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Results for: 'Action potentials'
Contraction cycle of a sarcomere
By: HWC, Views: 8175
• A single nervous signal releases Ca2+ ions into the sarcoplasm and initiates the contraction cycle. step 1. ATP hydrolysis • ATP provides the to move myosin molecules back into the energized configuration necessary to perform the power stroke. Step 2. Crossbridge attachment • Myosin...
By: Administrator, Views: 11206
Dendrites (from Greek δένδρον déndron, "tree"), also dendrons, are branched protoplasmic extensions of a nerve cell that propagate the electrochemical stimulation received from other neural cells to the cell body, or soma, of the neuron from which the dendrites project. Electrical stimula...
By: HWC, Views: 7593
■ The substrate makes contact with the active site. ■ A change in the shape of the enzyme occurs resulting in the transformation of the substrate. ■ A substrate may undergo decomposition, have its atoms rearranged, or two substrates may be synthesized. ■ The products of the reaction...
Olfaction. or the sense of smell
By: HWC, Views: 5144
Do you ever wonder how you can distinguish thousands of different odors? Olfaction. or the sense of smell, is used by all mammals to navigate, find food, and even find mates. We have millions of olfactory receptors for smelling in our nose. These receptor neurons bind water-soluble or volatil...
By: Administrator, Views: 10930
A reflex arc is a neural pathway that controls a reflex. In vertebrates, most sensory neurons do not pass directly into the brain, but synapse in the spinal cord. This allows for faster reflex actions to occur by activating spinal motor neurons without the delay of routing signals through the bra...
Helper T cell receptors, activation, proliferation, differentiation & action
By: HWC, Views: 7812
• Most cells which have CD4 on their surface become Helper T cells (TN cells). • The CD4 1 cells only recognize a foreign antigen when it is presented with an antigen presenting immune cell (APC) that includes MHC-II protein. • The Helper T cell antigen receptor must match the presented...
By: Administrator, Views: 492
Blood and lymph are two of the body's main fluids and are circulated through two separate but interconnected vessel systems. Blood is circulated by the action of the heart, through the circulatory system consisting largely of arteries, veins, and capillaries. Lymph does not actually circulate. ...
Cytotoxic T cell receptors, activation, proliferation, differentiation & action
By: HWC, Views: 8032
• Most cells which have CD8 on their surface become cytotoxic T cells (Tc cells). • CD8 T cells recognize a foreign antigen when it is presented in conjunction with the protein, MHC-I. • Nearly all nucleated cells in the body express MHC-I molecules. • T cells that recognize self-pe...
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