Unit 7 - anatomy: NS Organization & Function of the Cerebrum

Q: What are the primary functions of the CNS?

A: Thinking, memory, voluntary motor movements, and sensory perception.

Q: Name the main structures of the CNS and their primary functions.

A:

• Cerebral Cortex: Sensory/motor relay center & autonomic functions.

• Diencephalon: Autonomic functions & cranial nerve processing.

• Brainstem: Coordination of movement & balance.

• Cerebellum: Motor output, sensory input, reflexes & interface with the PNS.

• Spinal Cord: Transmission of signals between the brain and body.

Q: What is the composition of grey matter and white matter in the cerebral cortex?

A: Grey matter is on the outside (somas of neurons), while white matter (axons of neurons) is on the inside.

Q: Describe the organization of grey and white matter in the spinal cord.

A: Grey matter is on the inside, and white matter is on the outside.

Q: What are the deep nuclei in the brain?

A: Structures like basal nuclei and parts of the limbic system, formed around the ventricles and lateral to the thalamus.

Q: What are the main surface features of the cerebral cortex?

A: Fissures (deep grooves), sulci (shallow grooves), and gyri (hills).

Q: Name the lobes of the brain.

A: Frontal, parietal, temporal, occipital, and insular lobes.

Q: What is the significance of the longitudinal fissure?

A: It separates the left and right hemispheres of the brain.

Q: What are the main functional areas of the cerebral cortex

A:

• Frontal Lobe: Primary motor cortex, premotor cortex, intellect, and voluntary movements.

• Parietal Lobe: Somatosensory cortex and association areas.

• Temporal Lobe: Auditory cortex and association areas.

• Occipital Lobe: Visual cortex and association areas.

Q: What is the homunculus and its significance?

• A: A representation of the body within the brain, showing that more cortical neurons are dedicated to sensory and motor functions of the limbs than the trunk.

Q: Identify the primary motor and sensory cortex locations.

9. A: Primary motor cortex is located in the precentral gyrus; primary sensory cortex is in the postcentral gyrus.

Q: What are the types of white matter tracts in the brain?

12. A:

    • Commissural Fibers: Connect corresponding areas of the two hemispheres (e.g., corpus callosum).

    • Association Fibers: Connect different parts of the same hemisphere.

    • Projection Fibers: Connect the cerebral cortex with lower brain regions and the spinal cord.

Q: What are the functions of the basal nuclei?

A: Motor memory, initiation and cessation of movements, early motor learning, and skill development.

Q: Name disorders associated with basal nuclei dysfunction.

A: Huntington’s disease and Parkinson’s disease.

Q: What structures make up the limbic system?

A: Hippocampus, fornix, mammillary bodies, amygdala, and entorhinal cortex.

Q: What is the role of the hippocampus?

A: Important for forming memories, particularly contextual information (who, what, when, why).

Q: What is the function of the amygdala?

A: Involved in emotion, facial analysis, and assessing danger.

Q: What does the fornix do?

A: Connects the hippocampus to the mammillary bodies

Q: How does the thalamus contribute to memory?

A: It determines whether a memory is important and facilitates its processing.

Q: What are the types of memory?

A:

• Declarative Memory: Episodic (events) and semantic (facts).

• Procedural Memory: Skills and habits (muscle memory).

Q: What are the structures associated with short-term vs. long-term memory?

A: Short-term memory is often managed by the prefrontal cortex; long-term memory involves the hippocampus and cortex.

Q: What is the difference between anterograde and retrograde amnesia?

• A: Anterograde amnesia affects the ability to form new memories; retrograde amnesia affects the recall of previously formed memories.

Q: How do the cerebellum and basal nuclei differ in memory formation?

• A: The cerebellum is involved in novel tasks, while the basal nuclei manage skills and habits.

Q: What is the role of the thalamus in motor planning?

20. A: It determines which motor plan is best by comparing inputs from the basal nuclei and cerebellum.

Q: What is the overall organization of the cerebral cortex?

A: Superficial grey matter (neurons), deep grey matter (nuclei), and underlying white matter (axons) that includes commissural, association, and projection fibers.

Q: What are the main roles of the Cerebral Cortex?

• A: Responsible for higher brain functions such as thinking, memory, voluntary motor control, and sensory perception.

Q: Describe the primary functions of the Diencephalon.

• A: Acts as a sensory/motor relay center, controls autonomic functions, and processes information for cranial nerves.

Q: What functions does the Brainstem serve?

• A: Coordinates movement, regulates vital functions, and connects the brain to the spinal cord.

