- Second controlling system of the body - Nervous system is the fast-control system - Uses chemical messengers (hormones) that are released into the blood

- are chemical substances released by the glands into the blood - Each hormone will go to the target organ and binds its receptor

2 TYPES OF HORMONES EXIST

Inter-related regulation between the HYPOTHALAMUS, Pituitary and the endocrine gland.

OTHER TERM OF Inter-related regulation between the HYPOTHALAMUS, Pituitary and the endocrine gland.

- Also called adenohypophysis - Hormones produced 1. Growth Hormone 2. STIMULATING HORMONES - ACTH, TSH, FSH, AND LH 3. PROLACTIN

➔ Directed to the growth of skeletal muscles and long bones ➔ Play an important role in determining final body size

➔ Hyposecretion of GH during childhood ➔ Body proportions are fairly normal ➔ Person as a whole is a living miniature ➔ maximum adult height of 4 feet

➔ Hypersecretion of GH during childhood ➔ Individual becomes extremely tall; ➔ 8 to 9 feet is common

➔ Hypersecretion of GH occurs after long bone growth has ended ➔ Enlargement of facial bones lower jaw and the bony ridges underlying the eyebrows ➔ Enlarge feet and hands

➔ Breast is the only known target in humans ➔ After childbirth, it stimulates and maintains milk production by the mother ’s breast

➔ Also called the neurohypophysis ➔ This lobe does not secrete hormones but only stores hormones ➔ Antidiuretic hormone (vasopressin) ➔ Oxytocin

➔ It stimulates powerful contractions of the uterine muscle during labor, during sexual relations, and when a woman breast-feeds her baby ➔ Causes milk ejection in a nursing woman (let-down reflex)

➔ A chemical that inhibits or prevents urine production ➔ It increases blood pressure by causing constriction of the arterioles ➔ Vasopressin

➔ Also called epiphysis cerebri ➔ Secretes melatonin

➔ Peak levels occur at night and lowest during daylight “Sleep Trigger” that plays an important role in establishing the body’s day-night cycle.

➔ Located in the lower part of the anterior neck With two lobes connected by the isthmus ➔ thyroxine (T4) and triiodothyronine (T3) ➔ T3 is the most active hormone ➔ Function of T3/T4: ➔ Increase metabolic rate, essential for normal growth and maturation

MOST ACTIVE HORMONE IN THYROID GLAND

➔ released in response to an INCREASED calcium level in the blood Function: ➔ decreases bone resorption ➔ increases calcium excretion in the kidney to decrease the calcium levels

➔ Enlargement of the thyroid gland that results when the diet is deficient in iodine

➔ Hyposecretion of thyroxine ➔ Results in dwarfism ➔ Body proportions remain childlike ➔ Mentally retarded

➔ Hypothyroidism ➔ Physical and mental sluggishness ➔ Puffiness of the face, fatigue, poor muscle tone, low body temperature, obesity and dry skin

➔ Hyperthyroidism ➔ Heat intolerance, rapid heartbeat, weight loss, nervous and agitated behaviour ➔ Exophthalmos

➔ Increases bone breakdown by osteoclasts ➔ Increases Vitamin D synthesis ➔ Increases Calcium level in the blood ➔ Causes retention of calcium in the kidney.

a pair of gland resting on top of each kidney with 2 layers

● Secretes mineralocorticoids ● Secretes glucocorticoid ● Secretes androgens- sex hormones

● Secretes the catecholamines ● Epinephrine, and norepinephrine

➔ MineralocorticoidAldosterone ➔ Increases sodium retention, water retention secondarily ➔ Causes excretion of potassium ➔ Glucocorticoids ➔ Cortisol ➔ Increases fat and protein breakdown ➔ Increases glucose synthesis ➔ Inhibit inflammation and immune response ➔ Adrenal androgens ➔ Estrogens, androgens and progestins ➔ Insignificant in males Increase female sexual drives, pubic hair and axillary hair growth

The endocrine portion of the pancreas is the ___________

This islet is composed of three types of cells-

The ALPHA secrete _____

The BETA secrete _____

The DELTA secretes _____

➔ Causes Hypoglycemia by two mechanisms: ➔ Glucose breakdown glycolysis ➔ Glycogen production glycogenesis ➔ Needed by most body cells to allow Glucose to enter the cell membrane ➔ The brain cells, intestinal cells, the red blood cells and the islet cells do not need insulin for glucose entry

➔ Causes increased level of Glucose by: ➔ Glycogen breakdown glycogenolysis ➔ Glucose production gluconeogenesis

➔ Polyuria, Polydipsia and Polyphagia ➔ Blood levels of glucose ➔ 80 to 120mg/dL ➔ TypeI–IDDM ➔ Type II - NIDDM

➔ Aid in spermatogenesis ➔ Maintain functional reproductive organs ➔ Responsible for secondary sex characteristics ➔ Responsible for male sexual drives

THE GONADS: _____ ➔ The testes houses the Interstitial cells of Leydig which secrete ANDROGENS ➔ Testosterone ➔ Dihydrotestosterone ➔ Androsterone

THE GONADS: ____ ➔ The Follicular cells of the ovarian follicle secrete ESTROGEN and the corpus luteum secretes PROGESTERONE

➔ Aids in uterine and mammary gland development ➔ Maintains the structure of the external genitalia ➔ Produces the secondary sexual characteristics in female ➔ Maintains normal menstrual cycle

➔ Together with estrogen, maintains normal menstruation ➔ Increases body temperature ➔ Decreases muscle tone and peristalsis ➔ Maintains pregnancy