Search Results

Cardiac conductile cells

By: HWC, Views: 7968

• 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...

Body plan of euglena Animation

By: HWC, Views: 2042

Euglenoids are single-celled organisms that live in lakes and ponds. A contractile vacuole pumps out the water that diffuses into the cell from its hypotonic surroundings. The body is covered by a translucent pellicle composed of flexible strips of a protein-rich material. Light passe...

hGH (protein synthesis, growth and development)

By: HWC, Views: 8096

• Increased GHRH, a hypothalamic releasing hormone stimulated by low blood glucose, physical exertion, and increased sympathetic stimulation, stimulates the production of human growth hormone (hGH) from the somatotrophic cells of the anterior pituitary. • Human growth hormone targets cartil...

Acid-base imbalances - compensation of respiratory acidosis and alkalosis

By: HWC, Views: 7848

• When one pH balancing system is affected then the other balancing system attempts to correct, or compensate for, the pH imbalance. - Respiratory acidosis: • Excessive CO2 is present so blood pH becomes acidic. • Compensation is increased secretion of H+ into urine and reabsorption ...

Fermentation pathways

By: HWC, Views: 1661

Both lactate fermentation and alcoholic fermentation begin with pyruvate formed by glycolysis. During lactate fermentation, pyruvate molecules accept electrons and hydrogen from NADH. This transfer regenerates NAD± and converts pyruvate to lactate. The net energy yield is the two ATP...

Condensation and Hydrolysis Animation

By: HWC, Views: 1557

A condensation reaction joins two molecules together to form one larger molecule. An enzyme removes a hydroxyl group from one molecule and a hydrogen atom from another, then speeds the formation of a bond between the two molecules at their exposed sites. Typically the discarded atoms join t...

Requirements for nervous signals

By: HWC, Views: 7676

• The function of neurons is to allow communication between cells, thereby maintaining homeostasis. • Electrical signals, called membrane potentials, travel along the membranes of the neurons. • Voltage variability and distance traveled determine the type of nervous signal. 1. Graded...

Bone tissue types - compact and spongy

By: HWC, Views: 7795

Bone tissue types • There are two types of bone tissue: compact and spongy. • All the bones of the skeleton have both kinds of bone tissue. • Compact (dense) bone • Arranged in osteons (Haversian systems), units of lamellae laid down in adjoining series of concentric rings. • P...

Nucleic acid digestion -small intestine

By: HWC, Views: 7749

Nucleic acid digestion, which takes place in the small intestine, involves: • Pancreatic nucleases. • Brush-border enzymes in the small intestine. • Nucleic acids enter the small intestine dissolved in gastric chyme. • As gastric chyme enters the duodenum of the small intestine, p...