1-introduction to endocrinology Flashcards
what is a hormone
a chemical substance that is secreted by a gland or a tissue into body fluid and has a physiological control effect on other cells.
endocrine def
H produced and secreted within the body (where it has its effect)
opposite of endocrine and example
exocrine and digestive enzymes bc they are produced in the pancreas and excreted out
3 different times scales of hormonal effects and examples
seconds (epi, norepi): fight or flight
several days, weeks: cell growth that requires gene transcription
months (tyroxine and growth H): mito changes and becomes more powerful or drugs for example
what can the sympathetic ns stimulate
adrenal glands
what can the central ns control
pituitary gland
t/f all H are controlled by the ns
f: some but not all
t/f most hormones are produced at high levels to be able to regulate them easier
false, they are mostly produced at lower levels
what metabolic functions of the body are controlled by the endocrine system
-chemical reaction rate of cells
-transport of substances through cell membrane
-growth of body
-secretion of other hormones
t/f the biochemical process in each cell cannot occur without the endo sys
false, it can occur but it requires the endo sys for homeostasis
what metabolites do the H have the most impact on
proteins, fatty acids and glucose
what gland crosses the blood brain barrier
the pituitary
what is the top part of the pituitary connected to and the bottom part
the top part is connected to the hypothalamus and the bottom is connected to blood vessels
how many thyroid gland lobes does a person have and what shape
shapes vary and a person can have from 1 to 3 lobes
what can the hypothalamus control
body temp
bp
electrolytes
diff chemicals
thoughts, feelings, vision and smell
decides which H to use and which aren’t needed
what are the diff types of endocrine gland and tissues
pituitary
adrenal
thyroid
parathyroid
islets of Langerhans
ovaries
testes
placenta
duodenum
what are the diff types of endocrine glands
pituitary
adrenal
thyroid
parathyroid
ovaries
testes
duodenum
what are the 6 H secreted by the ant pituitary
GH
adrenocorticotropin (ACTH)
thyroid-stimulating H
follicle-stimulating H
luteinizing H
prolactin
which part of the pituitary is smaller and controlled primarily by other H
ant pit
what part of the pit comes from skin stem cells and nervous tissue stem cells
skin stem cells: ant pit
nervous tissue stem cells: post pit
which lobe of the pit is primarily under neuronal control
post pit (R lobe)
what are the H secreted by the post pit
antidiuretic H (vasopressant): controls bp in kidney
oxytocin
how many glands are part of the adrenal and where are they located
2 glands each on top of the kidneys
1 adrenal gland is divided into what parts and where are they located
cortex (superficial or external) and medulla (deep or internal)
what part of 1 adrenal gland is under H control and which is under neural control
the cortex is H control
medulla is neural control
what 2 catecholamine H are secreted by the medulla and to what sys is it directly connected to
adrenaline (major secretion)
noradrenaline (minor secretion)
directly connected to the sympathethic ns
where is the thyroid gland located
up in the sternal and mediastinal area of the thorax and is situated above the thymus which sits on top of the heart
what 3 H are secreted by the thyroid gland
thyroxine (T4)
triiodothyronine (T3)
calcitonin (produced in thyroid gland but goes elesewhere)
the parathyroid gland has how many glands and they are located where
4 located in the thyroid gland
what H is secreted by the parathyroid gland
parathyroid H (parathormone)
where are the islets of Langerhans located and what H do they secrete and what are they considered as
in the pancreas and secrete insulin and glucagon
endocrine tissue not gland
what do the ovaries produce
estrogen and progesterone
what do the testes produce
testosterone
what is the placenta considered as and what H does it make and what process are they involved in
endocrine tissue
it makes: human chorionic gonadotropin, estrogen, progesterone, somatomammotropin
embryogenesis
what do the brunner’s gland do and what are they a part of
secretin H signals to the pancreas and coordinates digestion
the duodenum contains brunner’S gland
is the brown adipose tissue an endocrine gland or tissue and what does it do
no bc it doesn’t secrete H
it receives H input to help regulate body temp
what are local H and give examples
primarily have specific local effects on specific tissues (not based on where they come from but where they have their effect)
-secretin
-cholecystokinin
-adrenocorticotropin
where is secretin released from and what does it do
released from the duodenum wall and is transported in blood to pancreas causing secretions for digestion
where is cholecystokinin released from and what does it do
released in small intestine and transported to gallbladder to cause gallbladder contractions
and to pancreas to cause secretion of digestive enzymes
where is the adrenocorticotropin H released from
the ant pituitary and stimulates the adrenal cortex to secrete adrenocortical H
what are general H and give examples
general H can be effective on many parts of the body and cause many reactions
-epi and norepi
-GH
-thyroid H (T3 and T4)
epi and norepi are secreted by what, cause constriction of what and has effects on what
-secreted by adrenal medulla under sympathetic stimulation, secreted by sympathetic n.
