1. Human Endocrine System

2. Human Endocrine System
The endocrine system consists of ductless glands that produce hormones
Hypothalamus, pituitary, pineal, thyroid, parathyroid, thymus, adrenal, pancreas, ovary, testes
Hormones are chemical messengers that travel through the blood stream and affect activities throughout the body.
Steroid hormones
Nonsteroid hormones
Human Endocrine System
Glands produce and release secretions. Endocrine glands (ductless) produce chemical substances called hormones and release them into the bloodstream. These glands include the hypothalamus, pituitary, pineal, thyroid, parathyroid, thymus, adrenal, pancreas, ovary and testes. Exocrine glands deliver secretions through a duct or tube to specific locations (salivary glands, sweat glands, mucous glands).
Hormones are chemical messengers that bind to target cells and affect cell activities. In general, the response of the body to hormones is slower and more long lasting than the response to nerve impulses. The release of hormones is controlled through a negative feedback system. Negative feedback systems are control mechanisms that operate by inhibiting a process or activity that originally led to starting the process or activity. For example, as glucose levels in the body increase, sensors in the pancreas signal the release of the hormone insulin. Insulin promotes the entry of glucose into cells, lowering glucose levels. As the glucose levels in the blood decrease, the pancreas stops secreting insulin.
Steroid hormones are produced from the lipid, cholesterol and are able to pass through cell membranes and bind to receptor proteins. Nonsteroid hormones are made from amino acids and generally cannot pass through the cell membrane. These hormones bind to a receptor site on the outside of a cell in order to initiate chemical reactions inside the cell.
References:
Campbell, N.E. & Reece, J.B. (2002). Biology,(6th ed.). San Francisco: Benjamin Cummings.
Raven, P.H. & Johnson, G.B. (2002). Biology, (6th ed.). McGraw-Hill.

3. Hormones
Hormones are chemical messengers that bind to target cells and affect cell activities
Nonsteroid hormones are made from amino acids and generally cannot pass through the cell membrane. These hormones bind to a receptor site on the outside of a cell in order to initiate chemical reactions inside the cell.
Steroid hormones are produced from the lipid, cholesterol and are able to pass through cell membranes and bind to receptor proteins.

4. Nonsteroid hormones – cannot go through cell membrane, must activate proteins in the cell membrane
Steroid hormones – can go through cell membrane to reach receptors inside the cell

5. Hormones have specific shapes that fit receptors or the surface of the target organ or structure they are going to influence
Bind with cell receptors
If incorrect receptor the particular hormone has no effect

8. The Brain Pituitary gland biology Animation
Endocrine Glands biology Animation
Section 35-3
Pons
Pituitary gland
Hypothalamus
Cerebrum
Medulla oblongata
Spinal cord
Cerebellum
Pineal gland
Thalamus

9. The Endocrine Glands Section 39-1 Hypothalamus
The hypothalamus makes hormones that control the pituitary gland. In addition, it makes hormones that are stored in the pituitary gland.
Pineal gland
The pineal gland releases melatonin, which is involved in rhythmic activities, such as daily sleep-wake cycles.
Thyroid
The thyroid produces thyroxine, which regulates metabolism.
Pituitary gland
The pituitary gland produces hormones that regulate many of the other endocrine glands.
Pancreas
The pancreas produces insulin and glucagon, which regulate the level of glucose in the blood.
Parathyroid glands
These four glands release parathyroid hormone, which regulate the level of calcium in the blood.
Ovary
The ovaries produce estrogen and progesterone. Estrogen is required for the development of secondary sex characteristics and for the development of eggs. Progesterone prepares the uterus for a fertilized egg.
Thymus
During childhood, the thymus releases thymosin, which stimulates Tcell development.
Testis
The testes produce testosterone, which is responsible for sperm production and the development of male secondary sex characteristics
Adrenal glands
The adrenal glands release epinephrine and nonepinephrine, which help the body deal with stress.

10. Glands I
Hypothalamus – coordinates activities of the nervous and endocrine systems and produces hormones to regulate the pituitary gland
Pituitary – produces hormones that direct the activities of other endocrine glands
Pineal – releases melatonin which is involved in rhythmic or cyclic activities
Thyroid – produces hormones that regulate metabolism and development
Parathyroid – helps maintain appropriate calcium levels

11. Glands II Thymus – involved with immune development during childhood
Adrenal – regulates the body’s stress response (epinephrine, norepinephrine, cortisol, aldosterone)
Pancreas – controls glucose levels in the blood (insulin, glucagon)
Ovary – secretes estrogen and progesterone to regulate reproduction
Testes – produces testosterone to control formation of sperm and sexual behavior

12. Negative Feedback
The level of one hormone in the blood inhibits or stimulates the production of another hormone or substance
Homeostasis biology Animation

13. CONTROL OF THE ENDOCRINE SYSTEM
REGULATED BY FEEDBACK MECHANISMS
EX: HEATING SYSTEMS

14. Negative Feedback
The release of hormones is controlled through a negative feedback system
Negative feedback systems are control mechanisms that operate by inhibiting a process or activity that originally led to starting the process or activity
For example, as glucose levels in the body increase, sensors in the pancreas signal the release of the hormone insulin
Insulin promotes the entry of glucose into cells, lowering glucose levels
As the glucose levels in the blood decrease, the pancreas stops secreting insulin.

16. Actions of Insulin and Glucagon
Section 39-2
Beta cells release insulin into the blood
Body cells absorb glucose
Blood glucose level increases
Liver converts glycogen to glucose
Blood glucose level decreases
Homeostasis: Normal blood glucose level
Blood glucose level increases
Blood glucose level decreases
Liver converts glycogen to glucose
Alpha cells release glucagon into blood

17. Disorders Goiter Grave’s Disease Diabetes
Enlargement of the thyroid gland due to the inability to manufacture thyroxin (hypothyroidism)
Grave’s Disease
Hyperthyroidism- over secretion of thyroxin
Diabetes
Insulin deficiency which results in elevated blood sugar level

18. Symptoms of Diabetes Excessive thirst Frequent urination
Extreme hunger
Unexplained weight loss
Glucose in urine
Fatigue
Vision problems
Numbness tingling in extremities
High infection rate

19. Calcium and glucose levels
Concept Map
Section 39-2
The Endocrine System
regulates
Growth
Water balance
Reproduction
Metabolism
Calcium and glucose levels
Response to stress
by means of the
by means of the
by means of the
by means of the
by means of the
by means of the
Pituitary
Ovaries
Testes
Thyroid
Pancreas
Adrenals
Parathyroids