1. Endocrine System Anatomy and Physiology
Notes Ch. 13e
Endocrine System
Anatomy and Physiology

2. Other Endocrine Glands
Other organs produce hormones that are part of the endocrine system. These organs are the thymus, the pineal gland, reproductive organs, and cells of the digestive tract, heart, and kidneys.
The pineal gland (in the brain) secretes melatonin. This is extremely important in circadian rhythms – day/night cycles or sleep/wake rhythms.

3. The thymus secretes the hormone thymosins
The thymus secretes the hormone thymosins. It affects production and differentiation of certain white blood cells.
It is very important in immunity.

4. Reproductive organs produce testosterone and estrogen and progesterone.

5. Stress and Its Effects
Stress may be physical or psychological, or both.
Physical stress can harm tissue. Extreme heat or cold, decreased oxygen concentration, infections, injuries, heavy exercise, and loud sounds all inflict physical stress.
Psychological stress are from real or imagined dangers, personal losses, unpleasant social interactions, or threatening factors.

6. Responses to Stress The hypothalamus controls the response to stress.
There are 2 stages of stress response – the immediate “alarm” stage and the long-term “resistance” stage.
Look at the picture to see how stress affects the body.

7. Life-Span Changes
With age, the glands of the endocrine system decrease in size and increase in the proportion of each gland that is fibrous.
Growth hormone – will lower in level and that decreases the strength of the skeleton and muscles.
The thyroid gland shrinks with age.
One of the most notable change is blood glucose regulation.