blood glucose Flashcards
give three features of the endocrine system
slower than nervous system
chemicals are used
long lasting effect
how do hormones travel round the body
in the blood stream
what else does the endocrine system do
carry hormones to their traget cells
what are target cells
they have cell surface receptors complementory to hormone chemical
what does the pancreus contain that allows the production of hormones
islet of langerhan
what does the islet of langerhan contain
alpha cells
beta cells
what do alpha cells do
produce hormone glucagon
what doe beta cells produce
the hormone insulin
other than the pancreus what else helps regulate blood glucose levels
the liver
what are the three things the liver uses to regulate blood glucose
the hormones
glycogenesis
glycogenolysis
glucongenesis
what does glycogenesis do
converts glucose to glucogen
why does the conversion of glucose to glucogen occour
when their is a too high glucose level in the blood
what is gycogenolysis
conversion of glycogen to glucose
what is gluconeogenesis
creation of new glucose from non crabohydrate stores
what is glucose created from when carbohydrate stores are unavailale
fatty acids
glycerol
how can glucose enter the blood stream
via diet
glycogenolysis
gluconeogenisis
what are the two hormones involved in regulation of blood glucose
insulin
glucagon
what is the role of beta cells
they detect the rise in blood glucose
when beta cells detect a rise in blood glucose what do they do
they secrete insulin into the blood stream
what do most cells have that allows the beta cells to work
glycoprotien receptors
what are these glycoprotien receptors for
insulin
what does this insulin then do
combine with receptors
what does the binding of insulin to glycoprotien recptors cause
change in tertiary structure and shape of glucose transport protein channels, opening them
what does thischange in tertiary structure and glucose transport protien lead to
an increase in the number of transport molecules
what does this increase in the number of transport molecules mean
activiation of enzymes wich convert glucose into glycogen and fat
what happens when blood glucose is too high
negative feedback
give an example of negative feedback
lowering of blood glucose
what is the first step of lowering blood glucose
increase rate absorbtion of glucose into cells (specifically muscle cells)
what is the second stage of lowering blood glucose
increased rate of respiration therefore increasing the uptake of glucose from the blood
what is the third stage of lowering blood glucose
increased rate of glycogenesis in liver and muscle cells
what is glycogenesis
conversion to glucose to glycogen
what is the fourth stage of lowering blood glucose
increased rate of conversion of glucose to fat
what do all these processes do
cause glucose rates to fall back to normal wich stops the secretion of insulin by b-cells to reduce
what is the full process of lowering blood glucose
increased rate of absorbtion of glucose into cells (specfically muscle cells).
increased rate of respiration therefore increased uptake of glucose from blood.
increase rate of glycogenesis - the conversion of glucose into glycogen- in liver and muscle.
increased rate in conversion of glucose to fat.
this causes blood sugar levels to fall which leads to the secreation of inslulin from b-cells to reduce.
what else aswell as insulin helps to lower levels of blood glucose
glycogon
what can be said about insulin and glycogon
work anataganistically = work together
what role to a cells play in regulating blood sugar levels
detect a fall in blood glucose and secreate glucagon into plasma
what cells ONLY bind to glucagon
liver cells
how do liver cells respond to glucagon
activating an enzyme to convert glycogen to glucose
increaseing GLUCONEOGENESIS
what is gluconeogenesis
production of glucose from non-carb sources, e.g amino acids or fatty acids
in terms of a cells what happens when blood glucose levels rise
the raising of blood glucose levels cause a cells to reduce the secretion of glucagon. another example of negative feedback