-cause constriction of blood vessels and increase arterial pressure
-has effects on most organs and tissues of the body
GH is released from what and causes what
ant pituitary
causes growth in all parts of the body
T3 and T4 are released from where and increase what
released from thyroid gland and increase chemical rx rate in almost all body cells that have a mitochondria
What does the chemical classification of H help us understand
how the H is produced and how it works on the body
what is cholesterol
a part of our cell mem because it is hydrophobic and lipophilic
what are steroid based H built from and why are they called like this
cholesterol
because testosterone is built from cholesterol and many anabolic steroids are made from testosterone
what can the adrenal cortex turn the cholesterol into and what can the placenta and ovaries turn cholesterol into
into many H such as cortisol and aldosterone
into estrogen
t/f our body needs cholesterol to make H
true
the steroid based H tend to cross what to get directly to where
tend to cross the plasma mem and get directly to the inside of the cell (cytoplasm or nucleus) bc the receptors for steroid based H are usually found within the cell nucleus or cytoplasm
what is the mechanism of steroid H pathway
1- steroid H enter cytoplasm of cell
2-binds with receptors(in some cases, the receptors are found within the nucleus not the cytoplasm)
3- diffuse or transported into nucleus
4-bind to and activate DNA strands
5- initiate transcription process of genes to form RNA messenger
6- RNA goes into cytoplasm thru nuclear pore complex
7- promote functions inside the cells
what is tyrosine
important amino acid to make proteins but it can also be turned into several diff H (thyroid gland can turn tyrosine into thyroxine (T4) and triiodothyronine (T3) )
(adrenal medulla can turn tyrosine into epi& norepi)
how does the thyroid gland use tyrosine to make H and why is it different than others
it adds iodine mol to tyrosine which makes T3 and T4 hydrophobic and lipophilic
because it makes their receptors be inside the cells
how does the adrenal gland use tyrosine
it hydroxylates tyrosine to make it hydrophilic and lipophobic
what is the pathway for thyroid H
1- binds w receptor in cell nucleus (in some cases, the receptors are found within the nucleus not the cytoplasm)
2-bind and activate RNA
3-initiate transcriptions of specific genes to form RNA messenger
4- RNA goes into cytoplasm thru nuclear pore complex
5- new proteins (enzymes) are formed and become the controller to promote metabolic activities in all cells of body
what is the pathway for substances that interact w receptors on the surface of the cell mem
1- bind w receptors on the cell mem
2-cause conformational change of proteins structures of the receptor
3-open or close channels for ions (Na or K) (change of meme permeability)
4- change of cell mem potential
5-cause cell excitation or inhibition
what H have receptors on the surface of the cell mem
epi nor epi and acetylcholine (bc they can’t enter since they are lipophobic and hydrophilic)
what is the diff btw a prot and a peptides
a prot is a long chain of amino acids that fold up unto an organized blob
a peptides is a shorter version (<20 aa) that doesn’t flod into a blob
what are examples of prot based H and what are their characteristics
ant pituitary H
post pituitary H
insulin and glucagon
parathormone
they are hydrophobic and lipophilic so they use receptors on the surface of cell mem
what is the pathway for prot based H
1-prot based H bind to receptors on mem (protrudes to ext of cell)
2-structure change in receptor
3-receptor becomes activated enzyme: adenyl cyclase
4-activate the formation of cyclic adenosine monophosphate (cAMP)
5- second messenger activates a cascade of enzymes
6-causes powerful effects on cells
