Uitwerking 3.2 - Impulsvorming
en geleiding
Leg in eigen woorden uit Het hart een elektrisch signaal
in een mechanisch signaal wordt omgezet.
Basically, the impulses start in the SA node - the primary pacemaker of the heart, then spread though
the contractile myocytes of the atria to reach the AV node. The AV node passes the signals onto the
AV bundle, then bundle branches, Purkinje fibers, and finally the ventricular myocytes.
Welke kanalen in het plasmamembraan van de
hartspiercel worden geopend als deze cel
depolariseert?
Voltage-gated ion channels.
Wat is het verschil tussen depolarisatie en
repolarisatie?
Cells are polarized, meaning there is an electrical voltage across the cell membrane. In a resting cell,
the membrane voltage, known as the resting membrane potential, is usually negative. This means
the cell is more negative on the inside.
At this resting state, there are concentration gradients of
several ions across the cell membrane: more sodium and
calcium outside the cell, and more potassium inside the cell.
These gradients are maintained by several pumps that bring
sodium and calcium out, and potassium in. An action potential
is essentially a brief reversal of electric polarity of the cell
membrane and is produced by voltage-gated ion channels.
These channels are passageways for ions in and out of the cell,
and as their names suggest, are regulated by membrane
voltage. They open at some values of membrane potential and
close at others.
When membrane voltage increases and becomes less
negative, the cell is less polarized, and is said to be
depolarized. Reversely, when membrane potential becomes
more negative, the cell is repolarized. For an action potential
to be generated, the membrane voltage must depolarize to a
critical value called the threshold.
Het verschil tussen depolarizatie en repolarizatie is dat tijdens de depolarizatie de
membraanpotentiaal stijgt naar ca. +10. Tijdens de repolarizatie daalt deze door kalium exit naar ca. -
65mv.
en geleiding
Leg in eigen woorden uit Het hart een elektrisch signaal
in een mechanisch signaal wordt omgezet.
Basically, the impulses start in the SA node - the primary pacemaker of the heart, then spread though
the contractile myocytes of the atria to reach the AV node. The AV node passes the signals onto the
AV bundle, then bundle branches, Purkinje fibers, and finally the ventricular myocytes.
Welke kanalen in het plasmamembraan van de
hartspiercel worden geopend als deze cel
depolariseert?
Voltage-gated ion channels.
Wat is het verschil tussen depolarisatie en
repolarisatie?
Cells are polarized, meaning there is an electrical voltage across the cell membrane. In a resting cell,
the membrane voltage, known as the resting membrane potential, is usually negative. This means
the cell is more negative on the inside.
At this resting state, there are concentration gradients of
several ions across the cell membrane: more sodium and
calcium outside the cell, and more potassium inside the cell.
These gradients are maintained by several pumps that bring
sodium and calcium out, and potassium in. An action potential
is essentially a brief reversal of electric polarity of the cell
membrane and is produced by voltage-gated ion channels.
These channels are passageways for ions in and out of the cell,
and as their names suggest, are regulated by membrane
voltage. They open at some values of membrane potential and
close at others.
When membrane voltage increases and becomes less
negative, the cell is less polarized, and is said to be
depolarized. Reversely, when membrane potential becomes
more negative, the cell is repolarized. For an action potential
to be generated, the membrane voltage must depolarize to a
critical value called the threshold.
Het verschil tussen depolarizatie en repolarizatie is dat tijdens de depolarizatie de
membraanpotentiaal stijgt naar ca. +10. Tijdens de repolarizatie daalt deze door kalium exit naar ca. -
65mv.
