Week 8- Basal And Limbic Flashcards
List components of basal ganglia
• Caudate nucleus• Putamen•
Globus pallidus (externus and internus)•
Subthalamic nucleus and• Substantia nigra
Where is putamen located
Central of basal ganglia
Where is nucleus accumbens
Inferior and anterior of basal ganglia
Superior section to amygdala
Where is lateral ventricle
Posterior and behind cellular bridges
Looks like helicopter plant
Where is amygdala
Inferior on basal ganglia. Most anterior inferiority
Anterior to tail of caudate (at end of tail)
List functions of basal ganglia
• Control of voluntary movements (facilitates and/or inhibits motor activity)•
Determine how rapidly a movement is to be performed and how large themovement must be•
Decrease muscle tone and inhibit unwanted muscular activity•
Regulate the muscle tone and thus helps in smoothening the voluntarymotor activities•
Control automatic associated movements, like swinging of arms duringwalking Pyramidal Tract
Name excitatory neurotransmitter
GLUTAMATE
Name inhibitory neurotransmitter
GABA
What is direct pathways
Initiates movement (increase motor activity)
Comes straight into thalamus
Motor cortex
Striatum
Internus
Thalamus
What is MSIT used for and what does it stand for
Shows the direct pathway for gLUTAMATE
Motor cortex
Striatum
Internus
Thalamus
What is the indirect pathway
• Terminates movement (inhibits/ decreases movement)•
MS EN IT (Mnemonic)or• Comes Straight,Exits, then Sidesteps Into Thalamus-
Motor Cortex-
Striatum-
Externus-
Nucleus (Subthalamic)- Internus
-thalamus
What is MS EN IT used for and what does it stand for
Indirect pathway
Motor cortex
Striatum
External
Nucleus (subthalamic)
Internus
Thalamus
What turns on motor cortex and what turns it off
Direct = turns on motor cortex
Thalami’s motor planning
Indirect= turning off motor cortex
Activation of inhibition
list clinical aspects for direct and indirect pathways
• Tremors, Athetosis, Chorea•
Parkinson’s disease• Huntington’s disease• Tourette’s syndrome
What is athetoid
Involuntary movements
Slow and tithing sitar muscle and extremities
What is chorea
Jerky movements
Non repetitive
what is hemiballismus
Violent movement confined to one side of the body
Proximal extremities of shoulder and pelvic girdle
What is Parkinson’s
Impairmtne of voluntary movement
Delay in movements
Rigidity
Termor
S-shuffling gait
M-mask like facies
A- Bradykineasia
R- rigidity
T- tremor
What is cause of Parkinson
Lesion to substania nigra and nigostriatal pathway which uses dopamine as neurot
Cellular loss + depigmentation in substantia nigra
What is substantia nigra
Critical brain region for production of dopamine
What is Limbic system a part of
Cortical and subcortical structures that form a ring around upper end of brainstem
Name cortical structure of Limbic system
• Limbic lobe : cingulate gyrus,uncus (olfactory cortex), insula• Hippocampu
List sub cortical structures of Limbic system
Amygdala
Diencephaloin, hypothalamus and thalamus
What is the role of Limbic system
Homeostatic functions
Olfaction
Memory
Emotions and drives
Where is homeostasis
Hypothalamus
What is homeostasis involved with
-body rhythms (day length via optical)
-release ADH reducing vol of urine when blood h20 drops
-releases lepton too reduce feeling of hunger when full
-release gherkin when hungry
-increase body temp to help immune system fight off pathogens
-^ production of cortisol for physical activity in stress
-thyroid hormones produced for metabolism
-oxytocin release doe interpersonal bonds. Sex and childbirth
What is olfaction and how does it help
T he olfactory system transmits sense of smell from olfactoryepithelium of nasal mucosa to the olfactory cortex of the brain•
• Olfactory epithelium and olfactory nerves•
Olfactory bulb, tract and striae• Olfactory cortical areas.
Where are olfactory cortical areas
• Primary olfactory cortex on the same side which located in theuncus on the inferomedial surface of the temporal lobe•
Some fibres connect with the limbic system•
The entorhinal area receives fibres profusely from primary olfactorycortex, hence it is sometimes called secondary olfactory cortex
Where is olfaction
Olfactory cortex
Where is memory
Hippocampus
What is hippocampus
Brain structure embedded in temporal lobe
• Curved elevation of grey matter•
Resembles a seahorse in coronal section•
Function – recent memory, processing long term memory andemotional response
What is memory split into
Short term- 5-9 items
Long term- infinite
Distributed network of neurons spread across outer layers of
brain
Where is emotions
Amygdala
How does amygdala affect Limbic system
Tastes all stimuli and signals to produce appropriate emotional reactions
Distinct regions called nuclei, generate different kinds of responses to fear
Fear is main emotion that amhygdala controls
Central neucleus- freezing
Basal nuclei- flight
Nuclei affecte by sex hormones
What is the difference between cortical and subcortical
Cortex= higher level functions. Decision making and language
Subcortex= beneath cortex. Primitive functions e.g. emotions in amygdala
where is substantia nigra located
midbrain
what is located in forebrain
motor cortex
caudate nucelus
putamen
subthalamic nuceli
globbulus palidus
describe the slow and accurate route of processing emotion
thalamus
sensory cortex ( extensively processed. takes time)
hippocampus (process consciously percied into form memories. compoares signals to previosu memories)
describe the quick route for processing emotion
thalamus
amygdala(emotional importance of stimuli is assessed)
-rapidy sends signals)
hypothalamus (hormonal changes. fight or flight)
