The endocrine system III Flashcards
What does the affinity of a hormone receptor represent?
The % of bound hormone at a certain conc
What would a hormone receptor having a high affinity mean?
A higher % bound hormone at the same concentration
What would a hormone receptor having a low affinity mean?
A lower % bound hormone at the same conc
What is the saturation point of a hormone/its receptors?
All the available receptors have a bound hormone
What is the relationship between the affinity of a receptor and its saturation point?
The higher the affinity, the quicker (i.e. at a lower hormone conc) the saturation point will be reached
What can the number of receptors be regulated by?
The availability of the hormone in the blood plasma
What is down regulation of hormone receptors?
When the blood hormone conc is low, the # of receptors is low
What is up regulation of hormone receptors?
When the blood conc of the hormone is high, the # of receptors increases
What does a hormone having a permissive role mean?
It can regulate the receptors for other hormones
What is an example of a permissive role?
Epinephrine and thyroid hormone
How many fatty acids are released when just thyroid hormone is present?
Little to none
How many fatty acids are released when epinephrine is present?
Small amount
How many fatty acids are released when both epinephrine and thyroid hormone are released?
Large amount
What are the four types of endocrine disorder?
Hyposecretion, hypersecretion, hyporesponsiveness, hyperresponeiveness
What is hyposecretion of a hormone?
Too little hormone is secreted
What is a disease that involves hyposecretion?
Type 1 diabetes
What is hypersecretion?
Too much hormone is secreted
What usually causes hypersecretion?
An endocrine tumor
What is an example of a consequence of hypersecretion?
Hypersecretion of ADH leads to higher water retention
Why does hypersecretion of ADH lead to higher water retention?
The collecting duct will be more permeable to water (more aquaporins) so more water is reabsorbed into the capillary bed in the kidneys
What is hyporesponsiveness?
Reduced responsiveness of the target cells to physiological levels of hormones
What is an example of a disease caused by hyporesponsiveness?
Type 2 diabetes
What is hyperresponsiveness?
Increased responsiveness of the target cells to physiological levels of hormone
What can hyperthyroidism cause?
Increased heart rate
