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.