THE ENDOCRINE SYSTEM (TEST 5)

Structures:

• Pituitary gland

• Thyroid gland

• Parathyroid

• Adrenal glands

• Pancreas

• Pineal and thymus glands

• Ovaries and testes (Part of reproductive and endocrine systems)

Functions:

• Secrete chemicals called hormones directly into the bloodstream. Control and integrate

• Many bodily functions. Action of hormones on target organs increase or decrease the target’ activity level .Maintains homeostasis. Together with the nervous system, the endocrine system controls many intricate activities of the body.

Pituitary gland (hypophysis)

-Tiny, pea-shaped structure at the base of the brain

-Consists of an anterior and posterior lobe

-Known as the “master gland” of the body

-Regulation of many of the body’s activities

-Stimulation of other glands to secrete their own specific hormones

-Effects of its hormones felt throughout the body

Thyroid gland

Two lobes on either side of the trachea

Secretion of three hormones:

-Calcitonin, which regulates normal blood levels of calcium and phosphate (in conjunction with parathyroid hormone)

-Triiodothyronine (T3), which increases the rate of cellular metabolism

-Thyroxine (T4), which increases the rate of cellular metabolism after being converted to T3 in the tissues

Parathyroid gland

Two pairs of pea-shaped organs located on the underside of the thyroid gland

Secretion of parathyroid hormone (PTH)

-Regulation of normal blood levels of calcium and

phosphate (in conjunction with calcitonin)

Pancreas

Elongated organ located just below the stomach in back of the abdomen

Secretion of two hormones:

-Insulin, which removes glucose from the blood by

promoting storage in tissues as carbohydrates when blood glucose levels are high

-Glucagon, which stimulates the release of glucose

from storage sites in the liver when blood glucose

levels are low

Pineal gland

Small, pinecone–shaped organ located deep within

the brain just behind the thalamus

Secretion of melatonin, which influences the

maturation of sexual organs during puberty

Thymus gland

-Butterfly-shaped organ located between the lungs

-Withers away during puberty, leaving adults with fat and connective tissue in its place

-Secretion of thymosin, which plays a role in

development of the immune response in infants

Ovaries

Function in the female reproductive and endocrine

systems

Secretion of two female sex hormones:

-Estrogen (estradiol), which stimulates

development of ova (eggs) and secondary sex

characteristics

-Progesterone, which prepares and maintains the

uterus in pregnancy

Testes

Function in the male reproductive and endocrine systems

Secretion of male sex hormone testosterone

-Responsible for the development of secondary sex

characteristics and sex drive

-Necessary for sperm production

-Maintenance of the reproductive organs in adult males

What is a target organ?

The organ or tissue that responds to a

hormone

What are common conditions that result in various

pathologies of the endocrine system?

Hypersecretion or hyposecretion of a

hormone

Why is the pituitary known as a master gland

Regulates many body activities; stimulates

other glands to secrete specific hormones

The endocrine glands secrete chemicals into the

bloodstream called

hormones

Graves Disease

Exophthalmos

• Common form of

hyperthyroidism

• Production of thyroid

hormone increases

Goiter

• Enlarged thyroid

(goiter).

• Elevated metabolic

rate, abnormal

weight loss, and

muscular weakness.

Treatment

• Depends on the patient’s age and the severity of

the disease.

• Antithyroid agents to block hormone synthesis

within the thyroid gland.

• Alteration in the structure of the thyroid gland

through surgery or radioactive iodine therapy.

• Beta blockers in combination with one of the

treatments listed above.

Mary is diagnosed with Graves disease and is concerned about

the abnormal protrusion of her eyeballs. The doctor explains it is

a common symptom of Graves disease, and the protruding

eyeballs is a condition called______

exophthalmos

The patient is scheduled for excision of her thyroid gland. This

surgical procedure is charted as______

Thyroidectomy

Mrs. N. presents with hyperthyroidism. She states her mom

had Graves disease and asks about the connection between

Graves disease and hyperthyroidism.

Mrs. N. presents with hyperthyroidism. She states her mom had Graves disease and asks about the

connection between Graves disease and

hyperthyroidism.

Cushing Syndrome Signs and Symptoms

• Hypersecretion of adrenal cortex, mainly cortisol.

• Round, “moon-shaped” face with acne .Muscle weakness, purple striated

marks on skin, and hirsutism. Head and trunk grossly exaggerated, with

pencil-thin arms and legs. “Buffalo” hump on upper back, peptic ulcer,

hypertension, and susceptibility to infection. Anxiety and depression

Cushing Syndrome Treatment

• Restore concentration of serum cortisol to normal levels.

• Varies according to the etiology.

• Drugs or radiation to suppress adrenocorticotropic hormone (A C T H)

secretion.

• Total adrenalectomy. Lifelong treatments of cortisol replacement

therapy.

• Surgery, followed by chemotherapy, when the syndrome is caused by tumors of the adrenal cortex

Growth Hormone

Imbalance: 

-Acromegaly

-Gigantism

-Dwarfism

Acromegaly

Hypersecretion of growth hormone (G H) during

adulthood. Fusion of growth plates at ends of long bones, which prevents person from growing taller.

