# Neurociència — Avançat (C1/C2) 2: Immunology & Neurobiology > [Català] Neurociència: Innate and adaptive immunity, antibody structure, action potentials, synaptic transmission, and sensory processing mechanisms - **Canonical URL:** https://flashcards.world/flashcards/sets/1ecda374-4add-4a97-9eb5-b3d6e9e256cd/ - **Markdown URL:** https://flashcards.world/flashcards/sets/1ecda374-4add-4a97-9eb5-b3d6e9e256cd.md - **Level:** advanced - **Languages:** ca → ca - **Total Cards:** 32 ## Flashcards (32 Cards) | # | Front (Term / Prompt) | Back (Definition / Answer) | Example | Multiple-Choice Options | | :--- | :--- | :--- | :--- | :--- | | 1 | How does myelin increase the conduction velocity of action potentials along axons? | It insulates the internodal axon to reduce membrane capacitance and prevent charge leakage, forcing action potentials to jump from node to node via saltatory conduction. | | | | 2 | Which cranial nerve provides the primary parasympathetic innervation to thoracic and abdominal visceral organs? | The vagus nerve (Cranial Nerve X). | | | | 3 | Which immunoglobulin isotype is secreted as a pentamer during the primary humoral immune response? | Immunoglobulin M (IgM), joined by a joining (J) chain. | | | | 4 | Which glial cells synthesize myelin in the central nervous system (CNS) versus peripheral nervous system (PNS)? | Oligodendrocytes in the CNS (myelinating multiple axons); Schwann cells in the PNS (myelinating a single axon segment). | | | | 5 | What ionic trigger couples action potential arrival at the presynaptic terminal to neurotransmitter exocytosis? | Opening of voltage-gated calcium channels (VGCCs) and influx of Ca2+, which binds synaptotagmin to trigger SNARE-mediated synaptic vesicle fusion. | | | | 6 | What receptors on innate immune cells recognize Pathogen-Associated Molecular Patterns (PAMPs) such as lipopolysaccharide (LPS)? | Pattern Recognition Receptors (PRRs), prominently including Toll-Like Receptors (TLRs, e.g., TLR4 for LPS). | | | | 7 | How do selective serotonin reuptake inhibitors (SSRIs) increase serotonergic transmission at central synapses? | They selectively block the serotonin transporter (SERT), preventing serotonin reuptake into the presynaptic terminal and prolonging its presence in the synaptic cleft. | | | | 8 | Which immunoglobulin isotype is most abundant in serum, crosses the placenta to confer passive neonatal immunity, and opsonizes pathogens? | Immunoglobulin G (IgG). | | | | 9 | How does temporal summation differ from spatial summation at the neuronal axon hillock? | Temporal summation combines multiple postsynaptic potentials generated in rapid succession at a single synapse; spatial summation combines potentials generated simultaneously at multiple distinct synapses. | | | | 10 | What is the immunological role of IgE, and which cells express high-affinity Fc-epsilon receptors that bind it? | IgE mediates defense against parasitic helminths and triggers type I hypersensitivity allergic reactions by binding Fc-epsilon-RI on mast cells and basophils. | | | | 11 | What is the primary excitatory neurotransmitter in the mammalian central nervous system, and what are its two major ionotropic receptors? | L-Glutamate; its primary ionotropic receptors are AMPA receptors and NMDA receptors. | | | | 12 | Where does T lymphocyte positive and negative selection occur, and what is the outcome of negative selection? | In the thymus; negative selection eliminates developing thymocytes that bind self-antigen/MHC complexes with high affinity to prevent autoimmunity (central tolerance). | | | | 13 | What key cytokines are produced by T helper 1 (Th1) versus T helper 2 (Th2) subsets, and what immune responses do they drive? | Th1 produces interferon-gamma (IFN-gamma) and IL-2 to drive cell-mediated immunity against intracellular pathogens; Th2 produces IL-4, IL-5, and IL-13 to drive humoral immunity, eosinophils, and parasite defense. | | | | 14 | What proteins constitute the core SNARE complex responsible for vesicle docking and fusion at the presynaptic active zone? | v-SNARE synaptobrevin (VAMP) on the vesicle, and t-SNAREs syntaxin-1 and SNAP-25 on the presynaptic plasma membrane. | | | | 15 | What is the membrane attack complex (MAC) in the complement cascade, and what is its cytolytic mechanism? | A multi-protein pore assembly (C5b-C6-C7-C8-poly-C9) that inserts into microbial lipid membranes, causing osmotic lysis and cell death. | | | | 16 | Why is the NMDA receptor unique among ligand-gated ion channels in requiring both ligand binding and membrane depolarization? | It