Unit 17 Endocrine System Flashcards
Hormone Features
- chemical messengers produced and secreted by endocrine organs and glands
- produced in small amount by specialized cells
- secreted into blood and transported by circulatory system
- Act on target tissues at another site
Endocrine organs and glands
communicate with other organs via
- central and peripheral nervous system
- hormones
- cytokines
- growth factors
endocrine organs and glands include
- pituitary gland
- thyroid gland
- parathyroid glands
- adrenal glands
- pancreas
- gonads
Pituitary gland
- at the base of the brain
- controlled by hypothalamus
- regulates activity of other glands and organs
Anterior Pituitary (hypopituitarism)
due to hypofunction or hyposecretion
-hereditary, malignant brain tumor, encephalitis, inflammation, or
Vascular changes in pituitary
Posterior Pituitary (neurohypophysis)
secretes hormones ADH and oxytocin
Functions of endocrine system
Production, storage, and secretions of hormones that control and regulate:
- growth and development
- metabolism & tissue maturation
- electrolyte (ion) and water balance
- inflammation and immune response
- heart rate and blood pressure
- level blood glucose and other nutrients
- reproductive functions
- muscle and fat distribution
Growth hormone (GH) deficiency in children
•pituitary dwarfism
–growth retardation, microcephaly, usually normal body proportions
Growth hormone (GH) deficiency in adults
•pituitary cachexia (complete atrophy of pituitary gland)
–emaciation (extremely lean), premature aging, loss of function of thyroid, adrenals, gonads
Hyperpituitarism in children
•giantism (gigantism)
–accelerated linear growth prior to closure of epiphyseal growth plate (hands and feet large)
–usually caused by pituitary benign tumor
Hyperpituitarism in adults
•acromegaly
–after fusion of growth plate
–usually caused by pituitary or hypothalamic tumor, or nonendocrine malignant tumor
–weight gain, growth of soft tissues, enlargement of small bones of hands, feet, face, and skull
Diabetes Insipidus
decreased secretion (hyposecretion) or action of antidiuretic hormone (ADH)
Symptoms of Diabetes Insipidus
excess fluid loss, polyuri a (overproduction of urine) dehydration, heart problems, kidney failure
Diabetes Insipidus is caused by
destruction of posterior pituitary or defects in kidneys
Thyroid gland
•Neck region •Secrete hormones –T3 (triiodothyronine) –T4 (thyroxine= tetraiodothyronine) – calcitonin •regulate body growth and metabolism •regulate blood level of calcium
Hypothyroidism
- may affect almost all body functions
* caused by chemicals, radiation, cancer, autoimmune disease, removal of thyroid gland or disease of pituitary gland
Hypothyroidism in infants
cretinism (congenital hypothyroidism)
•due to hypoplasia or aplasia
•growth and mental retardation (also low GH)
Hypothyroidism in adults
obesity, weight gain, slow metabolism
Endemic goiter
enlargement of thyroid gland usually due to lack of sufficient iodine
myxedema
result of acute illness, trauma or surgical removal of thyroid
Hyperthyroidism In children
increased body size (rapid growth)
Hyperthyroidism in adults
Graves’ disease
Graves’ disease
Autoimmune disease
abnormal antibodies similar to TSH mimic its function and continuously stimulate release of thyroid hormones
toxic goiter
disfigurement/ swelling in neck
Exophthalmos
protrusion of eyeballs, fibrous tissue become edematous (swollen)
Adrenal Glands
Paired, sit on top of kidneys
Adrenal glands produce and secrete
•Cortical hormones (steroid hormones) and Medullary hormones
Addison’s disease (hypoadrenalism)
Deficiency of cortical hormones ( more common in females)
-results in weakness, fatigue, nausea, vomiting, and increased skin pigmentation
Cushings syndrome (hyperadrenalism)
Increased secretion of cortical hormones
-abdominal striae (stretch marks)
Waterhouse-Friderichsen syndrome (hyperadrenalism)
Acute adrenal insufficiency due to hemorrhage into adrenal gland
Pheochromocytoma
Epinephrine & norephinepherine producing tumor in adrenal medulla
Parathyroid glands
Four (or more) tiny glands located on posterior part of thyroid gland
-regulates calcium and potassium levels in blood
Hyperparathyroidism
Excess of PTH in the blood
Hyperparathyroidism can result in complications such as
- arteriosclerosis
- kidney stones
- calcification of organ walls
- spontaneous fractures
Hypoparathyroidism
Caused by resection of thyroid gland or exposure of parathyroid gland to heavy metals
-results in hypocalcemia
Tetany
Sustained muscle contraction
Chvostek’s sign
Facial muscle spasm
trosseau’s sign
Arm muscle spasm
Pancreas
Below the stomach, produces and secretes insulin and glucagon to regulate blood sugar level
Hyposecretion of the pancreas causes
- gestational diabetes
- diabetes mellitus
Gestational diabetes
Elevated levels of estrogen and progesterone
Diabetes mellitus type 1
Juvenile onset
- 10-14 yrs old
- total or near total absence of insulin
Diabetes mellitus type 2
Associated with variable degrees of insulin resistance
Complications of type 2 diabetes mellitus
- abscess from infections
- dermopthy
- blisters
- ulcers
- yellow skin and nails
Gonads
Males: testes-produce sperm and secrete testosterone
Females: ovaries- produce ova and secrete estrogen
Hypergonadism
Abnormal increased activity of gonads before puberty-early onset of puberty
-more common in males
Hypergonadism in males
Aggressive behavior and increased risk of testicular cancer
Hypergonadism in females
May increase risk of ovarian cancer
Hypogonadism
Decreased activity of gonads Results in -delayed onset puberty -regression of secondary sexual characteristics -sterility
Hypogonadism in males
born without testes, or testes fail to descend
Hypogonadism in females
Missing or underdeveloped ovaries
Postmortem conditions
- edema
- discoloration
- deformities
- interference of circulation
- hemorrhage
