Hormonal Regulation and Homeostasis

Vocabulary practice flashcards covering the hormonal system, endocrine glands, homeostasis mechanisms, and blood sugar regulation as described in the lecture notes.

Homeostasis

The process of achieving or maintaining an equilibrium of internal parameters in response to changing conditions (stimuli).

Endocrine glands

Hormonal glands containing gland cells that act as receptors and produce hormones (secretions) into the bloodstream.

Hormones

Signaling substances or secretions formed in endocrine glands that act as effectors, traveling through the blood to target specific cells.

Lock-and-key principle

The mechanism where hormones only affect target cells that possess specific membrane receptors sensitive to that hormone.

Erythropoietin ($EPO$)

A hormone produced by kidney cells that stimulates the bone marrow to produce extra red blood cells to increase $O_2$ uptake.

Thyroxine

A thyroid hormone, also known as a metabolic hormone, that stimulates metabolism, energy production, cell growth, and cell multiplication.

$$TRH$$

Hypofysestimulerend hormoon produced by the hypothalamus to stimulate the pituitary gland.

$$TSH$$

Schildklierstimulerend hormoon produced by the pituitary gland that stimulates the thyroid gland to produce thyroxine.

Adrenaline

A hormone produced by the adrenal glands ($\text{bijnieren}$) in response to stress, resulting in higher blood pressure, heart rate, and faster breathing.

Hypothalamus

A part of the brain that produces TRH and acts as a conductor for regulating body temperature and stress responses.

Islets of Langerhans

Areas in the pancreas containing alpha ($\alpha$) and beta ($\beta$) cells which act as receptors to regulate sugar metabolism.

Insulin

A hormone produced by beta cells ($\beta\text{-cellen}$) when blood glucose is high; it enables cells to absorb glucose and stores excess as glycogen or fat.

Glucagon

A hormone produced by alpha cells ($\alpha\text{-cellen}$) when blood glucose is low; it stimulates the conversion of glycogen and fat back into glucose.

Glycogen

A polysaccharide that serves as a reserve substance, created in the liver and muscles by converting glucose.

Negative feedback

A regulatory mechanism where the result of a process (e.g., lowering blood sugar) leads to the inhibition of the initial stimulus (e.g., insulin production).

Diabetes Type 1

A condition starting at a young age where the immune system destroys insulin-producing beta cells, leading to insufficient insulin.

Diabetes Type 2

A condition occurring usually after age 40 where the patient becomes insulin-resistant, and target cells no longer respond to insulin.

Thermoreceptors

Receptors in the skin that detect cooling or warming and send impulses to the hypothalamus to maintain an ideal temperature of $37^\text{o}\text{C}$.

Cortisol

A stress hormone produced in the adrenal cortex ($\text{bijnierschors}$) during long-term stress to increase metabolism and blood glucose levels.

Noradrenaline

A stress hormone produced in the adrenal medulla ($\text{bijniermerg}$) that works with adrenaline during short-term stress situations.