Brain U3 Flashcards
cerebral cortex
- this is the thinking portion of the brain where we are processing sensory, motor, our personality and more
** where cognition occurs** - this is a blanket of gray matter that is marked by gyri and sulci
- covers the surface of the brain
- Forms discrete internal clusters called
cerebral nuclei
sulci
these are folds that convolute the surface of the cerebral cortex
- these separate the intervening gyri
- these are basically grooves
gyri
these increase the surface of the area of cerebral hemispheres and they allow for more space for cortical neurons
median longitudinal fissure
this is divides the two hemispheres (which are divided into lobes)
central sulcus
a deep groove that extends laterally from the longitudinal fissure
- it divides the primary sensory and motor areas of the cortex
- this divides frontal and parietal lobes
lateral sulcus
- lateral sulcus is a deep fissure in each hemisphere that separates the frontal and parietal lobes from the temporal lobe
parieto-occipital sulcus
a deep fissure that separates the occipital and the parietal lobes.
frontal lobe
this is the anterior part of the cerebral hemisphere
- anterior to the central sulcus
- the lateral boarder is at the lateral sulcus
- Voluntary motor activity
- contains the prefrontal cortex
Prefrontal cortex:
anterior portion of the frontal cortex
- this is made of three different parts: Dorsolateral prefrontal cortex, the orbitofrontal cortex, and the anterior cingulate cortex
- this is what sets us apart from other species
- this is where we do our higher level processing and thinking
parietal lobe
- Superoposterior part of each hemisphere
- Involved with general sensory functions:
tactile sensation, proprioception, taste, language, spatial orientation, and directing attention - contains the postcentral gyrus
- this is involved in the initial processing of some sensory information
- it integrates sensory info from multiple different senses and processes that infor together
Central sulcus anteriorly
Lateral sulcus inferiorly
Parieto-occipital sulcus posteriorly
Dorsolateral prefrontal cortex
- in the prefrontal cortex
Executive functions
- Organization and planning
- Managing behavior
- High-level decision-making
- Multitasking
- Working memory
Orbitofrontal cortex
- in the prefrontal cortex
- Modulating emotions
- Inhibition
- Adaptive learning, rewards, and emotion
- this is important for inhibiting behavior based on emotions –> helps us not act impulsively
- this does not develop until early-late 20s (explains why teens tend to be more impulsive
- the amygdala is important for processing emotions and works with the orbitofrontal cortex (the amygdala matures early teens)
Anterior cingulate cortex
- in the prefrontal cortex
- this is on the medial aspect of each hemisphere
- Motivational behavior
(helps us to be motivated to do a task and do it at a specific time) - Reward-based learning (Error detection Outcome monitoring)
- helps us to monitor the outcome of an action to see if it matches the intended outcome we had and if we detect an error then we can learn and do it differently the next time - Pain processing
Precentral gyrus
Beginning of the corticospinal tract
- this is what the primary motor cortex is on
temporal lobe
- this is near the ear
- Inferior to the lateral sulcus
- has a Superior, middle, and inferior gyri
- Involved with hearing and smell
- Medial temporal lobe is within it
occipital lobe
the region posterior to the parieto-occipital sulcus
cerebral hemispheres
- these are two divisions that separate the brain
- each one has lateralization
- they are not identical functionally but appear to be mirror images
- they are covered by cortex
- divided into lobes
- they are connected by a few white motor pathways
- they are divided by the medial longitudinal fissure
hemispheric lateralization
the specialization of the specific functions that one hemisphere does that are not done by the other
left cerebral hemisphere
- specialized language areas (reading, writing, speaking)
- important for analytical tasks (mathematical calculations and logical decision making
- premotor cortex involved in hand movements is larger in the left side of the brain for right handed individuals
right cerebral hemisphere
analyzes sensory information
- relates the body to the sensory environment
- interpretive centers permit you to identify familiar objects by touch, smell, slight, or taste
(recognizes faces and 3D relationships) - analyzes emotional context of conversation
(differentiating between “get lost!” and “get lost?”
