Quiz 5: Lecture: Cerebrum Flashcards
What is the largest part of the brain?
Cerebrum (Cortex)
What controls thoughts and intellectual functions & processes somatic sensory and motor information?
Cerebrum (cortex)
What is the cerebrum (cortex) divided into?
Left and right cerebral hemispheres
What is more elaborate in humans than in other vertebrates?
Cerebrum (cortex)
Mice have smooth/not as much cortical tissue
Parts of cerebrum:
Gyrus, Sulcus, Cerebral cortex, Cerebral white matter, Fissure
What is the Cerebrum also called?
Cerebral cortex
What does the folded surface of the cerebrum do?
Increases surface area
Gyri
Elevated ridges
Sulci
Shallow depressions
Fissures
Deep grooves
What is a deep sulcus called?
Fissure
What are some examples of fissures?
Longitudinal fissure, Sylvian fissure
How long is the cerebrum?
2 1/2 feet (consistent amount)
Gray matter location
In cerebral cortex and basal nuclei
White matter location
Deep to basal cortex, Around basal nuclei
What comprises gray matter?
cell bodies and dendrites (subcortical)
What comprises white matter?
axon (which part of neuron)
Which part makes myelin?
Aligodendricytes
What makes gray matter gray?
Nissil (ribosomes)
Top to bottom of brain
Corona radiata, gyrus; lateral ventricle, septum pellucidum; thalamus, 3rd ventricle; caudate, putamen; temporal lobe; substantia nigra (pars compacta), peduncle; Pons, medulla
What are the 4 structures of the cerebrum?
Gyri of neural cortex, Insula (island) of neural cortex, Longitudinal fissure, Lobes
Gyri of neural cortex function
Increase surface area (number of cortical neurons)
Insula (island) of cortex location
Lies medial to lateral sulcus
Where does the Insula (island) of cortex receive information from?
limbic system, thalamus, basal ganglia
Longitudinal fissure function
Separates cerebral hemispheres
Lobes function
Divisions of hemispheres named after overlying skull bones
The cerebrum parts on picture
Frontal lobe: Top left
Central sulcus: Top middle
Gyri of insula: Middle
Temporal lobe (pulled down): Bottom left
3 structures of the Cerebrum
Central sulcus, Lateral sulcus, Parieto-occipital sulcus
Central sulcus divides:
Anterior frontal lobe from posterior parietal lobe
Lateral sulcus divides:
Frontal and Parietal lobe from temporal lobe
Parietal-occipital sulcus divides:
Parietal lobe from occipital lobe
Three functional principles of the cerebrum:
- Each cerebral hemisphere receives sensory information from, and send motor commands to, the opposite side of the body (contralateral)
- The 2 hemispheres have different functions, although their structures are alike
- Correspondence between a specific function and a specific region of cerebral cortex is not precise
Lateral view (front to back):
Frontal lobe, Lateral sulcus, Precentral gyrus, Central gyrus, Postcentral gyrus, Parietal lobe, Occipital Lobe, Temporal Lobe (bottom middle), Cerebellum, Pons, Medulla oblongata
What is one main function of the frontal lobe?
Voluntary control of skeletal muscles
What is the posterior border for the frontal lobe?
Central sulcus
What is the anterior lobe for the parietal lobe?
Central sulcus
Parietal lobe function
Involved in constant perception of touch, pain, posture, vibration, etc.
What is below the Sylvian fissure?
Temporal lobe
Types of gyrus
Superior, middle, and inferior
What other functions are in the temporal lobe?
Hippocampus (involved in learning and memory), Amygdala
Midsaggital section of brain (front and back):
Temporal lobe, Frontal lobe, Cingulate gyrus, Precentral gyrus, Central sulcus, Postcentral gyrus, Parietal lobe, Parieto-occipital sulcus, Occipital lobe, Cerebellum, Pons, Medulla oblongota
White matter of the cerebrum are made of (3):
Association fibers, Commissural fibers, and Projection fibers
Association fibers (white matter of the cerebrum)
Connections within one hemisphere consist of:
Arcuate fibers and Longitudinal fasciculi
Arcuate fibers function
Short fibers; Connect one gyrus to another
Longitudinal fasciculus function
Longer bundles; Connect frontal lobe to other lobes in same hemisphere
Commiseral fibers (white matter of the cerebrum):
Bands of fibers connecting two hemispheres; Corpus callosum (about 200 million axons), Anterior commissure (about 50k axons)
What structure makes up the wall of the 3rd ventricle?
