Resting Membrane Potential and Ion Transport
41 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 typical resting membrane potential (RMP) value for a cell?

  • -90 mV
  • -70 mV (correct)
  • -50 mV
  • -30 mV

Which of the following factors primarily helps maintain the concentration gradients for sodium and potassium ions?

  • Diffusion
  • Electrostatic interactions
  • Cellular respiration
  • Ion transport (correct)

What is the function of the Na+/K+ pump in relation to resting membrane potential?

  • It relies solely on passive diffusion for ion movement.
  • It transports three sodium ions out for every two potassium ions in. (correct)
  • It passively allows sodium and potassium to diffuse equally.
  • It increases sodium concentration inside the cell.

Which ion has the most substantial effect on the resting membrane potential due to its higher permeability?

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

The 'salty banana' analogy is used to describe the distribution of which ion across the cell membrane?

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

What is the impact of negatively charged ions inside the cell on the resting membrane potential?

<p>They help establish the negative charge across the membrane. (D)</p> Signup and view all the answers

What does the Goldman Katz Equation help predict?

<p>The equilibrium potential for an ion when the membrane is permeable to multiple ions. (C)</p> Signup and view all the answers

What is the primary function of the cilia in olfactory receptor neurons?

<p>Facilitating signal transduction (A)</p> Signup and view all the answers

How many distinct odors can humans distinguish using their olfactory receptor neurons?

<p>10,000 odors (D)</p> Signup and view all the answers

What role does cyclic AMP (cAMP) play in olfactory signal transduction?

<p>It acts as a secondary messenger activating ion channels (C)</p> Signup and view all the answers

What is the function of glomeruli in the olfactory bulb?

<p>To process and encode specific odorant information (B)</p> Signup and view all the answers

What type of receptor are the odorant receptors classified as?

<p>G-protein-coupled receptors (GPCRs) (C)</p> Signup and view all the answers

What is the main pathway for retinal ganglion cells to transmit visual information to the brain?

<p>Via the optic nerve (D)</p> Signup and view all the answers

Which structure is primarily responsible for converting light into neural signals?

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

What role does the lateral geniculate nucleus (LGN) play in the visual pathway?

<p>It processes and relays visual information to the visual cortex (A)</p> Signup and view all the answers

Which part of the eye adjusts the size of the pupil based on light intensity?

<p>Sphincter pupillae and dilator pupillae (D)</p> Signup and view all the answers

What is the significance of visuotopic mapping in the striate cortex?

<p>It organizes visual input according to spatial locations in the visual field (B)</p> Signup and view all the answers

What does 'plasticity' in the striate cortex refer to?

<p>The adaptation of the visual system based on experience (A)</p> Signup and view all the answers

In terms of light perception, what is the range of the visible spectrum?

<p>400nm to 700nm (A)</p> Signup and view all the answers

Which component of the eye is responsible for initial light refraction?

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

How does the ciliary muscle contribute to vision?

<p>By adjusting the curvature of the lens (D)</p> Signup and view all the answers

What function does the aqueous humor serve in the eye?

<p>It nourishes the eye and maintains pressure (B)</p> Signup and view all the answers

What role does myelin play in action potential conduction?

<p>It enhances the speed and efficiency of neural impulses. (D)</p> Signup and view all the answers

What is the function of the nodes of Ranvier in saltatory conduction?

<p>They facilitate rapid conduction and maintain signal strength. (A)</p> Signup and view all the answers

What distinguishes electrical synapses from chemical synapses?

<p>Electrical synapses have gap junctions allowing direct cytoplasmic connections. (C)</p> Signup and view all the answers

Which type of synapse is more prevalent in the mammalian brain?

<p>Chemical synapses that provide greater signal modulation. (D)</p> Signup and view all the answers

What is a characteristic feature of gap junctions in electrical synapses?

<p>They are composed of connexons that permit free passage of ions. (B)</p> Signup and view all the answers

What is the primary role of neurotransmitters in chemical synapses?

