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Proteins Defined, Hierarchy & Composition of Cells

By: HWC, Views: 6154

Proteins are long chains of amino acids linked together by peptide bonds. Together with the other three biological macromolecules—carbohydrates, lipids, and nucleic acids—proteins are the building blocks of cells. Proteins are the most complex and abundant biological macromolecules in cel...

Anaphylaxis Animation

By: Administrator, Views: 9413

Anaphylaxis is a serious, life-threatening allergic reaction. The most common anaphylactic reactions are to foods, insect stings, medications and latex. If you are allergic to a substance, your immune system overreacts to this allergen by releasing chemicals that cause allergy symptoms.

Allergic Rhinitis

By: Administrator, Views: 9349

Allergic rhinitis, also known as hay fever, is a type of inflammation in the nose which occurs when the immune system overreacts to allergens in the air. Signs and symptoms include a runny or stuffy nose, sneezing, red, itchy, and watery eyes, and swelling around the eyes. The fluid from the nose...

Inflammation Animation

By: Administrator, Views: 9651

Inflammation is caused by a number of physical reactions triggered by the immune system in response to a physical injury or an infection. Inflammation does not necessarily mean that there is an infection, but an infection can cause inflammation.

Second Stage of Labor and Delivery

By: Administrator, Views: 515

During labor forceful contractions move the fetus down the birth canal and expel it from the uterus. Signs and symptoms that labor is about to start can occur from hours to weeks before the actual onset of labor. Braxton Hicks contractions Irregular contractions that begin in the second trim...

First Stage of Labor and Delivery Video

By: Administrator, Views: 9809

During labor forceful contractions move the fetus down the birth canal and expel it from the uterus. Signs and symptoms that labor is about to start can occur from hours to weeks before the actual onset of labor. Braxton Hicks contractions Irregular contractions that begin in the second trim...

Rh blood type and complications during pregnancy & Fertilization

By: HWC, Views: 4079

Complications can arise if an Rh- woman is impregnated by an Rh+ man. The fetus maybe Rh+. During childbirth, some of the fetal Rh+ cells may leak into the maternal bloodstream. The woman's immune system views the Rh+ as foreign and makes antibodies against it. If the woman becomes pr...

Natural Selection, Species Isolation and Real World Example

By: HWC, Views: 6087

`Natural selection' is the process in which organisms with adaptive traits survive and breed in greater number than organisms without such traits. Eventually, almost all of the individuals in the population will have the same adaptive trait. This was the concept presented by Charles Darwin in ...

Chemical Synapse Animation

By: HWC, Views: 4015

A neuromuscular junction is a chemical synapse between the axon endings of a motor neuron and a muscle cell. A narrow synaptic cleft separates the presynaptic cell (the motor neuron) from the postsynaptic cell (the muscle cell). The presynaptic cell contains vesicles filled with neurotransmitt...