Nervous System Review Guide PDF

**Nervous System Review Guide** **Short Answer Questions** 1. **Describe the basic structure of a neuron.** 2. **Differentiate between sensory neurons, motor neurons, and interneurons in terms of function.** 3. **What are the three main types of glia in the CNS, and what are their rol...

**Nervous System Review Guide** **Short Answer Questions** 1. **Describe the basic structure of a neuron.** 2. **Differentiate between sensory neurons, motor neurons, and interneurons in terms of function.** 3. **What are the three main types of glia in the CNS, and what are their roles?** 4. **Explain the difference between white matter and gray matter in the brain and spinal cord.** 5. **Outline the steps involved in a simple reflex arc, such as the patellar reflex.** 6. **Describe the mechanism of a nerve impulse, including the roles of polarization, depolarization, and repolarization.** 7. **What is a synapse, and what are its key components?** 8. **Briefly discuss the function of the cerebellum.** 9. **Compare and contrast the sympathetic and parasympathetic divisions of the autonomic nervous system.** 10. **What are the main functions of cerebrospinal fluid (CSF)?** **Short Answer Key** 1. A neuron consists of a cell body, dendrites (which receive impulses), and an axon (which transmits impulses). 2. Sensory neurons carry impulses from receptors to the CNS, motor neurons carry impulses from the CNS to muscles and glands, and interneurons connect sensory and motor neurons within the CNS. 3. Astrocytes support and anchor neurons to blood vessels, microglia perform phagocytosis, and oligodendrocytes form myelin sheaths in the CNS. 4. White matter is composed of myelinated axons, responsible for transmitting signals over long distances, while gray matter consists mainly of cell bodies and unmyelinated fibers, involved in processing information. 5. A stimulus activates a sensory receptor, sending an impulse along a sensory neuron to the spinal cord. The impulse synapses with a motor neuron, which transmits the signal to an effector (muscle) causing a response. 6. At rest, the neuron membrane is polarized. A stimulus triggers the opening of sodium channels, causing depolarization. This electrical disturbance propagates along the membrane. The membrane then repolarizes, restoring its resting state. 7. A synapse is the junction between two neurons where nerve impulses are transmitted. It consists of the synaptic knob of the presynaptic neuron, the synaptic cleft, and the plasma membrane of the postsynaptic neuron. 8. The cerebellum coordinates muscle movements, maintains balance, and contributes to smooth and precise motor control. 9. The sympathetic nervous system prepares the body for \"fight-or-flight\" responses during stress, while the parasympathetic nervous system promotes \"rest-and-digest\" functions, conserving energy and maintaining homeostasis. 10. CSF cushions the brain and spinal cord, provides nutrients, and removes waste products. It also contributes to maintaining a stable chemical environment for the CNS. **Essay Questions** 1. Discuss the role of myelin in nerve impulse conduction. How does the presence of myelin affect the speed of signal transmission? What happens when myelin is damaged, as in multiple sclerosis? 2. Describe the major anatomical divisions of the brain (brainstem, cerebellum, diencephalon, cerebrum) and outline the main functions of each. 3. Compare and contrast the structure and function of cranial nerves and spinal nerves. Provide examples of specific cranial nerves and their associated functions. 4. Explain the concept of a dermatome. How can knowledge of dermatomes be useful in diagnosing and treating neurological conditions? 5. Discuss various conditions or disorders that affect the nervous system, including both the central and peripheral nervous systems. Choose at least three conditions and describe their causes, symptoms, and potential treatments. **Glossary of Key Terms** - **Action potential:** A self-propagating wave of electrical disturbance that travels along the surface of a neuron membrane, transmitting a nerve impulse. - **Afferent neurons:** Sensory neurons that conduct impulses towards the central nervous system. - **Astrocytes:** Star-shaped glial cells that provide structural and metabolic support to neurons. - **Autonomic nervous system (ANS):** The part of the nervous system that controls involuntary functions, such as heart rate, breathing, and digestion. - **Axon:** The elongated projection of a neuron that conducts impulses away from the cell body. - **Brain stem:** The lower part of the brain that connects to the spinal cord and controls basic life functions, such as breathing and heart rate. - **Central nervous system (CNS):** The brain and spinal cord. - **Cerebellum:** A part of the brain responsible for coordinating muscle movements and balance. - **Cerebrospinal fluid (CSF):** The fluid that surrounds and cushions the brain and spinal cord. - **Cerebrum:** The largest part of the brain, responsible for higher-level cognitive functions, such as thinking, learning, and memory. - **Dendrites:** Branching projections of a neuron that receive impulses from other neurons. - **Depolarization:** A change in the electrical charge across a neuron\'s membrane that triggers an action potential. - **Dermatome:** An area of skin supplied by a single spinal nerve. - **Efferent neurons:** Motor neurons that conduct impulses away from the central nervous system to muscles or glands. - **Glia (neuroglia):** Supporting cells in the nervous system that provide structural support, insulation, and nutrients to neurons. - **Gray matter:** Nervous tissue composed primarily of neuron cell bodies and unmyelinated fibers, involved in processing information. - **Interneurons:** Neurons that connect sensory and motor neurons within the central nervous system. - **Myelin sheath:** A fatty covering around axons that speeds up nerve impulse conduction. - **Neuron:** A specialized cell that transmits nerve impulses. - **Neurotransmitter:** A chemical messenger that transmits signals between neurons across a synapse. - **Peripheral nervous system (PNS):** All the nerves outside the brain and spinal cord. - **Reflex arc:** The pathway of a nerve impulse in a reflex action, involving a sensory receptor, sensory neuron, interneuron, motor neuron, and effector. - **Repolarization:** The restoration of the resting electrical charge across a neuron\'s membrane after depolarization. - **Synapse:** The junction between two neurons, where nerve impulses are transmitted. - **White matter:** Nervous tissue composed primarily of myelinated axons, responsible for transmitting signals over long distances.