DAANCE module 1: Basic Sciences Verified A+

DAANCE module 1: Basic Sciences Verified A+ Central Nervous System Overview 1. Role of the Central Nervous System: To provide overall control of body functions. 2. Three Subdivisions of the Central Nervous System: - Central Nervous System (CNS) - Peripheral Nervous System (PNS) - Autonomic Nervous System (ANS) Nervous System Structure and Function 1. Cells of the Nervous System: Neurons 2. Responsibilities of Neurons: Conduct nerve impulses within the brain and from one body part to another. 3. Action Potential: The nerve's threshold of stimulus. An impulse travels along the neuron once the threshold is reached. 4. Relation to Synapse: When an impulse reaches the end of the neuron, it can pass to another neuron across a synapse. 5. Synapse Definition: A junction between two neurons. Depolarization/Repolarization 1. Depolarization Explained: When the outside of a nerve membrane, initially positively charged, becomes negatively charged due to the movement of charges into the membrane. 2. Substance Involved in Membrane Movement: Na+ ions (sodium). 3. Wave of Polarization: The movement of changing charges during depolarization. 4. Repolarization Explained: After an impulse, nerve fibers become repolarized, regaining their positive charge. 5. Relation to Local Anesthetics: Local anesthetics block Na+ ion movement through ion channels, preventing depolarization and slowing or stopping nerve impulses. Synapses 1. Terminal Button: The bulge at the end of the nerve that touches the next nerve. 2. Pre-synaptic and Post-synaptic: The nerve before (pre-synaptic) and after (post-synaptic) the synapse that is active. 3. Synaptic Cleft: The gap between two nerves that a nerve impulse must 'jump across.' 4. Substance Dependent on Synapse: Neurotransmitters. 5. Function of Neurotransmitters: Enable transmission of the depolarization wave to the next nerve's receptor sites. Central Nervous System Parts 1. Definition and Components of CNS: Overall control center of the body, consisting of the brain and spinal cord. 2. Parts of the CNS: - Cerebral Cortex - Core of the Brain - Cerebellum - Brainstem Cerebral Cortex 1. Parts of the Cerebral Cortex: 2 parts (paired cerebral hemispheres). 2. Main Responsibilities: - Thought - Learning - Memory - Consciousness - Sensory perception (pain, heat) - Initiation of muscle movement Core of the Brain 1. Main Purpose: Impulses pass through the core to or from the cerebral cortex. 2. Core Components Function: Serves as a relay station for sensory inputs to the cerebral cortex. 3. Other Important Structures Role: Play roles in autonomic functions and emotions. Cerebellum 1. Purpose of the Cerebellum: Coordinating center for sensory receptors (vision, hearing) and movement coordination. Brainstem 1. Location of the Brainstem: Between the brain's core and the spinal cord (inferiorly). 2. Three Parts of the Brainstem: Midbrain, Pons, Medulla Oblongata. 3. Control Centers in the Brainstem: Contains autonomic nervous system control centers. 4. Other Structures: Reticular formation, responsible for consciousness or arousal. Brainstem Functions 1. Lower Portion Components: Pons and medulla. 2. Function of the Pons: Connects to the cerebellum and controls coordination and movement. 3. Function of the Medulla: Contains centers that control blood pressure, heart rate, respiration, and digestion.