requires glutamate and glycine binding, plus sufficient membrane depolarization to eject a physiological magnesium ion (Mg2+) blocking the pore. | | | | 17 | What are the primary differences between innate and adaptive immunity regarding response speed, specificity, and immunological memory? | Innate immunity acts immediately (minutes/hours), uses broad non-specific pattern receptors, and lacks memory; adaptive immunity takes days to develop, is highly antigen-specific, and generates long-lived immunological memory. | | | | 18 | What two gating events terminate the action potential spike and initiate repolarization? | 1. Inactivation of voltage-gated Na+ channels (via their intracellular inactivation gate/ball-and-chain). 2. Delayed opening of voltage-gated K+ channels allowing K+ efflux. | | | | 19 | What anatomical structure forms the physical blood-brain barrier (BBB) to protect the central nervous system parenchyma? | Non-fenestrated brain capillary endothelial cells joined by continuous tight junctions (claudins/occludins), supported by pericytes and astrocyte end-feet. | | | | 20 | What cytotoxic molecules do CD8+ cytotoxic T lymphocytes and NK cells exocytose to induce apoptosis in virally infected target cells? | Perforin (which forms pores in the target plasma membrane) and granzymes (serine proteases that enter pores to trigger apoptotic caspase cascades). | | | | 21 | What electrical event initiates the depolarizing upstroke of a neuronal action potential once threshold is reached? | Rapid opening of voltage-gated Na+ channels, causing massive regenerative Na+ influx down its electrochemical gradient. | | | | 22 | What biochemical event produces microbicidal reactive oxygen species (ROS) in activated phagocytes during phagocytosis? | The respiratory (oxidative) burst, mediated by NADPH oxidase converting molecular oxygen to superoxide radicals. | | | | 23 | What synaptic plasticity phenomenon is widely recognized as the primary cellular model for learning and long-term memory formation? | Long-Term Potentiation (LTP), characterized by persistent strengthening of synapses following high-frequency stimulation. | | | | 24 | What genetic mechanism generates the vast repertoire of B cell receptors (antibodies) and T cell receptors? | V(D)J somatic recombination catalyzed by RAG1 and RAG2 recombinases, joined with junctional diversity by terminal deoxynucleotidyl transferase (TdT). | | | | 25 | Describe the quaternary subunit architecture of a monomeric immunoglobulin G (IgG) antibody molecule. | Two identical heavy (H) chains and two identical light (L) chains joined by covalent disulfide bonds, forming a Y-shape with two antigen-binding Fab arms and one crystallizable Fc stem. | | | | 26 | How do MHC Class I and MHC Class II molecules differ in their tissue distribution and antigen presentation pathways? | MHC I is expressed on all nucleated cells, presents endogenous cytosolic antigens to CD8+ cytotoxic T cells; MHC II is expressed on professional APCs (dendritic cells, macrophages, B cells), presenting exogenous antigens to CD4+ helper T cells. | | | | 27 | What is the resting membrane potential of a typical mammalian motor neuron, and what ion gradients establish it? | Approximately -70 mV, established by high intracellular K+ and high extracellular Na+ maintained by the Na+/K+ pump and passive inward K+ leak channels. | | | | 28 | What is the primary inhibitory neurotransmitter in the adult brain, and what ion passes through its ionotropic receptor channel? | Gamma-aminobutyric acid (GABA); binding to GABA-A receptors opens ligand-gated chloride (Cl-) channels, causing hyperpolarizing IPSPs. | | | | 29 | Which immunoglobulin class is predominantly found in mucosal secretions (saliva, tears, colostrum) as a secretory dimer? | Immunoglobulin A (IgA). | | | | 30 | What enzyme rapidly degrades acetylcholine in the synaptic cleft of the neuromuscular junction to terminate muscle excitation? | Acetylcholinesterase (AChE). | | | | 31 | Which neurotransmitter is depleted in the substantia nigra pars compacta in patients with Parkinson's disease? | Dopamine. | | | | 32 | What is the physiological cause of the absolute refractory period in excitable neuronal membranes? | Voltage-gated Na+ channels are locked in their inactivated state and cannot be reopened until the membrane repolarizes to resting potentials. | | | --- Study this deck interactively with FSRS-6 spaced repetition, audio review, and multiple-choice mode at [Flashcards World](https://flashcards.world/flashcards/sets/1ecda374-4add-4a97-9eb5-b3d6e9e256cd/).