1. Endocrine System  A system that consists of glands that transmit chemical messengers throughout the body.  HORMONES: chemical that circulates throughout the blood stream and influence the activity of distant cells -Protein (Amino Acid) based hormones: adrenaline and insulin -Lipid based hormones: estrogen and testosterone -Hormones affect specific cells called TARGET CELLS that contain receptors that recognize and bind to a specific hormone -RECEPTORS are proteins that are found inside and on the outside surface of the target cell

2. GLANDS GLAND: an organ that secretes hormones or non-hormone chemicals  ENDOCRINE  Masses of secretory cells  Ductless  Secrete their hormone directly into blood of capillaries or tissue fluids  EXOCRINE  Secrete non- hormonal materials into ducts  Transport materials inside and outside body to specific locations  Ex. Sweat glands, salivary, mucous and digestive glands

3. Functions of Hormones 1.Maintain homeostasis within the body Ex. Metabolism, muscle contraction, immune activities, interstitial fluid 2.Control growth and development 3.Regulate the reproductive system 4.Help establish circadian rhythms

4. Homeostatic Control  The N.S. and endocrine systems work together simultaneously to maintain control of body mechanisms  Due to feedback systems within the body the body is continuously monitored, evaluated and changed to any outside stimulus.  Any stimulus will trigger the N.S. to send messages in the form of nerve impulses to organs or glands (effector site) to bring about change  The N.S. quite often either stimulates or inhibits the release of hormones and hormones may promote or inhibit the generation of nerve impulses

5. ENDOCRINE GLANDS  There are 10 endocrine glands in this system  They are located throughout the body and regulate many of the vital body processes  Hypothalamus  Pituitary  Thyroid  Parathyroid  Thymus  Pancreas  Adrenal  Pineal  Testes and Ovary

6. HYPOTHALAMUS  Located inferior to the thalamus in the diencephalon  Regulates the activity of other glands and some nervous function, directly influences pituitary, kidney, ovaries and testes  Controls most of the emotions, feelings, mood, hunger, thirst, circadian homeostasis  Secretes releasing and inhibiting hormones, oxytocin

7. Pituitary  Antidiuretic hormone (ADH)  Follicle stim Hormone (FSH) (stim egg prod, sperm male)  Growth hormone (GH)  Lutinizing hormone (LH) (stim progest, estrog, ovulation)  Oxytocin (breast, uterus)  Prolactin (milk prod.)  Thyroid stim hormone (TSH) (reg thyroid)  Location: superior/anterior end of brain stem  Gland that regulates skeletal growth, stimulates development of male/female sex organs, kidney and thyroid function  Secretions will stimulate other target cells

8. Pineal  Located in the posterior diencephalon  Functions to control body sleep patterns, sexual development  Secretes the hormone melatonin -stim by dark, inhibit by light Other  Pineal cells show resemblance to retinal photoreceptors - when photorecep stim by light – neuro signal stim pineal - when photorecep stim by light – neuro signal stim pineal  A derivative of the amino acid tryptophan which functions in the CNS

9. THYROID  Located inferior to the larynx  Functions to increase rate of metabolism and maintains levels of calcium/potassium, helps construct bone  Stimulated by TSH  Secretes thyroxine (T4), triiodothyronine (T3), and calcitonin (calc from blood to bone )

10. PARATHYROID  Embedded in the posterior thyroid  Regulate calcium/potassium in body necessary for bone growth, muscle tone and neural activity  Secretes parathyroid hormone which increases calcium ions in blood

11. THYMUS  Located beneath the sternum and can be located lying over the base of the heart  Functions to support the immune system  Secretes thymosin that stimulates formation of T cells (WBC) - T-cells help regulate and destroy foreign invaders Food Fact – called sweet breads in calves Sweet breads and vegetables

12. PANCREAS  Located in the abdominal cavity posterior to stomach  Functions to maintain a steady flow of glucose or sugar in the blood and to keep the body supplied with fuel to produce and maintain stores of energy.  Secretes insulin, glucagon, somatostatin (suppress action of pancreas)

13. ADRENAL  Located on superior end of kidney  Regulate electrolyte uptake in kidney, sexual development, metabolism, immune system, -Flight or Fight response - stress, heart rate, breathing rate, blood pressure -Flight or Fight response - stress, heart rate, breathing rate, blood pressure  Secretes adrenaline, norepinephrine, cortisol, dopamine, aldosterone

14. Testes/Ovaries functions to produce sex characteristics  Testes  Located in the scrotal sac and secretes testosterone  Male characteristics, muscle mass/strength, sperm prod.  Ovaries  Located in the pelvic cavity and secretes estrogen and progesterone  Female characteristics, uterine control, cervix, breast and fat tissue, joints