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

By: HWC, Views: 7518

• 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 ...

Reflex arc construction

By: HWC, Views: 7765

• Somatic reflexes are the rapid, predictable, and automatic responses of skeletal muscle to changes in stimuli. • A reflex arc is the pathway followed by the nerve impulse producing the reflex. • Reflex arcs include: • Sensory receptor • Sensory neurons • Integrating c...

Digestion Animation

By: Administrator, Views: 11414

The mouth or oral cavity is formed by: - The hard and soft palates at the top or roof - the cheeks - the tongue - the lips Contains the teeth and salivary glands. The gingivae (gums) surround the necks of the teeth. The lingual frenulum is a thin fold of mucous membrane that connects...

Glucagon (glycogenolysis and gluconeogenesis)

By: HWC, Views: 7677

• 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...

Primary and secondary response to infection

By: HWC, Views: 7540

• Pathogens enter the body by penetrating the non-specific barriers in the skin and mucus membranes. • Pathogens first encounter macrophages and natural killer cells that carry out phagocytosis and cytolysis respectively. • A pathogen's first encounter with the immune system can promo...

Immune responses Animation

By: HWC, Views: 4637

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...

Oxygen transport - methods and oxyhemoglobin

By: HWC, Views: 7626

• The blood is the medium used for gas transport throughout the body. • Oxygen is only available in the lungs. Because the partial pressure of oxygen is higher in the alveoli than in the blood, oxygen diffuses into the blood and is transported to systemic cells. • At the tissues the par...

Cellular slime mold life cycle Animation

By: HWC, Views: 2033

Life cycle of Dictyostelium discoideum, a cellular slime mold Animation. Amoeba-like slime mold cells live in the soil, where they feed on bacteria. The free-living cells grow and reproduce by mitosis. When food dwindles, the amoebas stream toward one another in response to a chemical...

Rena arc construction

By: HWC, Views: 7770

• Somatic reflexes are the rapid, predictable, and automatic responses of skeletal muscle to changes in stimuli. • A reflex arc is the pathway followed by the nerve impulse producing the reflex. • Reflex arcs include: • Sensory receptor • Sensory neurons • Integrating cen...