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Page 1: Exchange of ions across membrane during AP is far to small to significantly affect concentration gradients across the membrane. The net number of ions

Page 2: Exchange of ions across membrane during AP is far to small to significantly affect concentration gradients across the membrane. The net number of ions

Exchange of ions across membrane during AP is far to small to significantly affect concentration gradients across the membrane. The net number of ions that enter or leave the neuron during 1 AP in squid giant axon is 4pmol/cm2, the number of Na+ ions in a volume of axons covered by 1 cm2 of membrane is 3 million times this amount. Comparable to effect on weight of diesel locomotive of having mouse climb aboard, thus thousands of APs can be generated even in small neuron before ion balance significantly affected

Page 3: Exchange of ions across membrane during AP is far to small to significantly affect concentration gradients across the membrane. The net number of ions

Page 4: Exchange of ions across membrane during AP is far to small to significantly affect concentration gradients across the membrane. The net number of ions

Page 5: Exchange of ions across membrane during AP is far to small to significantly affect concentration gradients across the membrane. The net number of ions

Page 6: Exchange of ions across membrane during AP is far to small to significantly affect concentration gradients across the membrane. The net number of ions

Page 7: Exchange of ions across membrane during AP is far to small to significantly affect concentration gradients across the membrane. The net number of ions

Page 8: Exchange of ions across membrane during AP is far to small to significantly affect concentration gradients across the membrane. The net number of ions

Page 9: Exchange of ions across membrane during AP is far to small to significantly affect concentration gradients across the membrane. The net number of ions

Page 10: Exchange of ions across membrane during AP is far to small to significantly affect concentration gradients across the membrane. The net number of ions

proprietàdei

recettori

proprietàdella

membrana

Page 11: Exchange of ions across membrane during AP is far to small to significantly affect concentration gradients across the membrane. The net number of ions

Page 12: Exchange of ions across membrane during AP is far to small to significantly affect concentration gradients across the membrane. The net number of ions

Page 13: Exchange of ions across membrane during AP is far to small to significantly affect concentration gradients across the membrane. The net number of ions

Page 14: Exchange of ions across membrane during AP is far to small to significantly affect concentration gradients across the membrane. The net number of ions

Page 15: Exchange of ions across membrane during AP is far to small to significantly affect concentration gradients across the membrane. The net number of ions

Page 16: Exchange of ions across membrane during AP is far to small to significantly affect concentration gradients across the membrane. The net number of ions

Page 17: Exchange of ions across membrane during AP is far to small to significantly affect concentration gradients across the membrane. The net number of ions

Sinapsi elettriche: implicazioni funzionali

1. Rapidità della trasmissione

2. Sincronizzazione

3. Accoppiamento metabolico

COMPORTAMENTI STEREOTIPATI E SINCRONIZZATI CONTROLLO MOVIMENTI SINCRONI

Page 18: Exchange of ions across membrane during AP is far to small to significantly affect concentration gradients across the membrane. The net number of ions

Sinapsi elettricheSinapsi elettriche

•• Nessun ritardo sinaptico (rapidità)

•• Trasmissione potenzialmente bidirezionale

•• Possono essere trasmesse sia depolarizzazioni sia iperpolariz-zazioni presinaptiche.

•• Nessuna inversione di polarità del segnale di input

COMPORTAMENTI STEREOTIPATI E SINCRONIZZATI

CONTROLLO MOVIMENTI SINCRONI

Sinapsi chimicheSinapsi chimiche

•• Ritardo sinaptico

•• Trasmissione sempre uni dire-zionale

•• Solo una depolarizzazione presinaptica è efficace per la trasmissione

•• Possibile un’inversione di polarità dello stimolo di input

COMPORTAMENTI COMPLESSIMODULABILE: POTENZIATA o

DEPRESSA

Page 19: Exchange of ions across membrane during AP is far to small to significantly affect concentration gradients across the membrane. The net number of ions

QuickTime™ e undecompressore TIFF (Non compresso)

sono necessari per visualizzare quest'immagine.

