Hypothalamus-Pituitary-Target Organ Axes: Feedback Control II Flashcards
What is considered primary and secondary when discussing hypo and hyper secretory conditions in Anterior Pituitary Hormones?
Primary is the hypo or hypersecretion of the anterior pituitary cells
Secondary is the hypo or hypersecretion of the hypophysiotropic hormones
What is meant by hypophysiotropic hormones?
The secretory or inhibitory hypothalamus hormones such as GHIH
What is Panhypopituitarism?
It is the decrease in secretion in all anterior pituitary hormones
Panhypopituitary Dwarfism is associated with which group of individuals?
Children
True or False: The body’s physical parts develop in proportion to one another
In general, yes true
Discuss Panhypopituitary Dwarfism (3 sentences)
- It is the deficiency of anterior pituitary hormones during childhood.
- Rate of development of the individual is greatly decreased
- Individual never passes through puberty as they never secrete sufficient quantities of gonadotropic hormones to develop adult sexual functions.
True or False: Panhypopituitarism in the adult and hypothyroidism are linked
True
Discuss Panhypopituitarism in the Adult (3 points)
- It is the decreased secretion in all anterior pituitary hormones leading to hypothyroidism.
- There is depressed production of glucocorticoids by adrenal glands => less cortisol
- There is suppressed secretion of gonadotropic hormones leading to loss of sexual function
How is Panhypopituitarism in the adult treated?
It is treated with adrenocortical and thyroid hormones
True or False: The growth hormone is wholly responsible for determining the rate and final magnitude of growth
False: It is essential for growth but other hormones and genes are resposible for determining rate and final magnitude of growth
What are other growth-influencing hormones?
Thyroid hormone and sex hormones
Give 3 aspects that determine rate and final magnitude of growth
Genetic determination
Adequate diet
Freedom from chronic disease/stressful environment
Normal levels of growth-influencing hormones (such as thyroid hormone and sex hormones)
What is the most abundant hormone produced by the anterior pituitary?
Growth Hormone
At what ages do you expect the highest and lowest levels of growth hormone in the body? Give the approximate concentrations (just be close)
Highest levels from infancy to young adult (5-20) at 6 ng/ml
Lowest levels in late adulthood and elders (40-70) at 1.6 ng/ml
How is age related to GH secretion?
As age increases, secretion decreases
Once growth has ceased, are GH concentrations in the blood still significant?
Yes
Other than growth itself, what is another major effect of GH?
Metabolic Effects
What are the target organs that GH binds to in order to exert its metabolic effects?
Adipose tissue, skeletal muscles, and liver
What’re the effects of GH on adipose tissue?
Increases mobilization of fatty acids from adipose tissue => increasing fatty acids in the blood and increased use of fatty acids for energy.
What are the effects of GH on glucose in the body
GH decreases the rate of glucose utilization throughout the body => increasing blood glucose. This is done by decreasing muscle uptake of glucose which is important in conserving glucose for the brain.
What is the effect of GH on insulin
GH causes GH-induced insulin resistance
What are the effects of GH on the rate of protein synthesis?
Increases the rate of protein synthesis in most cells of the body
Metabolic disturbances due to excess GH secretion are very similar to what disease?
Type II diabetes
List the metabolic effects of GH on the body
- Increases mobilization of fatty acids from adipose tissue
- Decreases rate of glucose utilization throughout the body (decrease muscle intake and GH induced insulin resistance)
- Increases the rate of protein synthesis in most cells of the body