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Results for: 'Voltage changes'
Requirements for nervous signals
By: HWC, Views: 6622
• The function of neurons is to allow communication between cells, thereby maintaining homeostasis. • Electrical signals, called membrane potentials, travel along the membranes of the neurons. • Voltage variability and distance traveled determine the type of nervous signal. 1. Graded...
Action potentials - electrical characteristics and generation
By: HWC, Views: 6571
• An action potential is the nervous impulse or signal for long distance communication. Each action potential is generated at the cell's trigger zone. • Action potentials are considered an all-or-nothing phenomena because they are either generated or not. • The generation of an action...
Electrical changes in the heart
By: HWC, Views: 6479
• ECG: Graph of the voltage changes that occur during the cardiac cycle. • Readings are taken by electrodes placed on the surface of the body. • Electrodes detect voltage changes caused by the electrical activity of the heart. • P wave = atrial excitation (atrial depolarization). ...
Phases of an Action Potential - Resting Potential, Threshold, Rising, Falling, & Recovery Phases
By: HWC, Views: 6092
In this tutorial, we will review the phases of an action potential measured from a small area of a neuron's membrane. The action potential can be divided into five phases: the resting potential, threshold, the rising phase, the falling phase, and the recovery phase. When the neuron is at rest,...
Membrane transport proteins - pores, gated channels and pumps
By: HWC, Views: 6743
• a Three different types of membrane ion transport proteins are required to produce and carry electrical signals: • Pores • Gated channels • Na+/ K+ pump • Pores are always open and allow the diffusion of Na+ and K+ ions across the membrane, down their concentration gradients...
Conduction of action potentials
By: HWC, Views: 6769
• Action potentials must be rapidly conducted over long distances in order for the nervous system to communicate with other cells. • Propagation of an action potential uses processes similar to those that generate the potential at the trigger zone. • a When a graded potential reaches ...
Resting membrane potential - electrical polarity and maintenance requirements
By: HWC, Views: 6449
• A resting membrane potential exists when there is a buildup of: 1. positive ions outside the membrane. 2. negative ions inside the membrane. • Membranes with opposing charges are said to be polarized. • The difference in charge applies only to the small distance across the membran...
Nervous pathway to the Neuromuscular (NMJ)
By: HWC, Views: 7171
• A nervous impulse, also called an action potential, starts from the brain or spinal cord to signal skeletal muscle cell contraction. Action potentials continue along a motor neuron to the muscle cell. • The signal to contract must cross a synapse - the neuromuscular junction (NMJ) - betwe...
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