Human Physiology – Peripheral Endocrine Glands

Flashcards summarizing key concepts from the lecture notes on human physiology related to peripheral endocrine glands and hormone functions.

Thyroid hormone synthesis

The process by which thyroid hormones (T3 and T4) are produced and stored using thyroglobulin and iodide.

Hypothyroidism

A condition characterized by insufficient secretion of thyroid hormones, leading to decreased metabolism.

Hyperthyroidism

A condition characterized by excessive secretion of thyroid hormones, causing increased metabolism.

Goiter

An enlargement of the thyroid gland that can occur in both hypothyroidism and hyperthyroidism.

Adrenal cortex

The outer layer of the adrenal glands that secretes hormones like mineralocorticoids and glucocorticoids.

Mineralocorticoids

Hormones secreted by the adrenal cortex that regulate sodium and potassium balance, such as aldosterone.

Glucocorticoids

Hormones like cortisol that exert metabolic effects and help the body adapt to stress.

Epinephrine

A catecholamine secreted by the adrenal medulla that enhances the body's fight-or-flight response.

Stress

A state of worry or mental tension caused by challenging situations, prompting a body's generalized reaction.

Anabolism

The metabolic process with the buildup of large organic macromolecules from smaller subunits.

Catabolism

The metabolic process involving the breakdown of large energy-rich organic molecules for energy.

Insulin

A hormone produced by the pancreas that lowers blood glucose levels and promotes storage of nutrients.

Glucagon

A hormone secreted by the pancreas that raises blood glucose levels by promoting glycogenolysis and gluconeogenesis.

Parathyroid hormone (PTH)

A hormone that raises plasma Ca2+ levels by acting on bones, kidneys, and intestines.

Vitamin D

A hormone that increases the absorption of calcium in the intestine and supports bone health.

thyroid gland

controls basal metabolic rate

adrenal glands

secrete hormones important for maintaining salt balance, nutrient molecules, and adapting stress

endocrine pancreas

secrete to metabolize nutrient molecules

parathyroid glands

secrete a hormone important for Ca2+ metabolism

C cells

are in between follicles and secrete calcitonin

Thyroid hormones

are stored and synthesized on the thyroglobulin molecule

Thyroxine-binding globulin

a plasma protein that selectively binds only thyroid hormone

Sympathomimetic effect

the thyroid hormone is amplified

Adrenal gland consists of

a steroid secreting cortex and a catecholamine secreting medulla

Mineralocorticoids, glucocorticoids, and sex hormones

are secreted by the adrenal cortex

The layers of the adrenal cortext

Zona glomerulosa, zona fasciulata, zona reticularis

Glucocorticoids

play a key role in adaptation to stress

Adrenal medulla consists of

sympathetic postganglionic neurons and cells that secrete catecholamines

Catecholamines

are secreted into the blood by exocytosis of chromaffin granules

Islets of Langerhans

endocrine cells scatted throughout the pancrease

alpha cells

secrete glucagon

beta cells

secrete insulin

Amylin

a hormone co-secreted with insulin by beta cells to help regulate blood sugar levels.

Glucagon secretions

is increased during a postabsorptive state and decreased during an absorptive state

Calcitonin

lowers plasma Ca2+ concentration

Vitamin D

hormone that increases Ca2+ absorption in the intestine