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8 Cards in this Set
- Front
- Back
- 3rd side (hint)
Define Homeostasis and state it's importance
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Homeostasis is a dynamic state of equilibrium within the body
it is vital for maintaining the balance within the body, ensuring optimal performance |
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Negative Feedback
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Negative feedback is a system used to maintain Homeostasis by shutting off the original stimulus
e.g. regulation of blood sugar in humans 1. ↑ blood sugar levels 2. insulin sends a signal to the liver, muscles and other cells to store the excess glucose 3. consequently, ↓ blood sugar levels |
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Positive feedback
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a stimulus produces a response that exaggerates or enhances the original change in conditions, rather than opposing it
e.g. Blood clotting 1. A damaged vessel releases chemicals into the blood stream which signal to other cells to come to the site 2. As the clot forms, more chemicals are released. These chemicals signal for more clotting agents 3. This system repeats until the damaged vessel is closed, no longer releasing chemicals and therefore ending the process |
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Define disease
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disease is a state of deviation from normal health or wellbeing
a disruption of Homeostasis |
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Levels of disease
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Metabolic - disruption in normal function of cells and organs
Inflammatory - reaction to injury or harmful agents Congenital/hereditary - cell altering Chronical - causes degeneration Cancer - abnormal cell growth (can be benign or malignant) |
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Types of disease
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Non-infectious
- caused by heredity, lifestyle, environment or nutritional deficiencies Infectious - caused by Bacteria, fungi, viruses or protozoa |
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Infectious disease examples
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Fungi
e.g. dermatophytes (athlete's foot) Bacteria e.g. cholera Viruses e.g. ebola Protozoa e.g. Plasmodium (causes malaria) |
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How are diseases spread?
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Direct Contact
- kissing - touching - vertical (via womb) - vector (carrier) Indirect Contact - contaminated food or water - air - fomites (objects carrying infection e.g. door handles) |
direct and indirect contact
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