Chapter 18 Flashcards
Specific cells that possess the receptors needed to bind and “read” the hormonal message when it arrives.
Target Cells
The hormone itself which does something that leads to the appearance of a second messenger.
First Messenger
May act as an enzyme activator, inhibitor, or cofactor, but the net result is a change in the rates of various metabolic reactions.
Second Messenger
A process in which the presence of a hormone triggers a decrease in the number of hormone receptors.
Down-Regulation
A process in which the absence of a hormone triggers an increase in the number of hormone receptors.
Up-Regulation
The pituitary gland.
Hypophysis
A tapering, funnel-shaped structure; in the brain, the connection between the pituitary gland and the hypothalamus; in the uterine tube, the entrance bounded by fimbriae that receives the oocytes at ovulation.
Infundibulum
Stimulates the synthesis and secretion of one or more hormones at the adenohypophysis.
Releasing Hormone
Prevents the synthesis and secretion of hormones from the adenohypophysis.
Inhibiting Hormone
The stimulation of energy production and heat loss by thyroid hormones.
Calorigenic Effect
A small endocrine gland that secretes steroids and catecholamines and is located superior to each kidney; also called adrenal gland.
Suprarenal
A type of diabetes mellitus in which insulin levels are normal or elevated, but peripheral tissues no longer respond normally.
(Type 2) Diabetes Mellitus
A type of diabetes mellitus; the primary cause is inadequate insulin production by the beta cells of the pancreatic islets.
(Type 1) Diabetes Mellitus
When stress lasts longer than a few hours, the individual enters this phase of the GAS. Glucocorticoids are the dominant hormones of this phase.
Resistance Phase
During this phase, an immediate response to the stress occurs. This response is directed by he sympathetic division of the autonomic nervous system.
Alarm Phase
When the resistance phase ends, homeostatic regulation breaks down and this phase begins. Unless corrective actions are taken almost immediately, the failure of one or more organ systems will prove fatal.
Exhaustive Phase
When two hormones may have additive effects, so that the net result is greater than the effect that each would produce acting alone. In some cases, the net result is greater than the sum of the hormones’ individual effects.
Synergistic Effect
When the first hormone is needed for the second to produce its effect.
Permissive Effect
Whe hormones may produce different, but complementary, results in specific tissues and organs.
Integrative Effect
The pattern of Hormonal and physiological adjustments with which the body responds to all for of stress.
General Adaptation Syndrome (GAS)
A condition caused by the hypo secretion of glucocorticoids and mineralocorticoids; characterized by an inability to mobilize energy reserves and maintain normal blood glucose levels.
Addison Disease
A condition caused by hypothyroidism at birth or in infancy; marked by inadequate skeletal and nervous system development and a metabolic rate as much as 40 percent below normal levels.
Cretinism
A condition caused by the hyper secretion of glucocorticoids; characterized by the excessive breakdown and relocation of lipid reserves and proteins.
Cushing Disease
A disorder that develops when the neurohypophysis no longer releases adequate amounts of ADH, or when the kidneys cannot respond to ADH.
Diabetes Insipidus
The presence of glucose in the urine.
Glycosuria
An abnormal enlargement of the thyroid gland.
Goiter
Abnormally high blood glucose levels.
Hyperglycemia
Muscle spasms affecting the face and upper extremities; caused by low Ca2+ concentrations in body fluids.
Hypocalcemic Tetany
Condition resulting from severe hypo secretion of thyroid hormones; characterized by subcutaneous swelling, hair loss, dry skin, low body temperature, muscle weakness, and slowed reflexes.
Myxedema
The production of excessive amounts of urine; a sign of diabetes.
Polyuria
A condition characterized by depression, lethargy, an inability to concentrate, and altered sleep and eating habits; linked to elevated melatonin levels in individuals exposed to only short periods of daylight.
Seasonal Affective Disorder (SAD)
