Nervous System Lecture 2: Electric Properties
10 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the electrical potential of a resting nerve cell?

-70mV

Which of the following is NOT a reason why the inside of a resting nerve cell has a negative electrical charge?

  • The Sodium-Potassium pump pumps more positive charge out of the cell than it pumps into it.
  • Ion channels allow movement of ions to the inside of the cell. (correct)
  • Positively-charged Potassium ions leak out through the cell membrane.
  • The cell membrane is selectively permeable, allowing only certain types of ions to pass through.
  • There are lots of negatively-charged proteins inside the nerve cell.

    • What is the name of the protein embedded in the cell membrane that helps maintain the resting membrane potential?

    Sodium-Potassium pump

    Ion channels are ion-specific.

    <p>True</p> Signup and view all the answers

    Which type of ion channel is always open?

    <p>Ungated ion channels</p> Signup and view all the answers

    What is the function of a gated ion channel?

    <p>To allow ions to pass through when triggered by a specific stimulus.</p> Signup and view all the answers

    What type of gated ion channel is responsible for the rapid depolarization of the cell membrane during an action potential?

    <p>Electrically-gated</p> Signup and view all the answers

    At rest, sodium channels are open.

    <p>False</p> Signup and view all the answers

    Potassium channels are always open.

    <p>False</p> Signup and view all the answers

    How does the movement of potassium through ungated channels contribute to the resting membrane potential?

    <p>Potassium ions are more concentrated inside the cell than outside. Because ungated potassium channels are always open, they allow a continuous flow of potassium ions out of the cell, contributing to a negative charge inside the cell.</p> Signup and view all the answers

    Study Notes

    Nervous System Lecture 2: Electrical Properties of a Resting Nerve Cell

    • Nerve cells communicate electrically. The electrical signal travels from the cell body down the axon. Chemical communication also occurs, but this lecture focuses on the electrical properties.
    • A resting nerve cell's interior is more negatively charged than its exterior. This difference is measured in millivolts (mV) and typically is -70mV.
    • The inside of the cell is more negative, while the outside is more positive.
    • Three reasons for the negative electrical charge of a resting nerve cell include
    • A higher concentration of negatively charged proteins inside the cell
    • The sodium-potassium pump
    • The behavior of ion channels

    Sodium-Potassium Pump

    • The sodium-potassium pump actively moves sodium ions (Na+) out of the cell and potassium ions (K+) into the cell. This process is critical in maintaining the cell's negative resting potential.
    • This pump requires energy in the form of ATP to function.
    • The pump actively moves 3 sodium ions out of the cell and 2 potassium ions into the cell; this creates an electrochemical gradient (difference in concentration on either side of the membrane).

    Behavior of ion channels

    • Ion channels are proteins that allow ions to pass through the cell membrane.
    • Channels can be either gated or ungated. Ungated channels are always open. Gated channels can open and close.
    • Several types of gated channels exist:
    • Voltage-gated channels: Open or close in response to changes in the membrane potential
    • Ligand-gated channels: Open or close in response to a specific chemical signal (ligand)
    • Mechanically-gated channels: Open or close in response to mechanical pressure or stretching
    • Ions move from areas of high concentration to low concentration.
    • At rest, sodium channels are mostly closed, allowing little sodium to cross the membrane; gated potassium channels usually allow some passive movement of potassium to maintain resting potential.
    • Ungated potassium channels allow potassium ions to leak out of the cell, contributing to the negative charge inside the cell.
    • Sodium channels are predominantly closed, keeping sodium ions outside of the cell.

    Nerve Cell Activation

    • When the nerve cell is activated, the membrane potential changes. This results in a rapid reversal of the electrical charge across the cell membrane.
    • This change in charge allows an electrochemical signal to travel along the axon.

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Related Documents

    Nervous System Lecture 2 PDF

    Description

    Explore the electrical properties of a resting nerve cell in this lecture quiz. Learn about the mechanisms behind the negative charge of the cell and the crucial role of the sodium-potassium pump. Test your understanding of nerve cell communication.

    More Like This

    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser