Clinical Medical Assisting

Chapter 15: Endocrine System

Chapter OverviewThe endocrine system is a network of glands that secrete hormones into the bloodstream. Hormones are chemical messengers used by the body to communicate between cells. Hormones are diverse, ranging in structure and function. Some hormones directly affect a target cell and some hormones alter gene expression in target cells, changing the production of regulatory proteins.

Most endocrine disorders are chronic, long-term conditions. You will also have the opportunity to educate patients about their endocrine disease and teach them to monitor their conditions with blood tests performed at home. Developing a strong rapport with your patients will promote compliance and improve health outcomes.

Overview (con’t)

Objectives• Identify combining word forms of the endocrine system and

their role for the formation of medical terms

• Define the structures and functions of the endocrine system

• Identify common diseases of the endocrine system and their treatment

• Identify common diagnostic procedures related to the endocrine system

Components of the Endocrine System

The body contains distinct types of glands: exocrine glands and endocrine glands.

Exocrine Glands

Exocrine glands secrete substances, including liquids, digestive enzymes, and hormones, through a duct or an organ.

Endocrine Glands

Endocrine glands secrete hormones directly into the bloodstream.

Adrenal Glands

A small, triangular adrenal gland is located above each kidney.

Pituitary GlandThe pituitary gland (also known as the master gland) is located behind the optic nerve, below the cerebrum, in the brain.

Thyroid Gland

The thyroid gland resembles the shape of a butterfly, with two lobes located on either side of the trachea and larynx.

Parathyroid Glands

Four parathyroid glands are located on the back of the thyroid.

Hypothalamus

The hypothalamus is located in the midbrain and coordinates and monitors the body’s state of homeostasis.

Pineal Gland

The pineal gland is located in the third ventricle of the brain.

GonadsCollectively, the ovaries and testes are known as gonads, or sex glands.

ThymusThe thymus is a very small, two-lobed organ located in the mediastinum, under the sternum and in front of the heart.

PancreasThe pancreas is located behind the stomach, in front of the second and third lumbar vertebrae.

Diseases and Disorders of the Endocrine System

The endocrine system is integrated with several other body systems to coordinate all body functions.

Thyroid DisordersThyroid hormones are necessary for the control of normal growth and metabolism.

Signs and Symptoms of Thyroid Disorders

Hypothyroidism decreases metabolic processes throughout the body.

Treatment of Thyroid Disorders

Hypothyroidism is treated by supplementing thyroid hormones.

Parathyroid Disorders

Similar to thyroid disorders, overactivity of parathyroid glands is called hyperparathyroidism and underactivity of glands is called hypoparathyroidism.

Signs and Symptoms of Parathyroid Disorders

If parathyroid glands are overactive, there will be a very high level of calcium in the body.

Treatment of Parathyroid Disorders

If calcium levels or symptoms are extreme, removal of the parathyroid gland is indicated.

Sex Hormone Disorders

In both males and females, decreased function of the gonads, or hypogonadism, inhibits the maturation of sex organs and prevents the appearance of secondary sex characteristics.

Signs and Symptoms of Sex Hormone Disorders

Hypogonadism in childhood prevents the onset of puberty.

Treatment of Sex Hormone Disorders

Levels of sex hormones decline naturally with age, but when the symptoms impair quality of life, hormone replacement therapy can be considered.

Adrenal Gland Disorders

Addison’s disease results from the decreased production of hormones in the adrenal cortex.

Signs and Symptoms of Adrenal Gland Disorders

The lack of corticosteroids in Addison’s disease impairs normal metabolism and causes electrolyte disturbances, particularly high levels of potassium.

Treatment of Adrenal Gland Disorders

Treatment of Addison’s disease requires supplementation of the deficient hormones.

Pituitary Gland Disorders

Hyperpituitarism is the abnormal increase in hormones produced by the pituitary gland.

Signs and Symptoms of Pituitary Gland Disorders

Giantism results in abnormally tall children due to the excessive growth of the long bones before puberty.

Treatment of Pituitary Gland Disorders

Giantism and acromegaly are treated by removing the pituitary tumor or the entire gland, if necessary.

Pancreas DisordersThe most common disorder associated with the dysfunction of the pancreas is diabetes mellitus (DM), a condition in which individuals do not produce or cannot use insulin.

Signs and Symptoms of Pancreas Disorders

In both type 1 and type 2 DM, the body’s cells are unable to metabolize glucose, which leads to abnormally high levels of glucose circulating in the bloodstream.

Treatment of Pancreas Disorders

Type 1 DM can be treated only with insulin.

Diagnostic Procedures of the Endocrine SystemMany diagnostic tests of the endocrine system can be performed with blood or urine samples.

Blood Glucose Monitoring

Blood glucose concentrations rise after a meal, and the levels are regulated by insulin and glucagon.

Glucose Tolerance Testing

A glucose tolerance test (GTT) measures the body’s ability to process a large amount of glucose in a short amount of time.

Hemoglobin A1c Testing

Glycosylated hemoglobin, or HbA1c, is the molecule that is formed when glucose attaches to hemoglobin in a red blood cell.

Thyroid Testing

Blood tests assess the levels of T3, T4, and TSH, which describe the function of the thyroid.

Skills for the Medical Assistant

As a medical assistant, you will have the opportunity to participate in several procedures relating to the endocrine system.

Blood Glucose Testing

Blood glucose testing using a glucometer or other automated testing device is common, both for screening for diabetes and for evaluating therapeutic regimens.

Equipment Needed

Besides a sterile lancet, you will need to be familiar with six other pieces of equipment.

StepsIn order to perform glucose testing, there are 11 steps you will need to know.

HbA1c TestingHbA1c measures long-term glucose control, which should be done one to two times each year for diabetic patients.

Equipment Needed

There are six pieces of equipment the medical assistant will need to use to perform HbA1c testing.

StepsThere are eight steps the medical assistant will need to know in order to perform HbA1c testing.

Insulin Administration

Patients with type 1 DM and some with type 2 DM require frequent injections of insulin.

Equipment Needed

• Vial of insulin• Insulin syringe with needle• Disposable gloves• Cotton balls• Alcohol wipes or isopropyl alcohol• Sterile adhesive bandage

Summary

Blood tests can help identify disorders of the endocrine system and assess treatment regimens. Diabetic patients require frequent blood glucose testing, and should maintain a log of daily blood glucose results and food and activities to identify patterns in glucose control.