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Membrane transport proteins - pores, gated channels and pumps

By: HWC, Views: 7845

• a Three different types of membrane ion transport proteins are required to produce and carry electrical signals: • Pores • Gated channels • Na+/ K+ pump • Pores are always open and allow the diffusion of Na+ and K+ ions across the membrane, down their concentration gradients...

Basic rhythm - control centers in medulla oblongata, spirograph and normal tidal cycle

By: HWC, Views: 7577

• Normal ventilation is rhythmic and involves continuous cycles of inspiration and expiration. • Various regions of the brain closely regulate this rhythmic pattern of ventilation. • The rhythmicity area in the medulla regulates the basic rhythm of ventilation. • The medullary rhy...

Apicomplexan life cycle Animation

By: HWC, Views: 2039

Malaria is caused by the sporozoan, Plasmodium. It is transferred to humans by mosquitoes. When an infected mosquito feeds, infective sporozoites move from her salivary glands into the human body. The bloodstream carries the sporozoites to the liver. Here, they reproduce asexually and...

Role of the respiratory system - effect of altered ventilation rates

By: HWC, Views: 7582

• 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...

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

By: HWC, Views: 8015

• 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. â€...

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

By: HWC, Views: 7855

• 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 ...

TRH/TSH/Thyroid hormone

By: HWC, Views: 7250

Thyroid hormone production • A decline in metabolic rate caused by increased metabolic need or physical exertion stimulates the production of thyrotropin hormone releasing (TRH) hormone from the cells of the hypothalamus. • Thyrotropin hormone releasing hormone targets the thyrotrophic ce...

Labor and Delivery - Placenta Cord

By: Administrator, Views: 350

Soon after a baby is conceived, a support system, comprised of the placenta and umbilical cord, begins to develop. These two structures are essential for sustaining a healthy pregnancy, explains Donald Davis, an obstetrician in Medicine Hat, Alta., and past president of the Society of Obstetricia...

Inflammation and Fever

By: HWC, Views: 8215

• 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...