Exam 2 study guide/ kahoot + lab questions

what are the two main division of the nervous system?

Central and Peripheral

What is the primary effect of excitatory postsynaptic potentials (EPSPs)?

They make the neuron more likely to fire an action potential

What is the role of acetylcholinesterase in synaptic transmission?

To break down acetylcholine after its action

Which cells support neurons but cannot conduct impulses?

Neuroglia

What is the role of dendrites in neurons?

Receive impulses

Which process moves organelles from cell body to axon terminals?

Axonal transport

What is the function of oligodendrocytes in the CNS?

form myelin sheaths

Which neurons are responsible for voluntary muscle control?

Somatic motor neurons

What is the primary role of astrocytes?

Regulate external environment

Which neurotransmitter is involved in muscle contraction?

Acetylcholine

What is the function of the blood-brain barrier?

Protect brain from toxins

Which ion is primarily responsible for depolarization?

Sodium (Na+)

What is the 'all-or-none' law in action potentials?

Threshold reached, AP occurs

What is the role of myelin in nerve conduction?

Increase conduction speed

Which neurotransmitter is inhibitory in the spinal cord?

Glycine

What is the primary excitatory neurotransmitter in the brain?

Glutamate

Which neurotransmitter is linked to the 'fight or flight' response?

Norepinephrine

What is the role of neurotrophins in the nervous system?

Promote neuronal growth

Which cells form the myelin sheath in the PNS?

Schwann cells

What is the primary function of microglia?

Phagocytize debris

Which neurotransmitter is involved in mood regulation?

Serotonin

What is the resting membrane potential of a typical neuron?

-70 mV

What is the correct order of nerve functions from first to last?

Sensory Input, Integration, Motor Output

Which of the following organs has a bipolar neuron?

Eyes

True or False: The resting potential in the neuron is -55mV

False

What portion of the neuron ends the cell body and starts the axon, and is the origin of action potentials?

Axon Hillock

Action potentials are "all or nothing" events and they primarily release ____________ ?

Yes, Neurotransmitters

What part of the action potential returns the membrane to the cell's resting potential (resting state)?

Repolarization

Central Nervous System (CNS)

consists of the brain and spinal cord, the main control center of the body. It receives, processes, and integrates information from the peripheral nervous system. Advanced concepts include the intricate organization of brain regions and their specialized functions (e.g., cerebrum, cerebellum, brainstem).

Peripheral Nervous System (PNS)

The PNS comprises all the nerves extending from the CNS to the rest of the body. It relays sensory information to the CNS and carries motor commands from the CNS to muscles and glands. Advanced concepts include the somatic and autonomic nervous systems, their subdivisions (sympathetic and parasympathetic), and neurotransmitter specificities.

Nervous Tissue

Nervous tissue is composed of two main cell types: Neurons and Neuroglia (Glial Cells)

Neurons

Neurons are the functional units of the nervous system, specialized for conducting nerve impulses. They are generally incapable of cell division. Advanced concepts include the different types of neurons (structural and functional classifications), their unique properties, and the mechanisms of signal transduction.

Neuroglia (Glial Cells)

Neuroglia support and protect neurons. They are capable of cell division. Advanced concepts include the diverse types of glial cells (astrocytes, oligodendrocytes, microglia, ependymal cells in the CNS; Schwann cells in the PNS), their specific functions, and their roles in maintaining the brain's environment.

Cell Body (Soma)

The cell body contains the nucleus and other organelles essential for neuronal function. Clusters of cell bodies are called nuclei in the CNS and ganglia in the PNS.

Dendrites

Dendrites are branched extensions of the neuron that receive incoming signals (graded potentials) and conduct them toward the cell body. Advanced concepts include dendritic integration and the role of dendritic spines in synaptic plasticity.

Axon

The axon is a long, slender projection that transmits nerve impulses (action potentials) away from the cell body to other neurons, muscles, or glands. Advanced concepts include axonal transport (anterograde and retrograde), its mechanisms, and its importance in neuronal function and disease.

Axon Terminals (Boutons)

Axon terminals are the specialized endings of the axon where neurotransmitters are released into the synapse. Advanced concepts include the role of calcium ions in neurotransmitter release and the mechanisms of synaptic vesicle fusion.

Myelin Sheath

The myelin sheath is a fatty insulating layer around some axons that increases the speed of nerve impulse conduction. It's formed by oligodendrocytes in the CNS and Schwann cells in the PNS. Gaps in the myelin sheath are called Nodes of Ranvier. Advanced concepts include saltatory conduction and demyelinating diseases (e.g., multiple sclerosis, Guillain-Barré syndrome).

