Endocrine System

Endocrine: Ductless Glands that secret hormones into the body

Functions Maintains homeostasis Long-term control using chemical signals. The endocrine system works in parallel with the nervous system to control growth and maturation along with homeostasis.

Hormones Chemical Messengers

Delivery System

Endocrine Gland Stimuli

Grouped into three classes based on their structure: Steroids Peptides Amines

Steroids Progesterone Aldosterone Made of Lipids derived from cholesterol. 2. Steroid hormones are secreted by the gonads, adrenal cortex, and placenta. Examples: Testosterone Progesterone Aldosterone

Peptides Short chains of Amino Acids Most hormones are peptides Processed by the E.R. and Golgi Apparatus Stored in vesicles- released when needed

Amines A modified amino acid- tyrosine Stored in the cytoplasm Example: epinephrine

Lipid Soluble: Such as Steroids

Hormones Regulate Gene Expression First Messenger   Second Messenger Regulates Gene Expression

Water Soluble- 2 messenger mechanism

Hypothalamus: Master Gland

Posterior Pituitary storage of hormones produced in hypothalamus Release upon neural impulse Diabetes insipidus- ADH deficiency – large amount of urine output

Anterior Pituitary Gland Produce and storage of hormones Production regulated by Hypothalamic hormones- GHRH, GHIH, TRH, CRH, GnRH, PIH

Regulation of Ant Pit. Hormones

Thyroid Hormone

Negative Feedback Regulation

Insulin and Glucagon- Regulation of Blood Sugar Levels

Regulation of Blood Volume and Pressure Antidiuretic hormone (ADH) is a chemical messenger molecule which is made in the hypothalamus and stored in the posterior pituitary gland. When osmoreceptors in the posterior pituitary sense blood which is too concentrated, ADH is released to increase water reabsorption by the kidneys.   Review the maintenance of water and salt balance by means of antidiuretic hormone (ADH) and aldosterone on pages 318 and 323, Construct feedback loop diagrams which illustrate the regulation of: 1. Water balance in the blood by ADH. 2. Salt balance in the blood by aldosterone.

Hormones You Need to Know Growth Hormone Thyroid Stimulating Hormone ACTH FSH and LH ADH and Aldesterone Thyroid Hormone PTH Glucagon Calcitonin Know: Name Where Produced Target Organ Effects