<p>To bind to receptors on the postsynaptic neuron triggering signaling pathways. (D)</p> Signup and view all the answers

What is a feature of reciprocal synapses?

<p>They enable mutual communication between two neurons. (D)</p> Signup and view all the answers

What do presynaptic cells contain to facilitate neurotransmitter release?

<p>Microtubules, mitochondria, and synaptic vesicles filled with neurotransmitters. (D)</p> Signup and view all the answers

What enhances the efficiency of presynaptic to postsynaptic communication in rectifying synapses?

<p>The preferential flow of current in one direction. (C)</p> Signup and view all the answers

What is the condition of monochromats regarding color perception?

<p>They are unable to distinguish colors at all. (D)</p> Signup and view all the answers

How do rods function in the darkness?

<p>They are depolarized, continuously releasing neurotransmitters. (D)</p> Signup and view all the answers

What role does the Lateral Geniculate Nucleus (LGN) serve?

<p>It serves as a relay station for visual signals to the primary visual cortex. (A)</p> Signup and view all the answers

Which of the following describes the function of the ventral stream?

<p>It is essential for object identification and color perception. (D)</p> Signup and view all the answers

What does visuotopic organization in the visual cortex refer to?

<p>The spatial correspondence between the retina and the visual cortex. (C)</p> Signup and view all the answers

What is the responsibility of retinal ganglion cells?

<p>They connect to the brain through the optic nerve and transmit visual information. (C)</p> Signup and view all the answers

Which aspect is true of the dorsal stream?

<p>It is known as the 'how' pathway, vital for motion perception. (D)</p> Signup and view all the answers

In which condition do cones function primarily?

<p>In bright light and enabling color vision. (B)</p> Signup and view all the answers

What is the role of the iris in the eye?

<p>It regulates pupil size for optimal light entry. (C)</p> Signup and view all the answers

Which of the following statements about binocular vision is correct?

<p>It is facilitated by the presence of ocular dominance columns in the visual cortex. (B)</p> Signup and view all the answers

Flashcards

What is Resting Membrane Potential (RMP)?

The difference in electrical charge across the cell membrane when the cell is at rest, typically around -70 mV.

How does diffusion contribute to RMP?

The passive movement of ions across the cell membrane, driven by differences in concentration.

What role do electrostatic interactions play in RMP?

The attractive or repulsive forces between charged particles, influencing their distribution and movement across the membrane.

How does the Na+/K+ pump contribute to RMP?

A protein pump that actively transports 3 sodium ions out of the cell for every 2 potassium ions it brings in, contributing to the negative charge inside the cell.

Signup and view all the flashcards

What is ion permeability and how does it affect RMP?

The relative ease with which different ions can cross the cell membrane. For example, at rest, potassium (K+) is more permeable than sodium (Na+).

Signup and view all the flashcards

What is the Goldman Katz Equation?

A mathematical equation used to predict the equilibrium potential for an ion when the membrane is permeable to multiple ions.

Signup and view all the flashcards

Explain the Salty Banana analogy for RMP.

A model that helps understand RMP by comparing the distribution of sodium ions inside and outside the cell to a banana, where the interior has a lower concentration of sodium.

Signup and view all the flashcards

Synapse

The space between two neurons where communication happens.

Signup and view all the flashcards

Chemical Synapse

This type of synapse uses chemicals to send signals between neurons.

Signup and view all the flashcards

Electrical Synapse

This type of synapse has direct connections between neurons, allowing signals to pass quickly.

Signup and view all the flashcards

Gap Junctions

These channels in electrical synapses allow direct communication between neurons.

Signup and view all the flashcards

Synaptic Vesicles

Neurotransmitters are stored in these tiny sacs in the presynaptic neuron.

Signup and view all the flashcards

Presynaptic Neuron

The neuron that sends the signal in a synapse.

Signup and view all the flashcards

Postsynaptic Neuron

The neuron that receives the signal in a synapse.

Signup and view all the flashcards

Reciprocal Synapses

These synapses allow signals to flow in both directions.

