Animal Body Systems - Neuron Potentials

<p>A red blood cell (B)</p> Signup and view all the answers

<p>The endocrine system and nervous system work together, providing both rapid and long-term regulatory processes for homeostasis. (C)</p> Signup and view all the answers

<p>Neurons have special mechanisms that allow them to regulate their membrane potential and currents. (B)</p> Signup and view all the answers

<p>-10 to -90 mV (B)</p> Signup and view all the answers

<p>The flow of electrical charge between two regions. (B)</p> Signup and view all the answers

<p>The unequal distribution of ions across the cell membrane. (C)</p> Signup and view all the answers

<p>Sodium (Na+) and Potassium (K+) (B)</p> Signup and view all the answers

<p>Synaptic potential (SP) (C)</p> Signup and view all the answers

<p>-70 mV (D)</p> Signup and view all the answers

<p>The unequal charge distribution across a cell membrane. (B)</p> Signup and view all the answers

<p>Passive diffusion of potassium ions through open potassium channels (D)</p> Signup and view all the answers

<p>It requires ATP to function. (A)</p> Signup and view all the answers

<p>Sodium-potassium pump, leak channels, negative intracellular proteins (D)</p> Signup and view all the answers

<p>To conduct a signal from the axon hillock to the axon terminals. (A)</p> Signup and view all the answers

<p>Graded potentials occur in dendrites and cell bodies, while action potentials occur only in axons. (D)</p> Signup and view all the answers

<p>Active transport by the sodium-potassium pump (A)</p> Signup and view all the answers

<p>The membrane potential moves away from the resting potential towards a more positive value. (A)</p> Signup and view all the answers

<p>It can be depolarizing or hyperpolarizing. (A)</p> Signup and view all the answers

<p>Graded potentials are localized and decrease in strength over distance, while action potentials are propagated without decrement. (B)</p> Signup and view all the answers

<p>It determines the strength of the stimulus required to trigger an action potential. (B)</p> Signup and view all the answers

<p>It pumps sodium ions into the cell and potassium ions out of the cell. (A)</p> Signup and view all the answers

<p>Leak channels (A)</p> Signup and view all the answers

<p>It involves the transport of charged molecules. (A)</p> Signup and view all the answers

<p>Sodium channels are closed and potassium channels are open. (A)</p> Signup and view all the answers

<p>An increase in the permeability of the membrane to potassium ions. (C)</p> Signup and view all the answers

<p>It ensures that the action potential travels in only one direction. (A)</p> Signup and view all the answers

<p>Myelin insulation prevents current loss, allowing for a faster flow of ions. (D)</p> Signup and view all the answers

<p>Action potentials in myelinated axons jump between nodes, while in unmyelinated axons they travel continuously. (B)</p> Signup and view all the answers

<p>The axon hillock is responsible for generating the action potential, and contributes to its rapid transmission down the axon. (D)</p> Signup and view all the answers

<p>Up to 100 m/s (A)</p> Signup and view all the answers

<p>Invertebrates lack myelinated axons. (B)</p> Signup and view all the answers

<p>Sodium ions continue to flow into the cell (C)</p> Signup and view all the answers

<p>To ensure that the action potential travels in one direction only. (B)</p> Signup and view all the answers

<p>It reduces the threshold for depolarization, making it easier to initiate an action potential. (A)</p> Signup and view all the answers

<p>They help to maintain a negative charge inside the cell by continuously allowing potassium ions to leak out. (C)</p> Signup and view all the answers

<p>The depolarization causes the sodium channels in the adjacent segment to open, leading to an influx of sodium ions. (A)</p> Signup and view all the answers

<p>Myelination increases the conduction velocity by reducing the leakage of ions across the membrane. (C)</p> Signup and view all the answers

<p>Action potentials only occur at the nodes of Ranvier, where the myelin sheath is absent. (D)</p> Signup and view all the answers

<p>It transports sodium ions out of the cell and potassium ions into the cell, re-establishing the concentration gradients for these ions that are necessary for the resting membrane potential. (D)</p> Signup and view all the answers

A rapid system that coordinates body functions in animals, except sponges.

An individual cell that transmits information in the nervous system.

Connection between an axon terminal and an effector cell.

A cell that responds to commands from the nervous system, like muscle or gland cells.

Electrical processes that occur at the neuronal membrane, crucial for signal transmission.

Active transport pump that moves 3 Na+ out and 2 K+ in, maintaining ion gradients.

The static electrical potential across a cell membrane, typically around -70 mV.

A pump that generates an electrical potential; Na+/K+ ATPase is one example.

Changes in membrane potential due to ion permeability changes; small and variable shifts.

Ion channels that are always open, allowing continuous ion flow, such as K+ channels at rest.

When the membrane potential becomes more positive inside, resulting in a reduced polarization.

An increase in membrane potential, making the inside more negative than resting potential.

The movement of K+ ions out of the cell through open channels, driven by a chemical gradient.

A rapid increase in membrane potential due to positive feedback from Na+ entering the neuron.

A phase following an action potential when a neuron cannot fire another AP, ensuring unidirectionality.

The process where an AP moves along an axon as ion flows depolarize the adjacent sections of the membrane.

In unmyelinated axons, APs propagate by the local flow of ions that depolarize neighboring segments.

The region where the axon begins, containing a high concentration of voltage-gated Na+ channels crucial for AP initiation.

A membrane protein that helps maintain RMP by pumping 3 Na+ out and 2 K+ in against their gradients.

A type of graded potential that can depolarize or hyperpolarize.

All-or-nothing signals initiated at the axon hillock.

The membrane potential that must be reached to generate an action potential.

Membrane proteins that open/close in response to changes in membrane potential.

The phase where K+ ions flow out, returning the membrane potential to resting state.

Movement of ions (like Na+ and K+) through channels that affect membrane potential.

Larger axon diameters result in faster conduction speeds, up to 40 m/s.

In myelinated axons, action potentials jump between nodes, increasing speed.

A protective insulating layer around axons that prevents ion loss and speeds up conduction.

Gaps in the myelin sheath where ion exchanges occur, allowing saltatory conduction.

Speed of action potentials can reach up to 100 m/s in myelinated axons, particularly in vertebrates.

Difference in electrical charge between regions measured in volts.

Flow of electrical charge between regions; opposite charges attract.

Unequal charge distribution across a cell membrane.

All living cells have a membrane potential; inside is negative relative to outside.

Neurons and muscle cells with large membrane potentials and mechanisms to regulate them.

Local changes in membrane potential in response to stimuli.

Rapid changes in membrane potential that propagate along the cell.