Endocrine System & Hormones Flashcards
What major processes are controlled by hormones
Reproduction, growth and development, mobilizing body defences against stressors, maintain electrolyte, water and nutrient balance of the blood, regulating cellular metabolism and energy balance
How does the endocrine system work
uses chemical messengers called hormones, which are released into the blood to be transported leisurely throughout the body
Define Hormones
Chemical substance secreted by cells into the extracellular fluids, that regulate the metabolic activity of other cells in the body.
What is amines
Organic compound that binds to what it needs in that area
What 2 ways can hormones be classified as
Amino acid-based molecules (including proteins, peptides and amines) or steroids (made by gonads and hormones produced by adrenal cortex)
Steroidal hormones trigger changes in cell by (6)
- Diffuse through the plasma membranes of their target cells.
- enters nucleus
- Binds to specific receptor protein
- hormone-receptor binds to specific sites on DNA
- activates certain genes to transcribe mRNA
- mRNA is translated in the cytoplasm, resulting in synthesis of new proteins.
Non-steroidal hormones trigger changes in cell by (4)
- hormone binds to membrane receptor
- setting off series of reactions that activates enzymes which
- catalyzes a reaction that produces a second messenger molecule (AMP) that
- oversees additional intracellular changes that promotes typical response of target cell to the hormone.
What is the meaning of Hormone
To arouse
Explain Direct Gene Activation (6)
Steroids use this. Being a lipid-soluble molecules, it can:
- diffuse through the plasma membranes of their target cells.
- enters the nucleus
- binds to a specific hormone receptor
- hormone-receptor complex then binds to specific sites on the cells DNA
- activating certain genes to transcribe mRNA
- mRNA is translated in the cytoplasm, resulting in the synthesis of new proteins
Explain second-messenger system (4)
Peptides bind to hormone receptors situated on target cells plasma membrane.
- the hormone binds to the membrane receptor
- activated receptor sets off a series of reactions that activates an enzyme
- enzyme catalyzes reactions that produce second messenger molecules that
- oversee additional intracellular changes that promote the typical response of the target cell to the hormone.
What determines whether a hormone will influence a given body cell
A hormone can influence a body cell only if that cell has receptors for that hormone on its plasma membrane or internally.
Why is it important that signal triggering a pain response come from the nervous system and not the endocrine
The endocrine system delivers commands slowly via hormones where as the nervous system uses electrical messages that are much faster
What is a hormone and a target organ
Hormone is a chemical messenger. Target organ of a hormone is the specific cell or tissue that the hormone affects
What major endocrine organ is part of the nervous system
Hypothalamus
What are two important differences between endocrine and exocrine glands
Endocrine glands are ductless and release their hormones into the interstitial fluid. Exocrine glands empty through ducts to an epithelial surface
Name the hormones of the Anterior Pituitary (6)
Growth Hormone (GH), Prolactin (PRL), Thyrotropic Hormone /Thyroid-stimulating hormone (TH) or (TSH), Adrenocorticotropic hormone(ACTH), 2 gonadotropic hormones: Follicle-stimulating hormone (FSH) and Lutenizing hormone (LH)
Why is the Posterior pituitary not an endocrine gland
It is used for storage of the hormones made by the hypothalmus.
What hormones does the pituitary gland release
Oxytocin and Antidiuretic homone (ADH)
What are the hormones of the Thyroid
T3(Triiodothyronine), T4 (Thyroxine), Calcitonin
Why is iodine important for proper thyroid gland function
Functional thyroid hormone has iodine as part of its structure
What does calcitonin do
Deposits calcium in bones. Ceases to work in adults.
What do Thyroid hormones do
Controls the rate at which glucose is burned or oxidized and converted to to body heat and chemical energy.
Also important in tissue growth and development, especially in reproductive and nervous systems.
What does the gonadotropic hormones do
FSH stimulates follicle development in the ovaries, produce estrogen. Readies eggs for ovulation. In men, stimulates sperm development by the testes.
