Unit Three: The Brain: Part 1 Flashcards
What is the cerebrum?
The largest region of the brain.
What does the cerebrum consist of? What does it lie on?
Paired cerebral hemispheres, which rest on the diencephalon and brainstem.
What originates in the cerebrum hemispheres?
Conscious thought processes and all intellectual functions.
What covers the paired cerebral hemispheres? What does this covering form?
A thick blanket of superficial gray matter (cerebral cortex). It forms the superior and lateral surfaces of the cerebrum.
What is the cortical surface marked by? (2)
- Gyri. 2. Sulci.
What is the difference between a gyrus and a sulcus?
The gyrus is the ridge and the sulcus is the groove.
What do gyri do?
Increase the surface area of the cerebral hemisphere, providing space for additional cortical neurons.
What does the cerebral cortex perform? What does this require?
The most complicated neural functions and these analytical and integrative activities require large numbers of neurons.
What fissure separates the two cerebral hemispheres?
The deep longitudinal fissure.
What is each hemisphere divided into?
Lobes.
Why are the lobes of the brain named what they are?
They are named after the overlying bones of the skull.
What is the central sulcus? (2)
- A deep groove that extends laterally from the longitudinal fissue. 2. Groove in the surface of a cerebral hemisphere, between the primary sensory and primary motor areas of the cortex.
What lobe is anterior to the central sulcus?
The frontal lobe.
What sulcus marks the inferior border of the frontal lobe?
The lateral sulcus.
What region is inferior to the lateral sulcus?
The temporal lobe.
Pulling back (reflecting) the temporal lobe to the side reveals what what?
The insula.
Where is the parietal lobe?
It extends posteriorly from the central sulcus to the parieto-occipital sulcus.
What region is posterior to the parieto-occipital sulcus?
The occipital lobe.
What does the central sulcus separate?
The motor and sensory portions of the cortex.
What does the precentral gyrus of the frontal lobe form?
The anterior margin of the central sulcus.
What is the surface of the precentral gyrus of the frontal lobe?
The primary motor cortex.
What do neurons of the primary motor cortex do?
Direct voluntary movements by controlling somatic motor neurons in the brainstem and spinal cord.
What are neurons of the primary motor cortex called?
Pyramidal cells.
What pathway is associated with voluntary motor control and the primary motor cortex?
The corticospinal pathway.
What is the function of the primary motor cortex in the frontal lobe?
Conscious control of skeletal muscles.
What is the function of the primary somatosensory cortex in the parietal lobe?
Conscious perception of touch, pressure, vibration, pain, temperature, and taste.
What is the function of the visual cortex in the occipital lobe?
Conscious perception of visual stimuli.
What is the function of the auditory and olfactory cortex in the temporal lobe?
Conscious perception of auditory and olfactory stimuli.
What do association areas in all lobes do? (2)
- Integration and processing of sensory data. 2. Processing and initiation of motor activities.
What does the postcentral gyrus of the parietal lobe form?
The posterior margin of the central sulcus.
What does the surface of the postcentral gyrus contain?
The primary somatosensory cortex.
What pathway provide the neurons in the primary somatosensory cortex? What do they provide?
Spinothalamic (ALS) tracts. Sensory information from touch, pressure, pain, and temperature receptors.
What results in sensory information being monitored at both a conscious and unconscious level?
Becuase the information is processed in both the primary somatoseonsory cortex at the same time that neurons deliver information to the basal nuclei and other centers.
Where does the gustatory cortex lie?
In the anterior portion of the insula and adjacent portions of the frontal lobe.
What information does the gustatory cortex receive?
Information from taste receptors of the tongue and pharynx.
What is each of the sensory and motor regions of the cortex connected to?
A nearby association area.
Do association area receive direct sensory information?
No.
Do association areas generate motor commands?
No.
What do association areas do? (2)
- They interpret sensory input arriving elsewhere in the cerebral cortex. 2. They then plan, prepare for, and help coordinate motor output.
What does the somatosensory association area allow for?
It allows for the understanding of the size, texture, and form of an object.
What is the premotor cortex?
The motor association area between the precentral gyrus and the prefrontal area.
