Endocrine 1

What are hormones?

Chemical messengers secreted by endocrine glands and transported in the blood that control metabolism, growth, and reproduction.

What are the major endocrine organs?

Hypothalamus, Pituitary Gland, Parathyroid, Thyroid, Adrenals, Ovaries, Testes, Pancreas.

What type of hormones are most common?

Most hormones are amino acids (proteins), while sex and adrenal hormones are steroids synthesized from cholesterol.

What is the size of the pituitary gland?

About the size of a pea.

Why is the pituitary gland known as the 'Master Gland'?

It controls other glands in the endocrine system.

How many hormones does the pituitary gland secrete?

It secretes 9 hormones (probably more).

What are the two lobes of the pituitary gland?

Posterior Pituitary (Neurohypophysis) and Anterior Pituitary (Adenohypophysis).

What does the posterior pituitary store?

Neurohormones made in the hypothalamus.

What type of tissue does the anterior pituitary contain?

Glandular tissue that manufactures and releases hormones.

What is negative feedback in hormone secretion?

Inhibits hormone release when the desired effect occurs.

What is positive feedback in hormone secretion?

Stimulates hormone release when the desired effect occurs.

What are the signals sent for hormone release?

Blood (Humoral), Nerve impulse (Neural), Hormonal (from target endocrine glands).

What is meant by half-life (t1/2) of a hormone?

Specific effectiveness period before a hormone is deactivated.

What is synergy in hormonal effects?

The combined effects of hormones are greater than individual effects.

What is antagonism in hormonal effects?

One hormone opposes the effect of another.

How does the hypothalamus control the pituitary gland?

It regulates pituitary function for homeostasis.

How are hormones released from the anterior pituitary?

They are linked via blood vessels (hypothalamo-hypophyseal portal system).

What hormones does the anterior pituitary secrete?

Growth Hormone (GH), Thyroid Stimulating Hormone (TSH), Adrenocorticotropic Hormone (ACTH), Follicle Stimulating Hormone (FSH), Luteinizing Hormone (LH), Prolactin (PRL).

What is the role of Growth Hormone (GH)?

Stimulates cell growth and muscle mass; mobilizes fat for fuel.

What are the key hormones from the posterior pituitary?

Oxytocin and Antidiuretic Hormone (ADH).

What is the function of oxytocin?

Stimulates contractions during childbirth and triggers milk release during suckling.

What does antidiuretic hormone (ADH) do?

Inhibits urine production and promotes water reabsorption.

What can inhibit the release of ADH?

Alcohol and diuretic drugs.

What is a consequence of deficiency of ADH?

Diabetes insipidus (not related to glucose).