Search Results

Properties of macromolecules (Explained with No Audio)

By: HWC, Views: 6677

The term thermoplast refers to a plastic, which when heated is soft and deformable, but which rehardens when cooled. The molecular structure of the macromolecules is comparable to a cotton ball in which the individual fibers of the macromolecules are shown. The fibers of the cotton ball can s...

Membrane transport proteins - pores, gated channels and pumps

By: HWC, Views: 7845

• a Three different types of membrane ion transport proteins are required to produce and carry electrical signals: • Pores • Gated channels • Na+/ K+ pump • Pores are always open and allow the diffusion of Na+ and K+ ions across the membrane, down their concentration gradients...

Epinephrine/NE (heart rate, altered blood flow, glycogenolysis & bronchodilation)

By: HWC, Views: 7652

• Stressors trigger increased sympathetic stimulation from the hypothalamus to the chromaffin cells of the adrenal medulla. • This causes the immediate release of epinephrine and norepinephrine (NE). • Epinephrine/NE binds to the cardiac muscles of the heart. • Cardiac muscle cells ...

Red Blood Cells - Erythropoietin (EPO)

By: HWC, Views: 7711

• 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...

Frequency of stimulation and force (Recruitment of motor units and force)

By: HWC, Views: 8042

• Muscle tension depends on the frequency of stimulation. • Muscle twitch: First stimulus. • Wave summation: When a second stimulus excites a partially relaxed muscle, producing a stronger contraction. • Unfused tetanus: Successive stimulations at the same frequency, producing a se...

Mechanisms of capillary exchange

By: HWC, Views: 7876

■ The primary role of capillaries is to permit the exchange of nutrients and wastes between the blood and tissue cells (via interstitial fluid). ■ Oxygen and nutrients move from the blood to the cells. ■ Carbon dioxide and other wastes move from the cells to the blood. The three ba...

Darwin's Observation (Fossils, Galapagos Islands & Africa ) and Natural Selection (Adaptive Traits)

By: HWC, Views: 7614

Along Darwin's voyage, he made many observations. Each one added to his understanding of how organisms change over time. Darwin was already familiar with fossils and knew that many fossils were very different from living organisms. But, also there were some fossils that were very similar to li...

Introduction to C-Section

By: Administrator, Views: 333

Caesarean section, also known as C-section, or caesarean delivery, is the use of surgery to deliver babies. A caesarean section is often necessary when a vaginal delivery would put the baby or mother at risk. This may include obstructed labor, twin pregnancy, high blood pressure in the mother, br...

Labor and Delivery - Placenta Cord

By: Administrator, Views: 350

Soon after a baby is conceived, a support system, comprised of the placenta and umbilical cord, begins to develop. These two structures are essential for sustaining a healthy pregnancy, explains Donald Davis, an obstetrician in Medicine Hat, Alta., and past president of the Society of Obstetricia...