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Cell mediated immune response to a viral infection Animation

By: HWC, Views: 3769

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...

Introduction to Insulin

By: Administrator, Views: 11845

The islets of Langerhans are composed of three major types of cells: Alpha cells secrete glucagon, elevating blood sugar. Beta cells secrete insulin, maintaining normal blood sugar. Delta cells secrete somatostatin, which suppresses release of glucagon and insulin. Hyposecretion or inadequa...

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

By: HWC, Views: 7835

• 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...

Red Blood Cells - Erythropoietin (EPO)

By: HWC, Views: 7727

• 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 aft...

Vascular tissues in a corn stem and a buttercup root

By: HWC, Views: 2239

Vascular tissues in a corn stem and a buttercup root. The cells that make up each tissue. Xylem conducts water and dissolved ions. It also helps mechanically support a plant. The cells, called vessel members and tracheids, are dead at maturity. Their lignified walls interconnect and serve as p...

Inflammatory response Animation

By: HWC, Views: 4290

Any tissue damage or bacterial invasion can bring about inflammation. The inflammatory response can be triggered by an invasion of bacteria, or by a cut or other physical damage to cells. Chemicals, such as histamine, released by the bacteria or damaged cells. accumulate in the tissue. Thes...

Cellular defenses (natural killer cells, phagocyte types & process of phagocytosis)

By: HWC, Views: 7476

• Lymphocytes that rapidly defend against abnormal (cancer) or virus-infected cells. • Found in blood, spleen, lymph nodes, and red bone marrow. • Lack receptors for binding with specific antigens. • Act upon cells displaying abnormal MHC antigens. • NK cells destroy cells in ...

Type of Cell Junctions - Desmosome, Hemidesmosomes and Gap Junctions

By: HWC, Views: 8089

Cell Junctions: Cell junctions are found in some multi-cellular organisms. They exist of complexes and are found between cells and between cells and other structures. The junctions provide a way for cells to connect and exchange signals. What are tight junctions, desmosomes, and gap junctions...

Glucagon (glycogenolysis and gluconeogenesis)

By: HWC, Views: 7608

• Exercise, or not having eaten recently, causes a decline in blood glucose concentration. • Low blood glucose stimulates alpha cells in the pancreatic islets to secrete glucagon. • Glucagon targets liver cells. • Glucagon causes liver cells to undergo: • Glycogenolysis, a proce...