Nervous System Flashcards
What does the central nervous system (CNS) consist of?
The CNS consists of the brain and spinal cord, encased in bone.
What are the main parts of the brain?
The main parts of the brain are the cerebrum, cerebellum, and brain stem.
What is the role of the cerebellum?
The cerebellum controls movement and has as many neurons as both cerebral hemispheres combined; its left side controls left body movements, and its right side controls right body movements.
What functions does the brain stem regulate?
The brain stem connects the cerebrum and cerebellum to the spinal cord and regulates vital functions like breathing, consciousness, and body temperature; damage is usually fatal.
How does the spinal cord function in relation to the CNS?
The spinal cord is a major information conduit to and from the brain; transection causes anesthesia and paralysis below the cut.
What differentiates the somatic from the visceral PNS?
The somatic PNS innervates skin, joints, and voluntary muscles, while the visceral PNS (autonomic nervous system) innervates internal organs, blood vessels, and glands, controlling involuntary functions.
How many pairs of cranial nerves are there, and where do they originate?
There are 12 pairs of cranial nerves, originating from the brain stem, primarily innervating the head.
What are the meninges and their function?
The meninges are three membranes (dura mater, arachnoid membrane, and pia mater) that encase and protect the CNS by enclosing the brain and spinal cord.
Describe the flow of cerebrospinal fluid (CSF) within the CNS.
CSF flows from the brain’s ventricles to the central cavities in the brain stem, exits to the subarachnoid space through apertures near the cerebellum-brain stem junction, and is absorbed into the bloodstream through arachnoid villi.
What are the origins and destinations of afferent and efferent axons?
Afferent axons carry information toward a particular point (e.g., toward the CNS), while efferent axons carry information away from a point (e.g., away from the CNS to muscles or glands).
How does the neural tube contribute to CNS development?
The neural tube forms from the fusion of neural folds and is the precursor to the entire CNS, including the brain and spinal cord.
What does the neural crest give rise to?
The neural crest gives rise to all neurons with cell bodies in the peripheral nervous system (PNS), among other structures.
Name the three primary brain vesicles and their contributions to brain development.
The prosencephalon (forebrain), mesencephalon (midbrain), and rhombencephalon (hindbrain) are primary vesicles that form the basis of the brain, differentiating into specific brain regions and structures.
What is the significance of the ventricular system in the brain?
The ventricular system is filled with CSF, provides cushioning for the brain, and is involved in nutrient transport and waste removal.
How does the structure of the cerebral cortex evolve across species?
The cerebral cortex evolves across species by increasing its surface area through the development of more gyri and sulci, without significant changes in thickness, indicating evolutionary expansion.
