Action Potential
Topics:
PDF:
Action potentials are depolarizations that start at the initial segment of an axon and are propagated toward the synaptic terminals. They are called “all-or-none” events because either an action potential is triggered or it is not; there is no in-between state. Prior to an action potential, the neuron is at rest, with a membrane potential of –70 mV. Now, if a stimulus depolarizes the cell to threshold, which is about –60 to –55 mV, voltage-regulated sodium channels in the membrane open. The sodium ions that rush across the cell membrane change the trans-membrane potential rapidly from threshold toward zero mV.
Duration: 00:53
Published: 11/25/2015
Filter by Topics:
ADHD
Attention deficit hyperactivity disorder, or ADHD, is a common neurobehavioral problem that affects children as well as some adults.
Some research suggests that the cause of ADHD ...
AIDS
White blood cells, which are produced in the bones, are a major component of the body's immune system. When an infectious organism such as a virus or bacteria enters the body, the ...
ALS
All voluntary movement in the body is controlled by the brain. Nerve cells in the brain, called upper motor neurons, initiate movement through the release of chemical signals call...
Abduction and Adduction of the Arm
Abduction is movement away from the midline of the body while adduction is movement towards the midline of the body. An example of this movement is swinging the upper limb to the s...
Abnormal Hemostasis: Embolus Causes a Stroke
The vertebral arteries are two major arteries supplying the brain. They pass through small openings in the cervical vertebrae called the transverse foramen. If the vertebral artery...
Abnormal Hemostasis: Overview of the Clotting Process
While blood clots are essential to the repair of injured tissues, clots can also put patients at risk of developing thrombosis, that may result in a heart attack or an ischemic str...
Explore:
About Us:
We're social
Stay connected with all of the latest
on your favorite social media platform.