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Metabolic Rate, Heat and Thermoregulation - response to heat and cold stresses

By: HWC, Views: 7940

• A neuron group in the anterior portion of the hypothalamus controls heat balance. • Neurons in the preoptic region of the hypothalamus integrate signals that come from thermoreceptors. • The temperature control center in the preoptic region propagates control signals to two other part...

Effect of the environment on coat color in the Himalayan rabbit Animation

By: HWC, Views: 3239

An organism's phenotype—the combination of traits that we observe—is the product of interactions between its genotype and the environment. For example. a Himalayan rabbit is completely white at birth. But within weeks, the fur on the rabbits ears, nose, tail. and lower legs darkens. The...

Factors that increase metabolic rate and heat production

By: HWC, Views: 7754

• All vital biochemical reactions are temperature dependent. • The overall rate at which metabolic reactions use energy is known as the metabolic rate. • Metabolic rate greatly determines body temperatures. • Temperature is maintained by balancing the loss of heat to the environment...

Stress and Immune System Animation

By: Administrator, Views: 10923

How stress and the immune system are linked. Immune response declines with age, limiting body's ability to identify and fight foreign substances. Loss of thymus cortex leads to reduced production of T lymphocytes, including T cells, NK cells, B lymphocytes. Frequency and severity of infectio...

Bone processes - resorption and deposition, remodeling and response to stress in adult bones

By: HWC, Views: 7916

• The process of remodeling bone tissues involves bone cells resorbing or depositing minerals into bone tissue. • During resorption, bone cells break down bone tissue and release calcium and other minerals for use by other cells in the body. • Bone cells also rebuild bone tissue by depo...

Epinephrine/NE (heart rate, altered blood flow, glycogenolysis & bronchodilation)

By: HWC, Views: 7651

• Stressors trigger increased sympathetic stimulation from the hypothalamus to the chromaffin cells of the adrenal medulla. • This causes the immediate release of epinephrine and norepinephrine (NE). • Epinephrine/NE binds to the cardiac muscles of the heart. • Cardiac muscle cells ...

Griffith's experiments

By: HWC, Views: 4860

In the late 1920s, Fred Griffith was attempting to develop a vaccine against a bacterium that causes pneumonia. To find out why two strains of the bacteria differed in their deadliness, he injected mice with four different mixtures. Mice injected with R cells remained healthy. When Griffith ex...

The Hypothalamus: The Body's Thermostat (Human Thermostat)

By: HWC, Views: 6957

Normal body function requires a relatively constant body temperature, which is regulated by the body's thermostat, a region of the brain called the hypothalamus. The hypothalamus generates a temperature set point for the body and appears to be the major site for the integration of temperature inf...

Homeostasis (range of body conditions, normal limits, mild stresses & severe stresses)

By: HWC, Views: 7693

Homeostasis: • Provides relative stability of the internal environment. • Results from constant adjustments. • Regulated by regulatory processes. • Requires system interplay. • Normal limits. • Temporary stresses. • Disruptions requiring medical intervention. • D...