5.2-5.3

Homeostasis

The maintenance of a stable internal environment within an organism achieved by various mechanisms responding to keep internal environments within certain limits.

Negative Feedback Loop

A mechanism that promotes stability in the internal environment by responding to changes in the body and adjusting variables to their original or optimal state.

Positive feedback loop

A mechanism that maintains the direction of the stimulus, potentially increasing the stimulus and forcing an organism out of homeostasis.

Receptors

Specialized structures that detect specific stimuli and initiate responses in an organism.

Thermoregulation

The process of maintaining core body temperature within a specific range through negative feedback pathways involving sensory inputs and effector responses.

Blood Glucose Level

The concentration of glucose in the blood, regulated by homeostatic mechanisms to ensure energy supply for the body's cells.

Heat loss mechanisms

Processes including conduction, convection, radiation, and evaporation through which organisms exchange heat with their environment.

Responding to cold

Involuntary responses like vasoconstriction, piloerection, shivering thermogenesis, and non-shivering thermogenesis that reduce heat loss and increase heat production when the body is cold.

Brown Adipose Tissue (BAT)

Specialized tissue for heat production, containing many mitochondria, fat-metabolizing enzymes, and an extensive vascular network.

Thyroid Hormones (T3 and T4)

Regulate metabolic processes, increasing heat production and body temperature, secreted in response to thyrotropin releasing hormone (TRH).

Insulin

Hormone secreted in response to high blood glucose levels, stimulates glucose uptake into cells, conversion to glycogen, and lowers blood glucose levels.

Glucagon

Secreted in response to low blood glucose levels and stimulates the breakdown of glycogen into glucose, thereby raising blood glucose levels.

Osmoregulation

Maintenance of internal balance between water and solute concentrations, crucial for regulating salt concentrations and biochemical processes.

Antidiuretic Hormone (ADH)

Regulates water reabsorption in the kidneys, released in response to increased blood osmolarity, decreasing urine output.

Homeostasis

Maintenance of a stable internal environment within an organism, involving endocrine and nervous systems to coordinate cellular activities.

Negative Feedback Loop

Mechanism that responds to changes in the body by adjusting variables back to their original state, maintaining stability.

Positive Feedback Loop

Mechanism that promotes a process rather than reversing the stimulus, amplifying the response.

Vasoconstriction

Constriction of blood vessels in response to cold temperatures, reducing heat loss.

Evaporative Cooling

Effective heat loss method through sweat evaporation, used by many animals to regulate body temperature.

Glycogen

Polymer storing glucose in the body, broken down into usable glucose for energy production during cellular respiration.

Homeostatic Mechanisms

Mechanisms that regulate the internal environment of the body to maintain functionality and health.

Endocrine System

System responsible for producing, storing, and releasing hormones that regulate various bodily functions.

Type 1 Diabetes

Autoimmune disease resulting from the destruction of insulin-producing beta cells in the pancreas, leading to insulin deficiency.

Hypoglycemia

Condition characterized by lower than normal blood glucose levels, causing symptoms like confusion, sweating, and fatigue.

Hyperthyroidism

Condition where excess thyroid hormones are secreted, affecting various bodily functions and metabolism.

Hyperthyroidism Symptoms

Include increased appetite, nervousness, tremors, fatigue, bulging eyes, sweating, and more.

Beta-Blockers

Drugs that manage hyperthyroidism symptoms by slowing down heartbeats and tremors.

Antithyroid Drugs

Medications that interfere with the thyroid's hormone production to reduce symptoms.

Radioactive Iodine Treatment

Permanent treatment for hyperthyroidism, where radioactive iodine is absorbed by the thyroid cells to kill them.

Thyroid Surgery

Involves removing part or all of the thyroid gland, leading to hypothyroidism and requiring lifelong thyroid hormone replacement therapy.