Welcome. In this lecture, we will be looking at the endocrine system. The endocrine system
acts with our nervous system to coordinate and integrate the activity of our body cells. It
does this by influencing metabolic activity via hormones that are transported in our blood.
Responses are slower, but longer lasting than that of the nervous system responses. And
when we study how the endocrine system works, we referred to this as endocrinology. So how
does the endocrine system actually control and integrate our body's processes? It controls
and integrates things like reproduction; maintenance of electrolytes, water, and nutrient
balance; growth and development; regulation of our cellular metabolism and our energy
balance; mobilization of body defenses. So when it comes to the endocrine system, it's
important to note that there are 2 types of glands in our body. First, we have exocrine glands.
These are going to produce non-hormonal substances so things like sweat or saliva or oils
and these have ducts that carry these secretions to the surface of the membrane. Exocrine
glands are different from our endocrine glands, which are going to produce hormones. Unlike
exocrine glands, endocrine glands do not have ducts. It is the endocrine glands that we will
focus on when we talk about the endocrine system in these lectures. The endocrine system is
going to be made up of several glands including the pituitary gland found in the brain, the
thyroid and parathyroid glands found in the cervical region of the body, the adrenal glands
which are going to be attached to the kidneys, and as well as the pineal gland which is also
found in the brain. The hypothalamus is also considered a neuroendocrine gland because it has
both nervous as well as endocrine tissues and does send hormones to other endocrine glands.
Some organs also have exocrine and endocrine functions. This includes the pancreas which is
going to secret insulin but also secretes some exocrine secretions as well. We also have the
gonads which are the testes in males and the ovaries in females. Also, in a pregnant woman
the placenta has both exocrine and endocrine functions as well. Other tissues and organs in
the body that have the ability to produce hormones include our adipose or fat cells as well
as our thymic cells in the walls of the small intestines, the stomach, the kidneys, and the heart.