The 2 hemispheres of the brain are covered by 3-5 mm of gray matter, also known as the __ __.
The cortex will receive information (affarents) from the cortical or subcortical sites, namely the ___.
Efferents go out to other cortical or subcortical areas, namely the __ __, ___, or ___. They travel down the __ __ on their way down to the subcortical areas, brainstem, or SC.
- cerebral cortex
- basal ganglia, brainstem, spinal cord
- internal capsule
Commissural fibers of the cortex connect one part of one hemisphere to another part in the other hemisphere. These fibers include the ___ ___, the largest connection, and the __ ___, the smaller connection.
Association fibers connect one part of one hemisphere to another part in that same hemisphere. There are two kinds of association fibers. The long association fibers, e.g. ___ ___, connects Broca's and Wernicke's areas. The __-___ fibers are shorter connections and connect to nearby structures.
- corpus callosum
- anterior commissure
- arcuate fasciculus
The two divisions of the cortex are __ and __.
The __ cortex covers all the lobes and everything you can see. 90% of the cortex is made up of this, and is divided into 6 layers.
The __ cortex is in the hippocampus, parahippocampal gyrus, olfactory cortices etc., has 3 layers, and is more primitive.
The cortex consists of 2 types of neurons: pyramidal and nonpyramidal.
Pyramidal cells make up 2/3 of the cortex. They are made up of one long ___ that extends from the base of the pyramidal cell. Pyramidal cells are most numerous, and give rise to long, apical ____ that go to the top layer of the cortex and branch into different layers. Pyramidal cells are known as the ___ cell of the cortex. The axons of pyramidal cells go to other cortical or subcortical areas of the same or opposite hemisphere. Pyramidal cells are excitatory and will communicate with other cells via ___, an excitatory NT. Pyramidal cells make longer connections.
Nonpyramidal cells consist of several ___. Axons do not leave the cortex. Most nonpyramidal cells are ___ that make shorter connections, and tend to be ___.
The neocortex is made of 6 layers that are separated by fibers. The name of each layer indicates the type of cell that predominates in that layer. Each layer has unique structure and contains different kinds of cells.
What is Brodman's classification system? What are the areas most responsible for speech, language, and cognition?
A way of mapping areas of the brain; each # is involved in different functions
- 44 & 45: Broca's
- 22: Wernicke's
- 11, 10, 46, & 9: Cognition
What are the areas of the neocortex?
- Primary sensory area
- primary motor area
- association areas
- limbic areas
Association areas are any brain regions that receive input from more than 1 ____ modality. They are involved in (5):
Unimodal association areas are next to ___ areas. They elaborate the function of primary areas for further processing. All input from unimodal association areas project to ___ areas.
Multimodal association areas respond to different ___ modalities. They are involved in high-level intellectual functions like generating ___ and ___. Multimodal association areas are found in these lobes (3).
What is an interesting fact about association areas?
- Planning, movement, integrating sensory information, generating more complex thoughts, and language
- thoughts and language
- Parts of temporal, parietal, and frontal
Sensory and motor cortices make up 5% of cortex; 95% made up of association areas
Hemispheres communicate via the ___ ___ and ___ ___. Division of labor between the two hemispheres is referred to as ____ (specialized functions of 2 hemispheres).
The LH is connected to muscles and receptors to the __ side of the body and vice versa. Each hemisphere has limited control of the same side, but most information crosses over to the opposite side.
What would happen without the corpus callosum?
- corpus callosum
- anterior commissure
Input that goes from LH couldn't be sent over to the RH; can only react to information on the side it innervates (LH->LH, RH->RH)
What is the test called that is used for lateralization of speech and language?
How does it work?
- Wada test
- Inject anesthetic into one of carotid arteries; patient is moving fingers and counting at same time; opposite fingers stop; if language is also on that side, patient stops counting (If injected into left carotid and patient stops counting, language in left hemisphere)
Damage to the right hemisphere:
Speech and language larger, happiness, interpret language more literally, writing, mathematical calculation
Auditory cortex larger (melody), planning, reasoning, comprehending spatial information (visual patterns), emotional content of speech, fear, anger, more involved in recognizing emotions in other people, comprehending language more figuratively, perception of music
Lack of incentive, difficulty planning and reasoning, flat affect
Split-brain patients have normal __, __, __ and ___, and motivated ___. Responses are NOT normal when __ stimuli are limited to __ side of the body.
What may severe the corpus callosum?
- sensation, movement, learning, memory, behavior
- Sensory, one