Neurilemma

The neurilemma is the outermost layer of the Schwann cell, which surrounds the axon in the PNS. It plays a crucial role in axon regeneration. The CNS lacks a neurilemma, which contributes to the limited regenerative capacity of CNS axons.

Axonal Transport

Axonal transport is the process by which materials are moved along the axon. Anterograde transport moves materials from the cell body to the axon terminal, while retrograde transport moves materials in the opposite direction. This process is essential for neuronal maintenance and function. Kinesin and dynein are motor proteins involved.

Neurotrophins

Neurotrophins are proteins that support neuronal survival, growth, and differentiation. Examples include nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), and glial-derived neurotrophic factor (GDNF). They are crucial for development and regeneration.

Resting Membrane Potential

The resting membrane potential is the electrical potential difference across the neuronal membrane when the neuron is not actively transmitting a signal. It's typically around -70 mV. Advanced concepts include the contributions of ion channels (leakage and voltage-gated), the sodium-potassium pump, and the relative permeability of the membrane to different ions.

Depolarization

Depolarization is a decrease in the membrane potential (making the inside of the cell less negative). It's usually caused by an influx of sodium ions (Na⁺).

Hyperpolarization

Hyperpolarization is an increase in the membrane potential (making the inside of the cell more negative). It's usually caused by an efflux of potassium ions (K⁺) or an influx of chloride ions (Cl⁻).

Threshold Potential

The threshold potential is the membrane potential that must be reached to trigger an action potential. It's typically around -55 mV.

Action Potential

An action potential is a rapid, all-or-none change in the membrane potential that propagates along the axon. Advanced concepts include the roles of voltage-gated sodium and potassium channels, the phases of the action potential (depolarization, repolarization, after-hyperpolarization), and the refractory period.

All-or-None Law

The all-or-none law states that an action potential either occurs completely or not at all; its magnitude is independent of the strength of the stimulus.

Refractory Period

The refractory period is the time after an action potential during which another action potential cannot be initiated. It has an absolute and relative phase

Saltatory Conduction

Saltatory conduction is the rapid propagation of action potentials along myelinated axons, where the action potential "jumps" between the Nodes of Ranvier

Synapse

A synapse is the junction between two neurons or between a neuron and a target cell (muscle or gland). There are electrical and chemical synapses.

Electrical Synapse

An electrical synapse involves direct electrical coupling between cells via gap junctions. Transmission is fast and bidirectional.

Chemical Synapse

A chemical synapse involves the release of neurotransmitters from the presynaptic neuron to the synaptic cleft, which then bind to receptors on the postsynaptic neuron. Transmission is slower and unidirectional.

Neurotransmitter

A neurotransmitter is a chemical messenger released from the presynaptic neuron that binds to receptors on the postsynaptic neuron, causing a change in its membrane potential.

Synaptic Vesicles

Synaptic vesicles are membrane-bound sacs in the axon terminal that store and release neurotransmitters

Synaptic Cleft

The synaptic cleft is the space between the presynaptic and postsynaptic neurons

Receptor

A receptor is a protein on the postsynaptic membrane that binds to a neurotransmitter, initiating a cellular response

Postsynaptic Potential

A postsynaptic potential is a change in the membrane potential of the postsynaptic neuron caused by the binding of a neurotransmitter to its receptor. Excitatory postsynaptic potentials (EPSPs) cause depolarization, while inhibitory postsynaptic potentials (IPSPs) cause hyperpolarization.

Spatial Summation

Spatial summation is the summation of postsynaptic potentials from multiple synapses at the same time

Temporal Summation

Temporal summation is the summation of postsynaptic potentials from a single synapse over time

Synaptic Plasticity

Synaptic plasticity is the ability of synapses to change their strength over time. Long-term potentiation (LTP) strengthens synapses, while long-term depression (LTD) weakens them. These processes are crucial for learning and memory

Long-Term Potentiation (LTP)

LTP involves an increase in synaptic strength due to repeated stimulation. It often involves the insertion of AMPA receptors

Long-Term Depression (LTD)

LTD involves a decrease in synaptic strength due to reduced stimulation. It often involves the removal of AMPA receptors

Presynaptic Inhibition

Presynaptic inhibition occurs when a neuron synapses onto the axon terminal of another neuron, reducing the release of neurotransmitter

Postsynaptic Inhibition

Postsynaptic inhibition occurs when an inhibitory neurotransmitter (e.g., GABA, glycine) hyperpolarizes the postsynaptic neuron

CNS Components

The CNS comprises the brain and spinal cord. Its primary function is to process sensory information and coordinate motor responses to maintain homeostasis