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

By: HWC, Views: 6746

• 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...

Immune responses Animation

By: HWC, Views: 3519

Overview of interactions in antibody-mediated and cell-mediated immunity Animation The antibody mediated immune response begins when a naive B cell encounters antigens from a pathogen, such as a bacterium. The B cell binds, processes, and displays this antigen. It is now an antigen-presenti...

HIV Infection: Viral life cycle

By: HWC, Views: 6013

The series of steps that HIV follows to multiply in the body. The process begins when HIV encounters a CD4 cell. The seven steps in the HIV life cycle are: 1) binding; 2) fusion; 3) reverse transcription; 4) integration; 5) replication; 6) assembly; and 7) budding. Many viruses f...

T cell receptors

By: HWC, Views: 6336

• T cells are responsible for cell-mediated immunity. • Each T cell contains a unique form of T cell receptor (TCR) on its membrane. • These T cell receptors are produced through a process of genetic recombination which is able to produce millions of different variations. • Each T ce...

B cells and antibodies

By: HWC, Views: 7464

What Are Antibodies? Antibodies, also known as immunoglobulins, are Y-shaped proteins that are produced by the immune system to help stop intruders from harming the body. When an intruder enters the body, the immune system springs into action. These invaders, which are called antigens, can be vi...

Cell mediated immune response to a viral infection Animation

By: HWC, Views: 2684

Intracellular pathogens are the targets of cell-mediated immune response. The process begins when a virus infects a macrophage. Another macrophage engulfs the same virus or an antigen from it. In both cells, enzymes cleave the viral antigens into small bits. The fragments move to the cell sur...

Nervous pathway to the Neuromuscular (NMJ)

By: HWC, Views: 7158

• 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...

Conduction of action potentials

By: HWC, Views: 6764

• 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 ...

Introduction to Human Immunodeficiency Virus (HIV)

By: Administrator, Views: 9561

Human immunodeficiency virus gains entry into helper T cells, uses the cell DNA to replicate, interferes with normal function of the T cells, and destroys the normal cells. 1 in 10 persons with AIDS: age 50 or older. 4% of all AIDS cases: age 65 or older. AIDS’ main form of treatment: an...