Widening and enlargement of facial

features, jaw, hands, and feet.

Treatment:

• Drug therapy with growth hormone.

• Surgery if a tumor is the cause

Gigantism

Hypersecretion of G H

during childhood.

Excessive growth of

bones and tissues due to

high level of G H.

Height changes of up to

6 inches in 1 year in

children. Abrupt

development, resulting

in abnormally increased

height.

-Drug therapy to suppress

secretion of growth

hormone. Surgery to

remove an adenoma or

radiation therapy to

destroy the adenoma.

Dwarfism

• Hyposecretion of

GH during

childhood.

• Lack of growth and

short stature but

with normal body

proportions.

GH imbalance Treatment

Hyposecretion of GH

Drug therapy with growth hormone

Surgery if a tumor is the cause

Hypersecretion of GH

Drug therapy to suppress secretion of growth hormone

Surgery to remove an adenoma or radiation therapy to destroy the

adenoma

Diabetes Mellitus

Group of metabolic diseases characterized by high glucose levels. Caused by defects

in insulin secretion, action, or both.

-Two primary forms

Type 1 (insulin-dependent) diabetes mellitus. Chronic metabolic disorder marked by

hyperglycemia. Inability of the pancreas to produce enough insulin to properly

control blood glucose levels. Most commonly diagnosed in children, adolescents, or

young adults.

Signs and Symptoms: Fatigue, polyphagia, polyuria, and polydipsia

Unplanned weight loss, Blurred vision (common in patients with hyperglycemia and

polyphagia)

Diabetic ketoacidosis with loss of metabolic control (for example, during periods of

infection or noncompliance with therapy)

‒ Type 2 (non–insulin-dependent) diabetes

mellitus.‒

Signs and

Symptoms:

Commonly asymptomatic. Polyphagia, polydipsia, and

polyuria .Frequent or slow- healing infections.

Fatigue and blurred vision (common in hyperglycemic patients).

Diabetes mellitus Treatment

Type 1

Specialized diet and regular exercise

Intensive foot and eye care

Medications, including insulin to lower blood glucose levels

Type 2

Calorie-restricted diet with regular aerobic exercise

Oral drugs

Increase pancreatic secretion of or cellular sensitivity to insulin

Decrease absorption of carbohydrates from the GI tract

Insulin injections (if oral combinations fail to regulate blood glucose

levels)

Ms. V. has type 1 diabetes and complains of

fluid retention and back pain. The physician

explains kidney disease is a complication of

untreated diabetes mellitus, and diagnoses

her condition as diabetic (nephropathy,

cytopathy, uropathy).

Nephropathy

Ms. T.’s fasting blood glucose laboratory

result is 150. This abnormally elevated

blood glucose level is charted as _____

hyperglycemia

Ms. T.’s fasting blood glucose laboratory result is 150. This

abnormally elevated blood glucose level is charted as______________

hyperglycemia

During a patient education session about diabetes, the nurse

explains that exact insulin measurement is important. Too much

insulin will result in an abnormally low blood glucose level, a

condition called________________________

hypoglycemia

Fasting blood glucose (F B G)

Measures blood glucose levels following a fast of at least 8 hours

Glucose tolerance test (G T T)

Measures blood glucose levels at regular intervals (usually 3

hours).Used to diagnose diabetes mellitus with higher accuracy

than other blood glucose tests.

Radioactive iodine uptake (R A I U) test

Administration of R A I U in pill or liquid form. Used as a tracer to

test how quickly the thyroid gland uptakes iodine from blood

Thyroid function test (T F T)

Detects increase or decrease in thyroid function. Measures levels

of thyroid-stimulating hormone, triiodothyronine (T3), and

thyroxine (T4)

Glucose testing with a glucometer

Monitoring test of glucose levels in the

blood (glycemia)

Self-monitoring, usually done before

meals and at bedtime

Piercing of skin, typically on the finger,

to draw blood

Application of blood to a test strip

Transphenoidal Hypophysectomy :

Endoscopic procedure to remove a pituitary tumor.

Incision of the sphenoid sinus (transphenoidal) without disturbing brain tissue.

Thymectomy:

Excision of thymus gland. Used to remove tumors of thymus. Used in treatment of

myasthenia gravis (M G).

Insulin delivery with an insulin pump

Small pump device delivers insulin subcutaneously.

Typically worn on the abdomen or buttocks. Insulin delivery with an insulin pump

(Continuous delivery of small amounts of insulin via a tiny catheter, as illustrated.

• Bolus of insulin delivered with the push of a button before meals or snacks.

‒ Provides closer to normal insulin levels.

Insulin injection sites

• Absorption and effectiveness

are determined by the injection

site.

• Rapid absorption

‒ Abdomen and then upper

arm and thigh areas.

• Slower absorption

‒ Subcutaneous fat and hip and

buttock areas.

• No injection within 2 inches of

the navel.