Human Endocrine System and Homeostasis

This set of vocabulary flashcards covers the human endocrine system, including specific glands like the adrenal, pancreas, pituitary, and thyroid, as well as the hormones they produce and their roles in homeostasis.

Adrenal glands

Glands located on top of the kidneys, each made up of an inner medulla and an outer cortex.

Aldosterone

A hormone secreted by the adrenal cortex that causes increased reabsorption of sodium ions from the filtrate in the nephrons of the kidney.

Cortisol

A hormone secreted by the adrenal cortex that increases the body's ability to resist stress in the long term.

Adrenalin

Known as the 'flight or fight' hormone, it is secreted by the adrenal medulla under situations of sudden danger, excitement, or stress to prepare the body for action.

Homeostasis

The processes that maintain a stable, relatively constant internal environment within an organism despite changes in the external environment.

Negative feedback

A mechanism that operates if a system is disturbed, setting off a sequence of events which counteract the disturbance to restore the system to its original state.

Islets of Langerhans

Groups of cells scattered throughout the pancreas that secrete hormones directly into the bloodstream.

Alpha cells

Cells in the islets of Langerhans that produce the hormone glucagon.

Beta cells

Cells in the islets of Langerhans that produce the hormone insulin.

Glucagon

A hormone that stimulates liver cells to convert stored glycogen into glucose to increase blood glucose levels.

Insulin

A hormone that promotes the uptake of glucose into body cells and stimulates muscle and liver cells to store glucose as glycogen.

Pituitary gland

Also known as the hypophysis, it is the 'master gland' attached to the hypothalamus that secretes various hormones to regulate other endocrine glands.

TSH (Thyroid-stimulating hormone)

A pituitary hormone that stimulates the thyroid gland to secrete thyroxin.

FSH (Follicle stimulating hormone)

A hormone that targets cells in the reproductive organs to undergo meiosis to form gametes.

GH (Growth hormone)

A hormone that targets the skeleton and muscles to promote growth by stimulating the synthesis of proteins.

Prolactin

A hormone that stimulates milk production in mammary glands.

Endocrine system

A system of ductless glands that produce and release hormones directly into the bloodstream to provide chemical coordination.

Hormones

Chemical messengers, usually proteins or steroids, secreted into the blood to carry instructions to specific target organs where they regulate metabolic reactions.

Exocrine glands

Glands that have ducts opening into a cavity, such as salivary glands or the digestive portion of the pancreas.

Gigantism

A growth disorder caused by the hypersecretion of GH before puberty, resulting in the over-development of the skeleton.

Acromegaly

A condition caused by the hypersecretion of GH after puberty, leading to the enlargement of bones in the face, hands, and feet.

Pituitary dwarfism

A condition caused by the hyposecretion of GH in children, resulting in under-development of the skeleton while maintaining normal body proportions.

Thyroid gland

A butterfly-shaped organ at the base of the neck that releases thyroxine to regulate metabolism.

Thyroxine

A hormone that increases the basal metabolic rate by regulating cellular respiration and body heat production.

Goitre

An enlargement of the thyroid gland often caused by a lack of iodine in the diet.

Basal metabolic rate

The amount of energy needed to maintain body functions at rest.

Hypothalamus

A part of the brain that acts as a link between the nervous and endocrine systems and regulates the pituitary gland.

ADH (Antidiuretic hormone)

A hormone produced by the hypothalamus that targets kidney collecting ducts to make them more permeable for water reabsorption.

Oxytocin

A hormone produced by the hypothalamus that stimulates uterine contractions and milk release after birth.

Oestrogen

A reproductive hormone produced by the ovaries responsible for secondary sexual characteristics and preparing the endometrium for pregnancy.

Progesterone

A hormone that works with oestrogen to bring about cyclic changes in the endometrium and helps maintain it during pregnancy.

Testosterone

A male reproductive hormone responsible for secondary sexual characteristics, sex drive, and the production of gametes.