Endocrine System

Endocrine Organs

Hypothalamus

Pineal Gland

Pituitary Gland (Anterior & Posterior)

Thyroid

Parathyroid

Thymus

Adrenal Gland

Pancreas

Gonads

Endocrine vs Exocrine

Endocrine: Release hormones into their surroundings 

• No special ducts

Exocrine: A gland that makes substances and releases them through a duct or opening to the body

Pancreas (Endocrine and Exocrine)

release insulin and glucagon/secreting digestive enzymes

Gastrin (Endocrine Function)

hormone the facilitates the secreting of stomach acids (HCl)

Hormones

a regulatory substance product in an organism and transported in tissue fluids to stimulate specific cells or tissues into action

Hormone Biomolecules can derive from:

Amino acids such as in the form of polypeptide 

Lipids such as in the form of steroids

Hormone Function

Hormones bind to specific target cells and will cause some kind of action to occur

Brain

Anterior pituitary

• Makes their own hormones

Hypothalamus

• Makes their own hormones

Posterior pituitary

• Holds hormones made by the hypothalamus

Posterior Pituitary

• Oxytocin

  • Causes increased contractions of the uterus during labor 

  • Stimulates ejection of milk in the duct of the breasts

• Antidiuretic Hormone (ADH)

  • Constricts blood vessels and control salt in water in body

  • Kidney to reabsorb water

Anterior Pituitary

• Adrenocorticotropic hormone (ACTH)

  • Triggers release of cortisol form adrenal glands

• Thyroid-Stimulating Hormone (TSH)

  • Activates release of thyroid hormones

• Growth Hormone

  • Promotes protein synthesis and growth

• Follicle-Stimulating Hormone (FSH)

  • Formation of ova or sperm

• Luteinizing Hormone

  • Stimulates ovulation in females and androgen in men

• Prolactin (PRL)

  • Stimulates milk production in mammary glands

Pineal Gland

• Melatonin

  • Involved in sleep-wake cycle

Thyroid

• Thyroxine (T4)

  • Increases rate of chemical reactions in cells

  • Helps control growth and development

• Triiodothyronine (T3)

  • Stimulates nervous system in wakefulness, alertness, responsiveness to external stimuli

• Calcitonin

  • Lowers blood calcium

Parathyroid

• Parathyroid hormone

  • Rises blood calcium

Thymus

• Thymosin

  • Helps make T cells

Adrenal Medulla

• Epinephrine

  • Works on the heart

• Norepinephrine

  • Works on blood vessels

• increases heart rate & respiratory rate

• Shifts blood flow to skeletal muscles

  • vasoconstriction & vasodilation

Adrenal Cortex

• Cortisol

  • a glucocorticoid (steroid hormone)

  • Helps maintain blood pressure

  • Increases blood sugar levels, decreases immune response

  • Anti-inflammatory & Anti-immune functions

• Mineralocorticoids (Aldosterone)

  • Steroid hormones that play a role in salt and water balance

Pancreas

• Insulin

  • Controls blood sugar levels and metabolism

  • Turns food into energy

  • Lower blood glucose levels

  • From B cells of islets of Langerhans

• Glucagon

  • Helps regulate blood glucose levels

  • Raises glucose from glucose stored in the liver 

  • From A cells of islets of Langerhans

Gonads

• Estrogen

  • Steroid hormone develops female sex characteristics

• Progesterone

  • Creates healthy uterine linin for menstrual cycle and pregnancy

• Androgen

  • Develops male sexual reproduction and characteristics

Hypothyroidism

Lower than normal plasma concentration of T3 and T4

• Symptoms: cold intolerance, weight gain, and lethargy dye to decreased metabolic rate

Hyperthyroidism

Greater than normal plasma concentration of T3 and T4

• Symptoms: heat intolerance, weight loss, and possibly goiter