Limbic System Anatomy

Question 1

In the Circuit of Papez, the Anterior Nucleus of the Thalmaus projects to where?

It is then continued ventrally into the temporal lobe by what?

Answer 1

Cingulate Gyrus

Parahippocampal gyrus

Question 2

The combination of the cingulate gyrus and the parahippocampal gyrus is considered…

Answer 2

the limbic gyrus

Question 3

the expansive head of the hippocampus is found within the medial portion of the temporal lobe, specifically in the …

Answer 3

dentate gyrus, immediately superior to the uncus

Question 4

What makes the hippocampal area unique?

Answer 4

one of the oldest portions of the cortex, has only 3 cell layers rather than 6

Question 5

Fibers on the superomedial surface of the hippocampus form the … as they lead to a … extending posteriorly.

Answer 5

fimbriae

crus

Question 6

The crura from the hippocampal fimbriae fuse to form…

This structure is suspended from the inferior edge of the …

Answer 6

Body of the Fornix

Septum Pellucidum

Question 7

At the anterior commissure, the body of the fornix will split into what components? Where do these components lead?

Answer 7

• anterior component
  
  • Septal nuclei and Nucleus Accumbens of the Basal Forebrain
• posterior component
  
  • extends through HT to reach mammillary bodies

Question 8

Mammillary bodies are immediately caudal to the …

Answer 8

infundibulum

Question 9

What is the primary input and output of the Mammillary Bodies?

Answer 9

• input
  
  • posterior component of fornix
• output
  
  • mammillothalamic tract (to anterior nucleus of thalamus)

Question 10

Mammillary bodies are frequently damaged d/t … causing…

Answer 10

alcoholism

memory impairment

Question 11

If the cingulate gyrus, fornix, or hippocampus is damaged, the pt is likely to have what issue?

Answer 11

impairment of memory and/or anterograde amnesia

long term recall is not affected, but pt loses ability to make new memories

Question 12

What area of the brain forms memories and what area keeps the memories?

Answer 12

hippocampus forms

association cortices keep the long-term memories

Question 13

The papez circuit is now seen as primarily.. while the Limbic system is generally interpreted as a center for…

Answer 13

a functional route for long-term memory formation

emotional response

Question 14

What are the 5 F’s of the Limbic system?

Answer 14

feeding

fleeing

fighting

feeling

fornicating

Question 15

Located at the rostral tip of the hippocampus is the…

It is involved by proximity in the circuit of papez but it also receives direct input from…

What else gets direct input from here?

Answer 15

amygdala

olfactory

septal nuclei of basal forebrain

Question 16

disruption of the amygdala leads to..

Answer 16

• generalized placidity and lack of fear
• hypersexuality
• hyperphagia
• oral fixation

Question 17

Where are the Nucleus Accumbens and Septal Nuclei located?

Where do they receive information from?

Answer 17

basal forebrain

anterior component of fornix along with amygdala

Question 18

What links the nucleus accumbens and the septal nuclei with the amygdala and the HT?

Answer 18

stria terminalis (white matter)

Question 19

What is the function of nucleus accumbens and septal nuclei?

Answer 19

reward/pleasure centers in the brain

lesions linked to addictive, reckless, or impulsive behavior

Question 20

What is the main NT of the amygdala?

What is the main NT of the Nucleus accumbens?

Answer 20

glutamate

dopamine

Question 21

What hypothalamic nuclei produce ‘rage’ or ‘fear’ responses when activated?

Answer 21

Ventromedial and premammillary nuclei

Question 22

What links the nucleus accumbens and septal nuclei with the Habenular Nuclei at the base of the pineal gland in the epithalamus?

Answer 22

Stria Medullaris

Question 23

What does the Habenular Nucleus do?

Answer 23

relay center between the limbic system and the brainstem/spinal cord

functions in negative rewards/negative feedback

Question 24

Where is the interpeduncular nucleus and what does it do?

Answer 24

in the midbrain tegmentum, superior to mammillary bodies

relay for limbic to brainstem

linked to withdrawal and other negative behaviors

Question 25

The small cluster of neurons in the ventral tegmentum immediately adjacent to the substantia nigra is called…

What is this important for?

Answer 25

Ventral Tegmental nucleus

dopaminergic center - projections to limbic and other centers - plays a role in ‘reward’ behaviors

pathological changes a/w personality change in PD or Schizophrenia

Question 26

The prefrontal and orbital portions of teh cerebral cortex are generally interpreted as centers for …

Answer 26

Affective Behavior

Question 27

Specifically the rostral portion of the insula is known to be tied to the limbic system, esp. with what?

Answer 27

emotional evaluation and emotional desire

Question 28

When talking about the emotional cortex, the nucleus accumbens is said to be part of..

Answer 28

basal ganglia

Question 29

The limbic system has both cortical and sub-cortical components. These interact through both the thalamus and basal ganglia. What kind of signals do each of them send?

Answer 29

thalamus - sending excitatory signals to the cortex

basal ganglia - sending inhibitory signals