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166 terms

A&P II Test 1

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Secretes chemicals that reach their target cells through the blood stream
The Endocrine System
Autocrine
What type of chemical messenger stimulates the cell that originally secreted it
Paracrine
What type of chemical messenger will act locally on nearby cells
Neurotransmitter
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
They bind to interact with a receptor on or in the target cell
What do all hormones have in common
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 _________
Amplitude-Modulated
Most endocrine glands communicate with their target tissues using _____ signals
Neurohormone
An intercellular chemical signal that is produced by neurons but functions like a hormone would be called a _______
Polypeptides, steroids, and proteins
What organic molecules include hormones?
Lipid-Soluble
Which chemical type of hormone has a longer half-life
Lipid-Soluble
Which chemical class of hormone is more likely to need a binding protein for transport in the blood?
Steroids
Members of which group of hormones are made from cholesterol?
The rate at which hormones are eliminated from the body
What does the half-life of a hormone allow one to determine?
Regulate activities of rapid onset and short duration
What do hormones with short half-lives do?
By the presence of specific receptor molecules on the target cells
How do hormones and target cells recognize one another?
As free hormones
How do most water-soluble hormones travel through the bloodstream?
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?
Hormonal
Secretion of one hormone by the action of another hormone is controlled by _____ stimuli
Humoral
Parathyroid hormone is released when blood calcium levels decrease, this is an example of control by _____ stimuli
Negative
Most hormones are regulated by _______ feedback mechanisms
Down-Regulation
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?
G protein
What is a regulatory protein associated with membrane-bound receptor molecules?
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?
To inactivate cyclic AMP
What does Phosphodiesterase function to do?
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?
Steroid
What type of hormone diffuses easily through the plasma membrane?
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
Neuropeptide
A chemical that is produced by a neuron that functions as a hormone is a _____
Endocrine
A chemical that is secreted into the blood by specialized cells; travels some distance to target tissues
Neurotransmitter
A chemical that is secreted by presynaptic terminal
Nuclear Receptor Model
What receptor model is used by most lipid-soluble hormones?
Membrane-Bound Receptor Model
What receptor model is an intracellular mediator?
Membrane-Bound Receptor Model
What receptor model is a G Protein?
Nuclear Receptor Model
What receptor model interacts with DNA?
Membrane-Bound Receptor Model
What receptor model is cyclic AMP or cyclic GMP involved?
Nuclear Receptor Model
What receptor model generally observes a latent period?
Nuclear Receptor Model
What receptor model is messenger RNA synthesis regulated?
Membrane-Bound Receptor Model
What receptor model has membrane channels that can be opened or closed?
Target Tissues
Hormones that act on specific tissues/cells are called _______
Paracrine Chemical Messengers
What chemical signals are released by cells and affect other cell type locally w/o being transported in blood?
Negative
Increasing levels of thyroid hormones decrease TSH levels. This is an example of _____ feedback.
Half-Life
The length of time needed to eliminate half a dose of a hormone is called its ______
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
What regulates the secretory activity of the pituitary gland?
Infundibulum
What is the connecting stalk between the hypothalamus and pituitary gland?
Neurohypophysis and Adenohypophysis
What are the two functional portions of the pituitary gland?
Posterior
The ____ pituitary has a direct connection with neurons of the hypothalamus
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 _____
Posterior pituitary
What does the hypothalamohypophysial tract connect the hypothalamus to?
Neurohormones
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.....
Increase anterior pituitary secretion
What do releasing hormones do?
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?
High solute of concentration within the body fluids
ADH is secreted in response to what?
The kidney tubules to retain more water
What will an increase of ADH secretion cause?
Decreased BP, increased ADH secretion, and decreased urine volume
What results in a decrease in blood volume?
Oxytocin
What hormone is sometimes given to women to induce labor?
ADH
What hormone is synthesized by the hypothalamus?
ADH secretion decreases
What happens if fluid intake increases dramatically over a short time frame?
Blood volume decreases and blood pressure decreases
ADH secretion will increase if ______
Osmoreceptors
Sweating causes water loss from the body. In creased water loss causes the blood solute concentration to increase. What "senses" this increase?
Increases
Urine volume ______ when ADH secretion decreases
ADH
What hormone is stored and released from the posterior pituitary?
Oxytocin
What hormone is responsible for causing contractions in smooth muscle during labor?
Nursing a baby
Oxytocin release is stimulated by what?
FSH
What hormone is secreted by the anterior pituitary?
Hypothalamus
What is ADH is synthesized by?
Anterior pituitary
What is TSH synthesized by?
Pituitary (hypophysis)
Which gland is located in the sella turcica (pituitary fossa)?
Growth Hormone
What hormone increases water reabsorption from the kidneys?
Growth Hormone-Inhibiting Hormone
(GHIH)
What hormone inhibits the secretion of growth hormone?
FSH
What hormone stimulates the development of follicles in the ovary?
LH
What hormone is required for ovulation and formation of the corpus luteum?
LH
Synthesis of progesterone in the ovary and testosterone in the testis is stimulated by what hormone?
