12 - Limbic System (Exam 3) Flashcards
Is the limbic system a true lobe?
No
It is a ring
What lobes does the limbic ‘lobe’ span across?
Frontal, parietal, and temporal lobes
What are the 4 major structures of the limbic system?
- Hippocampus
- Amygdala
- Septal nuclei
- Entorhinal area
What is the hippocampus responsible for?
Memory formation and learning
What is the amygdala responsible for?
Emotions and drive
What are the septal nuclei responsible for?
Reward mechanisms
What is the entorhinal area responsible for?
Receives sensory information and relays it to hippocampus for memory
Functionally, what is the hypothalamus a part of?
The limbic system
Hippocampus is the latin word for what?
Sea monster
Hippocampus resembles a seahorse
What are the 3 major portions of the hippocampus?
- Subiculum
- Hippocampus proper
- Dentate gyrus
What is the transition zone of cortex within the hippocampus?
Subiculum
What is the hippocampus proper mainly composed of?
Gray matter
Where is the major output center of the hippocampus?
Hippocampus proper
specifically the fornix
What is essential to forming new memories?
Neurogenesis - formation of new neurons - because new memories are always forming
What does the only white matter in the hippocampus proper form?
Forms fimbria at posterior end
fimbria form the fornix
What is the shape of the amygdala?
Almond shaped
What is the amygdala primarily associated with?
Fear
What are the 3 distinct nuclei of the amygdala?
- Basolateral
- Central
- Cortical medial
What is the function of the basolateral nucleus of the amygdala?
Attaches emotional significance to stimuli
What is the largest of the amygdala nuclei?
Basolateral nucleus
What is the function of the central nucleus of the amygdala?
Regulates visceral responses to emotional stimuli
What is the function of the cortical medial nucleus of the amygdala?
Plays a role in emotional responses to food
What are the septal nuclei and what is their function?
Small group of nuclei on the medial wall of the frontal lobe
Role in reward and pleasurable feelings
What does the Papez circuit connect?
Emotion and consciousness
What are the 4 steps of the Papez circuit?
- Cingulate cortex to hippocampus
- Hippocampus to mammillary bodies (via fornix)
- Mammillary bodies to thalamus anterior nuclei (via mammillothalamic tract)
- Thalamus anterior nuclei to cingulate cortex
What is a key structure in the extended Papez circuit that was not included in the original?
Amygdala
The fornix also extends to areas past MBs
What are the 2 types of long term memory?
- Explicit memory
2. Implicit memory
What is short term memory also referred to as?
Working memory
What is explicit memory also referred to as?
Declarative memory
What is implicit memory also referred to as?
Nondeclarative memory
What are the 2 types of explicit memory?
- Episodic (events)
2. Semantic (facts)
What are the 4 types of implicit memory?
- Skills
- Habits
- Emotional memory
- Conditioned reflexes (like Pavlov’s dog)
Alzheimer’s is involved with the degeneration of what in the brain?
Norepinephrine systems
How are emotions and memory connected?
Highly emotional events produce stronger memories
What is fear conditioning?
Where a neural stimulus becomes associated with an adverse event.
Dr. Aslakson stays away from electrical outlets so her mom doesn’t yell at her
How do positive and negative feelings have effects on our behavior?
Positive feelings are associated with reward
Negative feelings are associated with fear
Cat video with spooky hats
