Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

MD4001 Week 4 > 5. The limbic system, emotion, the hypothalamus, appetites > Flashcards

5. The limbic system, emotion, the hypothalamus, appetites Flashcards

1
Q

What is the limbic system physically?

A

It’s a system of interconnected discrete structures within the brain and brain stem largely forming a ring around the corpus callosum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Name 8 functions that are controlled by the limbic system

A
  1. Eating / Drinking
  2. Fighting/killing
  3. Sex drive
  4. Enjoyment
  5. Fear / anxiety
  6. Autonomic preparation
  7. Memory formation and recall
  8. Expression of emotion
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

4 main functions of the limbic system?

A
  1. Emotions and drives via the amygdala
  2. Homeostasis and motivation (autonomic and
    neuroendocrine) via the hypothalamus
  3. Olfaction via the olfactory cortex
  4. Memory via the hippocampus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Cortical structures of the limbic system?

A 
Corpus callosum
Cingulate syrus
mid brain edge
Parahippocampal gyrus
Temporal lobe
Corbital and medial prefrontal cortex
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Subcortical structures of the limbic system?

A 
Cognitive area:
Hippocampus
Mammillary body
Anterior nucleus of the thalamus
Mammillothalamic tract
Fornix
Emotional area:
Amydgala
Hypothalamus
Ventral basal ganglia
Anterior commissure
Mediodorsal nucleus of the thalamus
Optic chiasm
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Position fo the amygdala?

A

Found at the anterior tip of the hippocampus.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Role of amygdala as part of the limbic system?

A

Provides an emotional component to experiences & memory, and the ability to recognise FEAR, others.

Provides an appreciation of INNATE (baby precipice) and LEARNED FEAR and has extensive connections with all cortical association areas allowing integrative function

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What were the feat conditioning of little albert?

What was discovered?

A

Cruel experiments in which
little Albert was
conditioned with noise to
fear rats and rabbits

SOCIAL CONDITIONING of this sort however happens all the time in both the human and non-human primate worlds
We learn from, and fear to make, mistakes which have adverse effects

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

efferents and afferents of amygdala?

A

Most significant AFFERENTS are from FRONTAL, TEMPORAL AND PARIETAL lobes receiving cognitive information

Most significant EFFERENTS are to the HYPOTHALAMUS and LIMBIC cortex providing emotional cognisance, and visceral/homeostatic information

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is kluver-bucy syndrome?

A 
Bilateral temporal lobe lesions in all mammals produce a range of symptoms known as Kluver- Bucy syndrome
Symptoms:
1. Visual recognition impairments (visual agnosia)
2. Heightened sexual appetite
(Hypersexuality)
3. Loss of fear and conditioning
4. Oral tendencies (Hyperorality)
5. Flattened emotions
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the Ekman’s six types of universal facial expression?

A 
Anger
Fear
Disgust
Surprise
Happiness
Sadness
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Lesions of human amygdala results in…

A

a loss of recognition of fear and anger in other peoples faces, these subjects however can usually recognise the other 4 Ekman emotion types (i.e. sad happy disgust surprise and anger).
Other modalities such as vocalisation can also be misunderstood

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Result of electrical stimulation of amygdala (as well as the anterior hypothalamus & the PAG)?

A

causes anxiety, agitation and aggression in humans

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Role of amygdala and unconscious reactions?

A

A fast sub-cortical route for visual information which connects to thalamus to the amygdala and thence to the hypothalamus
e.g. arachnophobics showing a skin conductivity reaction when seeing a camouflaged spider, BEFORE they are aware of what it actually is/

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

The main effector of the limbic system….

A

the hypothalamus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Hypothalamus afferents as part of the limbic system

A

Neocortex
Pain and sensory integration in brainstem nuclei
Spinal cord
Amygdala

17
Q

Hypothalamus efferents as part of the limbic system?

A

—-> Neocortex –> Motivational strategies

–> Pain and sensory integration in brainstem nuclei –> Dulling pain and hunger

–> medulla –> Vomiting, respiration etc

–> Spinal cord –> Visceral motor function

–> Amygdala

–> ant. and post. pituitary –> Hormone release

18
Q

What are the 3 main effects exerted by the hypothalamus?

