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Evolutionary tree of life Animation

By: HWC, Views: 1384

An evolutionary tree of life that reflects mainstream thinking about the connections among major lineages (bya = billions of years ago, mya = millions of years ago). By about 3.8 billion years ago, chemical and molecular evolution had produced the first living cells. The first major divergenc...

Coaductile pathway, Timing of contraction signal & Conduction system and ECG

By: HWC, Views: 7926

• When the system is healthy, the signal to contract the entire conduction system originates in the SA node - known as the heart's pacemaker. • The SA node triggers contraction because it depolarizes at a faster rate than other parts of the conduction system. • The wave of excitation fr...

Language Areas Animation

By: Administrator, Views: 10887

Specific language areas of the brain. Many cortical (and non-cortical!) regions are involved in language processing. The primary language pathway begins in Wernicke’s area (posterior temporal lobe), which receives information from the auditory and visual cortices and assigns meaning (= lang...

What are Taste Receptors? How Does it Work? Animation

By: HWC, Views: 4598

Do you ever wonder how you can taste the foods you eat? It all starts with taste receptors in your muscular tongue. Taste receptor neurons are found in your taste buds but you are not looking at the taste buds. The raised bumps on the surface of the tongue that you see are specialized epith...

Krebs cycle : Formation of acetyl coenzyme A and Electron transport chain

By: HWC, Views: 7809

The oxidation of glucose to produce ATP is cellular respiration. Four sets of reactions are involved: Glycolysis Formation of acetyl coenzyme A Krebs cycle reactions Electron transport chain reactions • The second pathway of glucose catabolism, formation of acetyl coenzyme A, is a transi...

Cardiac conductile cells

By: HWC, Views: 7972

• In order for the heart to function properly, all of its cells must contract in a specific sequence. This sequence is determined by a pathway known as the conduction system. • Cardiac muscle cells have two attributes that enable the conduction system to work: • Connective. Action pot...

Calvin Cycle Explained!

By: HWC, Views: 7433

he light-independent reactions make sugars by way of a cyclic pathway called the Calvin cycle. The cycle begins when rubisco attaches a carbon from carbon dioxide to ribulose bisphosphate. The molecule that forms splits into two molecules of PGA. Each PGA gets a phosphate group from ATP a...

Regulation of GFR: autoregulation via tubuloglomerular feedback, neural & hormonal regulation

By: HWC, Views: 8901

• When blood pressure is above normal, rapid filtrate flow reduces ion retention so filtrate in tubule has more Na+, C1-, and water. • It is believed that vasoconstricting chemicals from the juxtaglomerular cells are released when the macula densa cells detect higher water and ion levels in ...

The Lac Operon in E. Coli

By: Administrator, Views: 11790

The lac operon (lactose operon) is an operon required for the transport and metabolism of lactose in Escherichia coli and many other enteric bacteria. Although glucose is the preferred carbon source for most bacteria, the lac operon allows for the effective digestion of lactose when glucose is no...