PITUITARY GLAND considered the master gland because it controls all of the endocrine glands throughout the body; it is located in the brain next to the hypothalamus (considered part of the nervous system and endocrine system). It has two distinct lobes:

i) Posterior Lobe: stores and releases hormones produced by the hypothalamus: 1. Antidiuretic Hormone (ADH): stimulates the kidney to become more permeable to water, conserves body water, less urine produced Hyposecretion: Diabetes Insipidus Hypersecretion: excessive water retention 2. Oxytocin: stimulates the contraction of the uterus during labor and mammary glands for milk secretetion.

ii) Anterior Lobe: produces the following hormones

1. Growth Hormone (GH): stimulates the general growth of bones, muscles and organs by increasing the uptake of amino acids, the metabolism of fats, and rate of cell division. Hyposecretion in children causes Dwarfism Hypersecretion in children causes Giantism and in adults Acromegaly

2. Prolactin: stimulates milk production and secretion Hyposecretion results in poor milk production Hypersecretion causes overproduction of milk

3.Follicle Stimulating Hormone (FSH): stimulates ovarian follicle(egg) development and spermatogenesis; also stimulates production of Estrogen by the ovaries. Hyposecretion no follicle and sperm development,low estrogen in females Hypersecretion ; multiple follicle development, high sperm count

4. Lutenizing Hormone (LH): stimulates ovulation and the production of progesterone by the corpus luteum in the female; in the male stimulates the interstitial cells to produce testosterone Hyposecretion: no ovulation, low progesterone and testosterone levels Hypersecretion:high levels of progesterone and testosterone

5. Thyroid Stimulating Hormone (TSH): stimulates the thyroid gland to release its hormones Hyposecretion: low thyroxin levels Hypersecretion: high thyroxin levels

6. Adrenocorticotropic Hormone (ACTH): stimulates the adrenal cortex to release its hormones. Hyposecretion: low Cortisol and aldosterone levels Hypersecretion: High Cortisol and aldosterone levels

7. Melanocyte Stimulating Hormone (MSH): stimulates the melanocytes in the skin to produce melanin; pigmentation in the skin, in response to UV exposure. Hyposecretion: low pigmentation Hypersecretion: dark pigmentation

THYROID GLAND: located in the neck, below the larynx; controlled by TSH secreted by the pituitary and it is also affected by levels of Iodine in the body. Secretes two main hormones:

1. Thyroxin: regulates cell metabolism by speeding up the rate of cell respiration and the utilization of glucose and oxygen. Hyposecretion: low metabolism, Cretenism in children, Myxedema in Adults Hypersecretion: increases metabolic rate, Grave’s Disease. Note: Iodine must be present to make thyroxin; this is why salt is iodized to prevent the disorder Goitre

2. Calcitonin: reduces the amount of calcium in the blood by stimulating the bones to inhibit calcium release. Hyposecretion: increased Ca2+ levels in blood Hypersecretion: decreases Ca2+ levels

PARATHYROID GLANDS: the four smallest glands in the body found imbedded in the tissues of the Thyroid gland. Secrete one hormone: Parathyroid Hormone (PTH): raise blood calcium levels by stimulating the release of Ca2+from the bones and promoting Ca2+ uptake from the kidneys. Hyposecretion: decreases Ca2+ levels Hypersecretion: increased Ca2+ levels

PANCREAS: located below the stomach and is considered both an exo and an endocrine gland. Contains specialized cells known as the Islets of Langerhans which secrete the following hormones:

1. Insulin: decrease blood glucose levels by stimulating the conversion of glucose to glucagon in the liver, increasing cell metabolism of glucose and making cells permeable to glucose Hyposecretion: Diabetes Mellitus Hypersecretion: low blood glucose levels (Hypoglycemia); insulin shock

2. Glucagon: increases blood glucose levels by stimulating the breakdown of glycogen to glucose in the liver and muscles. Hyposecretion: low glucose levels (Hypoglycemia) Hypersecretion: raised glucose levels (Hyperglycemia)

ADRENAL GLANDS: located above the kidneys; prepares body for stress, aid in the regulation of the mineral content of the blood and in the production of some sex hormones. Has two distinct parts:

i) Adrenal Cortex: the outer portion of the gland; stimulated by ACTH from the anterior pituitary. Produces: 1.Cortisol: a glucocorticoid that increases the levels of amino acids in the blood; which are converted into glucose therefore increasing blood sugar levels. Hyposecretion: Low glucose levels Hypersecretion: high glucose levels

2. Aldosterone: increases the movement of Na+and water out of the kidney and into the blood, in response to low blood pressure. Hyposecretion: low blood Na+, high volumes of urine Hypersecretion: High blood Na+, low volumes of urine.

3. Sex Steroids: produces a small amount of estrogen, progesterone and testosterone for use when the sex organs are non-functional This is why both males and females have all sex hormones present in their body.

ii) Adrenal Medulla: interior portion of the gland; its secretions work closely with the nervous system to help in stress responses:

1. Adrenalin: increases blood sugar levels by stimulating the conversion of glycogen to glucose, constricts blood vessels in skin, increases blood pressure, heart rate and breathing rate. Hyposecretion: inadequate response to stress Hypersecretion: overreaction to stress.

2. Noradrenalin: has effects similar but not as strong as adrenalin; it helps control blood pressure.

TESTES: the male gonads; produces the male sex hormone Testosterone it stimulates spermatogenesis, development and maintenance of the secondary male sex characteristics. Hyposecretion: low sperm production, inhibited sexual maturation Hypersecretion: increases sperm production,

OVARIES: the female gonads; produces the two female sex hormones:

1. Estrogen: responsible for the development and maintenance of the secondary sex characteristics. Promotes development of the endometrium lining; prevents ovulation after fertilization; directly regulated by FSH. Hyposecretion: underdevlopment of sex characteristics; inhibited menstruation Hypersecretion: early puberty

2. Progesterone: maintains the endometrium , inhibits uterine contractions and ovulation; directly regulated by LH. Hyposecretion: early menstruation, no maintence of endometrium Hypersecretion: no menstruation

PLACENTA: an organ formed during pregnancy; provides for connection between mother and child for exchange of wastes, nutrients and gases. Produces 1. Relaxin: relaxes the pelvic ligaments widening the birth canal. 2. Estogen and Progesterone: used to maintain the endometrium lining during pregnancy and prevents further ovulation