Hormornal Communication Flashcards
(30 cards)
What is hormonal communication?
The process by which hormones are transported in the blood to target organs to coordinate bodily functions.
What is a hormone?
A chemical messenger secreted by endocrine glands into the bloodstream that affects target cells.
What are endocrine glands?
Glands that secrete hormones directly into the blood (e.g. pituitary, adrenal, pancreas).
What are exocrine glands?
Glands that secrete substances into ducts (e.g. salivary glands).
What is the difference between steroid and peptide hormones?
Steroid hormones pass through cell membranes and act on DNA; peptide hormones bind to receptors on the cell surface.
What is the role of the adrenal glands?
Produce hormones like adrenaline (medulla) and corticosteroids like cortisol and aldosterone (cortex).
Where are the adrenal glands located?
Above the kidneys.
What hormones are secreted by the adrenal cortex?
Cortisol, aldosterone, and androgens.
What are the functions of cortisol?
Regulates metabolism, blood pressure, and immune responses.
What is the function of aldosterone?
Regulates salt and water balance, thus controlling blood pressure.
What hormones are secreted by the adrenal medulla?
Adrenaline and noradrenaline.
What is the function of adrenaline?
Increases heart rate, dilates pupils, and prepares the body for ‘fight or flight’.
What is the function of noradrenaline?
Increases blood pressure by causing vasoconstriction.
What is the pancreas?
A gland with both endocrine and exocrine functions, involved in blood glucose regulation and digestion.
What are the islets of Langerhans?
Endocrine regions in the pancreas that secrete insulin (beta cells) and glucagon (alpha cells).
What does insulin do?
Lowers blood glucose by increasing uptake by cells and promoting glycogenesis.
What does glucagon do?
Raises blood glucose by promoting glycogenolysis and gluconeogenesis.
What is glycogenesis?
The conversion of glucose to glycogen for storage.
What is glycogenolysis?
The breakdown of glycogen to glucose.
What is gluconeogenesis?
The formation of glucose from non-carbohydrate sources.
What is negative feedback?
A control mechanism where a change is reversed to maintain homeostasis.
What is positive feedback?
A mechanism that amplifies a change (e.g. oxytocin release during childbirth).
What is diabetes mellitus?
A condition where blood glucose levels are not properly regulated.
What is Type 1 diabetes?
An autoimmune condition where beta cells are destroyed, so no insulin is produced.