Q: What is the primary function of the Cerebellum?

A: Coordinates voluntary movements, maintains balance and posture, and integrates sensory information.

Q: Describe the role of the Spinal Cord in the CNS.

A: Acts as a conduit for signals between the brain and body; responsible for reflex actions.

Q: What distinguishes grey matter from white matter in the brain?

A: Grey matter contains neuronal cell bodies, while white matter consists of myelinated axons.

Q: How is grey and white matter organized in the spinal cord?

A: In the spinal cord, grey matter forms an "H" shape in the center, surrounded by white matter.

Q: What structures are included in the deep grey matter of the brain?

A: Basal nuclei (ganglia) and components of the limbic system.

Q: What are the names and functions of the primary fissures and sulci in the brain?

• A:

  • Longitudinal Fissure: Separates left and right hemispheres.

  • Central Sulcus: Divides the frontal lobe from the parietal lobe.

  • Lateral Fissure: Separates the temporal lobe from the frontal and parietal lobes.

Q: How do gyri and sulci contribute to brain function?

A: They increase the surface area of the brain, allowing for a greater number of neurons and more complex processing.

Q: Identify the main functions of the Frontal Lobe.

A: Involved in motor function, decision-making, problem-solving, and controlling behavior and emotions.

Q: What sensory modalities are processed in the Parietal Lobe?

A: Processes somatosensory information such as touch, pressure, pain, and temperature.

Q: Describe the main functions of the Temporal Lobe

A: Responsible for auditory processing, language comprehension, and aspects of memory.

Q: What is the primary function of the Occipital Lobe?

A: Processes visual information, including color, light, and motion detection.

Q: What is Broca’s area and its significance?

A: Located in the frontal lobe, it is crucial for speech production and language processing.

Q: What is Wernicke’s area responsible for?

A: Located in the temporal lobe, it is involved in language comprehension.

Q: What are commissural fibers and their function?

• A: Fibers that connect corresponding areas of the left and right hemispheres, facilitating interhemispheric communication (e.g., corpus callosum).

Q: Describe the role of association fibers.

A: Connect different regions within the same hemisphere, allowing for integration of information.

Q: What do projection fibers do?

A: Connect the cerebral cortex with lower brain structures and the spinal cord, relaying signals to and from the cortex.

Q: What specific functions do the basal nuclei serve?

A: Regulate voluntary motor movements, procedural learning, habit formation, and eye movements.

Q: Explain the pathway involving basal nuclei for motor control.

A: Premotor cortex → Basal nuclei → Thalamus → Back to premotor cortex, facilitating quick motor planning.

Q: What are the major disorders associated with dysfunction in the basal nuclei

A: Huntington’s disease (hyperkinetic movement) and Parkinson’s disease (hypokinetic movement).

Q: What is the primary function of the hippocampus?

A: Essential for the formation of new memories and learning; involved in spatial memory and navigation.

Q: How does the fornix contribute to limbic system function?

A: It acts as a major pathway connecting the hippocampus to other limbic structures, like the mammillary bodies.

Q: What role do mammillary bodies play in the limbic system?

A: Involved in memory processing and the emotional response to memories, particularly regarding smell.

Q: Describe the function of the amygdala in the limbic system.

A: Key in processing emotions, especially fear, and plays a role in emotional memory and recognition of emotional facial expressions.

Q: What is the role of the entorhinal cortex?

A: Acts as a major input/output area for the hippocampus, playing a critical role in memory and navigation.

Q: How does the thalamus determine the significance of memories?

A: It filters sensory information and relays important signals to the cortex, affecting memory consolidation.

Q: Distinguish between declarative and procedural memory.

A:

• Declarative Memory: Explicit memory for facts and events, involves conscious recall (e.g., episodic and semantic memory).

• Procedural Memory: Implicit memory for skills and actions, performed without conscious thought.

Q: Identify the brain structures associated with short-term and long-term memory.

A: Short-term memory is linked to the prefrontal cortex; long-term memory involves the hippocampus and temporal lobe structures.

Q: What is the difference between anterograde and retrograde amnesia?

• A: Anterograde amnesia prevents the formation of new memories post-injury; retrograde amnesia affects recall of memories formed before the injury.

Q: How do the cerebellum and basal nuclei contribute to memory?

A: The cerebellum is involved in the acquisition of new motor skills, while the basal nuclei help with the storage and execution of learned skills.

Q: What role does the thalamus play in motor planning?

A: It integrates information from the basal nuclei and cerebellum to determine the best motor plan for execution.