What does the premotor cortex do?
Uses memories of learned movement patterns to coordinate motor activities.
Damage to the visual association area may result in what?
Seeing letters quite clearly but not being able to recognize or interpret them.
Damage to the premotor cortex concerned with eye movemetns may result in what?
The ability to understand written letters and words but not read them because their eyes cannot follow the lines on a printed page.
What are characteristics of higher-order functions? (4)
- They are preformed by the cerebral cortex. 2. They involve complex interconnections and communication between areas within the cerebral cortex and between the cerebral cortex and other areas of the brain. 3. They involve both conscious and unconscious information processing. 4. They are not part of the programmed “wiring” of the brain; therefore, the functions are subject to modification and adjustment over time.
What is hydrocephalus?
A condition marked by an excessive accumulation of cerebrospinal fluid (CSF) within the brain ventricles.
What is the function of integrative centers?
To receive information from many association areas and direct extremely complex motor activities, as well as performing analytical functions.
What does the prefrontal cortex, or prefrontal association area of the frontal lobe do?
It integrates information from sensory association areas and performs intellectual functions, such as predicting the consequences of possible responses.
What are the two cortical areas associated with language in the left hemisphere?
- Wernicke’s area. 2. Broca’s area.
Where is the Wernicke’s area?
Near the auditory cortex in the temporal lobe.
What is the Wernicke’s area associated with?
Language comprehension.
Where is the Broca’s area?
Near the motor cortex.
What is the speech center (Broca’s area) associated with?
Speech production.
What does the speech center (Broca’s area) regulate?
The patterns of breathing and vocalization needed for normal speech, which involves coordinating the activities of the respiratory muscles, the laryngeal and pharyngeal muscles, and the muscles of the tongue, cheeks, lips, and jaws.
What does the Wernicke’s area receive information from and what does it play a role in and how?
- It receives information from the sensory association areas. 2. It plays an important role in your personality by integrating sensory information and coordinating access to visual and auditory memories.
What does damage to the speech center (Broca’s area) result in?
Being able to make sounds, but not words. Broken speech.
What are motor commands from the motor speech center adjust by?
Feedback from the auditory association area, also called the receptive speech area.
What is the function of the prefrontal cortex? (2)
- It coordinates information relayed from all of the cortical association areas. 2. In doing so, it performs such abstract intellectual functions as predicting the consequences of events or actions
When does the prefrontal cortex fully develop?
In the early twenties.
What can damage to the prefrontal cortex result in?
Difficulties in estimating temporal relationships between events.
What functions are specialized in the left hemisphere? (2)
- Language-based skills, such as reading, writing, and speaking depend on processing done in the left cerebral hemisphere. 2. Analytical and mathematical tasks.
Is the premotor cortex larger on the side opposite to that of the dominant hand?
Yes.
What functions are specialized in the right hemisphere?
- Analyzes sensory information and relates the body to the sensory environment. 2. Interpretive centers in this hemisphere permit you to identify familiar objects (including faces) by touch, smell, sight, or taste.
What does the white matter of the cerebrum carry?
Afferent information between the areas of the cerebral cortex and between the cerebral cortex and other brain regions.
What is the function of association fibers?
Interconnect cortical area within the same hemisphere.
What is the function of arcuate fibers?
Interconnect gyri within a lobe.
What is the function of longitudinal fasciculi?
Interconnect the frontal lobe with other cerebral lobes.
What are the two types of association fibers?
- Arcuate. 2. Longitudinal fasciculi.
Which association fiber is longest?
The longitudinal fasciculi.
What is the function of commissural fibers?
Link the two cerebral hemispheres together.
What are two examples of dense bands of commissural fibers?
- Corpus callosum. 2. Anterior commissure.
What is the function of projection fibers?
Link the cerebrum with other regions of the brain and the spinal cord.
What is the internal capsule?
The collection of afferent and efferent fibers of the white matter of the cerebral hemispheres, visible on gross dissection of the brain.
Where must all ascending and descending axons pass through to get to or from the sensory, motor, or association areas of the cerebral cortex?
The diencephalon.
What are the basal nuclei? Where are they?
