1. Endocrine System

2. Hormones
Hormones are chemicals that are secreted into the blood stream by the endocrine glands
Hormones are received by target cells throughout the body
Target cells have receptor proteins that help determine the response to the hormone
Different hormone/receptor combinations cause different responses

4. Types of Hormones Hormones Steroid Hormones
Diffuse directly into target cell
Lipid soluble
Made in SER of secreting cell
Peptide and Amine Hormones
Cannot directly enter target cell
Large polypeptide molecules
Insoluble in lipid

5. Steroid Hormone

6. Target Cell Creates Response

7. Chemical Structure of Steroids
Steroid hormones are created by modifying cholesterol molecules

8. Peptide and Amine Hormones
Peptide and Amine hormones are large molecules that are not lipid soluble and cannot enter target cells directly.

10. Glands of the Endocrine System
Hypothalamus
Connection between the Nervous System and the Endocrine System
Secretes Antidiuretic Hormone (ADH) to help maintain kidney functions
Secretes hormones into the pituitary gland to stimulate the production of other hormones

11. Pituitary Gland Sometimes called the “Master Gland”
Controls many other glands in the body
Directly connected to the Hypothalamus through neural connections

12. Pituitary Gland Hormone Effect Somatotropin (Growth Hormone)
Affects growth and development; stimulates protein production
Prolactin
Stimulates milk let down during lactation
Thyroid-stimulating hormone (TSH)
Stimulates the production and secretion of thyroid hormones
Luteinizing hormone (LH)
In females this LH acts on the ovary to stimulate the production of estrogens and induce ovulation. In males this LH acts on the testis to stimulate the production of testosterone.

13. Pineal Gland
Located in the center of the brain behind the Hypothalamus
Produces Melatonin which helps regulate sleep and waking cycle
Sometimes called the “Biological Clock”

14. Thyroid Located in front of the trachea
Responsible for maintaining Metabolism

15. Thyroid Hormone Effect Triiodothyronine (T3)
Body temperature, growth and heart rate
Thyroxine (T4)
Controls the metabolic processes in the body
Calcitonin
Stimulates calcium deposits to bones

17. Parathyroid Four small glands located on the back of the Thyroid
Help to maintain the amount of calcium in the blood to maintain muscle and nervous function

18. Parathyroid Releases Parathyroid Hormone when calcium levels are low
This causes bone break down and increased calcium absorption

19. Thymus Essential in the development of immune functions
Very large in childhood
Tissue is replaced by fat into adulthood
Produces humoral which stimulates the development of the lymphoid system

20. Adrenal Glands Located on each of the Kidneys
Divided into two sections
Cortex
Produces hormones essential to life
Medulla
Produces hormones not essential to life

21. Adrenal Glands Hormone Effect Cortisol
Immune suppression and stress response
Adrenaline (Epinephrine)
*** Also a neurotransmitter
Variety of reactions depending on the tissue.
Heart – Increases heart rate
Lungs – Increases respiration rate
Liver - Glycogenolysis
Noradrenaline (Norepinephrine)
*** Also a neurotrasmitter
Similar to Adrenaline

22. Pancreas Main control of the blood sugar in the body
Secretes Insulin or Glucagon as required to maintain blood sugar levels
Endocrine portion is called the Islets of Langerhans

23. Blood Sugar Homeostasis

24. Testes/Ovaries Development and maintenance of sex traits
Become more active at puberty
Produce steroid hormones

25. Testes/Ovaries Hormone Effect Estrogen
Maintaining female sex characteristics
Testosterone
Maintaining male sex characteristics
Progesterone
Stimulates the lining of the uterus and prepares the body for milk production
Inhibin
Inhibits the production of Follicle Stimulating Hormone (FSH) in the Pituitary gland