Neuro Exam 5 Lecture 3

Front 1

The cerebral cortex is a _________ structure

Back 1

layered- has very discrete layers of cells and connections between them

-We can differentiate different types of cortex based on the layering pattern and the number of layers that we see

Front 2

There are _________ categories of cortexes based on the layering patterns

Back 2

three

Front 3

In regards to the cyto-architecture of the cortex, what are the three different categories of cortexes based on the layering patterns?

Back 3

-Archicortex

-Paleocortex

-Neocortex

Front 4

Which category of cortex has the fewest layers? How many?

Back 4

Archicortex has three layers of cells

Front 5

There is only one structure in the brain that is considered archicortex. What is it?

Back 5

The hippocampus (so named because it reminded early anatomists of a seahorse)

Front 6

Which is considered to the be oldest of the cortexes?

Back 6

The archicortex

Front 7

Which of the cortexes is considered to be transitionary?

How many layers does it have?

Back 7

The paleocortex

3-5 layers

Front 8

The ___________ is particularly important for memory. This is considered what category of cortex?

Back 8

The hippocampus in the archicortex

Front 9

The _______________ is particularly important for olfaction

Back 9

Paleocortex

Front 10

The most extensive area of cortex is called the _____________. It makes up more than _______ % of the human cerebral cortex.

Back 10

Neocortex

90%

Front 11

How many layers does the neocortex have?

Back 11

six layers

(makes up more than 90% of the human cerebral cortex)

Front 12

What is very characteristic of the neocortex?

what does this allow for?

Back 12

It is highly convoluted

This is an adaptation that allows for a large amount of surface area to be contained within a finite amount of space inside of the cranial cavity

Front 13

There are _____ major types of neurons that we find in the cerebral cortex. What are they?

Back 13

2 major types:

-Pyramidal cells

-Granule cells

Front 14

____________ cells are large and tend to be primarily efferent (output) neurons

Back 14

pyramidal (remember efferent is relative and always means it is heading out somewhere; ie output)

Front 15

Pyramidal cells are primarily involved in ________ ____________ connections

Back 15

long distance

Front 16

_____1______ are smaller cells and can be considered as _______2______

Back 16

1. Granule cells

2. interneurons

Front 17

What are granule cells particularly important for?

Back 17

Receiving input into the cerebral cortex

Front 18

Are granule cells efferent or afferent neurons?

Back 18

afferent (input)

Front 19

_____1_______ cells are involved in much shorter, local connections than _______2______ cells

Back 19

1. Granule

2. Pyramid cells (long-distance connections)

Front 20

Good job

Back 20

You can do it! :)

Front 21

The different types of cells can be used to differentiate:

Back 21

different layers of the cortex

Front 22

How many layers are in the neocortex? What are they called?

Back 22

6 layers (from superficial to deep):

1. Molecular

2. External granular

3. External pyramidal

4. Internal granular

5. Internal pyramidal

6. Multiform

Front 23

Layer one, the molecular layer, of the neocortex has ____1____ neuronal cell bodies, and contains a lot of _____2_______

Back 23

1. very few neuronal cell bodies

2. dendrites of granule cells (the cells are in layer two)

Front 24

The dendrites located in layer one of the _________ cells in layer two) are making what type of connections?

Back 24

granule cells

the dendrites are making short local intracortical connections

Front 25

Layer two of the neocortex, the external granular layer, contains ____1_______ cells whose ____2_____ project into layer 1.

Back 25

1. granule

2. dendrites

Front 26

Layer three of the neocortex is called ____1______ and contains _____2_____ cells that are making what type of connections? Give an example.

Back 26

1. The external pyramidal layer

2.pyramidal cells

Cortico-cortico connections- projecting to more distant areas of the cortex (but still within the cortex). For example, the axons project a long way and may be connecting an area of the frontal cortex to an area of the parietal cortex

Front 27

_____________ connections are concerned with very short distance connections within one area of the cortex

Back 27

Local intracortical

Front 28

Which layer of the neocortex is considered to be the primary input layer to the cerebral cortex?

Back 28

layer IV- the internal granular layer

Front 29

Which layer of the neocortex is considered to be the primary output layer of the cerebral cortex?

Back 29

Layer V-the internal pyramidal layer

Front 30

What is the gateway to the cerebral cortex?

Back 30

the thalamus (VPL and VPM)

(the thalamus routes information to appropriate areas)

Front 31

The projections from the thalamus to the cerebral cortex are going to terminate on:

Back 31

the layer four granule cells (remember this is the primary input layer into the cerebral cortex)

Front 32

Layer V contains what type of cells?

What occurs here?