Signup and view all the flashcards

Rectifying Synapses

These synapses prefer signals flowing in one direction.

Signup and view all the flashcards

Olfactory Receptor Neuron

A specialized type of neuron responsible for detecting odor molecules, characterized by a unique bipolar structure with cilia extending into the nasal mucosa.

Signup and view all the flashcards

Olfactory Signal Transduction

The process by which olfactory receptor neurons convert an odorant molecule into a signal that the brain can understand.

Signup and view all the flashcards

Odorants

Chemical compounds that stimulate olfactory receptor neurons, triggering the sense of smell. Humans can distinguish around 10,000 different odorants.

Signup and view all the flashcards

Odorant Receptors

G-protein-coupled receptors (GPCRs) located on the cilia of olfactory receptor neurons that bind to specific odorant molecules.

Signup and view all the flashcards

Glomerulus

A small spherical structure in the olfactory bulb where axons from olfactory receptor neurons synapse with other neurons, playing a crucial role in processing olfactory information.

Signup and view all the flashcards

Visible Spectrum

The range of light wavelengths visible to the human eye, spanning approximately 400 to 700 nanometers, with violet at the shorter end and red at the longer end.

Signup and view all the flashcards

Iris

A ring of muscle tissue surrounding the pupil, responsible for controlling the amount of light entering the eye by adjusting the pupil size.

Signup and view all the flashcards

Intensity (Light)

The measure of light's brightness or intensity perceived by the eye. It's crucial for our visual experience.

Signup and view all the flashcards

Optic Axis

The imaginary line passing through the center of the lens, perpendicular to the cornea. It's the primary path through which light travels to the retina.

Signup and view all the flashcards

Visual Axis

The imaginary line starting from the viewing object and passing through the center of the cornea. It's the path light takes from the object to the eye.

Signup and view all the flashcards

Cornea

The outermost transparent layer of the eye that bends light rays as they enter. It initiates the process of focusing.

Signup and view all the flashcards

Lens

The transparent, flexible structure within the eye. It further refracts light to focus it precisely on the retina.

Signup and view all the flashcards

Retina

The light-sensitive inner layer of the eye that converts light into electrical signals that the brain can interpret.

Signup and view all the flashcards

Optic Nerve

The bundle of nerve fibers that carries visual information from the retina to the brain for processing.

Signup and view all the flashcards

Sphincter Pupillae

The muscle that contracts to make the pupil smaller in bright light, limiting the amount of light entering the eye.

Signup and view all the flashcards

Monochromat

Individuals who lack cones and are unable to perceive any colors.

Signup and view all the flashcards

Light Impact on Rods

Rods release neurotransmitters continuously in darkness, inhibiting bipolar cells. Light causes hyperpolarization of rods, reducing neurotransmitter release, activating bipolar cells.

Signup and view all the flashcards

Retinal Ganglion Cells

Specialized cells in the retina that transmit visual information to the brain via the optic nerve.

Signup and view all the flashcards

Lateral Geniculate Nucleus (LGN)

A relay station in the brain that receives visual signals from the retina and transmits them to the visual cortex.

Signup and view all the flashcards

Striate Cortex

The primary area in the brain dedicated to visual processing. It receives information from the LGN and carries out basic visual perception.

Signup and view all the flashcards

Visuotopic Organization

The organization of the visual cortex where the layout of neurons mirrors the spatial arrangement of the retina, preserving the spatial relationships in the visual scene.

Signup and view all the flashcards

Cells with Direction Selectivity

Neurons in the striate cortex that respond preferentially to specific directions of motion. These cells contribute to our perception of movement and shape.

Signup and view all the flashcards

Ocular Dominance Columns

Columns of neurons in the striate cortex that receive input primarily from one eye. These columns are essential for binocular vision and depth perception.

Signup and view all the flashcards

Ventral Stream

"What" pathway in the brain responsible for object identification, color perception, and detailed vision.

Signup and view all the flashcards

Dorsal Stream

"How" pathway in the brain involved in motion perception, spatial awareness, and the ability to track moving objects.