LH triggers ovulation and causes ruptured follicle to produce progesterone and some estrogen. In men, stimulates testosterone production.
What does prolactin do
It stimulates and maintains milk production in mothers breasts. Unknown in men
What does GH do.
Considered a metabolic hormone. Aids in growth of skeletal muscles and long bones.
What does oxytocin do
Stimulates powerful contractions of the uterine muscles during childbirth, sex and breast feeding. Causes milk ejection in a nursing woman.
What does the ADH so.
ADH prevents urine production. Causes kidneys to reabsorb more water from forming urine. Result is urine volume decreases and blood volume increases.
What hormone increases blood calcium levels, and which endocrine gland produces this hormone?
Parathyroid hormone made by the parathyroid
What hormone reduces blood calcium levels and which endocrine gland produces that hormone
Calcitonin produced by the thyroid gland
Which part of the adrenal gland is the glandular tissue and which has the neural tissue
Glandular tissue is cortex, neural tissue is medulla.
What 3 steroid hormones does the adrenal cortex produce
mineralocorticoids (aldosterone), glucocorticoids and sex hormones (mainly androgens but some estrogen)
What hormone stimulates the kidneys to reabsorb more sodium
Aldosterone
Which group of hormones produced by the adrenal cortex has some of the same effects as the hormones of the ovaries and the testes
Sex hormones (androgens and estrogen)
What is the function of mineralocorticoids and its target.
Regulating mineral (or salt) content of the blood. Target is the kidney
What does the glucocorticoids produce
Cortisone & cortisol
What are the function of glucocorticoids
promotes normal cell metabolism and helps body resist long term stressors by increasing blood glucose levels. They also control the more unpleasant effects of inflammation by decreasing edema.
What hormones does the adrenal medulla produce
Epinephrine (adrenaline), norepinephrine (nonadrenaline). Together called catecholamines.
What do the catecholamines do
Increase heart rate, blood pressure & blood glucose levels, and dilate the small passageways of the lungs.
What are is the difference of the adrenal medulla and cortex when coping with stress
Hormones of the adrenal medulla prepare the body to cope with a brief short term stressful situation (alarm phase of stress response)
Glutocorticoids from the adrenal cortex are more important in helping the body cope with long term stressors (operating in the resistance stage of stress response)
What do glucocorticoids do in long term stress response
Proteins and fats are converted to glucose or broken down for energy, Increase blood sugar, suppression of immune system.
Removal of which portion of the adrenal gland could be fatal
Adrenal Cortex
True or False: Pancreas is solely an endocrine gland
False
What does the pancreas produce and their functions
Insulin: increases cells ability to transport glucose across their plasma membranes. Sweeps glucose out of the blood so it’s effect is hypoglycemic.
Glucagon: raises level of glucose in the blood stream. Primary target the liver which stimulates break down of stored glycogen to glucose, releasing glucose into the blood.
Mrs. Bellamy’s husband has suffered a heart attack and is hospitalized. Would you expect her blood glucose levels to be elevated, normal or lower than normal? Why?
Elevated. because of her stress. When we are stressed, both glucocorticoids (adrenal cortical hormones) and epinephrine and norepinephrine (adrenal medullary hormones) are produced in increased amounts. Both sets of hormones promote rise in blood glucose levels
Insulin and glucagon are both pancreatic hormones. Which stimulates cellular uptake of glucose
Insulin
What does the pineal gland produce
Melatonin
What does the hormone of the pineal gland do
Melatonin establishes your day-night cycle by being a “sleep trigger”. Also believed to control the hormones of fertility.
Name the hormone of the Thymus gland
Thymosin
What does the hormone of the thymus gland do
assists in the development of white blood cells and the immune response
What are the hormones of the gonads
Estrogen, progesterone and testosterone
What does estrogen do
develops first and secondary sex characteristics in women and working with progesterone promotes breast development and cyclic changes in the uterine lining
What is progesterones job
Promotes growth of uterine lining
What is testosterones job
promotes growth and maturation of the reproductive system of males. Is necessary for continuous production of sperm
