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Anatomy & Physiology: Nervous System and Sensory Physiology

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Terms in this set (28)

  • Central Nervous System (CNS)

    The CNS consists of the brain and spinal cord. It processes, interprets, and stores information, issuing orders to muscles, glands, and organs.

  • Peripheral Nervous System (PNS)

    The PNS is composed of nerves outside the CNS. It transmits information to and from the CNS and includes sensory nerves relaying information from the body to the brain.

  • Somatic Nervous System

    Controls voluntary movements of skeletal muscles.

  • Autonomic Nervous System

    Regulates involuntary functions such as glands, blood vessels, and internal organs.

  • Neuron vs. Neuroglia

    Neurons transmit electrical and chemical signals. Neuroglia support neurons structurally and metabolically, maintaining homeostasis and protection.

  • Types of Neurons

    Bipolar: one axon, one dendrite (sensory organs). Multipolar: one axon, multiple dendrites (most CNS neurons). Unipolar: single process splitting into two branches (sensory PNS neurons).

  • CNS Neuroglial Cells

    Astrocytes: blood-brain barrier, nutrients. Oligodendrocytes: myelin sheath. Microglia: immune defense. Ependymal cells: produce cerebrospinal fluid.

  • PNS Neuroglial Cells

    Schwann cells: produce myelin sheath. Satellite cells: support neuron cell bodies in ganglia.

  • Resting Membrane Potential

    Typically about -70 mV in neurons; the electrical charge difference across the membrane at rest.

  • Threshold Potential

    Usually around -55 mV; the critical level to initiate an action potential.

  • Phases of Action Potential

    Polarization: inside negative. Depolarization: Na+ influx makes inside positive. Repolarization: K+ exits, inside returns negative. Hyperpolarization: inside more negative than resting.

  • Ion Channel Activity During Action Potential

    Depolarization: voltage-gated Na+ channels open. Repolarization: Na+ channels close, K+ channels open. Hyperpolarization: K+ channels remain open briefly.

  • Myelinated vs. Unmyelinated Neurons

    Myelinated: rapid saltatory conduction between nodes of Ranvier. Unmyelinated: slower continuous conduction.

  • Neurotransmitter

    Chemical messenger released by neurons to transmit signals across synapses; produced in the cell body and stored in synaptic vesicles.

  • Ionotropic vs. Metabotropic Receptors

    Ionotropic: ligand-gated ion channels, fast direct response. Metabotropic: G-protein coupled, slower indirect effects.

  • Synapse and Ion Channels

    Synapse is the junction between neurons where neurotransmitters are released. Ion channels can be passive (always open) or gated (voltage-, ligand-, or mechanically-gated).

  • Lobes of the Cerebrum and Functions

    Frontal: movement, planning, speech. Parietal: sensory perception. Temporal: auditory, memory. Occipital: visual processing.

  • Brain Stem Regions and Functions

    Midbrain: visual/auditory reflexes. Pons: relays signals, breathing regulation. Medulla Oblongata: controls heart rate, breathing.

  • Limbic System Components

    Hippocampus: memory. Amygdala: emotion. Hypothalamus: homeostasis.

  • White Matter vs. Gray Matter

    White matter: myelinated axons transmitting signals. Gray matter: neuron cell bodies and dendrites processing information.

  • Reflex Arc Components

    Stimulus → Receptor → Sensory neuron → Integrating center (spinal cord) → Motor neuron → Effector → Response.

  • Sympathetic vs. Parasympathetic Nervous System

    Sympathetic: fight or flight, mobilizes energy. Parasympathetic: rest and digest, conserves energy.

  • Cranial Nerves for Taste and Smell

    Taste: Facial (VII), Glossopharyngeal (IX), Vagus (X). Smell: Olfactory (I).

  • Photoreceptors in the Eye

    Rods: sensitive to low light, night vision. Cones: detect color and sharp vision (S-blue, M-green, L-red cones).

  • Accommodation in Vision

    Lens changes shape: rounder for near vision, flatter for distant vision.

  • Types of Pain

    Somatic: skin, muscles, joints. Visceral: internal organs. Referred: pain felt away from origin.

  • Phasic vs. Tonic Receptors

    Phasic: rapidly adapt (e.g., Pacinian corpuscles). Tonic: slow to adapt (e.g., nociceptors).

  • Hearing Pathway

    Sound waves → outer ear → tympanic membrane → ossicles → cochlear fluid → Organ of Corti → auditory nerve (VIII) → brain (temporal lobe).