What type of chemical messenger is realeased from neurons to activate an adjacent cell
The presence of a receptor specific for that hormone
What is it about a cell that identifies it as a target cell for hormones
Slower and more prolonged
The general, the response of target cells to endocrine stimulation is _______ that their response to nervous stimulation
Help coordinate growth, development, and reproduction
Hormones are intercellular chemical signals that _________
An intercellular chemical signal that is produced by neurons but functions like a hormone would be called a _______
Which chemical class of hormone is more likely to need a binding protein for transport in the blood?
The rate at which hormones are eliminated from the body
What does the half-life of a hormone allow one to determine?
By the presence of specific receptor molecules on the target cells
How do hormones and target cells recognize one another?
Chronic Hormone Secretion
Which pattern of hormone secretion, exemplified by thyroid hormones, remains relatively constant over long periods of time?
Episodic Hormone Secretion
Which pattern of hormone secretion, often observed in steroid reproductive hormones, will fluctuate over a monthly cycle?
Acute Hormone Secretion
Which pattern of hormone secretion, represented by epinephrine, can have dramatic changes in its concentration and circulating levels?
Chronic and Episodic Hormone Secretion
In general, lipid-soluble hormones exhibit which types of hormone secretion patterns?
Action of a substance other than a hormone, the nervous system, and other hormones
What can hormonal secretion be regulated by?
Parathyroid hormone is released when blood calcium levels decrease, this is an example of control by _____ stimuli
In some forms of diabetes, an insensitivity to insulin seems to be present. This insensitivity could be the result of ________
Produces an increase in the sensitivity of the target cell to the hormone
What does Up-Regulation do?
Increased in number or decreased in number
Hormone receptor molecules may be ____ in order to change the target cell's sensitivity to a given hormone
On the plasma membrane of their target cells
Where are receptors for most water-soluble hormones located?
In the nucleus or cytoplasm of their target cells
Where are receptors for most lipid-soluble hormones located?
1) G Protein subunits bind to receptor
2) GTP binds to the alpha subunit replacing GDP
3) G Protein subunits separate from the receptor
4)Alpha subunit separates from the other two subunits
5) Alpha subunit-GTP complex alters cell activity
Name the events that occur when a water-soluble hormone binds to its receptor on the plasma membrane
Bind to and activate protein Kinase
What is the role of cAMP when it acts as an intracellular mediator in cells?
Cyclic GMP might be produced to act as an intracellular mediator
When a hormone binds to a membrane-bound receptor.....
Ion channels could be opened, IP3 may be activated, cyclic AMP production may be increased, DAG may be activated
What could happen when a hormone binds to a membrane-bound receptor and activated G Proteins?
A cascade effect
The activation of a single G Protein results in the activation of several second messengers. This process is known as _______
Activation of mRNA synthesis (transcription)
What occurs when a hormone binds to a nuclear receptor?
Hormone receptor complex binds to DNA
Hormone binds to receptors in the nucleus (sometimes cytoplasm)
Messenger RNA synthesis is activated
Events in the nuclear receptor model
A chemical that is secreted into the blood by specialized cells; travels some distance to target tissues
Membrane-Bound Receptor Model
What receptor model has membrane channels that can be opened or closed?
Paracrine Chemical Messengers
What chemical signals are released by cells and affect other cell type locally w/o being transported in blood?
Increasing levels of thyroid hormones decrease TSH levels. This is an example of _____ feedback.
Regulating skeletal muscle contraction and strength
What is NOT a regulatory function of the endocrine system?
Regulating equilibrium and balance from the inner ear
What is NOT a regulatory function of the endocrine system?
Hypothalamus to anterior pituitary
Where does the hypothalamohypophysial portal system carry hormones to?
Hypothalamus to the posterior pituitary
The hypothalamohypophysial tract carries neurons from the _____ to the _____
Hormone secretion by the anterior pituitary is controlled by _____ of the hypothalamus
Carry action potentials to the posterior pituitary causing the release of oxytocin
A function of the hypothalamohypophysial tract is to.....
Action potentials from hypothalamic neurons
Hormones are released from the posterior pituitary when posterior pituitary cells are stimulated by what?
Construction of blood vessels
ADH is also called vasopressin because at high concentrations it causes what?
Decreased BP, increased ADH secretion, and decreased urine volume
What results in a decrease in blood volume?
ADH secretion decreases
What happens if fluid intake increases dramatically over a short time frame?
Sweating causes water loss from the body. In creased water loss causes the blood solute concentration to increase. What "senses" this increase?
Synthesis of progesterone in the ovary and testosterone in the testis is stimulated by what hormone?
Hypersecretion of what hormone causes increased metabolic rate, sensitivity to heat, and weight loss?
Binding to receptor molecules in the nucleus
How does a thyroid hormone interact with its target tissue?
High to increase body temperature
John Smith works at a ski resort in the winter. What are his thyroid hormone levels like in the winter?
TSH from the anterior pituitary
What hormone is involved in the regulation of thyroid hormone levels?
Blood calcium levels decrease
The rate of secretion of parathyroid hormone increases when what happens?
Accidental removal of the parathyroid glands during surgery
After surgery of removing an aggressive tumor of the thyroid, the patient's blood calcium levels began declining to life-threatening levels. What is the decline most likely due to?
Increase heart rate, increase BP, and decrease gastric tract motility
What would an injection on epinephrine do to the body?
Sympathetic nervous system
Where does the primary stimulus for release of adrenal medullary hormones come from?
What is the major secretory product of the zona glomerulosa of the adrenal cortex?
Increased plasma levels of cortisol
What will decrease glucocorticoid (cortisol) secretion by the adrenal cortex?
High cortisol levels will begin to cause ACTH levels to decline
What would occur if both ACTH and cortisol levels increase?
Hyposecretion of mineralocorticoids (aldosterone)
What condition could result in polyuria (excess urine)
Insulin secretion decreases; glucagon secretion increases
What happens when blood sugar levels decrease?
Increased insulin secretion immediately following a meal will result in increased _____
Breakdown of glycogen in the liver releasing glucose
What helps to keep blood nutrients at normal levels 6-8 hrs after a meal?
A person with insulin-dependent diabetes mellitus (IDDM) forgets to take their insulin, what does this cause?
Increased epinephrine and glucagon release
During exercise, the energy needed to sustain skeletal muscle cell contraction comes from what?
Photoperiod (daily amount of daylight)
What regulates the amount of melatonin secreted by the pineal body?
The amount of water reabsorbed by the kidney when ADH is present is (greater, lesser, or equal) than the amount of water reabsorbed by the kidney when ADH is absent
The level of ACTH during stress is (greater, lesser, or equal) than the level of ACTH during relaxation
The metabolic rate if thyroid hormones are under secreted (greater, lesser, or equal) than the metabolic rate if thyroid hormones are over secreted
The blood calcium levels if parathyroid secretion decreases (greater, lesser, or equal) than the blood calcium levels if parathyroid hormone secretion increases
What patient is most likely to have a destructive tumor of anterior pituitary that destroys TSH secreting cells?
What patient is most likely to have a proliferative tumor of anterior pituitary cells that produce TSH?
The hypothalamohypophysial portal system extends from the hypothalamus to the ______