Hormonal Communication Flashcards
endocrine system
a communication system using hormones as signalling molecules
hormones
proteins or steroid molecules that are released by endocrine glands into blood and they act as messengers carrying the signal to the specific target organ/tissue
target cells
for non-steroid hormones cells that posses a specific receptor on their membrane- shape is complementary to the hormone
adrenal cortex
outer layer of the adrenal gland
adrenal gland
one of a pair of glands lying above the kidneys which release adrenaline and other hormones (corticoids)
adrenaline
hormone which stimulates the body to prepare for fight or flight
adrenal medulla
inner layer of the adrenal gland
beta cells
found in the islets of Langerhans that secrete insulin
glucagon
hormone that causes an increase in blood glucose concentration
insulin
hormone released from the pancreas that causes blood glucose levels to go down
diabetes mellitus
condition which blood glucose levels can’t be controlled effectively
stem cells
unspecialised cells that have the potential to develop into any type of cell
types of hormones
protein and peptide hormones (derivatives of amino acids)- not soluble
steroid hormones- soluble so enter nucleus and have direct effect
endocrine glands
ductless glands that consist of a group of cells that manufacture and release a hormone directly via capillaries into the blood
endocrine organs
pituitary gland, thryoid gland, thymus, adrenal glands, pancreas, ovaries, testes
how do target cells work
for non-steroid hormones, must possess a specific receptor complementary to the shape of the hormone to initiate changes in the cell
each hormone is different so only the target cells with specific receptor will respond
how are target cells distributed
when receiving an endocrine signal, either grouped together in a target tissue or widely dispersed in a number of tissues
first messenger
non-steroid hormones, signalling molecules outside the cell that bind to the membrane and initiate an effect inside the cell
second messenger
first causes the release of another signalling molecule in the cell, stimulating a change in the activity of the cell
roles of the pancreas
digestion- secretes digestive enzymes
metabolism- regulation of carbs, lipids etc., produces primary messengers
2 main secretions of the pancreas
pancreatic juices containing enzymes secreted into the s. intestine
hormones secreted from islets of Langerhans into the blood
what enzymes does fluid from the pancreatic duct contain
pancreatic amylase, trypsinogen, lipase, sodium hydrogencarbonate to make it more alkaline
endocrine tissues
islets of Langerhans contains alpha and beta cells
alpha cells
secrete glucagon to raise glucose concentration