Endocrine System

purpose of endocrine system

maintain physiological and psychological stability despite constant changes in external and internal environments

effects of hormones

• differentiate reproductive and CNS in utero

• growth and development

• coordination of reproductive system

• maintenance of optimal internal environment

• corrective adaptive responses during emergencies

define exocrine

hormones secreted into a duct to reach external surface or target internal structure

define endocrine

hormones secreted into extracellular space to ultimately enter bloodstream

describe horomones

chemical messengers, regulate metabolic functions

three types of hormones

• amino acid derivatives

• peptide/protein

• lipid derivative

types of hormone receptors

• water soluble

• lipid soluble

difference between water and lipid soluble receptors

water soluble receptors outside the cell because hormones cannot cross membrane easily, lipid soluble receptors inside the cell because hormones can cross membrane easily

factors of hormon-receptor interaction

• blood levels of hormone

• number of receptors

• receptor affinity (quality)

describe neural control regulation of endocrine

sympathetic nervous system, fight or flight

describe humoral control regulation of endocrine

ions or nutrients in blood, example is blood sugar and insulin

describe negative feedback loop

suppressed by high levels of hormone, stimulated by low levels of hormone

describe positive feedback loop

stimulated by high levels of hormone, suppressed by low levels of hormone

examples of positive feedback loop hormones

oxytocin during labor, estrogen and luteinizing hormone during ovulation

describe direct loop

feedback acts directly on cells that secrete the substance, usually acting on pituitary gland

describe indirect loop

feedback goes to controlling centers that can excite or inhibit cells that secrete the substance, usually acting on hypothalamus

aging effects on endocrine system

• decrease in function

• physically shrinking of glands and more fibrous

• highly variable

• dependent on sex

describe hypothalamus

controls pituitary gland

hormones produced by hypothalamus

ADH, oxytocin

define adenohypophysis

regulation of anterior pituitary gland by hypothalamus through typical endocrine pathway (hormone travel through blood)

define neurohypophysis

regulation of posterior pituitary gland by hypothalamus through neurological pathway (hormone travel through nerves)

hormones produced by anterior pituitary gland

human growth hormone, prolactin, ACTH, TSH, FSH, LH

purpose of human growth hormone

increase protein synthesis, break down fat, increase blood glucose

purpose of prolactin

lactation after pregnancy

purpose of ACTH

stimulate adrenal gland for release of glucocorticoid hormone

purpose of TSH

stimulate thyroid to make T4 and T3

purpose of FSH

follicle growth, estrogen secretion, spermatogenesis

purpose of LH

promote ovulation, progesterone secretion in females, testosterone secretion in males

describe hyperpituitarism

excessive secretion of GH, leading to excessive secretion of other anterior pituitary hormones

results of hyperpituitarism

giantism, acromegaly

describe giantism

pediatric condition, excessive growth and abnormal height

describe acromegaly

enlarged hands and feet, larger jaw, hand and spine arthritis

treatment for acromegaly

surgical removal of anterior pituitary gland, radiation, hormone therapy post surgery

PT considerations for acromegaly

musculoskeletal weakness, joint mobility, exercise intolerance

results of hypopituitarism

pituitary dwarfism, effect on other endocrine organs

causes of hypopituitarism

removal of anterior pituitary gland, post hemorrhage, tumors, malnutrition, traumatic brain injury

which cause of hypopituitarism is reversible

malnutrition

treatments for hypopituitarism

remove cause of hypopituitarism, lifetime hormone replacement

hormones released by posterior pituitary gland

ADH, oxytocin (all from hypothalamus)

