Page 103 - Alaska A & P Primer

Uncontrolled diabetes can also lead to a dangerous form of metabolic acidosis called ketoa- cidosis. Deprived of glucose, cells increasingly rely on fat stores for fuel. However, in a glucose-deficient state, the liver is forced to use an alternative lipid metabolism pathway that results in the increased production of ketone bodies (or ketones), which are acidic.
The build-up of ketones in the blood causes ketoacidosis, which—if left untreated—may lead to a life-threatening “diabetic coma.” Together, these complications make diabetes the seventh leading cause of death in the United States.
Diabetes is diagnosed when lab tests reveal that blood glucose levels are higher than nor- mal, a condition called hyperglycemia. The treatment of diabetes depends on the type, the severity of the condition, and the ability of the patient to make lifestyle changes. As noted earlier, moderate weight loss, regular physical activity, and consumption of a healthful diet can reduce blood glucose levels. Some patients with type 2 diabetes may be unable to con- trol their disease with these lifestyle changes, and will require medication.
Historically, the first-line treatment of type 2 diabetes was insulin. Research advances have resulted in alternative options, including medications that enhance pancreatic func- tion.
17.10 Organs with Secondary Endocrine Functions
In your study of anatomy and physiology, you have already encountered a few of the many organs of the body that have secondary endocrine functions. Here, you will learn about the hormone-producing activities of the heart, gastrointestinal tract, kidneys, skeleton, adi- pose tissue, skin, and thymus.
Some organs have a secondary endocrine function. For example, the walls of the atria of the heart produce the hormone atrial natriuretic peptide (ANP), the gastrointestinal tract produces the hormones gastrin, secretin, and cholecystokinin, which aid in digestion, and the kidneys produce erythropoietin (EPO), which stimulates the formation of red blood cells. Even bone, adipose tissue, and the skin have secondary endocrine functions.
17.11 Development and Aging of the Endocrine System
As the body ages, changes occur that affect the endocrine system, sometimes altering the production, secretion, and catabolism of hormones. For example, the structure of the ante- rior pituitary gland changes as vascularization decreases and the connective tissue content increases with increasing age. This restructuring affects the gland’s hormone production. For example, the amount of human growth hormone that is produced declines with age, resulting in the reduced muscle mass commonly observed in the elderly.
As the body ages, changes occur that affect the endocrine system, sometimes altering the production, secretion, and catabolism of hormones. For example, the structure of the ante- rior pituitary gland changes as vascularization decreases and the connective tissue content increases with increasing age. This restructuring affects the gland’s hormone production. For example, the amount of human growth hormone that is produced declines with age, resulting in the reduced muscle mass commonly observed in the elderly.
Testosterone levels also decline with age, a condition called andropause (or viropause); however, this decline is much less dramatic than the decline of estrogens in women, and much more gradual, rarely affecting sperm production until very old age. Although this means that males maintain their ability to father children for decades longer than females, the quantity, quality, and motility of their sperm is often reduced.
As the body ages, the thyroid gland produces less of the thyroid hormones, causing a grad- ual decrease in the basal metabolic rate. The lower metabolic rate reduces the production of body heat and increases levels of body fat. Parathyroid hormones on the other hand, increase with age. This may be because of reduced dietary calcium levels, causing a com- pensatory increase in parathyroid hormone.
However, increased parathyroid hormone levels combined with decreased levels of calci- tonin (and estrogens in women) can lead to osteoporosis as PTH stimulates demineraliza- tion of bones to increase blood calcium levels. Notice that osteoporosis is common in both elderly males and females.
Increasing age also affects glucose metabolism, as blood glucose levels spike more rapidly and take longer to return to normal in the elderly. In addition, increasing glucose intoler- ance may occur because of a gradual decline in cellular insulin sensitivity. Almost 27 per- cent of Americans aged 65 and older have diabetes.
17.11 OBJECTIVES
1. Describe the effects of aging on the endocrine system
17.10 OBJECTIVES
1. Describe the location, structure and function of the pancreas
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State of Alaska EMS Education Primer - 2016
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