Masses of gray matter that lie within each hemisphere deep to the floor of the lateral ventricle. They are embedded in the white matter of the cerebrum.
What structures does the basal nuclei include?
- Caudate nucleus. 2. Lentiform nucleus.
What does the lentiform nucleus consist of? (2)
- A lateral putamen. 2. A medial global pallidus.
What is the claustrum?
A thin layer of gray matter lying close to the putamen.
What are the three functions of the basal nuclei?
- Subconsciously control and integrate skeletal muscle tone. 2. Coordinate learned movement patterns. 3. Process, integrate, and relay information from the cerebral cortex to the thalamus.
Do the nuclei initiate particular movements?
No.
What do the caudate nucleus and putamen do when walking?
Control the cycles of arm and leg movements that occur between the time you decide to start walking and the time you decide to stop.
What is the function of globus pallidus?
Controls and adjusts muscle tone, particularly in the appendicular muscles, to set body position in preparation for a voluntary movement.
What is the function of the claustrum?
Plays a role in the subconscious processing of visual information.
What is the function of the lentiform nucleus?
Subconscious adjustment and modification of voluntary motor commands.
What does the limbic system include?
Nuclei and tracts along the border between the cerebrum and diencephalon.
Is the limbic system grouping a functional one or a structural one?
A functional one. It includes components of the cerebrum, diencephalon, and mesencephalon.
What does the amygdaloid body act as?
An integration center between the limbic system, the cerebrum, and various sensory systems.
What does the limbic lobe consist of?
Gyri and deeper structures adjacent to the diencephalon.
Where is the cingulate gyrus?
Superior to the corpus callosum.
What do the dentate gyrus and parahippocampal gyrus conceal?
An underlying nucleus, the hippocampus.
Where is the hippocampus?
Deep within the temporal lobe.
What is the fornix?
A tract of white matter connecting the hippocampus with the hypothalamus.
What do mammillary bodies contain?
Motor nuclei that control reflex movements associated with eating, such as chewing, licking, and swallowing.
Where are the mammillary bodies?
Prominent nuclei in the floor of the hypothalamus.
What does the anterior nucleus of the thalamus do?
Relays visceral sensations from the hypothalamus to the cingulate gyrus.
What is the reticular formation?
An interconnected network of brainstem nuclei.
What does stimulation of the reticular formation result in? What does stimulation of adjacent parts of the hypothalamus result in?
Heightened alertness and generalized excitement. It results in the opposite effect.
What are the 5 divisions of the brain?
- Telencephalon. 2. Diencephalon. 3. Mesencephalon. 4. Metencephalon. 5. Mylencephalon.
What structures are in the diencephalon?
Everything thalamus. 1. Hypothalamus. 2. Thalamus. 3. Epithalamus.
Where does the spinocortical tract begin?
At the primary motor cortex.
In what Brodmann area is the precentral gyrus located?
BA 4.
Where is working memory maintained?
In the dorsolateral prefrontal cortex.
What functions is the orbitofrontal cortex involved in? (3)
- Modulating emotions. 2. Inhibition. 3. Adaptive learning, rewards, and emotion.
What functions are associated with the anterior cingulate cortex? (3)
- Motivational behavior. 2. Reward based learning (error detection; outcome monitoring). 3. Pain processing.
What functions is the dorsolateral prefrontal cortex associated with? (2)
- Executive functions. 2. Working memory.
What brain part is associated with the anterolateral pathway? Why?
The anterior cingulate cortex. Because it is involved in pain processing.
Where is the mesencephalon also known as?
The midbrain.
What three divisions make up the brain stem (from brain towards end of spinal cord)?
- Mesencephalon. 2. Metencephalon. 3. Mylencephalon.
What is cerebral nuclei?
Discrete internal clusters formed by the cortex covering the surface of the brain.
What two structures are in the metencephalon?
- Pons. 2. Cerebellum.
What structure is in the mylencephalon?
The medulla oblongata.
What is Broca’s aphasia?
When a patient can understand spoken language but has difficulty communicating verbally.
In what Brodmann’s areas is the postcentral gyrus located?
3,1,2.
What is contained on the superior temporal gyri?
The auditory cortex.