Back 32

large pyramidal cells

This is the primary output layer so the pyramidal cells send their axons a very long distance, exiting the cortex for the subcortical nuclei (such as basal nuclei), the brainstem, and the spinal cord.

Front 33

Pyramidal cells are primarily associated with _________ projections

Back 33

descending

-to places like the subcortical nuclei (such as basal nuclei), the brainstem, and the spinal cord.

Front 34

The deepest layer of the neocortex is the __________ layer (layer VI).

What is this layer used for?

Back 34

Multiform layer

Not a very interesting layer- contains very few neuronal cell bodies and is kind of transitional into the subcortical white matter.

Front 35

layer _____ contains very short distance local connections that are being processed by the dendrites of the granule cells that are extending up into this layer

Back 35

one (intracortical short distance connections)

Front 36

Layer three contains pyramidal cells that are projecting to other areas of the cortex

The connections that we particularly associate with the layer three cells within the same hemisphere are called____________ fibers

Back 36

association fibers

-They interconnect different areas of the cortex within the same hemisphere

Front 37

The term association means:

Back 37

that we are interconnecting functionally different areas of the cerebral cortex

-an example of an association tract is the superior longitudinal fasciculus

Front 38

The neurons that we associate with those association projections are the ____________ cells in the layer three cortico-cortico connections

Back 38

pyramidal cells

Front 39

We also have connections that actually cross the midline (so between hemispheres) in layer three. What are these fibers called?

Back 39

Commissural fibers

(commissural indicates that they are crossing the midline to the opposite cerebral cortex

Front 40

What do commissural fibers of layer three in the neocortex connect?

Back 40

They interconnect homologous areas of the cortex between the hemispheres, so the functionally similar/same area, but on the separate hemisphere

So for example, there are connections between premotor cortex in the left hemisphere and premotor cortex in the right hemisphere

Front 41

Cortico-cortico connections are associated with layer _______ neurons and can have two different types of fibers. What are they?

Back 41

three

-association fibers (same hemisphere, different functional areas)

-commissural fibers (different hemispheres- same functional areas)

Front 42

There are two major commissural connections. What are they?

Back 42

-The corpus callosum (the biggest one)

-anterior commissure (much smaller)

Front 43

What are the commissural fibers that connect more inferior portions of the temporal lobe?

Back 43

anterior commissure

Front 44

The _________________ is the structure that connects the homologous areas on opposite hemispheres

Back 44

corpus callosum

Front 45

With ___________ fibers, you have fibers that are originating from the cortex (layer 5) and descending to subcortical structures (subcortical nuclei), the brainstem, and the spinal cord, and you also have ascending fibers that are entering the cortex (layer 4) via the thalamus.

Back 45

projection

Front 46

Ascending fibers entering the cortex (being routed via the thalamus) are going to terminate on _____1____ cells in layer 4 (primary input layer), and the descending layers are originating in layer five from ___________ cells, the those projections descend to a variety of structures (subcortical nuclei: basal ganglia nuclei, brainstem, or spinal cord

Back 46

1. granule

2. larget pyramidal

Front 47

What is it called when someone is born without a corpus callosum?

Back 47

agenesis of the corpus callosum

Front 48

What is a treatment for severe epilepsy? What occurs?

Back 48

A callosotomy ("split brain). Epileptic seizures that originate in certain areas of the cortex can distribute and disperse to other areas of the cortex particularly by using the corpus callosum as their pathway.

It was discovered early on that one could cut, or sever most/all of the corpus callosum and really helped to control an individuals seizures

Front 49

When a callosotomy was performed on an individual in adulthood, what occurs?

Back 49

the individual in their "normal life" is virtually asymptomatic. From talking to this individual or observing their behavior, you wouldn't really outwardly notice anything different about that individual (unless you do specific things)

Front 50

What is an agnosia?

Back 50

An agnosia is an inability to recognize an object, even though your sensory systems are unaffected

Front 51

With a callosotomy, or "split brain" patient, if you set up an experimental apparatus in a very specific way, you can produce what is called a hemiagnosia. Why does this occur?

Back 51

This has to do with the fact that these individuals have a very specific pathology, or phenomenon in which they have trouble recognizing objects on a particular side in their visual field

Front 52

What is a visual agnosia?

Back 52

an inability to recognize an object, even though your visual system is working just fine

Front 53

The right visual field is processed in the ___________ cerebral hemisphere

Back 53

left

Front 54

In the experiment with the "split brain" patient, If the object is projected onto the right visual field, and that information is processed in the left hemisphere (like normal because of the partial crossing of the optic chiasm), how would the patient be able to identify the object? Why?

Back 54

the patient would be able to identify the object with both verbal and non-verbal cues.

