The Endocrine system Flashcards
What is the Endocrine system?
The hypothalmus controls the pituitary gland. the pituitary gland secretes numerous hormones via the blood to control activity of certain organs. it is for long distance communication.
How do steroid hormones communicate ?
They are water soluble. they can diffuse across the plasma membrane.
How do protein hormones communicate?
They can not diffuse across the plasma membrane. They bind to receptors on the plasma membrane and raise the concentration of cAMP. cAMP then activate the activity of the cell
What are the different sections of the pituitary gland?
Anterior gland
Posterior gland
How does the hypothalamus control the pituitary gland?
1) it secrets releasing factors into thea portal system to the anterior pituitary
2) the hypothalmus has neurosecretory cells that secrete hormones Vasopressin and Oxyticin directly into the posterior pituitary.
which Hormones are secreted by the anterior pituitary?
1) Growth Hormone
2) thyroid stimulating Hormone (TSH)
3) Adrenocorticotropic Hormone (ACTH)
4) Prolactin
5) Follicle stimulating Hormone (FSH) or Intestinal Cell stimulating Hormone (ICSH)
6) Luteinizing Hormone
What are the Hormones secreted by the posterior pituitary?
1) Vasopressin or Anti-diuretic Hormone(ADH)
2) Oxytocin
What is the function of Growth Hormone?
Causes growth of the body; all cells in all body parts. Important for growth in the adolescent stage. post adolescence it continue to play a role in metabolism (protein synthesis and increasing blood glucose concentration
What are defects of touch/little growth hormone?
To much at an early age lead to gigantism
to little leads to dwarfism
What is the function of Thyroid stimulating Hormone (TSH)?
stimulate the thyroid gland. thyroxine T4 and triiodothyronine T3 is secreted by the thyroid. It increases the overall metabollic rate of the body
what is the function of Adrecorticotropic Hormone(ACTH)?
stimulates production of cortisol by the adrenal cortex.
What is the function of Prolactin?
Plays a role in development of the breast after pregnancy and the secretion of milk after child birth
What is the function of Antidiuretic Hormone?
also called vasopressin causes rise in the arterial pressure and enhances the rate of water reabsorption by the renal tubules.
What is the function of Oxytocin?
Contraction of the uterus and other smooth muscles. Makes milk flow by stimulating myoepithelial cells in the breast
Where is the adrenal gland located?
oTop of the kidneys
What hormones are secreted by the adrenal cortex?
1) Mineralocorticoids- e.g. aldosterone
2) Glucocorticoids - e.g. cortisol
3) Sex hormones - e.g. testosterone and estrogen
What transmitter is secreted by the adrenal cortex?
epinephrine (adrenaline)
norepinephrine (noradrenaline)
What is the function of the Mineralocorticoids?
Regulation of electrolyte balance of the body
it promotes the retention of sodium and the secretion of potassium in the urine.
What is the function of the Glucocorticoids?
Influence metabolism of fats, proteins and sugar.
concentration of glucose in the blood rise by decreasing the uptake of sugar by the cells
degradation of proteins and the increase of the use of fat for energy.
What is the purpose of the sex hormones?
Responsible for the differentiation af the sex organs in the males and females.
Where is the thyroid gland located?
anterior of the neck
explain the anatomy of the thyroid gland.
it is composed of follicles lined with thyroid glandular cells. they produce a thyroglobulin which contain thyroxin a thyroid molecule.
What does thyroxine do?
Combines with plasma proteins. they increase the synthesis of proteins and the number of mitochondria in the cell. Which increase the production of ATP. promotes cellular metabolism.
What is hyperthyroidism?
Excess thyroid secretion. This causes a increased metabolic rate.
