Search Results

ACTH/Cortisol (glycogenolysis, protein catabolism, lipolysis and gluconeogenesis)

By: HWC, Views: 7576

• A decline in blood glucose concentration stimulates corticotropic cells in the anterior pituitary to produce adrenocorticotropic hormone (ACTH). • ACTH binds with cells in the zona fasciculata of the adrenal cortex. • Increased ACTH promotes the production of cortisol, the major gluco...

Proteins Defined, Hierarchy & Composition of Cells

By: HWC, Views: 7196

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...

Fertilization Animation

By: Administrator, Views: 429

At conception, the gender and other biologic traits of the new individual are determined. The zygote is genetically complete and immediately begins to divide, forming a solid mass of cells called a morula. When the developing embryo (stage of development between weeks 2 and 8) reaches the ute...

A Human Karyotype Preparation Animation

By: HWC, Views: 4883

Blood is collected from the person being analyzed. The blood is added to a growth medium that also contains a chemical that stimulates mitosis. The cells are allowed to grow in this medium for two or three days at body temperature. Colchicine is added to arrest cell division at metaphase. T...

Embryonic development - Week 3

By: HWC, Views: 7752

Week 3 (gastrulation) • Three primary germ layers are formed which provide cells for organ formation in the following months. • These germ cell layers are formed by a process known as gastrulation, which involves rearranging epiblast cells. • As cells from the epiblast migrate, a fain...

How Hemoglobin Picks Up and Delivers Oxygen

By: HWC, Views: 7027

All of the cells in our bodies require oxygen (02) for survival and must release carbon dioxide (CO2) as a waste product. The respiratory and circulatory systems work together as delivery systems for these gases. The lungs exchange these gases between the environment and the bloodstream. The bloo...

Hormonal feedback loop components & Glucagon (glycogenolysis and gluconeogenesis)

By: HWC, Views: 7528

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 ...

Gastrulation: cross section of the frog

By: HWC, Views: 6795

Gastrulation Most animals enter a phase early in development called gastrulation. In this phase, a tiny ball or disc of cells rearranges to form three embryonic layers of tissue, called germ layers. The germ layers of the embryo—now called a gastrula—are called the endoderm, mesoderm, and eco...

Four Giant Convection Cells oF Earth

By: HWC, Views: 7042

Earth Has Four Giant Convection Cells Earth's climates range from dry and cold at the poles to wet and warm at the equator. These climates are dictated largely by the amount of solar radiation that a region receives. Solar radiation warms the Earth and the surrounding air, setting up convection c...