Page 20: Exchange of ions across membrane during AP is far to small to significantly affect concentration gradients across the membrane. The net number of ions

Un modello di sinapsi elettrica: la sinapsi Un modello di sinapsi elettrica: la sinapsi motoria gigante del gamberomotoria gigante del gambero

Accoppiamento elettrico nell’Aplysia californica

Page 21: Exchange of ions across membrane during AP is far to small to significantly affect concentration gradients across the membrane. The net number of ions

L’accoppiamento metabolico dovuto a L’accoppiamento metabolico dovuto a gap gap junctionjunction: astrociti: astrociti

Rilascio di glutammatoRilascio di glutammato

¯̄

attivazione di recettori glutammatergici astrocitari di tipo metabotropicoattivazione di recettori glutammatergici astrocitari di tipo metabotropico

¯̄

rilascio di Ca2+ IP3-mediatorilascio di Ca2+ IP3-mediato

¯̄

amplificazione del segnale di Ca2+ amplificazione del segnale di Ca2+

¯̄

propagazione del segnale di Ca2+ via gap junctionpropagazione del segnale di Ca2+ via gap junction

¯̄

attivazione delle NOS - produzione di NOattivazione delle NOS - produzione di NO

¯̄

vasodilatazionevasodilatazione

Chapter 6 Cell Membrane and Movement Across the Membrane

MOVEMENT ACROSS MEMBRANES MEMBRANE STRUCTURE

Resting Membrane Potential Review Recall there is an uneven distribution of charged substances (mainly ions) across the cell membrane of every cell in

Different movement across plasma membrane

across the cell membrane?

Transport Across Cell Membrane

Lectures on Medical Biophysics - Masaryk University and thermometry-18.pdfOrigin of Biopotentials Cells transport ions across their membrane leading to ion concentration differences

Transport across the Membrane

The Sodium-Potassium Pump Consists of molecules in the neuronal membrane Exchanges NA+ ions for K+ ions across the membrane Requires energy for active

Transport Across the Cell Membrane...Active Transport Some molecules (ions) move across the cell membrane against concentration gradient It is energy (ATP) dependent movement of substances

TRANSPORT OF IONS AND SMALL MOLECULES ACROSS CELL …kbp-srmc.yolasite.com/resources/Chapter 7.pdf · MOLECULES ACROSS CELL MEMBRANES T he plasma membrane is a selectively permeable

MEMBRANE STRUCTURE AND MEMBRANE TRANSPORT IN …kbfr.agrobiologie.cz/download/1_pp_text.pdf · Fig. 1.4. The scheme of membrane transport. The exchange of ions and solutes across

Transport of ions across plasma membranes

Transport Across the Membrane (6.3)

Cellular Transport Transport across the Membranecontains transport proteins that help transport ions across the membrane. 4. When substances attain equal distribution over ... •Capillaries

an Web view9) Membrane-bound proteins that use metabolic energy to move ions across the plasma membrane are called _____ pumps

The Cell Membrane and Transport Across the Cell Membrane

Molecular Motors...Types of Motors 1. Pump - Membrane protein that transports ions and small molecules across the membrane. 2. Rotary Motor - Membrane-bound structure having a spinning

Transport Across the Plasma Membrane. Plasma Membrane Transport Molecules move across the plasma membrane by:Molecules move across the plasma membrane

Active Transport - OpenStax CNX · 2016. 11. 17. · active transport moves ions across a membrane and creates a di erence in charge across that membrane. The primary active transport

a8) Transport Across the Membrane

Transport Across Membrane

TRANSPORT ACROSS CELL MEMBRANE-II

Cell Membrane Function (Movement Across the Cell Membrane)

Membrane processing across the vinification chaintechnovin.gr/wp-content/uploads/2014/03/MEMBRANE... · mEmBRANE PROCESSING ACROSS THE VINIfICATION CHAIN Membrane processing across

Chapter 7 Transport of ions in solution and across membranes · Transport of ions in solution and across membranes 7-1. Introduction ... Transport of ions in solution and across membranes

HANDOUT - Cell Transport Packet · 11. active transport will remove ___ ions, while taking in potassium ions 12. channel ___ can help move things across the membrane 16. organelle

Transport of ions across plasma membranes - JU Medicine€¦ · Depolarization Repolarization Refractory period Contraction Membrane potential (mV) Rapid depolarization due to Na+

Movement Across the Membrane

Transport of Ions and Small Molecules Across Cell Membranes Objectives: Review how membrane transport is accomplished with the help of proteins – facilitated

Transport across plasma membrane

Movement across cell membrane 2014

Homeostasis and Transport - Ringgold School District · Homeostasis and Transport ... The permeability of a cell membrane is determined ... move potassium ions across the cell membrane

Transportation across cell membrane

Transport of Materials Across the Cell Membrane · 2019-02-28 · e) 2+Ca ions can move through the cell membrane by simple diffusion. ___ f) Simple diffusion may use a channel protein