1. The Endocrine system

2. There is a difference between endocrine and exocrine glands.
Endocrine: the cells, tissues, and organs that secrete hormones directly into the body fluids. Ex: thyroid gland
Exocrine: parts which send secretions through ducts(tubes) to some internal or external surface. Ex: salivary gland
Endocrine glands and their hormones help to regulate metabolic processes.

3. Endocrine Glands Pituitary Pineal Thymus Hypothalamus Thyroid
Parathyroids
Adrenal
Pancreas
Gonads

4. Hormones
Hormones are chemical messengers that cause an effect on target cells. Hormones are very potent and are either peptide hormones or steroid hormones.
Peptide: chains of amino acids that bind to receptors on target tissue. This changes the metabolism of the cell.
Steroid: complex rings of Carbon and Hydrogen that bind to molecules that enter the cell. Change genetic activity of the cell.

5. Pituitary Located at base of the brain
Some hormones signal other glands to produce hormones:
FSH(follicle stimulating hormone) signals sex cell maturation
LH( lutenizing hormone) signals ovulation
Some hormones do not signal other glands:
GH (growth hormone) stimulates Î use of amino acids by bones and muscles
Prolactin-stimulates mammary glands to produce milk
Oxytocin-signals uterus to contract

6. Pineal Gland Found deep in the brain
Controls your circadian rhythm(sleep/wake cycle)
Melatonin: produce base on the amount of light
Î light decrease amount of melatonin
Decreased light increases the amount of melatonin

7. Thymus Gland Found behind sternum in front of heart/shrinks as you age
Plays role in immune system
Thymosin: increases production of WBC

8. Hypothalamus Inside the brain
Connects the endocrine system to the nervous system
Fight or flight response
Doesn’t produce a hormone but can communicate with the adrenal glands and they will produce hormones

9. Pancreas Found posterior to the stomach Attached to small intestine
Functions as exocrine and endocrine
Plays a role in digestive system and endocrine
Special endocrine cells called islets of Langerhans
Insulin: decreases concentration of glucose in the blood by promoting uptake in cells of liver and skeletal muscles
insulin
Glycogenesis=glucose------ glycogen( in liver)

10. Pancreas, cont.
Glucagon: increases concentration of glucose in blood by stimulating breakdown of glycogen into glucose
glucagon
Glycogenolysis=glycogen------glucose(liver)

11. Gonads Sex organs Female (ovary)
Estrogen: stimulates development of female sex characs ( breasts, high voice)
Progesterone: helps prepare uterus for pregnancy
Male (testes)
Testosterone: stimulates development of male sex characs (muscle, hair, enlarged larynx. Aggression, sex drive)

12. Thyroid Located on either side and in front of the trachea
Thyroid hormone: increases the rate of metabolism in most body cells
Calcitonin: decreases the concentration of Calcium in blood “Tone it down”

13. Parathyroids There are 4 of these glands
Very small and on back side of thyroid gland
PTH: parathyroid hormone-causes an increase in concentration of Calcium in blood. Opposes Calcitonin. “Put it up”

14. Adrenal Glands Found perched on top of both kidneys
Each gland has an outer layer( cortex) and an inner section (medulla)
Medulla
Epinephrine: increases HR, RR, BP, cardiac contraction, but decreases digestion
Norepinephrine: same effects, but chemically different
Cortex
Aldosterone: regulates concentration of electrolytes (Na, K) promotes water conservation and decreases urine production
Cortisol: decreases inflammation; helps regulate blood sugar