The Endocrine System

Endocrine System

• System that “communicates” to control body functions

• Uses chemicals called hormones• Hormones come from glands• Unlike digestive glands, these glands are

ductless

*If they are ductless, how do they “communicate” with the body?

Major Glands of the Endocrine System

• hypothalamus• pituitary• thyroid• parathyroid glands• adrenal glands• pineal gland• pancreas*• reproductive organs (gonads)

Hypothalamus

• found in the brain, lower central part• regulation of satiety, metabolism and body

temperature• regulates the pituitary gland– somatostatin: stops release of growth hormone

Pituitary Gland

• found below the hypothalamus, pea-sized

• “most important gland of the endocrine system”

• produces a vast number hormones

• ex: growth hormone, TSH, ACTH, LH, FSH, prolactin

• ex: vasopressin, oxytocin

Thyroid Gland

• found in the lower front part of the neck

• regulates body metabolism

• maintains normal blood pressure, heart rate, digestion

Parathyroid glands

• pair of glands adjacent to the thyroid gland

• regulates calcium in bone and blood

Adrenal glands

• found on top of your kidneys• adrenal cortex and adrenal medulla• outer: corticosteroids – regulate metabolism,

salt and water balance• inner: catecholamines – deals with physical

and emotional stress (ex: adrenaline)

Pineal body

• regulates circadian rhythm• SAD (seasonal affective disorder)

Pancreas

• has both exocrine and endocrine function• “communicates” with the liver by hormones• islets of Langerhans– insulin – glucagon

Homework

• Pheromones• Sex hormones– androgens– estrogens