Cellular Communication Overview

<p>The depolarization spreading to nearby areas. (C)</p> Signup and view all the answers

<p>The K⁺ channels are still open, leading to hyperpolarization. (D)</p> Signup and view all the answers

<p>Paracrine (C)</p> Signup and view all the answers

<p>Intracrine involves self-binding without leaving the cell. (C)</p> Signup and view all the answers

<p>Ligand gated ion channels (B)</p> Signup and view all the answers

<p>It responds only to specific signals. (B)</p> Signup and view all the answers

<p>Cell surface receptors respond faster than intracellular receptors. (D)</p> Signup and view all the answers

<p>It blocks the receptor's response. (C)</p> Signup and view all the answers

<p>Receptors reach their maximum binding level. (A)</p> Signup and view all the answers

<p>Receptors are specific to certain stimuli they perceive. (A)</p> Signup and view all the answers

<p>Nucleus receptors (C)</p> Signup and view all the answers

<p>The efflux of K⁺ ions. (D)</p> Signup and view all the answers

<p>Action potential. (C)</p> Signup and view all the answers

<p>Neurotransmitters transmitted by synapses (A)</p> Signup and view all the answers

<p>Receptor numbers decrease. (B)</p> Signup and view all the answers

<p>Steroid hormones (C)</p> Signup and view all the answers

<p>They initiate action potentials if a certain threshold is reached. (C)</p> Signup and view all the answers

<p>It binds strongly even at low concentrations. (C)</p> Signup and view all the answers

<p>It maintains the balance between Na⁺ and K⁺ ions by expelling Na⁺ and taking in K⁺. (A)</p> Signup and view all the answers

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

<p>Receptor potential (B)</p> Signup and view all the answers

<p>-55 mV (D)</p> Signup and view all the answers

<p>They are proportional to the strength of the stimulus. (D)</p> Signup and view all the answers

<p>End Plate Potential (A)</p> Signup and view all the answers

<p>It helps maintain a negative charge inside the cell. (B)</p> Signup and view all the answers

<p>They decrease in amplitude as they move away from the stimulus site. (A)</p> Signup and view all the answers

<p>The membrane must reach the threshold value of approximately -55 mV. (D)</p> Signup and view all the answers

<p>Depolarization (D)</p> Signup and view all the answers

<p>+30 mV (D)</p> Signup and view all the answers

<p>To maintain a resting potential of around -70 mV. (D)</p> Signup and view all the answers

<p>A threshold must be achieved for an action potential to occur. (C)</p> Signup and view all the answers

<p>K⁺ ions exit the cell, resulting in a more negative membrane potential. (B)</p> Signup and view all the answers

<p>During the absolute period, a second action potential cannot occur. (C)</p> Signup and view all the answers

<p>To ensure signals travel in one direction. (D)</p> Signup and view all the answers

Cell communication where the signal molecule acts within the same cell without leaving it.

Cell communication involving direct contact between cells.

Cell secretes a signal, and the same cell receives and reacts to it.

Short-distance signaling between nearby cells.

Nerve cells transmit signals using neurotransmitters across synapses.

Hormones travel through the bloodstream to distant target cells.

Located on the cell membrane, these receptors receive signals from outside the cell.

Located inside the cell, these receptors typically bind lipid-soluble molecules (e.g., steroids).

A receptor only binds to a specific ligand molecule, ensuring the signal is received correctly.

The strength of the bond between a receptor and its ligand.

Maximum binding occurs when all receptor binding sites are occupied by ligands.

Different molecules can compete for the same receptor, impacting signaling.

Increasing the number of receptors in response to decreased ligand or constant stimulus.

Decreasing the number of receptors in response to continuous stimulation.

A molecule that binds to a receptor and activates it, triggering signal transmission.

A molecule that binds to a receptor and blocks signal transmission.

The electrical charge difference across the membrane of a neuron when it's not transmitting a signal, typically around -70 mV.

An active transport mechanism that pumps 3 sodium ions out of the cell and 2 potassium ions in, using ATP. This helps maintain the resting potential.

Passive channels that allow potassium ions to leak out of the cell, contributing to the negative charge inside.

The minimum level of depolarization required to trigger an action potential, typically around -55 mV.

A rapid, short-lasting change in membrane potential that travels down the axon of a neuron, carrying information.

A temporary, localized change in membrane potential that varies in magnitude depending on the stimulus strength.

A graded potential generated by sensory receptors in response to stimuli such as touch, temperature, or pain.

A graded potential that occurs at the postsynaptic membrane of a synapse, triggered by neurotransmitter release from the presynaptic neuron.

A period during an action potential when a new action potential cannot be triggered, regardless of the stimulus strength. This is due to inactive voltage-gated sodium channels.

The process where multiple signals combine to create a larger potential in a cell, often exceeding a threshold.

The period following the ARP during which a new action potential can be initiated, but only with a stronger stimulus than usual. This occurs as sodium channels are reactivating, but potassium channels are still open, making the cell hyperpolarized.

The movement of an action potential along an axon. This occurs through depolarization spreading to nearby areas, causing a chain reaction of action potentials.

Specialized channels in cell membranes that open or close in response to changes in membrane potential, allowing ions to flow in or out.

Action potential propagation in unmyelinated axons occurs continuously along the axon membrane, as depolarization spreads to adjacent areas.

The process where the membrane potential becomes more positive, usually due to the influx of positive ions like Na⁺.

Action potential propagation in myelinated axons occurs by jumping between gaps in the myelin sheath called nodes of Ranvier. This allows for faster and more efficient signal transmission.

The process where the membrane potential returns to its resting state, usually due to the efflux of positive ions like K⁺.

A temporary state where the membrane potential drops below the resting potential, usually due to an excess of K⁺ efflux.

The period of time after an action potential where it is difficult or impossible to generate another action potential, ensuring unidirectional signal transmission.