Caudate
What theory did Roger Sperry disprove?
Blank slate theory (Any neuron can do another neuron’s job- didn’t”t know about localization)
What did Roger Sperry discover about the brain?
He found that the human brain has specialized functions on the right and left, and that the two sides can operate practically independently.
Projection fibers (white matter of the cerebrum):
pass through the diencephalon; Link cerebral cortex with diencephalon, brainstem, cerebellum, spinal cord, and internal capsule
What is the internal capsule?
all ascending and descending projection fibers
Anterior view of the Cerebrum:
Upper middle: Longitudinal fissure
To the side: Projection fibers of internal capsule
Middle middle: Corpus callosum
Lower middle: Anterior commissure
What separates the motor and sensory areas of the Cortex?
Central sulcus
Motor areas comprise these 3:
Precentral gyrus of frontal lobe; Primary motor cortex; Pyramidal cells
Precentral gyrus of frontal lobe function
Directs voluntary movement
Primary motor cortex is the surface of:
Precentral gyrus
Pyramidal cells are neurons of:
Primary motor cortex
Sensory areas of the Cortex are made up of (2):
Postcentral gyrus of parietal lobe, Primary sensory cortex
Postcentral gyrus of parietal lobe function:
receives somatic sensory information (touch, pressure, pain, vibration, taste, and temperature)
Primary sensory cortex is the surface of:
Postcentral gyrus
The 4 special sensory cortexes are:
Visual cortex, Auditory cortex, Olfactory cortex, Gustatory cortex
Visual cortex location and function
Occipital lobe; Information from sight receptors
Auditory cortex location and function
Temporal lobe; Informaton from sound receptors
Olfactory cortex location and function
Temporal lobe; Information from odor receptors
Gustatory cortex location and function
Moves- parietal, inferior, lateral (google says frontal and insular lobes)
Information from taste receptors
The Cerebrum: Association areas
Cortical regions that interpret sensory information or coordinate motor responses
Sensory association areas function
Monitor and interpret arriving information at sensory areas of cortex
Somatic motor association area (premotor cortex) function
Coordinates motor responses (learned movements)
What are the 3 sensory sssociation areas?
Somatic sensory association area, Visual association area, Auditory association area
Somatic sensory association area function
Interprets input to primary sensory cortex (e.g., recognizes and responds to touch)
Visual association area function
Interprets activity in visual cortex
Auditory association area function
Monitors auditory cortex
Integrative Centers are located:
in lobes and cortical areas of both cerebral hemispheres
Integrative centers function
Receive information from association areas; Direct complex motor and analytical activities
(Help put everything together)
General interpretive Area is also called
Wernicke’s area
General interpretive area is present in:
Only one hemisphere
General interpretive area function
Receives information from all sensory association area; Coordinates access to complete visual and auditory memories
Other integrative areas of the cerebrum include (2):
Speech center, Prefrontal cortex of frontal lobe, Brodmann areas
What is the speech center associated with? What is its function?
Associated with general interpretive area; Coordinates all vocalization functions
Prefrontal cortex of frontal lobe function:
Integrates information from sensory association areas, Performs abstract intellectual activities (ex: predicting consequences of events or actions)
The left hemisphere generally contains the:
General interpretive area and the Speech center
The prefrontal cortex of each hemisphere is involved with:
Conscious intellectual functions
What are Brodmann areas?
Patterns of cellular organization in cerebral cortex
Hemispheric Lateralization
Functional differences between left and right hemispheres; Each cerebral hemisphere performs certain functions that are not ordinarily performed by the opposite hemisphere
Which hemisphere is the dominant hemisphere?
