Name:___________________________________________
Date:_____ Period:______
Chapter 13: Endocrine System
I. Introduction and General Characteristics of the Endocrine System
A. The endocrine glands secrete hormones.
B. Hormones diffuse from __glands__ into Blood Stream and eventually act on organs.
C. Paracrine secretions are near the target.
D. Autocrine secretions are affect self (targets itself) .
E. Exocrine glands secrete substances into ducts.
F. Endocrine glands and their hormones control target cells or organs.
G. Endocrine hormones also play vital roles in homeostatsis.
H. The larger endocrine glands are thyroid, adrenal, thymus.
II. Hormone Action
A. Introduction
1. Hormones are released into blood stream.
2. They diffuse into the cell and are carried into the nucleus.
B. Chemistry of Hormones
1. Introduction
a. Most hormones are steroids.
b. Nonsteroid hormones include insulin and glucagon.
2. Steroid Hormones
a. Steroids are any hormone affecting the development and growth of sex organs.
b. Examples of steroid hormones are estrogen, testosterone, cortisol.
3. Nonsteroid Hormones
a. Examples of hormones called amines are _______________________ .
b. Protein hormones are composed of ____________________________ .
c. Examples of protein hormones are _____________________________ .
d. Hormones called glycoproteins are produced by __________________ .
e. Peptide hormones are _______________________________________ .
f. Peptide hormones come from _________________________________ .
g. Prostaglandins are ____________________________________ and are
produced ___________________________________________________ .
C. Actions of Hormones
1. Introduction
a. Hormones exert their effects by passing through the plasma (cell) membrane and going
13-1
Name:___________________________________________
Date:_____ Period:______
Chapter 13: Endocrine System
into the cell .
D. Prostaglandins
1. Prostaglandins are a group of lipids.
2. Some prostaglandins regulate labor and devlivery.
3. The variety of effects prostaglandins can produce include infamation, swelling, pain, stiffness,
redness, warmth.
III. Control of Hormone Secretion
A. Introduction
1. Hormones are continually exrete (release) in urine and broken down
in the liver.
2. Increasing or decreasing blood levels of hormones requires Positive or negative feedback loops.
B. Control Sources
1. Control of hormone secretion is regulated by feedback loops.
2. The hypothalamus controls body temp, hunger, thirst, etc….
3. Tropic hormones stimulate other endocrine glands.
4. An example of an endocrine organ directly stimulated by the nervous system is hypothalamus.
5. Some endocrine glands respond to changes in the external environment.
6. As a result of homeostatsis, hormone levels remain relatively stable.
IV. Pituitary Gland —Other Endocrine Glands
A. Introduction
1. The pituitary gland is located in the brain.
2. The two portions of the pituitary are anterior and posterior.
4. The anterior lobe secretes the following hormones: THSm FSH, LH, growth hormone.
5. The posterior pituitary secretes the following hormones: oxytocin and vasopressin.
6. The hypothalamus controls most of the pituitary gland’s activities.
7. The posterior pituitary receives impulses from hypothalamus.
8. Hormones from the hypothalamus controls the anterior pituitary.
9. The hypophyseal portal veins are blood vessels that connect the hypothalamus to the anterior
pituitary.
D. Thyroid Gland
1. The thyroid gland consists of 2 lobes.
2. The thyroid gland is located in the neck.
13-2
Name:___________________________________________
Date:_____ Period:______
Chapter 13: Endocrine System
F. Thyroid Hormones
1. The three hormones produced by the thyroid gland are thyroxin (T3), T4, and calcitonin.
2. The actions of thyroxine and triiodothyronine are regulat metabolism.
3. The secretion of T3 and T4 are controlled by TSH - thyroid stimulating hormone.
G. Parathyroid Glands
1. Parathyroid glands are located on the thyroid.
2. Usually a person has 4 parathyroid glands.
I. Parathyroid Hormone
1. The actions of PTH are regulate calcium nd phosphorus levels.
2. The secretion of PTH is controlled by parathyroid gland.
J. Structure of the Glands – Adrenal Glands
1. The adrenal glands are shaped like triangles.
2. The two parts of an adrenal gland are cortex and medulla.
4. Sex Hormones
a. The sex hormones are secreted by gonands (ovaries and testies).
b. The actions of the sex hormones are develop sex organs.
c. Examples of sex hormones are testosterone, estrogen, progesterone.
M. Pancreas
1. The pancreas is located below the stomach.
N. Hormones of the Pancreatic Islets
1. The actions of glucagon are raises blood glucose (sugar) levels.
2. The secretion of glucagon is controlled by pancreas.
3. The actions of insulin are lowers blood glucose (sugar) levels.
4. The secretion of insulin is controlled by pancreas.
O. Hormones of Other Endocrine Glands
1. The pineal gland is located in the brain.
2. The pineal gland produces the hormone melatonin.
3. The functions of melatonin are sexual development and sleep cycles.
4. The thymus gland is located in the chest.
5. The thymus gland secretes a group of hormones called thymosins.
6. The function of thymosin is immunity.
7. Reproductive organs that secrete hormones are gonands.
13-3
Name:___________________________________________
Date:_____ Period:______
Chapter 13: Endocrine System
8. Examples of hormones produced by reproductive organs are estrogen, testosterone.
9. The hormone produced by the heart is ANF – atrial natiuretic factor.
10. The hormone produced by the kidneys is EPO – erthyropoietin and calcitrol.
13-4