Endocrine system Flashcards
Endocrine glands
are ductless
secrete hormones directly into the bloodstream
products are released into the interstitial space around the cells, from where they diffuse into the capillaries and reach the target organ
Examples of endocrine glands
pituitary gland ovaries testes thyroid gland adrenal glands pineal body
Both endocrine and exocrine glands are
stomach
pancreas
Exocrine glands
have a duct
secrete/excrete products (metabolites, enzymes and other substances)
products are secreted to the duct, through which they flow to exterior surface
Examples of exocrine glands
sweat glands salivary glands mammary glands liver prostate gland duodenum
Hypothalamus
the main neural control center of the endocrine system = “masterswitchboard”
GNRH (gonadotrophin-releasing hormone)
TRH (thyroid-releasing hormone)
Pituitary gland
pea-sized
“master gland”
controls the function of most other glands and secrete hormones
produces and releases 7 hormones in response to commands from the hypothalamus
TSH
stimulates the thyroid gland to produce thyroid hormones
Growth hormone
act upon certain body tissues, do not affect specific organ
stimulates protein synthesis and cell division in cartilage and bone tissue
regulates the bone and muscle growth and physical development
is important in children to excite growth
Prolactin
act upon certain body tissues, do not affect specific organ
travels to the breast tissue glands of nursing mothers
facilitates milk production
THYROID GLAND
located in the neck/ is found in the lower part of the neck below the larynx
produces 3 hormones – T3, T4, calcitonin
T3, T4 – collectively called the THYROID HORMONE
produced in the follicles of the thyroid gland
affects body growth, metabolic rate, development of bones and skeletal muscle
thyroid hormones affect many vital functions such as heart rate
thyroxine accelerates the release of energy in the tissues
Hypothyroidism
too little thyroid hormone = decreased production of the thyroid hormone
reduced metabolism
one of the common causes is Hashimoto’s disease
hypothyroidism can result from treatment of hyperactive thyroid
changes in the structure of the thyroid gland
can be treated with thyroid hormone pills
Symptoms of hyperthyroidism
Feeling tired Feeling nervous, stressed Feeling warm Shortness of breath during exercise Loss of strength Menstrual problems Weight loss Increased heart rate = rapid heartbeat Diarrhoea Psychological complaints – fear, irritability in some cases the thyroid gland might be enlarged the symptoms don’t occur at the same time
Goitre
enlarged thyroid gland
diffuse/localized
multiple nodules or generalized swelling of the thyroid gland = thyroid enlargement
is one of the most common thyroid problems
it has several causes such as infection
iodine deficiency
benign or malignant disease
malignant disease is extremely rare
Before treating goitre the underlying cause must be determined
can be treated with surgery or with radioactive iodine
Treatment of hyperthyroidism
treatment depending on the cause
can be treated with medication to reduce the production of thyroid hormone
another option is treatment with
radioactive iodine to stop the function of thyroid cells
surgery can also treat it
GRAVES’ DISEASE
it is an autoimmune disease where your body produces antibodies to stimulate the thyroid gland which produces excessive thyroid hormone more than the requirement for normal functioning of the body
It may also cause eye problems
Symptoms of hypothyroidism
Feeling tired Feeling cold Heart problems Increased in weight Depressed feelings Hair loss Hoarse and deeper voice Bowel problems in some cases the thyroid gland might be enlarged
HASHIMOTO’S DISEASE
there is an immune response of the body against the thyroid gland which causes decreased function of the thyroid
Symptoms of goiter
Visible swelling in the neck
Problems with swallowing or breathing
thrill – palpable vibration felt with the hand causes by increased blood flow in diffuse enlargement, for example in Graves’ disease
bruit – audible noise heard through stethoscope over the gland
PARATHYROID GLANDS
are embedded in the back of the thyroid gland secrete PTH (parathormone)
PTH (parathormone)
increases blood calcium - stimulates bone calcium release into the bloodstream, increases the calcium absorption rate in the gastrointestinal tract and kidneys
maintains plasma calcium levels within normal limits
ADRENALS
sit/located on the top of each kidney
are located in retroperineum
they derive some of their blood supply from the renal artery
