Chapter 3: Functional Anatomy of the Nervous System I: Cerebrum & Subcortical Structures
Which of the following statements best describes the cerebrum?
A. The cerebrum is derived from telencephalon, forms the largest part of the brain, and consists of the left and right cerebral hemispheres, which are separated by the central sulcus.
B. Each of the 4 main anatomic lobes—the frontal, parietal, occipital, and temporal lobes—contains a significant area dedicated to sensory and motor functions.
C. The locations of primary, secondary, and tertiary gyri and sulci are invariant among human individuals.
D. The right and left cerebral hemispheres are exact anatomic and functional mirror images of each other, although the right hemisphere receives sensory input from and controls the left side of the body, whereas the left hemisphere receives sensory input from and controls the right side of the body.
E. In addition to 4 anatomic lobes, 2 functional lobes, called the insular and limbic lobes, located deep within the brain, have been characterized in humans.
E. The left and right cerebral hemispheres are separated by the longitudinal fissure (also known as the deep sagittal fissure). Only the parietal, occipital, and temporal lobes contain substantial cortical areas dedicated to sensory processing, and only the frontal lobe has substantial cortical areas dedicated to motor function. However, because they are all well connected, all the lobes do contribute to sensory processing and motor function. The locations of the primary gyri and sulci are very similar among humans, but the secondary and tertiary gyri and sulci can be located differentially among individuals. The right and left hemispheres are not functionally identical because some functions such as language are lateralized and/or more prominent on 1 side of the brain. The insular lobe and limbic lobe are considered the fifth and sixth “functional” lobes but are not visible from the exterior view of the brain.
Which of the following statements best characterizes the cerebral cortex?
A. Human brain contains only 1 type of cerebral cortex, called neocortex, that is composed of 6 layers.
B. Individual association areas receive substantial inputs from both primary sensory and primary motor areas.
C. The smallest functional unit of the neocortex is a cylinder of neurons approximately 2 to 3 mm in height and approximately 0.5 mm in diameter, called a cortical column.
D. The human neocortex represents approximately 25% of the cerebral gray matter.
E. The cerebral hemispheres contain the cerebral cortex, which is the thin layer of gray matter that is covered by the cerebral white matter and meninges.
C. The human brain contains both neocortex (6 layers) and allocortex (3 to 4 layers); for example, the hippocampus is allocortex. Association cortices are mainly involved in processing either sensory or motor information, but not both. The cortical column is considered the smallest functional unit, and columns have been identified in both visual and somatosensory cortex. The human neocortex is large and represents about 75% of cerebral gray matter. The cortical gray matter lies on top of the cerebral white matter and underneath the meninges.
Which of the following best characterizes structures in the temporal lobe?
A. The amygdala is an integration center that is critical for the processing of mainly pleasant emotions and euphoria.
B. The hippocampus, entorhinal cortex, and perirhinal cortex are critical for encoding and storing all long-term declarative and spatial memories.
C. The olfactory cortex is a type of neocortex that receives inputs from the olfactory bulb and olfactory nerve via relay from the thalamus.
D. The auditory cortex is involved in perceiving sounds, assigning meaning to those sounds, and remembering sounds.
E. The ventral regions of the temporal lobe form the dorsal stream, or “where” pathway involved in visual processing that aids in the processing of object location and movement.
D. The amygdala processes many emotions, including pleasant and negative emotions such as fear. Although the hippocampus and associated structures are required for encoding declarative and spatial memories, most explicit memories are thought to be stored in many other areas of the cerebral cortex. Olfactory sensory information is not relayed by way of the thalamus. The primary and secondary auditory cortices are located in the temporal lobe. The ventral regions of the temporal lobe form the ventral stream, or “what” pathway involved in visual processing that aids in object and facial recognition.
Which of the following best describes the thalamus?
A. The thalamus transmits sensory information to the cerebral cortex and is involved in cognitive functions, but is rarely involved in providing information for motor control.
B. The gateway to the cerebral cortex, the thalamus is located between the cerebral cortex and midbrain/brainstem, adjacent to the basal ganglia, and dorsal to the cerebellum, with extensive connections with these regions and the spinal cord.
C. The thalamus contains a single nucleus with specialized subdomains with specific connections to the cerebral cortex, basal ganglia, brainstem, and cerebellum.
D. The thalamus regulates basic life- and species-sustaining functions such as fluid balance, energy metabolism, thermoregulation, and drinking, feeding, and reproductive behaviors.
E. Every sensory system involves relay of information from ascending tracts or cranial nerves to the thalamus, which then transmits sensory information to the specific primary sensory cortex.
B. As the “gateway” to the cerebral cortex, the thalamus transmits sensory, motor, and cognitive information between the cerebral cortex and the spinal cord, basal ganglia, brainstem, and cerebellum. The thalamus contains at least 60 individual nuclei that form specific connections. The basic life functions listed are the job of the hypothalamus. As mentioned earlier, the thalamus does not relay information from the olfactory nerve.
Which of the following statements best describes the basal ganglia (BG)?
A. The BG are involved in the control and coordination of voluntary motor movements, decisions about motor actions, procedural learning, motivation, and reward.
B. Anatomically, the BG include the striatum (formed from the caudate nucleus and putamen), globus pallidus, substantia nigra, hypothalamus, and thalamus.
C. The BG form direct connections with the cerebral cortex and cerebellum for rapid exchange of motor initiation and reward information.
D. The BG are associated with the acquisition of habits and are the main region linked to declarative memory.
E. Loss of neurons in the BG is associated with all forms of dementia, including Alzheimer disease, Huntington disease, amyotrophic lateral sclerosis (ALS), and Parkinson disease.
A. The BG control voluntary movements including motor initiation and motivation-based movements and procedural (a type of implicit) learning and is involved in cognition of motivation and reward. Anatomically, the BG do not include the thalamus. The BG communicate with the cerebral cortex by way of the thalamus; they do not have direct input to the cerebral cortex. The BG are not required for declarative memory, only for nondeclarative/procedural memory. Loss of neurons in the substantia nigra, a component of the BG, is associated with only Parkinson disease and Huntington disease.