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.