How the body regulates itself! Endocrine System How the body regulates itself!

Endocrine Glands Produce hormones and release them into the blood stream (ductless glands) Pituitary, thyroid, parathyroid, adrenal, pineal, thymus and thyroid

Endocrine Organs Pancreas Gonads: testes and ovaries

Neuroendocrine organ Hypothalamus: it receives information from the blood to direct the pituitary

Hormones Long distance and long lasting chemical signals that travel through blood and lymph They regulate the metabolic functions of other cells in the body (target cells)

Hormones regulate target cells by: Altering plasma membrane permeability or potential (opening and closing ion channels) Stimulates synthesis of proteins and regulatory molecules Activates or deactivates enzymes Induces secretory activity Stimulates mitosis

Endocrine Glands Pituitary: the master endocrine gland-produces at least 9 hormones Controlled by the hypothalamus Produces growth hormone (stimulates bone and skeletal muscles (lengthening and mass) Oxytocin: initiates uterine contractions, milk, and sexual arousal and connection to others (cuddle hormone)

Thyroid Gland Located at the anterior neck, on the trachea Thyroid hormone: 2 parts Thyroxine (T3): metabolic function of all cells Triiodothyronine (T4): trapping iodine Calcitonin: lowers blood calcium levels

Hypothyroidism: underactive, tiredness, weight gain HI Hypothyroidism: underactive, tiredness, weight gain Goiter: enlargement due to lack of iodine (iodized salt) Grave’s Disease: hyperthyroidism, shaky, enlarged eyes, anxiousness

Parathyroid Glands Usually 4 tiny glands Chief cells secrete PTH: increases blood calcium

Adrenal Glands Sit on top of the kidneys

Adrenal Glands Mineralocorticoids: (aldosterone) hormones that regulate electrolytes - (Sodium, potassium ions) Glucocorticoids: (cortisol) break down lipids into glucose during stress- excess can cause inflammation response Adrenal medulla hormones: norepinephrine and epinephrine-fight or flight

Pancreas Glucagon: releases glucose into the blood stream Insulin: lowers glucose level by increasing intake into cells Diabetes: deficiency in insulin-high blood sugar Symptoms: polyuria (excessive urination), polydipsia (excessive thirst) , polyphagia (excessive hunger) Hypoglycemia: low blood sugar- confusion, anxiety, too low-death

The Gonads Ovaries: estrogen and progesterone Testes: testosterone

Pineal gland Produces melatonin: peak levels at night make us sleepy, low levels at midday make us feel very awake Receives direct input from the visual pathways about light, and helps with circadian rhythms

Thymus Thymic hormones are necessary for T-cell production and the function of the immune system