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Flashcards: Unit 2 physiology
Acetylcholine
Neurotransmitter involved in muscle activation and autonomic nervous system.
Action Potential
Rapid electrical signal traveling along neurons.
Actin
Protein forming microfilaments in muscle fibers and cells.
Astrocyte
Glial cell supporting neurons and forming part of the blood-brain barrier.
Axon Hillock
Region where an action potential is initiated.
Axon Terminal
End of a neuron where neurotransmitters are released.
Ca2+ (Calcium Ions)
Key ion in neurotransmitter release and muscle contraction.
Dendrite
Neuron extension receiving input signals.
Depolarization
Reduction in membrane potential making the inside of a cell less negative.
Gap Junction
Direct connection allowing electrical signals to pass between cells.
Graded Potential
Small changes in membrane potential, localized to a specific region.
Gray Matter
Brain and spinal cord regions rich in neuron cell bodies.
Hyperpolarization
Increase in membrane potential making the inside more negative.
Myosin
Protein involved in muscle contraction by interacting with actin.
Neuron
Basic unit of the nervous system, transmitting electrical signals.
Nodes of Ranvier
Gaps in myelination on axons where action potentials regenerate.
Oligodendrocytes
Glial cells producing myelin in the central nervous system.
Receptor Channels
Ion channels activated by ligands to initiate cellular responses.
Schwann Cells
Glial cells producing myelin in the peripheral nervous system.
Sensory Receptors
Cells detecting environmental stimuli like light, sound, and chemicals.
Synapse
Junction between neurons or between a neuron and a target cell.
Voltage-Gated Ion Channels
Channels opening in response to voltage changes.
White Matter
Nervous system regions rich in myelinated axons.
ACTH (Adrenocorticotropic Hormone)
Hormone stimulating cortisol release from the adrenal cortex.
Adenylate Cyclase
Enzyme converting ATP to cyclic AMP (cAMP) in signaling pathways.
Adrenal Cortex
Outer layer of the adrenal gland producing hormones like cortisol.
Amplifier Enzyme
Enzyme amplifying signals by producing large amounts of second messengers.
Anterior Pituitary
Gland releasing hormones like ACTH and FSH under hypothalamic control.
CRH (Corticotropin-Releasing Hormone)
Hormone stimulating ACTH release.
Cyclic AMP (cAMP)
Second messenger in signal transduction.
Endocrine Cell
Cell releasing hormones into the bloodstream.
Epinephrine
Hormone and neurotransmitter involved in the "fight or flight" response.
Glucagon
Hormone increasing blood glucose levels by promoting glycogen breakdown.
G-Protein Coupled Receptors
Receptors activating intracellular signaling cascades.
Hormone
Chemical messenger secreted by endocrine glands.
Inositol Triphosphate (IP3)
Second messenger involved in calcium release.
Insulin
Hormone reducing blood glucose by promoting cellular uptake.
Negative Feedback
Regulatory mechanism maintaining homeostasis by inhibiting initial signals.
Neurohormone
Hormones released by neurons into the bloodstream.
Paracrine Signals
Chemical signals affecting nearby cells.
Phospholipase C
Enzyme generating second messengers in signaling pathways.
Posterior Pituitary
Releases hormones like oxytocin and vasopressin.
Second Messenger
Intracellular signaling molecules like cAMP and IP3.
Lens
Focuses light onto the retina in the eye.
Muscle Fiber
Muscle cell responsible for contraction.
Nociceptors
Pain-detecting sensory receptors.
Photoreceptor
Retina cells detecting light (rods and cones).
Pupil
Eye opening controlling light entry.
Retina
Light-sensitive tissue in the eye.
Sarcomere
Functional unit of muscle contraction.
Sarcoplasm
Cytoplasm of a muscle cell.
Sarcoplasmic Reticulum
Stores and releases calcium in muscle cells.
Tropomyosin
Protein regulating actin-myosin interaction.
Troponin
Calcium-binding protein controlling muscle contraction.
Vestibular Apparatus
Inner ear structure involved in balance.
Cellular Anatomy of a Neuron
Dendrites, axon hillock, axons, and synaptic terminals.
Graded Potential vs. Action Potential
Graded potentials are localized; action potentials propagate.
Processes of Action Potential
Depolarization, repolarization, hyperpolarization.
Chemical vs. Electrical Synapse
Chemical uses neurotransmitters; electrical uses gap junctions.
Blood-Brain Barrier
Protective barrier controlling substance entry to the brain.
General Organization of Nervous System
Central (CNS) vs. Peripheral (PNS).
Sympathetic vs. Parasympathetic
"Fight or flight" vs. "rest and digest."
Afferent vs. Efferent Pathways
Afferent brings signals to the CNS; efferent sends signals from CNS to effectors.
Anterior vs. Posterior Pituitary
Anterior produces hormones; posterior stores hypothalamic hormones.
Endocrine vs. Exocrine
Endocrine releases into blood; exocrine releases into ducts.
Neurotransmitter vs. Hormone
Neurotransmitters act locally; hormones act systemically.
HPA and APT Axes
Hypothalamic-pituitary-adrenal and anterior-pituitary-thyroid pathways.
Pathophysiology of Diabetes Mellitus
Dysregulation of insulin and blood glucose.
Basic Physiology of Senses
Mechanisms of vision, hearing, smell, taste, and touch.
Structure of Muscle
Sarcomeres, myofibrils, actin, and myosin.
Basic Physiology of Muscle Contraction
Role of calcium, tropomyosin, and troponin.
Neuromuscular Junction
Synapse between motor neuron and muscle fiber.
Outer vs. Middle vs. Inner Ear
Sound transmission and balance detection.
Signal Transduction Pathways
Receptor activation, second messengers, and cellular responses.
Intracellular vs. Membrane Receptors
Intracellular for lipophilic hormones; membrane for hydrophilic.
Neuroendocrine Reflex
Neural signals triggering hormonal release.
Simple Endocrine and Neural Reflex
Direct hormone release or neuron activation.
Spinal Reflex Arc
Sensory input to motor response pathway.