D3.3 Homeostasis

Homeostasis

The maintenance of a stable internal environment within preset limits despite fluctuations in the external environment.

Insulin

A hormone secreted by the beta cells of the pancreas that promotes the uptake of glucose by body cells.

Glucagon

A hormone secreted by the alpha cells of the pancreas that stimulates the liver to convert glycogen into glucose, thus raising blood sugar levels.

Negative feedback

A control mechanism that reduces the output or activity of a system to return a variable to its set point.

Blood glucose

The concentration of glucose in the blood, with a normal range of 70 to 130 mg/dl.

Diabetes

A group of diseases characterized by high blood glucose levels due to issues with insulin.

Type 1 Diabetes

An autoimmune disease where the body's immune system attacks insulin-producing beta cells in the pancreas.

Type 2 Diabetes

A condition where the body’s cells become resistant to insulin, often associated with obesity and lifestyle factors.

Thermoregulation

The process by which an organism regulates its body temperature within a narrow range.

Osmoregulation

The regulation of osmotic concentration to maintain water and solute balance within the body.

Vasoconstriction

The narrowing of blood vessels, which reduces blood flow to the skin and thus decreases heat loss from the body.

Vasodilation

The widening of blood vessels which increases blood flow to the skin, enhancing heat loss.

Hypothalamus

A region of the brain that regulates body temperature and water balance.

Antidiuretic Hormone (ADH)

A hormone released from the pituitary gland that regulates water reabsorption in the kidneys.

Nephron

The functional unit of the kidney that filters blood and produces urine.

Ultrafiltration

The process in the glomerulus where blood is filtered under pressure to form glomerular filtrate.

Selective Absorption

The process by which the kidneys reabsorb useful substances from the filtrate back into the blood.

Brown Adipose Tissue

A type of fat tissue that generates heat through uncoupled respiration, helping to maintain body temperature.

Hydrogen Bonds

Weak attractions between hydrogen atoms and more electronegative atoms that contribute to water's unique properties.

Latent Heat of Vaporization

The amount of heat required to convert a unit mass of a substance from liquid to gas at its boiling point.

Peripheral Thermoreceptors

Sensors located in the skin that detect changes in external temperature.

Thyroxin

A hormone produced by the thyroid gland that regulates metabolism and body heat.

Alpha Cells

Cells in the pancreas that produce glucagon.

Beta Cells

Cells in the pancreas that produce insulin.

Glycogen

A stored form of glucose, primarily found in the liver and muscle cells.