Search results for: 'Phases of An Action Potential'

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By: HWC, Views: 6654

Respiration is the exchange of gases between the atmosphere, blood, and cells The combination of 3 processes is required for respiration to occur Ventilation (breathing) External (pulmonary) respiration Internal (tissue) respiration The cardiovascular system assists the respiratory system b...

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Helper T cell receptors, activation, proliferation, differentiation & action

By: HWC, Views: 6770

• 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...

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Lymphatic System Animation

By: Administrator, Views: 449

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. ...

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Cytotoxic T cell receptors, activation, proliferation, differentiation & action

By: HWC, Views: 7006

• 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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Mutations and translation

By: HWC, Views: 3209

A mutation, which may arise during replication and/or recombination, is a permanent change in the nucleotide sequence of DNA. Damaged DNA can be mutated either by substitution, deletion or insertion of base pairs. Mutations, for the most part, are harmless except when they lead to cell death or t...

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Flexor reflex & Crossed extensor reflex

By: HWC, Views: 6594

• The flexor reflex is a response to pain. This reflex is polysynaptic, ipsilateral, and intersegmental. • Pain receptors are stimulated causing increased frequency of action potentials to be generated and conducted along the sensory neuron axon. • The sensory impulses excite several ass...

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Stretch reflex & Tendon reflex

By: HWC, Views: 6393

• The stretch reflex is a response to the stretching of muscles. It is monosynaptic and ipsilateral. • Stretching stimulates receptors in the muscle spindle of the agonist (stretched) muscle. • One or more action potentials are generated by the receptors and propagate along the axon of ...

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Pores and Ion Channels

By: HWC, Views: 5891

Transmembrane channels, also called membrane channels, are pores within a lipid bilayer. The channels can be formed by protein complexes that run across the membrane or by peptides. They may cross the cell membrane, connecting the cytosol, or cytoplasm, to the extracellular matrix. Membrane po...

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Hormonal feedback loop components

By: HWC, Views: 6803

The endocrine system maintains many body conditions within normal limits with feedback loops. Each endocrine feedback loop maintains homeostasis using the following components: ■ Stimulus - a change in a body condition. ■ Production cell - an endocrine cell that produces a hormone after b...

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