Search results for: 'The Pressure Flow Model in a Plant'

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By: Administrator, Views: 13168

Its nervous tissue consists of millions of nerve cells and fibers. It is the largest mass of nervous tissue in the body. The brain is enclosed by three membranes known collectively as the meninges: dura mater arachnoid pia mater The major structures are the: cerebrum cerebellum dienc...

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Mechanics of Sound Animation

By: Administrator, Views: 12121

Process of Hearing Sound waves are directed to the eardrum, causing it to vibrate. These vibrations move the three small bones of the middle ear (malleus, incus, and stapes). Movement of stapes at oval window sets up pressure waves in the perilymph and endolymph. Process of Hearing The wav...

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Properties of macromolecules (Explained with No Audio)

By: HWC, Views: 7783

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...

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Role of the respiratory system - effect of altered ventilation rates

By: HWC, Views: 8754

• Dissociation of the chemical substances in the body fluids can result in the production of free hydrogen ions. • The pH scale is used to measure the concentration of hydrogen ions in solution. • Normal blood pH values vary around 7.4. • When hydrogen ion concentration increases, t...

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Barriers - eye structures, digestive mucosa, respiratory mucosa & genitourinary mucosa

By: HWC, Views: 9176

• Eyebrows, eyelids, eyelashes and conjunctiva serve to trap microbes preventing their invasion. • Tearing (lacrimation) is a protective mechanism that washes away microbes that attempt to enter the eyes. • Salts, mucus, and lysozymes in tears neutralize substances and bacteria. �...

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Factors that affect conduction rates (myelination, axon diameter & temperature)

By: HWC, Views: 9010

• Several factors determine the rate of conduction of action potentials: • Myelination • Axon diameter • Temperature • The step-by-step depolarization of an axon is called continuous conduction and occurs along unmyelinated axons. • Neurons in the PNS have many axons that ...

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

By: HWC, Views: 9193

• 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...

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

By: HWC, Views: 8753

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...

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Inflammation and Fever

By: HWC, Views: 9383

• Inflammation is an immune response that can occur anywhere in the body, but is observed most frequently on the skin. • It provides early protection by preventing infection from spreading to other parts of the body. • Inflammation also promotes repair of damaged tissues. Inflammat...

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