reticular activating system produces _________.”
Sleep
True or False? Tumors or destruction of RAS produces coma or unconsciousness.
TRUE!!!
What forms the Descending reticular system?
The reticulospinal tract
What are the Inhibitory functions of the Descending Reticular System?
- Smoothness and accuracy of voluntary movements
- Reflex movements
- Regulates muscle tone
- Maintenance of posture
- Control vegetative functions
What are the Facilitatory functions of the Descending reticular system?
- Maintain musle tone
- Activates ARSA
- Facilitates Autonomic functions
- Important in sleep or wakefulness
Which areas of the brain are Arousal centres?
- Substantia nigra
- Posterior part of hypothalamus
- Pontine reticular formation
- The locus ceruleus
Which areas of the brain lead to sleep?
The raphe nuclei and Pre-optic area
What is the term given to the electrical response of the brain to a sensory stimulus?
The Evoked potential
Fill in the blanks. “ When recording an EEG, The direction and strength of dipole depends on ___________.”
The summation of EPSP and IPSP
Fill in the blanks. “ When recording an EEG , The The frequency of generation of cortical dipoles depends on ___________.”
Cortical neuronal activity
What does the EEG measure?
The EEG measures the summation of graded Post Synaptic Potentials ( PSP’s)
Where is the Exploring electrode placed ?
It is placed on the Primary Receiving area and related sense pathway is stimulated
Fill in the blanks. “ In an EEG, The first surface positive -negative wave is called the___________.”
Primary Evoked potential
Fill in the blanks . “ In an EEG , The later non- specific response is called the ___________.”
Diffuse Secondary response
What is the normal number of electrodes to be used in a n EEG?
Use 21 electrodes but more can be added.
How are electrodes spaced during an EEG?
Electrodes are spaced at 10% or 20% of distances between specified anatomic landmarks
True or False? In an EEG , Odd number electrodes over right and even number over left hemisphere.
FALSE!! Odd are on the LEFT
Even are on the RIGHT
What is the frequency of Beta waves for the EEG?
14-30 Hz
What is the Amplitude for Beta Waves?
2-20 µV (small amplitude)
What is the frequency of Alpha waves?
8- 13 Hz
What is the amplitude of Alpha waves ?
20-60 µV
Which EEG waves are Characterized by very irregular and slow wave patterns ?
Delta waves
Which EEG waves are found present in periods of deep sleep in people?
Delta waves
What is the frequency of Theta waves ?
2-7 Hz
What is the amplitude of Theta waves ?
20-100µV
What is the frequency of Delta waves?
.5- 3.5 Hz
What is the amplitude of Delta waves?
20-200µV
Which EEG waves are believed to be more common in children than adults?
Theta waves
Which EEG waves responds to Relaxed wakefulness?
Alpha waves
Which EEG waves occur with sudden sensory stimuli?
Gamma waves ( 36-44 Hz)
Which type of sleep accounts for 20-25% of total sleep time?
REM Sleep
What type of sleep is associated with Viscera - Motor activity?
NREM sleep
What are the stages of the NREM sleep?
Drowsiness ( Stage I)
Light sleep ( Stage II)
Moderate sleep ( Stage III)
Deep sleep ( Stage IV )
What is the neurotransmitter associated with Rem sleep ?
Noradrenaline
What is the neurotransmitter associated with Non- Rem sleep?
Serotonin
What are the sleep zones in the brain?
- Diencephalic sleep zone ( In posterior hypothalamus)
- Medullary synchronizing zone ( In reticular formation of medulla)
- Basal forebrain sleep zone ( Preoptic area and diagonal band of Broca)
True or False? During slow wave sleep there is marked reduction in cholinergic, noradrenergic, and serotonergic activity of brainstem.
TRUE!!
What are the neurotransmitters of Slow wave sleep?
- GABA
- Galanin (peptide)
- Ventrolateral preoptic nucleus (VPLO neurons of hypothalamus particularly active during sleep, and project inhibitory neurotransmitter )
- 5HT (from raphe nuclei acting to reduce sensory output to inhibit motor activity )
- Alpha-melanocyte secreting hormone
True or False? In REM sleep there is increase in activity of amygdala and visual association area but decrease in activity of prefrontal and parietal cortex.
TRUE!!
Fill in the blanks. “ Pontine cholinergic neurons sends impulses to occipital cortex via __________.”
The Lateral Geniculate body
Sleep walking is common among what ages?
5 & 12 years