Endocrine System
2nd control system; works with the nervous system for homeostasis;
exerts slow acting for long lasting control; releases hormones that
interacts w/ target organs to cause changes.
Hormone
chemical messengers that are released into the blood through body
tissues and cells
Target organs
organs that respond to particular hormones
Glands
composed of epithelial tissue that produce and secrete products
Endocrine gland
secretes hormones into the blood or lymph (ductless)
Exocrine gland
releases products at body surfaces onto epithelial membranes via
ducts. (duct)
Pituitary gland
the master gland; separates into anterior and posterior pituitary gland
Anterior pituitary gland
produces hormones:
Tropic hormones: gonadotropins; adrenocorticotropic hormone; thyroid
stimulating hormone
Other hormones: prolactin; growth hormone
Gonadotropins
stimulates the gonads
Adrenocorticotropic hormone
regulates hormone production
Thyroid-stimulating hormone
regulates growth
Growth hormone
regulates growth
Prolactin
regulates breast development
Posterior pituitary gland
stores hormones: oxytocin and antidiuretic hormone
Oxytocin
stimulates urine contraction
Antidiuretic hormone (ADH)
conceives water
Homeostatic imbalance: diabetes insipidus
Gigantinism
hyper secretion of growth hormone in children
Acromegaly
hyper secretion of growth hormone in adults
Thyroid gland
2 lobes connected by the isthmus
2 hormones: Thyroid hormone; Calcitonin
Thyroid hormone
Thyroxine (T4) & Triiodothyronine (T3); control metabolic rate
Calcitonin
stimulates deposition of calcium into the bones
Parathyroid glands
located posterior of the thyroid gland (4)
regulates calcium balance by increasing secretion of from bone and
decreasing excretion from kidneys.
Adrenal glands
secretes corticosteroids; divided into outer (cortex) and middle (medulla)
Hormones: glucocorticoids; mineralocorticoids; gonadocorticoids
Glucocorticoids
increases blood glucose during stress
Mineralocorticoids
regulates water and electrolyte balance
Gonadocorticoids
sex hormones
Pancreas
regulates blood glucose levels
Hormones: insulin and glucagon
Insulin
decreases blood glucose
Glucagon
increases blood glucose
Gonads
Female ovary (estrogen and progesterone) and Male testis (testosterone)
Thymus
involved in maturation of T lymphocytes
Pineal Glands
produces melatonin which peaks at night and makes us sleepy