Signup and view all the flashcards

Study Notes

Resting Membrane Potential (RMP)

  • RMP is the difference in charged particle distribution across a cell membrane when not stimulated.
  • Typically around -70 mV.
  • Maintained by diffusion of ions, electrostatic interactions, and ion transport (Na+/K+ pump).
  • The Na+/K+ pump actively transports 3 sodium ions out of the cell for every 2 potassium ions it brings in, contributing to the negative charge inside the cell.
  • negatively charged ions and proteins inside the cell are also key.
  • Salty banana analogy: intracellular Na+ concentration is lower than extracellular, while K+ concentration is higher inside the cell.

Ion Transport

  • Facilitated mainly by the Na+/K+ pump.
  • Crucial for maintaining concentration gradients.
  • Requires energy (ATP) for its function.

Goldman Katz Equation

  • Predicts the equilibrium potential for an ion across a membrane.
  • Used to estimate the membrane potential if the membrane is permeable to multiple ions.
  • Consider permeability ratios of different ions.

Permeability Ratios (at rest)

  • Potassium (K+) : Chloride (Cl-) : Sodium (Na+) ≈ 1 : 0.45 : 0.04.
  • K+ has the greatest impact on the resting membrane potential due to its higher membrane permeability.

Changes in Extracellular K+ Concentration

  • Increase in extracellular K+ decreases the concentration gradient, resulting in depolarization (neuron closer to firing).
  • Decrease in extracellular K+ increases the concentration gradient, leading to hyperpolarization (neuron further from firing).

Factors Influencing Membrane Potential

  • Diffusion of ions, especially potassium, creates a net positive charge loss inside the cell.
  • Active transport by the Na+/K+ ATPase pump causes a net loss of positive charge.
  • Electrochemical gradients also impact K+ movement, influencing charge balance.

Action Potentials

  • Initiated by changes in membrane voltage.
  • Hyperpolarization—adding negative charges; depolarization—adding positive charges.
  • Threshold: generally around -55 mV.
  • Essential for communication between neurons.

Phases of Action Potential

  • Resting: Stable membrane potential.
  • Threshold: Graded potentials reach a critical level triggering the action potential.
  • Depolarization: Influx of sodium ions increases membrane potential positively.
  • Repolarization: Outflux of potassium ions returns membrane potential to negative.
  • Refractory Period: Brief period where the neuron is less excitable following an action potential; absolute and relative refractory periods exist.

Refractory Periods

  • Absolute Refractory Period: brief window where another action potential cannot be produced due to inactivation of Na+ channels.
  • Relative Refractory Period: additional stimulus required to trigger another action potential due to hyperpolarization.

Voltage-Gated Channels

  • Critical for action potential propagation (specifically Na+ and K+ channels).
  • Na+ channels rapidly open during depolarization allowing Na+ influx and close slowly.
  • K+ channels open later, increasing K+ permeability, and contribute to repolarization.

Action Potential Summary

  • All-or-nothing events initiated at a threshold.
  • They facilitate fast electrical signal transmission.

Studying That Suits You

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

Quiz Team

Related Documents

Resting Membrane Potential (RMP) - 2nd Week Notes PDF

Description

Explore the concept of Resting Membrane Potential (RMP) and its significance in cellular biology. This quiz delves into ion transport mechanisms, particularly the Na+/K+ pump, and introduces the Goldman Katz Equation for membrane potential calculations. Test your understanding of these fundamental physiological processes.

More Like This

Resting Membrane Potential in Cells
26 questions

Resting Membrane Potential in Cells

StylizedVitality6510 avatar
StylizedVitality6510
Resting Membrane Potential Overview
13 questions

Resting Membrane Potential Overview

CaptivatingHeliotrope4847 avatar
CaptivatingHeliotrope4847
Neuroscience Chapter on Resting Membrane Potential
41 questions

Neuroscience Chapter on Resting Membrane Potential

IndulgentCombinatorics3456 avatar
IndulgentCombinatorics3456
Use Quizgecko on...
Browser
Open
Browser
Browser