Endocrine System Flashcards
Role of endocrine system
Homeostasis - maintain normal balance of body internal environment
(Slower changes)
What do the endocrine glands secrete
Hormones - chemical messengers
Endocrine glands
Pituitary gland
Pineal gland
Thyroid glands
4 parathyroid glands
Thymus
2 adrenal glands
Pancreatic islets
2 ovaries OR 2 testes
What processes do hormones influence
Growth and development
Stress response
Nutrition
Reproduction
How do disorders of endocrine system occur
Too much (hyper) of a hormone being produced.
Too little (hypo) of a hormone produced.
What results in a lack of insulin being produced
Diabetes - endocrine disorder
Why study endocrine system
Clinical presentation
Oral manifestations of endocrine diseases
Behaviour
Medical emergencies
Where is the pituitary gland situated and what attaches it
In hypophyseal fossa of sphenoid bone below hypothalamus.
Attached to hypothalamus by a stalk
What system do the hypothalamus and pituitary gland work
Negative feedback regulation
What is negative feedback
Helps control homeostasis within body;
Releases hormones when levels are too low.
Initiates changes to decrease production of hormone if levels too high.
Hormones secreted by anterior pituitary
Growth hormone
Prolactin
Thyroid stimulating hormone
Corticotrophin releasing hormone
Gonadotrophins
Hormones secreted by posterior pituitary
Oxytocin
Anti diuretic hormone
Functions of growth hormone in children
Promotes growth of;
Skeleton
Muscles
Connective tissue
Kidneys
Liver
Pancreas
Adrenal glands
Function of growth hormone in adults
Maintenance and repair
Function of thyroid stimulating hormone
TSH stimulates growth and activity of thyroid gland
Function of adrenocorticotrophic hormone
ACTH stimulates activity of adrenal cortex, increases output of steroid hormones (cortisol)
Function of prolactin
Stimulates lactation (milk production) after birth.
Gonadotrophin hormones released in response to luteinising hormone from hypothalamus.
What occurs after puberty in the anterior pituitary
2 gonadotrophic (sex hormones) in males and females
Follicle stimulating hormone
Stimulates production of gametes
Luteinising hormones
Stimulates ovaries to produce oestrogen/progesterone
And
Testes to secrete testosterone
Function of oxytocin
Promotes contraction of uterus.
Works with prolactin to produce breast milk.
Function of anti diuretic hormone (vasopressin)
Influences resorption of water by kidney tubules, results in concentration of urine.
Stimulates contraction of muscular tissues of capillaries and arterials, results in raised blood pressure.
Where is the thyroid gland situated
In the neck
Front of larynx and trachea
Hormones secreted by thyroid gland
Thyroxine
Triiodothyonine
Calcitonin
What is essential for production of thyroid hormones
Iodine
Functions of thyroxine and t3 (triiodothyronine)
Physical growth and mental development
Metabolism
Nervous and cardiovascular systems
Mobility of GI tract
Female reproductive cycle and lactation
Functions of calcitonin
Regulates blood calcium
Storage of calcium in bones
Excretion of calcium by kidneys
Opposes action of parathormone
Hormone produced by parathyroid gland and function
Parathormone.
Important in maintenance of plasma calcium levels.
Works with calcitonin to regulate blood calcium.
How does parathormone raise blood calcium
Uptake by small intestine
Around resorted by kidneys
Why is calcium needed
Muscle contraction
Blood clotting
Nerve impulse transmission
Where are the adrenal glands situation
Small triangle shaped glands that sit on top of the kidneys
2 parts of adrenal glands
Cortex - outer
Medulla - inner
What regulated hormone secretion in adrenal glands
Negative feedback system from hypothalamus and pituitary gland
Hormones produced in adrenal gland
Glucocorticoids (cortisol)
Mineralocorticoid (aldosterone)
Epinephrine (adrenaline)
Norepinephrine (noradrenaline)
Function of glucocorticoids (cortisol)
Glucose metabolism produce in response to stress.
Unwanted side effects of glucocorticoids
Suppress immune system and wound healing.
Functions of aldosterone (mineralocorticoid)
Electrolyte balance in the body.
Regulate volumes of sodium and potassium.
Secreted when low blood sodium levels are present or when potassium increases.
Hormones produced by adrenal medulla
Epinephrine- adrenaline
Norepinephrine- noradrenaline
What response is adrenaline concerned with
Fight or flight
Effects of adrenaline
Increase in; metabolic rate, heart rate and blood pressure.
Dilation of; pupils, bronchioles, blood vessels of muscles, heart and brain.
Converts glycogen to glucose.
Effects/function of noradrenaline
Maintenance of blood pressure
Vasoconstriction (expect coronary arteries)
Hormones secreted by pancreatic islets
Insulin
Glucagon
Somatostatin
What hormones are concerned with maintaining homeostasis of blood glucose levels
Insulin
Glucose
What hormones inhibits secretion of insulin and glucagon
Somatostatin
Function of insulin
Regulate blood glucose and other absorbed nutrients.
Reduces blood glucose levels.
Functions of glucagon
Increases blood glucose levels.
Converts glycogen into glucose and gluconeogenesis.
Hormones produced by ovaries and their function
Oestrogen and progesterone;
Regulate menstrual cycle
Sexual maturity in women.
Hormones produced by testes
Spermatozoa and testosterone.
Sexual maturity in men
Secondary sexual characteristics.
Location and secretion of thymus gland
In chest behind sternum.
Secretes hormone thymosin.
Function of thymosin
Development of T-lymphocytes for cell mediated immunity.
Responsible for growth and maturation of thymus and other lymph tissue.
As we get older, production declines along with T-lymphocyte effectiveness.
Hormone secretion of pineal gland
Produces hormone melatonin.
Secretion is suppressed by daylight.
Melatonin functions
Inhibits development of ovaries and testes before puberty.
Initiates and maintains sleep.
What does the thymus gland play an important part in
Immunity