A 
1. Vegetative functions
Cardiovascular regulation
Thirst
Appetites
Temperature, blushing; pallor
Sexual excitement
  1. Endocrine functions
    Control over anterior pituitary gland hormone release through the connecting blood supply
3. Behavioural functions
General level of activity up to and including ‘rage’ for pursuit of food, water, sex etc
Ingestion/disinterest in/of food
Fear and punishment behaviour
Increased sexual drive
19
Q

Describe the reward system within the limbic system

A

The mesolimbic dopamine system (or reward system) originates in the ventral tegmental area of the midbrain, and project via dopaminergic pathways to the:
1. medial prefrontal cortex (mPFC)
2. amygdala
3. Hippocampus
These then project to the nucleus accumbens via glutamatergic pathway
And then to the the ventral pallidum via GABAergic pathway

20
Q

What is the basis of people with addition and the connection to the limbic system?

A

Drugs of abuse such as psycho stimulants (e.g. cocaine) opiates (e.g. heroin) , ethanol cannabinoids and nicotine are currently thought to have a final common dopaminergic pathway feeding into the limbic system

21
Q

Role of anterior insular cortex?

Link to huntingtons?

A

Provides introspection which allows the interpretation of sensation as JOY or DISJUST

Patients with Huntington’s disease (a progressive frontal cortex degenerative disease) show IMPAIRMENT of VISUAL characteristics associated with DISGUST. The extent of the impairment is dependent of the amount of damage to the insular

22
Q

Role of limbic system with pain recognition?

A

The limbic system interconnects with structures involved in pain and pain perception such as the PAG
The PAG is able to reduce activity in the ascending pain pathway, its effects are agonised by endorphins and so opiates.

23
Q

PAG?

A

Periaqueductal in midbrain

24
Q

How does the circumstance perception alter perception of pain?

A

The perception of pain is dependent on the perception of the circumstances.

Sadistically inflicted pain stimuli hurts MORE. Accidentally inflicted pain stimuli from a friend hurts less
E.g. The placebo effect of saline injections or a parental kiss to child wound can reduce pain.
Emotional relief of pain is blocked by nalaxone, so pain returns.

25
Q

Electrical stimulation of PAG produces analgesia which can be ________ by nalaxone (Opioid receptor blocker)

A

Electrical stimulation of PAG produces analgesia which can be blocked by nalaxone (Opioid receptor blocker)

26
Q

Role of ventromedial portion of the prefrontal cortex in depression?

A
  1. The ventromedial portion of the prefrontal cortex has a reduced activity
    -This area is normally associated with goal setting, forward planning, and
    ascribing meaning to perceptions.
    -The ventromedial prefrontal cortex has mass reduction ( from loss of glial cells not neurones) in individuals with familial depression
    -Bi-polar sufferers have no activity during depression and hyperactive during manic phases.
    -This portion of brain as it is modulated by NTs with dysfunctions associated with depression
27
Q

Role of cingulate gyrus in depression

A

Unusual activity seen in clinical depression (normally reduced activity)

However, In bi-polar patients the anterior portion becomes more active during depression and less active during manic periods (opposite to ventromedial cortex).

CG thought to be a straddle between emotion and cognition

28
Q

Areas of the brain involved in depression?

A

Ventromedial portion of the prefrontal cortex

Cingulate gyrys

29
Q

Which Imbalances in limbic neurotransmitters and glucocorticoids are associated with depression?

A

NTs:
Serotonin
Dopamine
NE

Elevated blood glucocorticoid levels are a response to exposure to prolonged stressors

30
Q

How does stress elevate glucocorticoid levels?

How does this relate to depression via serotonin receptor expression?

A

The pituitary releases ACTH which signals the adrenal glands to release glucocorticoid - Prep for fight or flight.
Glucocorticoid is detected by the hippocampus which then activates the hypothalamus into releasing corticotrophin releasing hormone (CRH). CRH causes release of adrenocorticotrophic Hormone (ACTH) which causes the release of more glucocorticoids.
Normally cortical receptors feed back into the system blocking production of CRH but left unchecked (as in depressives) this results in excess glucocorticoids
Increased glucocorticoids affects the expression of serotonin receptors leading to depression and possible suicide

31
Q

What was frontal lobotomy?

Result in patients>

A

Aim to seperate the limbic cortex at the level of the frontal lobes

Resulted in patients with disinhibition, a lack of forward planning, lowered executive function and multitasking abilities.

32
Q

What is agnosia?

A

inability to interpret sensations and hence recognise things

33
Q

Where is the ventral tegmental area?

A

Midbrain

where the reward system orginates from

34
Q

Other name for reward system?

A

Mesolimbic dopamine system

35
Q

What does the mPFC of the reward system stand of?

A

Medial PreFrontal cortex

36
Q

What structure is at the head of the caudate nucleus?

A

Nucleus accumbens

37
Q

What is introspection?

A

Examination/observation of one’s own emotions

MD4001 Week 4 (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions