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B cells and antibodies

By: HWC, Views: 8523

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...

How does asthma work?And How do you treat asthma?

By: HWC, Views: 6683

These are the parts of the respiratory system. Sinuses and Nasal Passages Mouth Windpipe (Trachea) Lungs Airways (Bronchial Tubes) Airsacs (Alveoli) When we breathe, air moves easily in and out of the lungs. The small airways are also called bronchial tubes. The side of the tube is...

DNA Replication

By: HWC, Views: 4613

DNA replication is the process by which a double-stranded DNA molecule is copied to produce two identical DNA molecules. Replication is an essential process because, whenever a cell divides, the two new daughter cells must contain the same genetic information, or DNA, as the parent cell.

Muscle cell structures - actin, myosin and titin filaments

By: HWC, Views: 7892

Once the muscle cell has been excited it will contract. • A muscle action potential will trigger the release Of Ca2+ ions into the sarcoplasm. • The Ca2+ ions bind to the regulatory proteins and trigger contraction. • Within skeletal muscle cells are structures that provide the ability...

Labor and Childbirth - The Three Stages of Labor: Dilation, Expulsion & Placental مراحل الولادة

By: HWC, Views: 8182

Regulation of labor and birth - effects of estrogen and oxytocin on onset of labor • Just prior to birth, high placental corticotropin-releasing hormone levels stimulate the production of more estrogen. • High estrogen levels overcome the inhibitory effects of progesterone on uterine sm...

Origin of organelles Animation

By: HWC, Views: 1390

Possible origins of the nucleus and other organelles. Some prokaryotic cells have infoldings of their plasma membrane. These infoldings may have served as channels from the cytoplasm to the cell surface. These membranous folds may have evolved into the endoplasmic reticulum and the nuclear e...

Gastrin (protein digestion)

By: HWC, Views: 7748

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...

Proteins Defined, Hierarchy & Composition of Cells

By: HWC, Views: 7213

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...

Neural regulation of mechanical digestion- CNS voluntary, ANS & ENS controlled involuntary movements

By: HWC, Views: 7702

• The gastrointestinal [GI] tract is basically a muscular tube that contains and processes food as it moves from the mouth to the anus. • Mechanical digestive functions consist of both voluntary and involuntary muscle contractions and relaxation including: • Chewing and swallowing food....