Left hemisphere
In most people, left brain (dominant) controls:
Reading, writing, and math; Decision making; Speech and language
Right central hemisphere relates to:
Senses (touch, smell, sight, taste, feel); Recognition (faces, voice inflections)
Left cerebral hemisphere parts (front to back):
Prefrontal cortex, Speech center, Writing, Auditory cortex, General interpretive center (language and mathematical calculation), Visual cortex (right visual field)
Right cerebral hemisphere parts (front to back):
Prefrontal cortex, Anterior commissure, Analysis by touch, Auditory cortex, Spatial visualization and analysis, Visual cortex (left visual field)
Brain activity is assessed by:
An electroencephalogram (EEG)
How are EEGs used to monitor brain activity?
Electrodes are placed on the skull, Patterns of electrical activity (brain waves) are printed out
What are the 4 categories of brain waves?
Alpha waves, Beta waves, Theta waves, Delta waves
Alpha waves:
Found in healthy, awake adults at rest with eyes closed
Beta waves
Higher frequency; Found in adults concentrating or mentally stressed
Theta waves
Found in children; Found in intensely frustrated adults; May indicate brain disorder in adults
Delta waves
During sleep; Found in awake adults with brain damage
The Cerebrum Synchronization
A pacemaker mechanism (Synchronizes electrical activity between hemispheres); Brain damage can cause desynchronization
The Cerebrum Seizure
Is a temporary cerebral disorder; Changes the electroencephalogram; Symptoms depend on regions affected
The neural cortex is found on the surface of the ____.
Cerebral hemispheres and cerebellum
Axons of mitral cells of the olfactory bulb project to the:
olfactory cortex
Olfaction (bottom to top):
Mucous membrane of nasal cavity, Olfactory receptors, Cribiform plate of ethmoid, Mitral cells, Olfactory bulb, To olfactory cortex
Where do the striate arteries enter the brain?
Anterior perforated substance
Ventral view of brain for olfaction (front to back; left then right)
Frontal lobe, Olfactory bulb (with cut ends of olfactory nerves), Olfactory tract, Anterior commissure, Temporal lobe, Note location of Uncus relative to brain stem, Cut surface of brainstem
Orbitofrontal cortex, Anterior perforated substance, Rhinal sulcus, Uncinate gyrus (Uncus), Parahippocampal gyrus, Cut surface of brainstem
Components of the Visual System:
Retina, Optic nerve, Optic tract, Lateral geniculate nucleus, Optic radiation, Primary visual cortex
The Visual System parts (4):
Eyeball, Optic nerve, Optic chiasm, Optic tract
Direction of Visual System:
Optic nerve > Optic chiasm > Optic tract > LGN of thalamus > Occipital lobe
The Visual System parts (front to back):
Optic tract, Optic nerve, Optic radiation, Lateral geniculate nucleus, Optic chiasm, Eyeball
Lesions of specific segments of the visual system produce:
Typical visual field defects
Approaches to the Study of Brain Function
Animals and humans: anatomy, physiology, and behavior
Tract tracing; Single unit recordings; Behavioral studies, pharmacology
Approaches to the Study of Brain Function
Patients with focal brain lesions
Behavioral studies & post-mortem anatomy; Structural imaging: In vivo structure/function correlations
Approaches to the Study of Brain Function
Neuroimaging/brain mapping
Functional neuroimaging
Localization of function in the Nervous System is based on
Phrenology (based on racism)
What is Broca responsible for?
Localization of Function in Nervous System; finding Broca’s area
Lateralization of language on
Left
Localization of function in the nervous system: Imaging inside the brain
Computed tomography (CT)
brain imaging method using computer controlled X-rays of the brain
Preferred method for looking for strokes, tumors, bone fractures
CT
Imaging inside the brain-
Before:
Now:
Before: took them through serial
Now: spiral technology (faster, defined)
Brain imaging method using radio waves and magnetic fields of the body to produce detailed images of the brain
Magnetic resonance imaging (MRI)
Computer makes a sort of “movie” of changes in the activity of the brain using images from different time periods
Functional MRI (fMRI)
brain-imaging method in which a radioactive sugar is injected into the subject and a computer compiles a color-coded image of the activity of the brain with lighter colors indicating more activity
Positron emission tomography (PET)
How does PET work?
Take baseline measurement then ask questions; areas of increased metabolism; seeing increases and decreases in change in activity
Claustrum
Was thought to be on, off switch but not true
