(MOS) Endocrine, Lymphatic, and Immune System Lesson

Endocrine, Lymphatic, and Immune System Lesson

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The endocrine system works very closely with the nervous system to control many activities in your body. The hypothalamus is a portion of the brain that controls the endocrine system through a tiny structure called the pituitary gland. This tiny pea-sized shaped structure is connected to the hypothalamus. The pituitary gland secretes hormones. The endocrine system consists of glands located throughout the body producing a variety of hormones into your bloodstream. Hormones are called chemical messengers because they travel throughout your body as they attach to cells and change their function. The pancreas secretes the hormone insulin. This hormone allows glucose to enter the cells. The human growth hormone stimulates growth, repair, and reproduction in bone and muscle cells. The adrenal glands are located above the kidneys. It produces a hormone, glucocorticoids, that are responsible for reducing inflammation. Thyroxin is produced by the thyroid glands in the neck and regulates the rate at which chemical reactions such as digesting and using food occurs.

Why is the skin often regarded as the first line of defense against disease? What happens if the body is invaded by a harmful organism? How does the body defend itself? What role do the body's glands play in maintaining good health? Listen to the  presentation below for answers to these questions.

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Skin is a soft outer covering of the body. The adjective cutaneous means "of the skin" (from Latin  cutis, skin). In mammals, the skin is the largest organ of the integumentary system made up of multiple layers of ectodermal tissue, and guards the underlying muscles, bones, ligaments and internal organs. The skin forms a barrier to help keep bacteria from getting inside; this is considered the first line of nonspecific defense. The skin is actually the largest organ in the body and is referred to as the Integumentary System.

White blood cells (or leukocytes) are a part of the immune system and help our bodies fight infection. They circulate in the blood so that they can be transported to an area where an infection has developed. White blood cells surround and destroy bacteria and some viruses that get into the blood; this is a specific defense response because these reactions are specific to the kind of pathogen involved.

The lymphatic system, somewhat similar to the circulatory system, is a network of vessels throughout the body that is very important in protecting against infections. Plasma diffuses through the capillary walls taking nutrients along with it into cells. When plasma leaves the blood, it is referred to as "lymph".

 

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