secrete glucocorticoids, small amounts of androgens and estrogens (responsible for some secondary sex characteristics), mineralocorticoids, adrenalin, noradrenalin
adrenal hormones control heart rate, blood pressure, maintain fluid and mineral balance, the response to stress or infection
Aldosterone
is most important regulator of sodium and potassium
CORTISOL
too much glucocorticoids causes hump and stretchmarks
EPINEPHRINE (ADRENALIN) AND NOREPINEPHRINE (NORADRENALIN)
raise the blood levels of sugar and fatty acids
increase the heart rate and it’s force of contraction
prepares the body for “Fight or Flight” response – enable to think quicker, fight harder, run faster
OVARIES
are the side of estrogen and progesterone synthesis
ESTROGEN
is necessary/required to form the ovum during oogenesis
prepares the uterus for implantation of a fertilized egg
PROGESTERONE
prepares the breast for lactation during pregnancy
works with estrogen to regulate the menstrual cycle
TESTES
secrete testoteron
TESTOSTERON
is required for sperm formation during spermatogenesis
is responsible for the development of male external genitalia and secondary sexual traits such as beard growth, chest hair, enlarged thyroid cartilage
PALPITATIONS
awareness of rapid or irregular heartbeat
FINE TREMOR
very slight involuntary movements
HEAT INTOLERANCE
inability to cope with high temperatures
INSULIN
is released from pancreas in response to rising blood glucose level
allows to get energy from the food
allows the glucose to get into the cells where it can be used for energy, it’s “key” unlocking the door to the cells
decreases blood glucose level
DM TYPE 1
the body isn’t making insulin at all
autoimmune response against the insulin producing cells in the pancreas, due to for example viral pancreatitis
10% of cases, more severe form
often found under 40s
most common type found in childhood
usually starts in childhood or adolescence (w okresie dojrzewania)
glucose can’t get into cells because of the lack of insulin
lowering the level of glucose through kidneys
treated with/the management of type I diabetes includes subcutaneous self-injections of insulin to avoid coma
daily dose is 1 unit per 1 kg body weight
DM TYPE 1 SYMPTOMS
Frequent urination = poliuria Persistent thirst = polydipsia Thrush or genital itching Slow wound healing Blurred vision (accumulation of glucose in lens) Tiredness, feeling lethargic Weight loss (breaking down fats tools) Symptoms come quickly = rapid onset
DM TYPE 2
Either the body isn’t producing quite enough insulin (insufficient amount of insulin for the needs of the body) or the insulin it is producing isn’t working properly.
overweight (80%) or healthy weight
almost 90% of cases
most common in the over 40 age group in the white population and in the over 25 age group in the South Asian population.
glucose can’t always get into the cells because the locks to the cell doors have become furred up with fat deposits. - That means that the insulin can’t open the cell doors properly.
In response to this, the pancreas produces
even more insulin so the blood glucose levels continue to rise and the insulin levels continue to rise
This situation is further complicated by the cells which are desperate for energy - sending out emergency signals to the liver to release stored glucose
the pancreas can wear out
DM TYPE 2 SYMPTOMS
Frequent urination
Thirst
Thrush or genital itching
Slow wound healing
Blurred vision (accumulation of glucose in the lens)
Tiredness, feeling lethargic
Weight loss (breaking down fats tools) in some people
Symptoms come very slowly or some people don’t have symptoms at all = gradual onset
DM TYPE 2 TREATMENT
Initially it may be sufficient to make changes to the food you’re eating and to take extra physical activity or lose any weight that may be appropriate.
Type 2 diabetes is a progressive condition and most people will need some form of medication to treat it
treated with special diet, weight reduction, oral hypoglycaemic drugs
Metabolism
is the process by which foods are transformed into basic elements which can be utilized by the body for energy or growth
Acromegaly
a disease caused by excessive function of pituitary gland
Myxoedema
=obrzęk śluzowaty
metabolic disorder due to insufficient function of the thyroid gland
Hyperparathyroidism
excessive secretion of the parathyroid gland
ACTH
adrenocorticotropic hormone
FSH
follicle stimulationg hormone
LH
luteinising hormone
LTH
luteotropic hormone
STH
somatotropin
MSH
melanocyte stimulating hormone
ADH
antidiuretic hormone
ATP
adenosine triphosphate
BMR
basal metabolic rate
