Lecture 15 Flashcards
What are the major components of the Central Nervous System (CNS) in humans, and what are the terms of orientation used in the CNS, especially in the human brain stem and spinal cord?
The major components of the Central Nervous System (CNS) in humans include the brain (cortex and subcortex) and the spinal cord, which is housed in the spinal column. In terms of orientation, in the human CNS:
Anterior is equivalent to rostral.
Posterior is equivalent to caudal.
Superior is equivalent to dorsal.
Inferior is equivalent to ventral.
How do orientation terms differ in the human CNS compared to reptiles, and what are the terms used for brain slices?
In reptiles, orientation terms remain consistent throughout the CNS. In humans, these terms change below the midbrain. Terms for brain slices include horizontal, coronal, and sagittal.
What is the function of the spinal cord in the CNS, and how does sensory information enter and motor commands exit it?
The spinal cord, housed in the spinal column, serves as a pathway for sensory information entering the CNS via the dorsal portion and for motor commands exiting via the ventral portion. This enables reflexes and coordinated movements.
What are the main divisions of the cerebral cortex in the human brain?
The cerebral cortex in the human brain is divided into two hemispheres (left and right), each of which is further divided into four lobes: the frontal lobe, parietal lobe, occipital lobe, and temporal lobe. Additionally, there is an insular cortex hidden inside the lateral sulcus.
What are gyri and sulci, and what is the significance of the longitudinal fissure, lateral sulcus, and central sulcus in the cerebral cortex?
Gyri are the ridges, and sulci are the fissures or grooves found on the cerebral cortex. The longitudinal fissure separates the two cerebral hemispheres, while the lateral sulcus separates the temporal lobe from the frontal and parietal lobes. The central sulcus separates the frontal and parietal lobes and is critical for defining the functional areas of the cortex.
How are the frontal, temporal, and parietal lobes further divided, and what structures are involved in these divisions?
The frontal lobe is divided into three gyri (superior, middle, inferior) that run anterior-posterior, meeting the precentral gyrus at the precentral sulcus. The temporal lobe has superior, middle, and inferior gyri. The parietal lobe includes the postcentral gyrus, and the intraparietal sulcus (IPS) separates its superior and inferior portions. These divisions play a crucial role in organizing brain functions and processing information.
What is the role of the corpus callosum in the brain?
The corpus callosum is the primary fiber tract that connects the two cerebral hemispheres. It facilitates communication and information exchange between the left and right hemispheres of the brain.
Which brain structure is responsible for coordination and motor control?
The cerebellum, located in the brain stem’s dorsal aspect, plays a crucial role in coordinating movements and motor control.
Name one of the subcortical structures in the brain and briefly describe its function.
One subcortical structure is the thalamus, which serves as a sensory relay center, relaying sensory information to the appropriate areas of the cerebral cortex for processing
List three main structures that make up the basal ganglia.
The basal ganglia comprises the Caudate Nucleus, Putamen, and Globus Pallidus as its main structures.
What are the two parts of the brain stem, and what functions are associated with them?
The two parts of the brain stem are the midbrain and the hindbrain (which includes the pons and medulla). The midbrain is associated with functions such as visual and auditory processing (Superior and Inferior Colliculi). The pons and medulla are responsible for essential functions like breathing and heart rate regulation.
Explain the role of the ventricular system in the brain.
The ventricular system consists of interconnected cavities filled with cerebrospinal fluid (CSF). It helps maintain brain structure, cushioning it against physical trauma, and provides buoyancy. The CSF also assists in waste removal and chemical signaling in the brain.
Which brain structure is responsible for relaying sensory information to the cerebral cortex?
The thalamus acts as a sensory relay center, transmitting sensory input to the appropriate regions of the cerebral cortex for further processing.
What is the primary difference between white matter and gray matter in the brain?
White matter primarily consists of axons, which are nerve fibers responsible for transmitting signals between different parts of the brain. Gray matter contains cell bodies of neurons and is involved in processing information
How does Brodmann’s map of the cerebral cortex categorize different brain regions?
Brodmann’s map categorizes different brain regions based on the microscopic appearance of the cortex, particularly the arrangement of neurons and their layers. It assigns unique numbers to distinct areas, each associated with specific functions.
