Endocrine System Flashcards

Flashcards based on lecture notes about the endocrine system.

What is the main difference between endocrine and exocrine glands?

Endocrine glands secrete hormones directly into the bloodstream and have no ducts, while exocrine glands secrete chemicals through ducts onto a surface.

Define 'hormone'.

An organic chemical substance secreted by an endocrine gland and carried in the bloodstream to a target organ to regulate metabolic reactions.

What is a 'target organ' in the endocrine system?

Cells that respond to a specific hormone due to having receptor sites for that hormone.

Describe an 'endocrine gland'.

A vascular, ductless gland that secretes hormones directly into the bloodstream.

Name two hormones secreted by the posterior lobe of the pituitary gland.

ADH (Antidiuretic Hormone) and Oxytocin.

Name three hormones secreted by the anterior lobe of the pituitary gland.

GH (Growth Hormone), TSH (Thyroid Stimulating Hormone), FSH (Follicle Stimulating Hormone), LH (Luteinizing Hormone), and Prolactin.

What does 'hyper' mean in the context of endocrine disorders?

Over-secretion of a hormone.

What does 'hypo' mean in the context of endocrine disorders?

Under-secretion of a hormone.

Name three disorders related to Growth Hormone (GH).

Gigantism, Dwarfism, and Acromegaly.

Name two disorders related to Thyroxin.

Hyperthyroidism, Hypothyroidism, Myxoedema and Cretinism

What hormones are produced by the pancreas and what cells produce them?

Alpha cells produce Glucagon and Beta cells produce Insulin.

Name a disorder that occurs due to a problem with the pancreas.

Diabetes.

Name two hormones secreted by the adrenal gland.

Adrenalin/Epinephrine, and Aldosterone.

What hormone is regulated by FSH and what structure produces it?

Estrogen, produced by the growing Grafian follicle.

What hormone is regulated by LH and what structure produces it?

Progesterone, produced by the corpus luteum.

What is the function of estrogen?

Involved in the formation and maintenance of secondary sex characteristics in females; also important in bone resorption and enlargement of the uterus and breasts during pregnancy.

What is the function of progesterone?

Prepares the uterus for pregnancy; involved in the formation and maintenance of the endometrium and uterus. Also involved in the reduction of contractility of the uterus and stimulates the growth of mammary glands.

What hormone is produced by the testes?

Testosterone.

Maintaining a constant internal environment in the body irrespective of the external environment can be described as?

Homeostasis

Name three factors that must be kept constant for optimal functioning during homeostasis.

Glucose levels, Water content, Salt concentration, O2 and CO2 concentrations, Body temperature, Metabolic waste, and pH.

What mechanisms are responsible for maintaining homeostasis?

Negative Feedback Mechanisms (NFM).

Describe how negative feedback mechanism works when the blood sugar is too high.

The beta cells detect the raised glucose levels, releasing insulin. Insulin goes to liver and muscles where Glucose is converted to glycogen. Cell membranes become more permeable to glucose, thus glucose levels are reduced.

Describe how negative feedback mechanism works when the blood sugar is too low

The alpha cells detect the decreased glucose levels, releasing glucagon. Glucagon goes to liver where Glycogen is broken down into glucose, which then causes Glucose levels to increase

What is the function of LH and FSH in males?

LH and FSH stimulate spermatogenesis and testosterone secretion by the testes.

Besides testosterone what other hormone is released by the Testes?

Inhibin

What are the effect of reproductive hormones, FSH and estrogen, on the ovaries?

ovarian growth of tissues follicle (egg)

What hormone causes repair of the uterine wall?

Estrogen

What hormone causes proliferation of uterine wall in preparation for implantation?

Progesterone