purpose of ADH

water retention in kidneys

purpose of oxytocin

uterine contractions, lactation

describe SIADH

excessive release of ADH, life-threatening

causes of SIADH

cancer

results of SIADH

increased water retention, hyponatremia

management methods for SIADH

sodium intake management, tumor removal, symptom management

PT considerations for SIADH

monitor vital signs, assess cardiovascular responses, manage sodium levels

describe diabetes insipidus

decreased secretion of ADH, rare

results of diabetes insipidus

polyuria, polydipsia, hypernatremia

management methods for diabetes insipidus

resection of tumor, replacement of ADH

PT considerations for diabetes insipidus

monitor BP due to blood volume fluctuations

define polyuria

excessive urination

define polydipsia

excessive thirst

what controls thyroid gland

anterior pituitary gland through TSH, calcium and phosphate in blood

hormones produced by thyroid

T4, T3, calcitonin

purpose of T4

regulate metabolism

purpose of T3

regulate metabolism

purpose of calcitonin

reduce blood calcium, inhibit osteoclast, decrease excretion of calcium and phosphate

causes of goiter

deficiency in iodine

symptoms of goiter

enlarged thyroid, dysphagia, hoarseness

results from goiter

hypothyroidism

treatments for goiter

iodine supplements

describe graves disease

autoimmune disease producing long acting thyroid stimulator antibody

results of graves disease

hyperthyroidism

treatments for graves disease

inhibit thyroid hormone synthesis, destroy thyroid tissue, surgically remove thyroid, radiation on thyroid

symptoms of graves disease

symmetrical goiter, exophthalmos, internal heat intolerance, tachycardia, UE tremors, weight loss, increased bowel movement, periarthritis, calcified tendinitis, proximal muscle weakness

define periarthritis

inflammation of soft tissue around joints

define calcium tendinitis

buildup of calcium crystals in tendons

define exophthalmos

bulging eyes

why is there significant weight loss from graves disease

hyperthyroidism increases metabolism

result of TSH levels during hyperthyroidism

lower levels due to negative feedback loop

differential diagnosis for enlarged neck

could be goiter, Hodgkins lymphoma

differential diagnosis for unexplained weight loss

could be graves disease, cancer

differential diagnosis for abnormal cardiac response

could be cardiovascular disease, graves disease

PT considerations for graves disease

• monitor vital signs

• awareness of heat intolerance and reduced exercise capacity

• possible hypothyroidism after treatment

• manage neuromuscular issues (periarthritis, calcified tendinitis, proximal muscle weakness)

differentiate hypothyroidism type I and II

type I is hormone deficient, type II is hormone resistant

causes of hypothyroidism

thyroiditis, thyroid ablation

define ablation

procedure using heat, cold, electricity to destroy abnormal or diseased tissue

treatments for hypothyroidism

thyroid hormone replacement

symptoms for hypothyroidism

weight gain, fatigue, non-pitting edema of face, irritability, dry skin, muscular weakness, bradycardia, impaired memory

define myxedema

chronic hypothyroidism that can lead to myxema coma

thyroiditis is commonly known as

hashimotos disease

describe hashimotos disease

autoimmune response attacking thyroid tissue, more prominent in women

symptoms for hashimotos disease

enlarged thyroid, dysphagia, hypothyroidism symptoms, increased sensitivity to cold

treatments for hashimotos disease

thyroid hormone replacement, surgery to remove goiter

describe thyroid cancer

rare, large percentage of endocrine cancers, most common in women between 40 to 60 years

causes of thyroid cancer

exposure to radiation

treatments for thyroid cancer

remove thyroid, radioactive iodine, hormone replacement

imaging techniques to use for thyroid cancer

ultrasound to check for assymetrical thyroid, PET scan for radiation from thyroid

what type of imaging technique is most commonly used for most endocrine organs

ultrasound because of soft tissue and cheapest technique

PT considerations for hypothyroidism

aware of activity intolerance, manage musculoskeletal issues, skin care, possible development of exercise induced myalgia, rhabdomyolysis, possible hyperthyroidism from hormone replacement

define myalgia

muscular pain

define rhabdomyolysis

rapid muscle tissue breakdown and release of toxic proteins due to myalgia

hormones produced by parathyroid

PTH

purpose of PTH

• regulate bone metabolism

• regulate plasma calcium plasma phosphate levels

• increase blood calcium

• active osteoclast

• inhibit osteoblast

• release calcium from bone

• reabsorption of calcium by kidneys and GI tact

define osteoclast

agent that destroys bone

define osteoblast

agent that builds bone

relationship between plasma calcium and plasma phosphate

inverse relationship