Endocrine System Flashcards
(20 cards)
Pituitary Gland
“Master gland”
Adenohypophysis and neurohypophysis
Releases hormones regulating many glands
Influenced by seasonal changes and emotional stress
Secretes endorphins reducing pain sensitivity
Controls ovulation, catalyst for testes and ovaries to create sex hormones
Hypothalamus
Connects to pituitary gland through infundibular or pituitary stalk
Regulates ANS and other endocrine glands by influencing pituitary gland
ANS: Body temp, thirst, sexual behavior, sleep, appetite, sweating, rage, fear, blood pressure
Thyroid Gland
Below the larynx, right and left lobes joined by isthmus
Produces thyroxine and triiodothyronine
Controls rate cells burn fuel from food
Increased thyroid hormones = increased rate of chemical reactions
Parathyroid Glands
Four on the posterior surface of thyroid lateral lobes
Produces parathyroid hormone
Antagonist to calcitonin, maintain calcium and phosphorus blood levels
Increases resorption of calcium and phosphorus from bone to blood
Secretion stimulated by hypocalcemia, inhibited by hypercalcemia
Calcium levels affect clotting, neuromuscular excitability, and cell membrane permeability
Adrenal Glands
Two adrenal glands, on top of each kidney
Adrenal Cortex:
Outer portion
Produces corticosteroids
Regulates H2O/Na balance, stress response, immune system, sexual development and function, metabolism
Adrenal Medulla:
Inner portion
Produces epinephrine
Increases HR and BP when increased stress
Pancreas
Upper left quadrant, duodenum to spleen
Endocrine and exocrine tissues
Islets of Langerhans produce pancreatic hormones
Alpha Cells: Glucagon
Beta Cells: Insulin
Work together to maintain consistent level of glucose in bloodstream and stores of energy in body
Steroid Hormones
Prostaglandins
Created from phospholipid membranes by all cells
Unique: Do not circulate in blood, only exert effects where they are made
Wide variety of effects; inflammation, pain, vasodilation, vasoconstriction, nutrient metabolism, blood clotting
Amine Hormones
Catecholamines - Epi, Norepi, Dopamine
Made from adrenal medulla chromaffin cells
SNS stimulation releases them into bloodstream
Epi - fight or flight - CV and metabolic
Other - cardiac contractility, vasoconstriction, glycogen breakdown, insulin blocking, increasing metabolic rate, airway dilation
Peptide Hormones
Insulin
Released with elevated blood glucose
Increases cellular uptake of blood glucose
Stimulates muscle and liver glucose storage
Increases amino acid transport across liver, muscle, and adipose tissue
Affects all systems, goal reducing blood glucose
Pituitary: GH, FSH, LH ,TSH, ACTH, Prolactin
Stimulation via hypothalamus
Release of GH to bone and muscle, FSH, LH, and P to sex organs, TSH to thyroid, ACTH to adrenal cortex
Growth and development, reproduction development and function, increased T3/T4, increased adrenal steroids
Pituitary: Antidiuretic Hormone
Decreased water content
Antidiuretic hormone released to kidneys
Increases H2O reabsorption, conserves H2O, increases BP by stimulating contraction of muscles in small arteries
Adrenal Cortex: Aldosterone (Mineralocorticoid)
Low blood Na/High blood K
Aldosterone released to kidney
Increases reabsorption of Na by kidneys to blood, excretion of K by kidney to urine
Adrenal Cortex: Cortisol (Glucocorticoid)
ACTH released
Cortisol released to GI
Influences food metabolism, anti inflammatory effect in large amounts
Adrenal Medulla: Epinephrine
Sympathetic impulse from hypothalamus during stress
Epinephrine released to CV and metabolic systems
Increases HR and contractility, energy production, muscle vasodilation
Adrenal Medulla: Norepinephrine
Sympathetic impulse from hypothalamus during stress
Norepinephrine released to CV and metabolic systems
Increased vasoconstriction in skin, viscera, and muscle
Pancreas: Glucagon
Hypoglycemia
Glucagon released to liver
Glycogen - glucose
Increased blood glucose
Pancreas: Insulin
Hyperglycemia
Insulin released to all body systems
Stimulates sorage of glucose, increasing fat, carb, protein storage
Decreases blood glucose
Parathyroids: Parathormone
Hypocalcemia
Parathormone released to bone, kidney, intestinal mucosa
Reabsorption of calcium from bones to blood (also inhibit calcitonin)
Increases blood calcium
Thyroid: Thyroxine (T4 ) and Triiodothyronine (T3)
TSH released
T3 & T4 released to all tissues
Increased cellular metabolism
Thyroid: Calcitonin
Hypocalcemia
Calcitonin released to plasma
Increases calcium storage in bone
Decreases blood calcium
