ENDOCRINE GLAND FUNCTIONS

 

 

THYROID

 

1.     T₃, T₄      INCREASE METABOLISM IN BODY CELLS

 

2.     CALCITONIN      LOWER BLOOD CALCIUM

 

 

PARATHYROID          

 

1.     PARATHYROID           INCREASE BLOOD CALCIUM

     HORMONE

 

 

ADRENAL CORTEX

 

1.     MINERALOCORTICOIDS     INCREASE SODIUM REABSORPTION

 

2.     GLUCOCORTICOIDS       INCREASE BLOOD SUGAR (GLUCOSE)

 

3.     ANDROGEN,            MAINTAIN 2ND SEX CHARACTERISTICS

     ESTROGENS, ETC.

 

ADRENAL MEDULLA

 

1.     EPINEPHRINE      INCR. BLOOD PRESSURE, INCR. HEART RATE, DILATE BRONCHI

 

2.     NOREPINEPHRINE     INCREASE BLOOD PRESSURE BY CONSTRICTING VESSELS

 

PANCREAS

 

1.     INSULIN              LOWER BLOOD SUGAR (GLUCOSE TO GLYCOGEN)

 

2.     GLUCAGON             INCREASE BLOOD SUGAR (GLYCOGEN TO SUGAR)

 

 

PITUITARY (ANTERIOR)

 

1.     GROWTH HORMONE         STIMULATE BONE AND TISSUE GROWTH    

 

2. TSH STIMULATES PRODUCTION OF T4 AND GROWTH OF                  THYROID GLAND

 

3.     ACTH            STIMULATES SECRETION OF HORMONES FROM ADRENAL                               CORTEX

 

4.     FSH/LH           STIMULATES OOGENESIS

 

5.     PROLACTIN        PROMOTES GROWTH OF BREAST TISSUE AND MILD                                   SECRETION 

 

PITUITARY (POSTERIOR)

 

1.     ADH (VASOPRESSIN)     STIMULATES REABSORPTION OF WATER

                 INCREASES BLOOD PRESSURE

 

2.     OXYTOCIN         STIMULATES LABOR AND MILK PRODUCTION

    

 

OVARIES

 

1.     ESTROGEN             DEVELOP/MAINTAIN 2ND SEX CHARACTERISTICS

 

2.     PROGESTERONE          PREPARATION/MAINTENANCE OF UTERUS IN PREGNANCY

 

 

TESTES

 

1.     TESTOSTERONE          DEVELOP/MAINTAIN 2ND SEX CHARACTERISTICS

ABNORMAL CONDITIONS OF THE ENDOCRINE SYSTEM

 

 

THYROID GLAND

 

 

A.     HYPERTHYROIDISM (OVERACTIVITY)

 

     •     GRAVES'S DISEASE (THYROTOXICOSIS)

 

          1.     INCREASED HORMONE PRODUCTION

 

          2.     INCREASED METABOLIC RATE

 

          3.     EXOPHTHALMIA - SWELLING OF TISSUE BEHIND EYE

 

B.     HYPOTHYROIDISM     (UNDERACTIVITY)

 

     •     MYXEDEMA - ADULT CONDITION

 

          1.     ATROPHY OF THE GLAND

 

          2.     DRY, PUFFY SKIN (EDEMA) DUE TO COLLECTION OF                    MUCUS-LIKE MATERIAL

 

          3.     INCREASED BLOOD LIPIDS LEADS TO ATHEROSCLEROSIS

 

 

 

PARATHYROID GLANDS

 

 

A.     HYPERPARATHYROIDISM (EXCESSIVE PRODUCTION)

 

     1.     HYPERCALCEMIA - CALCIUM LEAVES BONES

 

     2.     INCREASED RISK OF FRACTURES, e.g., OSTEOPOROSIS

 

     3.     RENAL CALCULI (STONES, NEPHROLITHIASIS)

 

B.     HYPOTHYROIDISM (DEFICIENT PRODUCTION)

 

     1.     HYPOCALCEMIA - CALCIUM STAYS IN BONES

 

     2.     LEADS TO MUSCLE AND NERVE WEAKNESS AND CONSTANT MUSCLE                 CONTRACTIONS - TETANY    

ADRENAL CORTEX

 

A.     HYPERSECRETION

 

     1.     ADRENAL VIRILISM - EXCESSIVE OUTPUT OF MALE HORMONES

 

          •     OCCURS IN ADULT WOMEN

 

          •     AMENORRHEA

 

          •     HIRSUTISM - EXCESSIVE FACIAL AND BODY HAIR

 

          •     DEEPENING OF THE VOICE

 

     2.     CUSHING'S DISEASE

 

          •     OBESITY AND MOON-LIKE FACE

 

          •     BUFFALO HUMP - EXCESSIVE FAT DEPOSITS IN UPPER BACK

 

          •     HYPERGLYCEMIA

 

          •     HYPERNATREMIA - EXCESSIVE SODIUM RETENTION

 

          •     HYPERTENSION

 

B.     HYPOSECRETION

 