This is because there is no need to use the corpus collosum, it is already able to access those language areas, so the individual can identify the object verbally, and they can also identify it using non-verbal cues

Front 55

How would the split brain patient be able to identify an object projected onto their left visual field? Why?

Back 55

The patient would be able to identify the object non-verbally (i.e. pointing, feeling the shape and identifying it), but would be unable to identify the object verbally. This is because the information from the left visual field is processed in the right hemisphere, and the speech and language areas are in the left hemisphere, and without a corpus callosum, that information has no way to travel from the right to left hemisphere, so it is like it is on the tip of their tongue, but they can't verbalize it (or write it or anything)

Front 56

language areas are very much lateralized in the _________ hemisphere

Back 56

left

Front 57

The ____________ hemisphere tends to be more involved in emotional processing

Back 57

right

Front 58

What is an experiment that was done that demonstrated hemispheric dominance?

Back 58

the chimeric face (a face in which half is male and half is female)

Front 59

What occurs when a person with a callosotomy, or split brain, is asked to focus on the central portion of a chimeric face where the female is in their left visual field, and the male is in their right visual field?

Back 59

When the patient is asked to say whether the face is male or female, the left hemisphere dominates and the patient reports seeing a male (verbalization is dominant in the left hemisphere). However, when the patient is asked to point to a male or female face that matches the face they are viewing, the right hemisphere dominates and the patient points to a female face (because the act of pointing and spatial recognition is a much more right hemisphere dominant function).

Front 60

The person that did this experiment had a cool quote in his acceptance speech for the nobel prize :)

Back 60

"the great pleasure and feeling in my right brain is more than my left brain can find the words to tell you." -Roger W. Sperry

:)

Front 61

With the association cortexes, what does association mean?

Back 61

You're putting two and two together. You can be taking two different types of incoming sensory information (such as hearing and vision) and putting those together, or you can be performing associative functions on a single type of sensation

Front 62

We will see areas of the cortex that are __________, meaning that they are involved in only one form of sensation, but they are important in terms of interpreting that sensation.

Back 62

unimodal

Front 63

The ___________________ helps an individual recognize an individual object that they are looking at after it has been processed by their primary visual cortex

Back 63

unimodal visual association cortex

Front 64

Where are the areas of multimodal association cortex

Back 64

areas that are very predominantly in the frontal lobe (prefrontal lobe), both on the lateral aspect and the medial aspect, as well as areas on the parietal cortex (lateral and medial aspect)

Front 65

Areas of cortex that are going to be bringing in and receiving information from different kinds of sensory processes are called:

Back 65

multimodal association cortex

Front 66

If you smell smoke and you hear crackling, you would think: fire. What type of association area would be used for this example?

Back 66

multimodal association cortex - it is receiving information about smell, it is receiving information about sounds (hearing), and it makes a logical decision about what you are experiencing.

Front 67

_____________ association cortex is going to be responsible for most of our highest cognitive functions- everything from executive decision making and personality types of traits, as well as ability to recognize and navigate through your spatial environment

Back 67

Multimodal association cortex

Front 68

What are the functional areas that are included in the frontal lobe?

Back 68

-Primary motor cortex

-premotor cortex

-supplementary motor cortex

-frontal eye field

-Broca's speech area (left hemisphere)

-Prefrontal multimodal association cortex

Front 69

What are some of the specific functions that are processed in the frontal lobe?

Back 69

-Movements of the face and body

-Motor planning

-Eye movements

-Language (motor speech)

-executive/emotional cognition

(decision making, planning, etc.)

31 minutes in slide 17

Front 70

If we have a lesion to brodeman's area 4 (primary motor cortex/precentral gyrus), this will produce a:

What is one of the ways this could occur?

Back 70

contralateral spastic hemiplegia

a lesion through middle cerebral artery (branch of internal carotid artery)

Front 71

_______________ is an inability to perform a voluntary movement, even though there is no paralysis of those muscles.

Back 71

an apraxia

Front 72

What could produce an apraxia?

Back 72

Lesions to Brodeman's area 6 (supplementary and premotor areas that area involved in motor planning) -It is a contralateral lesion

Front 73

A lesion to the ____________ will affect our gaze, so we will have a loss of contralateral gaze

Back 73

frontal eye field

Front 74

What occurs when we have a lesion to the motor speech area AKA, _____________?

Back 74

Broca's area

Broca's aphasia occurs

Front 75

What are the functional areas of the parietal lobe?

Back 75

-Primary somatosensory cortex

-Unimodal association cortex

-Wernicke's speech hemisphere (left hemisphere parieto-temporal cortex)

-Parietal multimodal association cotex

Front 76

What are some of the specific functions that are processed in the parietal lobe?