central white matter
this is covered by the gray matter of the cerebral cortex
- contains myelinated fibers forming bundles that connect one cortical area to another or that connect areas of the cortex to other regions in the brain
- has three types of bundles:
o Commissure fibers
o Association Fibers
o Projection Fibers
Commissure fibers
these link two cerebral hemispheres together
association fibers
these interconnect areas of cortex within a single cerebral hemisphere
projection fibers
these link the cerebrum with other regions of the brain and spinal cord
diencephalon
Gray matter deep in the brain surrounded by the cerebral hemispheres - Composed of three paired structures Thalamus Hypothalamus Epithalamus
- this connects the brainstem and the cerebral hemispheres
thalamus
the largest mass of nuclei in the entire CNS
- these nuclei provide integration and relay centers for sensory and motor pathways
- all ascending sensory info from the spinal cord and cranial nerves synapses in thalamic nuclei and then the information is relayed to the cerebrum or the brain stem (except for the olfactory nerve and spinocerebellar tract)
- the dorsal column medial lemniscus pathway and the ALS pathway of the spinal cord have relays in the thalamus
divisions of the brain
- telencephalon
- diencephalon
- mesencephalon
- metencephalon
- myelencephalon
what is something to remember about the differences of the white and gray matter of the brain and spinal cord
- the white matter is more deep in the brain and the gray matter is more superficial where as in the spinal cord the gray matter is deep and the white matter is superficical
- the gray matter is both is still unmyelinated axons, cell bodies and dendrites
- the white matter is myelinated axons in both
motor areas of the cerebral cortex
these control voluntary motor functions
sensory areas of the cerebral cortex
these provide conscious awareness of sensation
multimodal association areas in the cerebral cortx
these are where integration and interpretation of sensory and motor information occurs
-this is where higher thoughts and personality come from; this takes into consideration out past experiences to think, plan, and make decisions
cytoarchitecture
- this is the way the brain is layered
- there are a possible 6 layers of brain layers, some regions have all six others do not
- structure governs function!!!
- the design and layout of neurons in certain areas is based on what that area needs to do
telencephalon
(cerebrum and lobes)
mesencephalon
midbrain
- metencephalon
pons and cerebellum
- think they met at the metencephalon
myelencephalon
- medulla oblongata
- this is the connection between the brain and spinal cord
- there are many myelinated axons traveling through this
rostral
toward the nose
caudal
toward the tail
what is important to remember about the brain and its axis of orientation
- it is slightly different than other areas
- ventral is referring to inferior and dorsal is referring to superior (this is different compared to how we use these words to describe the spinal cord)
phrenology
this is an ancient theory and some still believe it today but it is not true
- it talks about the shape of one’s skull and how that is based on the size and shape of that person’s brain and that can determine how smart someone is or how good they are at doing something
brodmann’s areas
this is the work of Korbinain brodmann
- he created a map of the brain based on cytoarchitectural differences in different brain regions
- the areas are numbered 1-52
- *this slide was skipped in class**
corpus callosum
this is the largest pathway that connects the hemispheres
- the fibers in this pathway take the shortest route to get to their destination
- the anterior connects the frontal lobes and the posterior connects the posterior regions of the brain like the occipital lobe
what happens to the corpus callosum with a traumatic brain injury
the corpus callosum can be stretched and strained.
- one hemisphere of the brain will move away from the falx cerebri and move toward the skull whereas the other will ram into the falx cerebri
- the areas of the corpus callosum that are the farthest from the axis of the brain will be the most strained ( we saw this on the heat map on the slide in class)
what is the falx cerebri
this is a thick layer of tissue that dives down between the two hemispheres in the median longitudinal fissure
what are the networks of the brain
these connect different areas of the brain and they contain both white and gray matter
default mode network
- this is activated when we are not performing a task; daydreaming, mind wandering, thinking about others
- this can be altered by concussions and psychiatric conditions
salience network
this is switching between the default mode and the central executive network
- this helps us determine what is the most important thing to attend to at a given moment
- tells us what to pay attention to whereas the executive is helping us to maintain that attention and prioritize a task
- in class she gave the example of when you hear an ambulance when you are driving you use this to determine where the ambulance is, do you need to pull over, is it actually on another street and you can hear it but can ignore it, etc
central executive network
this engages your conscious brain to think and maintains attention on a prioritized task
anterior commissure
this connects the medial temporal lobe regions
post central gyrus
- a prominent gyrus in the lateral parietal lobe of the human brain
- It is the location of the primary somatosensory cortex, the main sensory receptive area for the sense of touch
- this has the sensory homunculus
homunculus
this is a representation of the body on the cortex
- the motor or sensory distribution along the cerebral cortex of the brain
- these are present in each hemisphere and represent the contralateral side of the body
somatosensory association cortex
- this is within the parietal lobe and is directly posterior to the primary somatosensory cortex
- this integrates and interprets sensory information
- this is taking info from the past and adding it to the present
- these are constantly working to help us understand what we are feeling in our environment
sensory homunculus
- this is in the postcentral gyrus of the parietal lobe
- as you move from medial to superior to lateral, the representation of each body part gets larger, showing there is more degree of touch or sensation doing to that are
- lower extremity: the lower extremity neurons are located along the midline on the midline on the medial aspect of each hemisphere within the medial longitudinal fissure
- arms and upper extremity: these are more superior
- hands face and tongue: these are all located more lateral
primary somatosensory cortex
- this is on the post central gyrus
- this is posterior to the central sulcus
- this receives general somatic sensory info from touch and pressure receptors
- discriminative touch and pressure from the dorsal column medial lemniscus pathway and some info from the ALS pathway come here
- contains the sensory homunculus
working memory
this is taking in information, integrating it and using it right away - class definition: used for temporarily storing and manipulating information
- in class she said “repeat the words apple, table penny”
- this is using that to take in the info and use it right away