Endocrine System Flashcards
Key functions
endocrine glands (specialized ductless glands) that secrete hormones that travel through the bloodstream to signal specific target cells throughout the body
endocrine and nervous systems can work independently or in concert to achieve and maintain homeostasis
maintain homeostasis, respond to stress, sexual reproduction, BP, water/sodium balance
Glands of endocrine system
hypothalamus
pituitary gland
thyroid gland
parathyroid gland
adrenal gland
pancreas
testes and ovaries
Hypothalamus
located below thalamus and cerebral hemisphere
connects to pituitary gland
responsible for regulating ANS function through connection to pituitary gland (sweating, thirst, sex, BP, sleep, body temp)
Pituitary gland
located below hypothalamus
“master gland” of endocrine; releases hormones that regulate several other endocrine glands
Thyroid gland
anterior trachea, butterfly shape
produces hormones that affect cellular metabolism
Parathyroid glands (4)
located on posterior thyroid gland
produces hormones that affect serum calcium levels
Adrenal glands (2)
one located on top of each kidney
adrenal cortex: produces corticosteroids
- regulate water and sodium balance, body’s response to stress, immune system, sexual development and function
adrenal medulla: produces epinephrine and norepinephrine
- increase HR and BP when there is an increase in stress
Pancreas
alpha cells (islet of Langerhans)- produce glucagon
- convert glycogen to glucose to increase blood glucose levels in the presence of hypoglycemia
beta cells (islet of Langerhans)- produce insulin
-increases fat, protein, and carb storage which lowers blood glucose levels in the presence of hyperglycemia
Testes and Ovaries
produce testosterone and estrogen/progesterone, respectively
Hypothalamus Dysfunction
tumor, inflammation, surgical transection, trauma
Pituitary Dysfunction
tumor, ischemic necrosis, infiltrative dx, inflammation, iatrogenic (radiation)
hypopituitarism: short stature, delayed puberty, diabetes insipidus (“water diabetes”)
hyperpituitarism: acromegaly, gigantism, hirsutism (excessive hair growth in women typically in places where men grow hair), galactorrhea, amenorrhea, infertility
Adrenal Dysfunction
Addison’s disease: hypofunction of adrenal cortex
- decreased cortisol and aldosterone
Cushing’s syndrome: hyperfunction of adrenal gland
- increased cortisol
-“moon face” and “buffalo hump”
Thyroid Dysfunction
hypothyroidism: proximal muscle weakness, weight gain, increase in BP, fatigue, retarded growth and development, constipation
hyperthyroidism: weight loss, decrease in BP, nervousness/anxiety, exophthalmos, enlarged thyroid
Graves’ disease: most specific cause of hyperthyroidism (women over 20)
- goiter, heat intolerance, tremor, palpitations, weight loss
Parathyroid Dysfunction
hypoparathyroidism: decreased bone resorption
- tx: immediate increase of serum calcium levels
hyperparathyroidism: increased bone resorption
-tx: immediate decrease of serum calcium levels
Pancreas Dysfunction
Type 1 DM: pancreas fails to produce enough or any insulin
-tx: exogenous insulin injections
Type 2 DM: resistance to insulin action and inadequate insulin secretion
- hyperglycemia
tx: diet, exercise, medication, insulin injections
Gestational diabetes: increased insulin resistance resulting in increased blood glucose levels during pregnancy
hyperglycemia >180-200 mg/L
hypoglycemia <70 mg/L
DM:
-fasting plasma glucose: >125 mg/L (normal: <100)
-oral glucose test: >200 mg/L (normal: <140)
-A1c testing: >6.5% (normal: 5.7%)