Back 76

-Somatosensation of the face and body

-Language (receptive speech

-Spatial cognition (particularly multimodal)

Front 77

________ speech area is an area that is involved in language reception

Back 77

Wernicke's

Front 78

A lesion to the primary/unimodal somatosensory cortex (Brodeman's area 3,1,2) in the parietal lobe will produce:

Back 78

A contralateral hemianestesia (a loss of all somatosensation)

Front 79

A lesion to Wernicke's area will produce:

Back 79

Wernicke's aphasia (receptive aphasia)

Front 80

If there is a lesion to the unimodal association cortex involved in somatosensation, this produces ______________. What is this?

Back 80

Astereognosis (would be contralateral)

-inability to recognize an object by touch because of that lesion to the unimodal association cortex that is involved in interpreting the sensations that are coming into the primary somatosensory cortex

So for example, you couldn't reach into your pocket that has coins and whatever and know what you are touching

Front 81

The __________ lobe is very much dominated by vision

Back 81

occipital

Front 82

What are the functional areas of the occipital lobe?

Back 82

-primary visual cortex

-unimodal visual association cortex

Front 83

What are some specific functions that are processed in the occipital lobe?

Back 83

vision

Front 84

What occurs if you lesion the primary visual cortex in the occipital lobe?

Back 84

A contralateral homonymous hemianopsia

Front 85

What is it called when someone looks at something and they are receiving that information and have an inherent understand of what they are looking at, but they are unable to recognize it? (inability to recognize an object from visual cues)

How does this occur?

Back 85

Visual agnosia

Occurs due to a lesion to the unimodal visual association cortex

Front 86

What are the functional areas located in the temporal lobe?

Back 86

-Primary auditory cortex

-Unimodal auditory association cortex

-Wernicke's speech area (left hemisphere parieto-temporal cortex)

-Memory (in direct continuity with the hippocampus)

Front 87

What are functions processed in the temporal lobe

Back 87

-Hearing

-Language (receptive speech)

-memory formation

Front 88

If you lesion the auditory unimodal association cortex in the temporal lobe, what occurs?

Back 88

Auditory agnosia, which is the inability to recognize sounds (like they could hear a bird chirping and they wouldn't be able to tell you what it is)

Front 89

When you have a lesion to the temporal lobe, if you lesion the portion involved in memory, then you may lose the ability to produce new memories. What is this called?

Back 89

anterograde amnesia (like in 50 first dates)

Front 90

If you have an inability to recognize faces (like you can't recognize who it is that you are talking to or looking at), you may have a lesion to what area?

What is this called?

Back 90

You may have a lesion to the fusiform face area

(on the inferior aspect of the temporal lobe)

This is called prosopagnosia

Front 91

A deficit in comprehension and/or production of language is called:

Back 91

Aphasia (produced by a lesion to a language area)

Front 92

the ________________ is an association projection between Broca's and Wernicke's area

Back 92

Arcuate fasciculus

Front 93

Language is very much lateralized in the __________ hemisphere in which lobes?

Back 93

Left hemisphere

-frontal lobe (Broca's)

-parietal lobe (Wernicke's)

-temporal lobe (Wernicke's)

Front 94

______________ area is very specific to the production of speech- called the actual motor or expressive speech area

Back 94

Broca's

Front 95

If you have damage to Broca's area, what does this lead to?

Back 95

Broca's Aphasia- A difficulty in producing language.

They have no problem with their mouth (not paralyzed), but they have an inability to speak fluently. They have a great deal of difficulty getting the words off of their tongue and require a lot of attempts to say the correct words. Even though they can't produce the speech normally, their comprehension is fine, so they are quite aware of the deficit. Not only can they not produce language verbally, but they wouldn't be able to write effectively, they can't read aloud, etc. If this person used sign language, then their ability to sign would be affected as well.

Front 96

With __________ aphasia, they are able to understand the question, and the answer is on the tip of their tongue, but they just can't get it out)

Back 96

Broca's (can get out common colloquialisms quite easily though, like curse words, because it is so frustrating)

Front 97

Broca's aphasia would mean you had a lesion in Brodmann's areas ________, _________ (frontal lobe)

Back 97

44, 45

Front 98

With Wernicke's aphasia, is the individual aware of the deficit?

Back 98

no, the patient is unaware of the deficit

Front 99

Wernicke's aphasia would result from a lesion in Brodmann area _______

Back 99

22 (parieto-temporal cortex)

Front 100

Wernicke's aphasia is considered sensory or receptive aphasia, so someone with this condition would have:

Back 100

difficulty comprehending language

Front 101

Can someone with Wernicke's aphasia speak fluently (produce speech)?

Back 101

They can, but the speech is gibberish. This is sometimes called word salad.

Front 102

So be super thankful for your ability to speak and express yourself :)

Back 102

Good job!