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Stomach peristalsis & Enterogastric reflex

By: HWC, Views: 8429

• Food enters, distending the stomach. • Stretch receptors activate enteric reflexes that promote peristaltic movements. • These movements, called mixing waves, begin to mix the food with stomach secretions. • Mixing waves force the digesting food (chyme) toward and through the pylo...

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

By: HWC, Views: 10139

• 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 ...

Hershey Chase Experiments

By: HWC, Views: 6176

Hershey and Chase knew that T4 bacteriophages consist of proteins and DNA. They asked which viral component must enter a bacterial cell to infect it: DNA or protein? They grew viruses with either radioactive sulfur, which labels the viral protein, or radioactive phosphorus, which labels DNA. ...

Introduction to filtration - filtrate formation and composition

By: HWC, Views: 9184

• At the nephron, the three process responsible for the formation of urine include: • Glomerular filtration. • Tubular reabsorption. • Tubular secretion. • During filtration, a filtrate is formed within the renal tubule. • Reabsorption is the conserving of water and many s...

What is Reverse Osmosis?

By: HWC, Views: 6183

Osmosis is when a solvent, such as water, moves from a low-solute concentration solution to a higher-solute concentration solution through a semipermeable. Osmosis is an example of diffusion (a special case of diffusion) in which the molecules are water, and the concentration gradient occurs a...

What is Reverse Osmosis?

By: HWC, Views: 6697

Osmosis is when a solvent, such as water, moves from a low-solute concentration solution to a higher-solute concentration solution through a semipermeable. Osmosis is an example of diffusion (a special case of diffusion) in which the molecules are water, and the concentration gradient occurs a...

Ventilation - phases and driving forces

By: HWC, Views: 9072

Respiration is the exchange of gases between the atmosphere, blood, and cells The combination of 3 processes is required for respiration to occur Ventilation (breathing) External (pulmonary) respiration Internal (tissue) respiration The cardiovascular system assists the respiratory system b...

Forming urine ( influencing factors), Forming dilute urine & Forming concentrated urine

By: HWC, Views: 9456

• The amount of urine produced by the nephron depends on : • Body fluid volume. • Body fluid composition. • Dilute urine is formed when the body is normally hydrated. • The medullary osmotic gradient determines the osmolarity of the filtrate. • Filtrate osmolarity increase...

Respiratory System Animation

By: Administrator, Views: 398

Respiratory system: nose pharynx larynx trachea bronchi lungs Respiratory system’s primary function: Furnish oxygen (O2) for use by individual tissue cells and take away their gaseous waste product, carbon dioxide (CO2), through act of respiration. External respiration Lungs are vent...