Thyroid Gland
If you removed the anterior pituitary what would it affect the functioning of?
FSH & LH
GnRH regulates the release of what hormones?
ADH
Osmoreceptor cells in the hypothalamus are involved in the secretion of what hormone?
Thyroid hormone
Hypersecretion of what hormone causes increased metabolic rate, sensitivity to heat, and weight loss?
Iodine
Which ion is necessary for thyroid hormone production?
Thyroglobulin
T3 & T4 are stored in the lumen of thyroid follicles as part of the ____ molecule
Thyroxine-Binding Globulin (TBG)
What are most T3 & T4 molecules bound to in the blood?
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?
Hyperthyroidism
Increased metabolic activity and weight loss are associated with what?
Weight gain
What is associated with hyposecretion of thyroid hormones?
TSH from the anterior pituitary
What hormone is involved in the regulation of thyroid hormone levels?
Bone
What is a target tissue for parathyroid hormone?
Blood calcium levels decrease
The rate of secretion of parathyroid hormone increases when what happens?
Decreases the release of phosphate from the bone
What is NOT an action of PTH?
PTH
What hormone allows kidneys to retain calcium?
Cardiac arrhythmias occur
What happens with hypocalcemia?
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?
Adrenal glands
What are the endocrine glands located on top of the kidneys?
Norepinephrine
What hormone is NOT secreted by the adrenal cortex?
Adrenal Medulla
What plays a role in the adaptation of the body for physical activity?
Blood pressure
Epinephrine increase what?
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?
Mineralocorticoids
What is the major secretory product of the zona glomerulosa of the adrenal cortex?
Cortistol
What hormone does the adrenal cortex of the adrenal gland secrete?
Increased plasma levels of cortisol
What will decrease glucocorticoid (cortisol) secretion by the adrenal cortex?
Depression of the immune response
What might be the result of hypersecretion of glucocorticoids?
High cortisol levels will begin to cause ACTH levels to decline
What would occur if both ACTH and cortisol levels increase?
Adrenal androgens
What stimulates the growth of public hair in females?
Hyposecretion of mineralocorticoids (aldosterone)
What condition could result in polyuria (excess urine)
Pancreas
What gland is both an endocrine gland and en exocrine gland?
Increase the uptake of glucose by its target tissues
What is a function of insulin?
Insulin
High blood glucose levels cause an increased secretion of what?
Gamma cells
What is NOT a type of cell found in the pancreas?
Glucagon
What do alpha cells secrete?
Islets of Langerhans (Pancreatic Islets)
Both glucagon and insulin are produced in the ______
Insulin secretion decreases; glucagon secretion increases
What happens when blood sugar levels decrease?
They feel intensely hungry
What happens to a person when their insulin levels low?
Liver
Glucagon primarily influences the cells of the ____
Glycogen Synthesis
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?
Hyperglycemia
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?
Thyroid
What gland does NOT produce reproductive hormones?
Photoperiod (daily amount of daylight)
What regulates the amount of melatonin secreted by the pineal body?
Development and maturation of the immune system
What is the function of thymosin?
Greater
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
Greater
The level of ACTH during stress is (greater, lesser, or equal) than the level of ACTH during relaxation
Lesser
The metabolic rate if thyroid hormones are under secreted (greater, lesser, or equal) than the metabolic rate if thyroid hormones are over secreted
Lesser
The blood calcium levels if parathyroid secretion decreases (greater, lesser, or equal) than the blood calcium levels if parathyroid hormone secretion increases
Calcitonin
What hormone decreases blood calcium levels?
TSH
What hormone stimulates synthesis of thyroid hormones?
ACTH
What hormone increases adrenal cortex secretions?
Prolactin
What hormone is involved in milk production?
Thymosin
What hormone is involved in the development of the immune system?
Pancreas
What gland secretes the hormone glucagon?
Ovary
What gland secretes the hormone progesterone?
Adrenal Cortex
What gland secretes the hormone cortisol?
Thyroid
What gland secretes the hormone T3?
Anterior Pituitary
What gland secretes the hormone prolactin?
Cells of the adrenal cortex
What cell type produces mineralocorticoids?
Cells of the parathyroid gland
What cell type produces PTH?
Beta cells
What cell type produces insulin?
Neurosecretory cells
What cell type produces ADH?
Follicular cells of the thyroid
What cell type produces T3?
Patient C
What patient is most likely to have a destructive tumor of anterior pituitary that destroys TSH secreting cells?
Patient A
What patient is most likely to have a proliferative tumor of anterior pituitary cells that produce TSH?
Patient D
What patient is most likely to have a goiter due to iodine deficiency?
Testosterone
What hormone aids in spermatogenesis?
Estrogen and progesterone
What hormones are involved in the menstrual cycle?
Posterior
The ______ pituitary is a neural extension of the hypothalamus?
Adenohypophysis
What is another name for the anterior pituitary?
Anterior pituitary
The hypothalamohypophysial portal system extends from the hypothalamus to the ______
Alpha
Glucagon is synthesized by the _____ cells of the pancreas?