Singh 6: The Forebrain

Question 1

What are the following structures associated with?

Limbic system

Thalamus

Basal Ganglia

Hypothalamus

Answer 1

Limbic system: emotion (amygdala)

Thalamus: relay center of the brain

Basal gangli: motor control

Hypothalamus: maintenence of the status quo

Question 2

The central sulcus seperates the ____ from the ___

Answer 2

The central sulcus seperates the frontal lobe from the parietal lobe

Question 3

Explain the following terms:

Commisures

Association fibers

Projection Fibers

Answer 3

Commisures connect left and right hemispheres (biggest example is the white matter band called the corpus collosum)

Association fibers: within one hemisphere

Projection fibers: cortex to caudal

Question 4

Where are broca’s are and wernicke’s area located?

Answer 4

MOSTLY on the left hemisphere

for right handed people

it is not bilatteral, only on one side

Question 5

Explain the areas involved in the following when you read outloud:

Perception of visual info

Integration of visual info

Comprehending visual info (i.e. words)

Speaking the words

Answer 5

Perception of visual info: visual input–> primary visual cortex

Integration of visual info: visual cortex–> visual association cortex

Comprehending the visual info: visual association –> Wernicke’s area

Speaking the words:

Wernicke’s area–> Broca’s area

Question 6

Explain the dorsal stream vs the ventral stream in terms of vision?

“where” vs “what”

Answer 6

Dorsal: occipitalparietal “where information”… aka you can say the apple is in your hand

Ventral: occipitaltemporal, the “what”, aka you can identify the object as an apple

remember : Where is the door

and Vwhat is that

Question 7

The basal ganglia is related to what?

What are the divisions of the basal ganglia?

Answer 7

Basal ganglia is related to motor control and motivated actions

Striatum: nucleus accumbens (reward center) and caudate

Lentiform: putamen, globus pallidus

Question 8

Explain in general terms what the thalamus does

Answer 8

The thalamus is the relay center of the brain

It processes sensory info and relays it to the cerebral cortex

Question 9

Explain the two important parts of the thalamus

Answer 9

Medial geniculate nuclei : associated with hearing

Lateral geneiculate nuclei: associated with vision

Question 10

Thalamus:

The medial geniculate nucleus receives info from the _______, via the _________ (part of midbrain), and projects it to the _______

Answer 10

Thalamus:

Medial geniculate nucleus receives info from the cochlea, via the inferior colliculus, and projects it to the auditory cortex

Question 11

Thalamus:

The lateral geniculate nucleus receives into from the ______ via the _______, and projects it to the ____

Answer 11

Thalamus:

Lateral geniculate nucleus receives into from the retina via the superior colliculus and projects it to the occipital lobe

Question 12

The Hypothalamus Integrates:

1.

2.

3.

Explain

Answer 12

The hypothalamus integrates: endocrine function, autonomic function, and motivated behaviors

Homeostasis: fluid balance, temp regulation, stress response, cicadian rhythm, sleep and arousal

Motivated behaviors: sleep, feeding, reproduction, sickness

Question 13

Coronal view of hypothalamus:

Perventricular area important for?

What structure seperates the medial and lateral hypothalamus?

Answer 13

Periventricular area: neuroendocrine function

Medial: site of limbic input

Lateral: relay station, hunger center

What seperates the medial and lateral hypothalamus is called the fornix

Question 14

Ventromedial part of hypothalamus is the _____ center

Getting a lesion in the middle part of your hypothalamus would cause what?

Answer 14

Middle part of the hypothalamus is the SATIETY center

Lesion would cause uncontrolled eating

Question 15

Anterior hypothalamus is in control of what kind of regulation?

Answer 15

Anterior hypothalamus: thermoregulation

menopause: hot flash

Question 16

Explain the HOME pneumonic with the limbic system

Answer 16

Functions of the limbic system

Homeostasis

Olfaction

Memory

Emotion

Question 17

How does the limbic system effect emotion?

Three effector systems for the behavioral expression of emotion:

1.

2.

3

Answer 17

Somatic motor system: behavioral expression of emotion (aka smiling)

Endocrine system

Autonomic System

Question 18

Explain the papez circuit

Answer 18

Essentially

when we get all riled up and scared the amygdala triggers the hypothalamus—> thalamus—> neocortex

the neocortex can calm you down depending what is going on

also the hippocampus and memory can triger these things

Question 19

What does the amygdala do?

What is it assocaited with?

Answer 19

The amygdala relates enviornmental stimuli to coordinated behavioral, autonomic, and endocrine responses seen in self preservation

Associated with:

gut reactions

Fear conditioning

Forms associative memories

Social/facial recognition

PTSD

Question 20

The cortex is important for what?

What does Phineas Gage have to do with the cortex?

Answer 20

Cortex keeps inappropriate behaviors in check

Phinneas Gage had a lesion in his ventromedial/prefrontal cortex

Question 21

Where is the amygdala and limbic system located?

What is near it?

Answer 21

amygdala: medial TEMPORAL lobe

Hippocampus is also in the temporal lobe

temporal lobe also has wernicke’s and broca’s areas as well

therefore, pt having strange smells, weird emotional response, fear—- temporal lobe seizure

Question 22

Explain which sections of the forebrain are bathed by each artery

Anterior cerebral

Posterior cerebral

Middle cerebral

Answer 22

Anterior cerebral: frontal cortex, lower extremity motor function

Posterior cerebral: occipital lobe

Middle cerebral: upper extremity motor issues, SPEECH problems (temporal lobe)