Endocrine System Flashcards
Chemical messenger of the endocrine system that is secreted into the blood, travels distant target tissue, and binds to specific receptors
Hormone
Two chemical categories of hormone
Lipid soluble
Water soluble
Example of lipid soluble
Steroids
Thyroid hormones
Fatty acid derivative
Examples of water soluble
Proteins
Peptides
Amino acid derivatives
Three types of stimuli result in hormone secretion
Humoral
Neural
Hormonal
____ stimulation is stimulated by hormones that are sensitive to circulating blood levels of certain molecules such as glucose calcium or sodium
Humoral stimuli
Stimuli cause hormone secretion in direct response to action potential in neurons
Neural
___ stimulation of other hormone secretion is common in Endo.System.
Hormonal
Two processes regulate the over all blood levels of hormones
Negative and positive feedback
A hormone that binds to nuclear receptors located inside the nucleus of the target cell
Lipid soluble hormones
Hormones that by to membranes-bound receptors, which are integral membrane proteins
Water-soluble hormones
Is connected to the hypothalamus of the brain INFUNDIBULUM
Pituitary gland
Hormones in anterior pituitary
growth hormone
thyroid stimulating hormone
melanocyte stimulating hormone
Examples of posterior Pituitary
Antidiuretic hormone and oxytocin
Gland that secretes thyroid hormones
Thyroid gland
Control the metabolic rate of tissues
Thyroid hormones
Helps regulate blood calcium levels that is secretes by the thyroid gland
Calcitonin
Secretes parathyroid hormone
Parathyroid gland
Hormone that helps regulate blood calcium levels that can be found in parathyroid gland
Parathyroid hormone
Secrets primarily epinephrine and some norephinephrine
Adrenal medulla
Three classes of hormones that adrenal cortex secretes
Glucocorticoids
mineralocorticoids
adrenal androgens
Secretes insulin in response to elevate levels of blood glucose and amino acid
Pancreas
Increases the rate at which many tissues including adipose tissue, the liver and skeletal muscle pick up Glucose and amino acids
Insulin
Secrets glucagon in response to reduce blood glucose and increase the rate at which the liver releases glucose into blood
Pancreas
Secret somatostatin in response to food intake
Pancreas
Inhibits insulin and glucagon secretion and gastric tract activity
somatostatin
Secretes testosterone
Testes
Secretes estrogen and progesterone
Ovaries
Secretes thymosin, which enhances the function of immune system
Thymus
Secretes melatonin which may help regulate the onset of puberty by acting on the hypothalamus
Pineal gland
4 classes of chemical messenger
Autocrine
Paracrine
Neurotransmitter
Endocrine
Stimulates the cell that originally secreted it and sometimes nearby cells of the same type
Autocrine chemical messengers
Produced by wide variety of tissues and secreted into extracellular fluid
Paracrine chemical messengers
Produced by neurons, activates adjacent cell
Neurotransmitters
Secreted into the vlood by specialized cells
Endocrine chemical messengers
Functions of the endocrine
Metabolism Control of food intake and digestion Tissue development Ion regulation Water balance Heart rate and bp regulation Control of blood glucose and other nutrients Control of reproductive functions Uterine contractions and milk release Immune system regulation
Hormones small in size and low solubility in aqueous fluids
Travel in the bloodstream attached to binding proteins
Lipid soluble hormones
Are dissolved in blood and circulate as free hormones. Do not attach to binding proteins.
Diffuse into tissue spaces slower
Water-soluble hormones
Neurons that secrete chemical messengers directly into the blood
Neuropeptides
