Download Jenny Yin Endocrine System Maintain homeostasis Local Hormones

Jenny Yin
Endocrine System
● Maintain homeostasis
● Local Hormones Diffuse to Nearby Target Cells
● Hormones of the Endocrine System Are Transported by the Circulatory System
● Hormones Bind to Specific Receptors on Target Cells
● Hormone Release Is Regulated by Feedback Mechanisms
● Mammals Have Both Exocrine and Endocrine Glands
● The Hypothalamus Controls the Secretions of the Pituitary Gland
● Hypothalamic Hormones Control the Anterior Pituitary
● The Anterior Pituitary Produces and Releases a Variety of Hormones
● The Posterior Pituitary Releases Hormones Produced by Cells in the Hypothalamus
● The Thyroid and Parathyroid Glands Influence Metabolism and Calcium Levels
● The Pancreas Is Both an Exocrine and an Endocrine Gland
● The Sex Organs Secrete Steroid Hormones
● The Adrenal Glands Have Two Parts That Secrete Different Hormones
● Other Sources of Hormones Include the Pineal Gland, Thymus, Kidneys, Heart, Digestive Tract, and Fat Cells
● The hypothalamus contains neurosecretory cells, which produce hormones that are either transported to the
posterior pituitary and released into the bloodstream or are transported to the anterior pituitary to stimulate or
prevent the secretion of hormones from the endocrine cells there.
● The posterior pituitary is not a true endocrine gland because it does not produce the hormones released from
this area.
● The hypothalamic hormones, oxytocin and antidiuretic hormone (ADH), are released from the posterior
pituitary and are transported to their target tissues in the body, where they control lactation and water balance,
respectively.
● The anterior pituitary produces and releases its own hormones, under the control of the hypothalamus. These
hormones travel to the rest of the body and either stimulate the release of hormones from other endocrine
glands or act directly on tissues of the body.
● The posterior pituitary is not a true endocrine gland because:
● The posterior pituitary does not produce the hormones that it releases, and therefore is not considered a true
endocrine gland.
● Secretions from which of the following endocrine glands is controlled by releasing or inhibiting hormones
from the hypothalamus?
● Releasing and inhibiting hormones from the hypothalamus control hormone secretion in the anterior pituitary.
● Hypothalamic hormones such as antidiuretic hormone (ADH) and oxytocin, that act directly on tissues of the
body, must be released from which part of the pituitary?
● Correct: The posterior pituitary does not produce its own hormones. Hormones from the hypothalamus are
released from this site
● How do hormones from the hypothalamus get to the anterior pituitary gland?
● The releasing and inhibiting hormones from the hypothalamus travel a short distance from one capillary bed in
the hypothalamus to a second capillary bed in the pituitary.
● Most peptide or amino acid hormones must bind to a receptor located in the plasma membrane, because they
are lipid insoluble--they cannot pass through the phospholipid bilayer of the membrane.
● That binding activates an enzyme that converts ATP into cyclic AMP (cAMP), a second messenger.
● Cyclic AMP initiates a cascade of reactions within the cell, which results in the conversion of reactant
molecules into specific products.
● Most steroid hormones bind to a receptor located inside the cell--in many cases, inside the nucleus. Being
lipid soluble, steroid hormones can diffuse easily into their target cells.
● That binding produces an active hormone-receptor complex, which will then bind to a DNA molecule in the
nucleus.
● That action stimulates the expression of a specific gene and facilitates the binding of RNA polymerase to the
promoter region of the gene.
● Transcription leads to the production of a specific protein.
● The ultimate product is determined by the specific hormone and by the type of target cell.
Jenny Yin
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If you wanted to design a drug that could pass across a cell membrane and have an effect on activity inside the
cell, what characteristic should you give it?
Lipid-soluble molecules are able to pass across membranes because they can mix with the phospholipids found
in the membrane.
Steroid hormones exert their action by:
Being lipid soluble, steroid hormones can cross the plasma and nuclear membrane of a cell, where they may
exert their effect on the expression of genes after binding to an internal receptor.
What represents the "first messenger" when the mechanism of action for a hormone involves the production of
a "second messenger"?
The hormone is considered the "first messenger" and when it binds to its specific receptor, a second messenger
such as cAMP will be produced.
Insulin is a small (51 amino acid) protein that is produced by the pancreas, which signals the body's cells to
take up glucose from the blood. Where do you think the insulin receptor is located in the cell?
Being a peptide hormone, insulin is not lipid soluble and therefore it must utilize a membrane receptor and a
second messenger system.
Adrenocorticotropic Hormone
What hormone stimulates the cortex of the adrenal gland to produce its hormones?
adenohypophysis
What gland produces TSH, ACTH, FSH, LH, GH, and PRL?
adrenal medulla
What gland produces epinephrine and norepinephrine?
aldosterone
What hormone raises levels of sodium in the blood?
antidiuretic hormone
What hormone causes the kidneys to conserve water by putting it back into the blood?
calcitonin
What hormone lowers the level of calcium in the blood?
cortisol
What hormone controls the body's long term response to stress?
epinephrine
What hormone stimulates the fight or flight response?
estrogen
What hormone controls the maturation of the oocyte into an egg cell?
follicle stimulating hormone
What pituitary gland hormone stimulates the gonads to produce gametes?
glucagon
What hormone raises blood glucose levels?
gluconeogenesis
The process of making glucose from non-carbohydrate precursors such as amino acids and fatty acids is
_____________________.
glycogenolysis
The process of breaking down of glycogen in the liver in order to release glucose into the blood is
___________________.
growth hormone
What hormone stimulates mitosis in bone and muscle especially during childhood?
hormonal
The stimulus for production of thyroid hormone is __________ stimulation.
humoral
The stimulus for production of parathyroid hormone is __________ stimulation.
hypothalamus
What is the source of the releasing hormones that stimulate the adenohypophysis to release its hormones?
Jenny Yin
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insulin
What hormone lowers blood glucose levels?
luteinizing hormone
What hormone causes the gonads to produce sex hormones?
neural
The stimulus for the release of ADH, oxytocin, and epinephrine is __________ stimulation.
neurohypophysis
What gland produces ADH and oxytocin?
oxytocin
What hormone stimulates uterine smooth muscle contraction during labor?
pancreas
What gland produces insulin and glucagon?
parathyroid
What gland produces the hormone that raises blood calcium levels?
parathyroid hormone
What hormone raises the levels of calcium in the blood?
prolactin
What hormone stimulates milk production by the mammary glands?
testosterone
What hormone controls the development of sperm cells?
thyroid
What gland produces T3/T4 and calcitonin?
thyroid hormone
What is the body's major metabolic hormone?
thyroid stimulating hormone
What hormone stimulates the thyroid gland to produce thyroid hormone?
thyroxine
What is the chemical name of the T4 version of thyroid hormone?
triiodothyronine
What is the chemical name of the T3 version of thyroid hormone?