ENDOCRINE SYSTEM Flashcards
Which type of hormone is able to easily diffuse across the membrane?
Steroid
True or False: Endocrine glands secrete chemical messages directly into the bloodstream
True
True or false: The growth hormone axis contains at least one example of a negative feedback loop.
True
GHRH directly triggers the release of which of the following hormones?
Growth Hormone
A person has a genetic mutation in the receptor for GH that prevents the hormone from binding to target cells. What levels of IGF-1 do you find in the person?
A) Higher than Normal
B) Lower than Normal
C) Normal
Lower than Normal
True or False: If an adult develops a tumor on their pituitary gland that causes a prolonged excessive release of GH, they are likely to develop the condition gigantism, in which they grow unusually tall.
False
Growth hormone has which of the following effects on the body? Select all that apply.
A) Decreases amino acid uptake
B) Activates osteoblasts and chondrocytes
C) Decreases protein synthesis in muscle and bone
D) Triggers the release of IGF-1 by the liver
B) Activates Osteoblasts and Chondrocytes
and D) Triggers release of IGF-1 by the liver
A person is lacking (through genetic mutations) the receptor for a steroid hormone. Which of the following observations are correct?
A) There are fewer receptors in the plasma membrane of the cell.
B) Even if the hormone is present, there will NOT be a change in gene expression.
C) There are more receptors in the cytoplasm.
D) The hormone fails to enter the cell.
B) Even if the hormone is present, there will NOT be a change in gene expression.
Sometimes a child will begin puberty early (before age 8 or 9), called “precocious puberty’” What effect would this have on their stature? Think about the effect on bone growth.
They will be tall for their age at first but short as an adult
A genetic mutation results in the suppression of rapid chondrocyte division. What is the result of the mutation?
Reduced intersitial growth
Osteoporosis commonly occurs in older women as estrogen levels drop. Why?
Because estrogen stimulates osteoblasts
Secretion of parathyroid hormone results in the activation of osteoclasts. This will have what effect?
Raise blood calcium levels
A patient develops a tumor in one of their parathyroid glands, causing an increase in the release of parathyroid hormone into the blood. What would be the result?
High blood concentration than normal
What and where is the parathyroid hormone?
The parathyroid glands are located behind the thyroid and these hormones help to regulate free calcium concentrations in our body
What does too much calcium levels do to parathyroid release?
Inhibit by Hypercalcmia
What does to little calcim do to parathyroid release?
Stimulated by hypocalcimia
Overproduction of GH in children results in ____
Gigantism
What happens at the closure of epiphyseal plates?
Osteoblasts outcompete chondrocytes and it is completely ossified
Think back to our discussion about cell membrane transport from the beginning of the course. Based on the chart above and your own prior knowledge, which of the following hormones would be able to diffuse directly through the cell membrane?
Progesterone and Testosterone because they are steriod hormones
True or False: Human growth hormone will bind to an intracellular receptor to create a hormone-receptor complex.
False; Human growth hormone is a protein hormone, so it cannot diffuse into a cell to reach an intracellular receptor. Instead, it will bind to a cell membrane receptor.
A person has a genetic mutation in the receptor for GH that prevents the hormone from binding to target cells. What levels of IGF-1 do you find in the person?
Lower levels than normal; If GH cannot bind to target cells, then it will not be able to trigger the production of IGF-1 in target cells in the liver, leading to lower levels of IGF-1.
The hypothalamus is a part of which region of the brain?
Diencephalon
A patient develops a tumor in one of their parathyroid glands, causing an increase in the release of parathyroid hormone into the blood. What would be the result?
Higher blood calcium concentrations than normal (hypercalcemia). PTH stimulates osteoclasts to release calcium from the skeleton into the blood and prevents the kidneys from removing as much calcium from the blood. This has the effect of raising blood calcium levels.
A patient develops a problem with their thyroid, where the thyroid is unable to produce calcitonin. What would be the result?
Hypercalcemia.
Calcitonin causes calcium to be stored in the skeleton and/or removed from the blood by the kidneys. Without calcitonin, calcium levels in the blood would therefore increase (hypercalcemia).
