The Endocrine System Flashcards
The endocrine system function
- maintenance of internal homeostasis
- the regulation of growth and development of an organism
Hormones
Chemical messengers
Hormones are transported by
Bloodstream to all cells
What cells are affected by the hormone
Target cells that have a reception for that hormone
What is the Master gland
Pituitary
What does the pituitary do
Communicates w hypothalamus to control many body activities. Link between nervous and endocrine systems
Location of pituitary
Base of brain
How many hormones does the pituitary secrete
9
What are the 6 major hormones from the pituitary
Growth hormone: helps fat be used for energy
Thyroid- stimulating hormone: stimulates growth of the thyroid gland
Adrenocorticotropic hormone: stimulates growth of the adrenal gland
Follicle stimulating hormone: growth of the ovarian follicles, production of estrogen in females, testosterone
Luteinizing hormone: stimulates ovulation and produces progesterone in females
Oxytocin: released during childbirth; causes contraction of uterus
Diseases of the pituitary
Gigantism and dwarfism
Gigantism
Over secretion if GH prior to puberty
Excessive growth in long bones
Treatment: drug therapy to inhibit GH release
Dwarfism
Under production of GH during childhood
Lone bone growth decreased
Body is proportional and intelligence is normal
Treatment: early diagnosis and injections of GH fore five or more years
Function of thyroid gland
Regulates metabolism, growth, development and blood calcium levels
Location of the thyroid
Butterfly shaped mass going in neck of the trachea; shaped like an H
Hormones of the thyroid
Thyroxine
Calcitonin
Thyroxine
Increases metabolic rate; regulates growth and development
Calcitonin
Lowers blood calcium by accelerating storage in bones
Calcium is necessary for blood clotting muscle contractions rn holding cells together
Diseases of Thyroid
Hyperthyroidism
Graves’ disease
Hypothyroidism
Cretinism
Hyperthyroidism
Over production of thyroxine increases metabolism
Causes weight loss, increases appetite, fatigue, high bp, nervousness, irregular menstrual periods
Treatment: antithyroid med, surgical removal of thyroid
Graves’ disease
Severe form of hyperthyroidism
More common in women
Symptoms: strained and tense facial expression, nervous, irritability
Goiter: enlarged swelling of thyroid
Hypothyroidism
Under production of thyroxine causes slow metabolism
Weight gain depression , fatigue, puffiness of face hands and feet
Treatment: drugs like levothyroxine
Cretinism
When hyperthyroidism occurs since infancy or childhood, growth and development don’t occur normally.
Lack of mental and physical growth resulting in mental retardation and malformation
Sexual development and physical growth doesn’t reach beyond 7-8 yr old children
Function of parathyroid
Raises blood calcium
Hormone of parathyroid
Raises blood calcium to maintain proper levels of circulating calcium
Function of adrenal glands
Helps the body prepare for and deal w stress
Location of adrenal glands
“Suprarenal” glands above each kidney
Hormones of the adrenal gland
Epinephrine: adrenaline and norepinephrine are released in emergency or stress situations to raise blood glucose levels and prep the body for the fight or flight response
Cortisol: stress hormone that raises blood glucose by stimulating the breakdown of proteins.
Function of the pancreas
Maintains blood glucose homeostasis after eating
Also functions as an exocrine gland- secretes pancreatic juices that are carried to small intestines to aid in digestion
Location of pancreas
Behind stomach
Hormones of the pancreas
Insulin- lowers blood glucose, promotes storage of glycogen in liver and muscles
Glucagon- raises blood glucose
Function of the thymus
Activating cells in the immune system
It stops during puberty
Where is the thymus located
Under sternum
Hormone of thymus
Thymosin: stimulates production of antibodies in early years
Function of ovaries
Regulate menstruation and female sexual characteristics
Function of testes
Stimulate sperm production and male sex characteristics
In scrotal sac and suspended outside the body
Hormone of the testes
Testosterone- regulates sexual characteristics of a male
Pineal gland
Regulates sleep/wake cycle
Located in brain
Hormone of the pineal gland
Melatonin- released at night to make you sleepy
Anabolic steroids
Synthetic form of testosterone used to treat some disease.
Meg side effects:
Aggressive, hallucinations, high bp, low sperm count, breast reduction, seeping of voice
How does the endocrine system regulate homeostasis
Through negative feedback, when the amount of a particular hormone in the blood reaches a certain level, the endocrine system send signals that stop the release of that hormone
Explain the pancreas
- Pancreases releases insulin when there is too m uh sugar in blood
- Insulin’s tomulates the liver to remove sugar from the blood and store it as glycogen
- When there isn’t enough sugar in the blood, pancreas releases glucagon
- Glucagon signals liver to release glucose back into the blood
Leptin
Fat cells produce this when they are filled. It is transported to the brain where it suppresses a person appetite. When the fat is used the amount of lepton decreases which causes brain to start to feel hunger again