     1.     ADDISON'S DISEASE

 

          •     DEFICIENT AMOUNTS OF MINERAL AND GLUCOCORTICOIDS

 

          •     HYPONATREMIA - EXCRETION OF LARGE AMOUNTS OF WATER AND                                    SALTS (ELECTROLYTES)

 

          •     WEIGHT LOSS

 

PANCREAS

 

A.     HYPOSECRETION - DIABETES MELLITUS

 

     1.     LACK OF INSULIN SECRETION

 

     2.     RESISTANCE OF INSULIN TO PROMOTE SUGAR, STARCH, FAT METABOLISM             IN CELLS

 

          a.     TYPE I (INSULIN-DEPENDENT)

 

           •     USUALLY CHILDHOOD ONSET

 

           •     PATIENTS USUALLY THIN

 

           •     PANCREATIC CELLS DO NOT SECRETE INSULIN

 

           •     REQUIRES FREQUENT INJECTIONS OF INSULIN

 

          b.     TYPE II (NON-INSULIN DEPENDENT)

 

           •     PATIENTS USUALLY OLDER

 

           •     OBESITY COMMON

 

           •     RELATIVE INSULIN DEFICIENCY

 

           •     TARGET TISSUES RESISTANT TO ACTION OF INSULIN

 

     3.     PRIMARY COMPLICATIONS AND SYMPTOMS

 

          a.     HYPERGLYCEMIA

 

          b.     GLYCOSURIA

 

          c.     POLYURIA AND POLYDIPSIA

 

          d.     KETOACIDOSIS - FATS IMPROPERLY BURNED

 

          e.     HYPOGLYCEMIA IF TOO MUCH INSULIN TAKEN

 

     4.     SECONDARY COMPLICATIONS

 

          a.     DIABETIC RETINOPATHY - DESTRUCTION OF BLOOD VESSELS                                          

          b.     DIABETIC NEPHROPATHY - CAUSES RENAL INSUFFICIENCY;                                            POSSIBLE HEMODIALYSIS OR TRANSPLANT

 

          c.     ATHEROSCLEROSIS - DESTRUCTION OF BLOOD VESSELS

 

          d.     DIABETIC NEUROPATHY - PAIN OR LOSS OF SENSATION,                        ESPECIALLY IN THE EXTREMITIES

PITUITARY

 

A.     ANTERIOR PITUITARY (ADENOHYPOPHYSIS)

 

     1.     HYPERSECRETION

 

          a.     ACROMEGALY - ENLARGED EXTREMITIES AFTER PUBERTY

 

           •     EXCESS GROWTH HORMONE

 

           •     CAUSES BONES IN HANDS, FEET, FACE, JAW TO GROW ABNORMALLY LARGE BUT NOT LONG BONES

 

          b.     GIGANTISM - ABNORMAL OVERGROWTH BEFORE PUBERTY

 

           •     PROPORTIONAL STIMULATION OF OVERGROWTH OF ALL BONE AND TISSUE

 

     2.     HYPOSECRETION

 

          a.     PANHYPOPITUITARISM

 

           •     DEFICIENCY OF ALL PITUITARY HORMONES

 

           •     ADVERSELY AFFECTS ADRENAL, THYROID, OVARIES, AND TESTES

 

B.     POSTERIOR PITUITARY (NEUROHYPOPHYSIS)

 

     1.     HYPOSECRETION

 

          a.     DIABETES INSIPIDUS

 

           •     DECREASED SECRETION OF ANTIDIURETIC HORMONE (VASOPRESSIN)

 

           •     FAILURE OF KIDNEYS TO REABSORB (HOLD BACK) WATER AND SALTS

 

           •     POLYURIA AND POLYDIPSIA

 

    

ENDOCRINE TESTS AND PROCEDURES

 

 

LABORATORY TESTS

 

GLUCOSE TOLERANCE TEST - MEASURES GLUCOSE LEVELS IN BLOOD SAMPLES COLLECTED FASTING, 30 MINUTES, 1, 2, 3 HOURS AFTER INGESTING PRESCRIBED AMOUNT OF GLUCOSE.  TEST FOR DIABETES MELLITUS

 

 

SERUM AND URINE TESTS - MEASUREMENT OF SUBSTANCES (SEE TEXT) IN THE      BLOOD AND URINE TO DIAGNOSE ENDOCRINE DISORDERS

 

 

THYROID FUNCTION TESTS - MEASURE LEVELS OF T₄, T₃, AND TSH IN BLOOD

 

 

 

CLINICAL PROCEDURES

 

 

CT SCANS - TRANSVERSE VIEWS OF ENDOCRINE GLANDS

 

 

THYROID SCAN - RADIOACTIVE COMPOUND INJECTED INTRAVENOUSLY AND LOCALIZES IN THE THYROID GLAND.  SCANNER CREATES IMAGES.

 

 

ULTRASONOGRAPHY - HIGH FREQUENCY SOUND WAVES USED TO PRODUCE IMAGES      AS WAVES BOUNCE OFF ORGANS, E.G., ENDOCRINE GLANDS