Flashcards in Endocrine System Deck (75):
What is the Endocrine System?
glands, tissues, and cells that secrete hormones
What are 2 properties of the endocrine glands?
produce hormones and lack ducts
List the endocrine glands
pituitary glands, thyroid gland, parathyroid gland, adrenal lands and pineal gland
List non-endocrine glands
hypothalamus, pancreas, ovaries and testes, and placenta
State the differences between Nervous and Endocrine system
Nervous: neurotransmitter, local, responds quickly, and stops quickly
Endocrine: hormones, general and widespread, responds slowly, and persist after stimulus stops
What are the 2 types of hormones?
amino acid-based and steroids
Which type of hormones are synthesized from cholesterol?
List hormones that are steroids
testosterone, estrogen, aldosterone, cortisol, and progesterone
How do hormones alter activity of target cells?
opening or closing ion channels, stimulating protein synthesis, activating or deactivating enzymes, inducing secretions, and stimulating mitosis
How do water-soluble hormones interact with target cells?
cannot enter target cells, act on receptors in plasma membrane, and coupled by G proteins to intracellular second messengers
How do lipid-soluble hormones interact with target cells?
can enter target cells, and act on intracellular receptors that directly activate genes
What are the steps in the cAMP signaling?
1. Hormone binds receptor
2. Receptor activates G protein
3. G protein activates adenylate cyclase
4. Adenylate cyclase converts ATP to cAMP
5. cAMP activates protein kinases
What non-steroid hormones also uses this mechanism?
What are the steps of the intracellular receptors?
1. The steroid hormone diffuses through the plasma membrane and binds to an intracellular receptor
2. The receptor hormone complex enters the nucleus
3. The receptor-hormone complex binds a hormone response element
4. Binding initiates transcription to the gene to mRNA
5. The mRNA directs protein synthesis
What is up-regulation compared to down-regulation?
up-regulation increases the cell number of receptors which then becomes more sensitive to a while down-regulation reduces cell number of receptors which then becomes less sensitive to a hormone
What are the 3 ways that multiple hormones that act on same target?
permissiveness, synergism, and antagonism
Describe synergism. give an example
two or hormones act together to produce an effect that is greater then sum of their separate effects. EP and glucagon
Define permissiveness. Give an example
one hormone cannot exert its full effects without another hormone being present. Estrogen and progesterone
Define antagonism. Give an example
one hormone opposes action of another hormone. Insulin and glucagon
What are the three types of stimuli?
humoral, neural, and hormonal
How is hormone synthesis and secretion regulated?
by negative feedback
Which hormones respond to neural stimuli?
oxytocin, ADH, NE, and EP
Which hormones respond to humoral stimuli?
Calcitonin, PTH, insulin, and glucagon
Which hormones respond to hormonal stimuli?
ALL pituitary hormones, TH, testosterone, estrogen, and progesterone
What is another name for the pituitary gland?
What connects the hypothalamus to the posterior pituitary?
What is the pos. pituitary glands composed?
What is the ant. pituitary composed?
What runs through the infundibulum and formed by axons of neurons?
What allows the ant. pituitary respond to the hormones secreted b the hypothalamus?
hypophyseal portal system
Which 2 hormones are secreted by the post. pituitary?
ADH and oxytocin
What are the functions of oxytocin?
triggers milk ejection and uterine contractions during childbirth
What are the function of ADH?
prevents large amounts of urine production by stimulating kidney tubule cells to reabsorb water and return to blood stream
What results when there is ADH deficiency?
What are the Six hormones secreted by the ant pituitary?
Prolactin, FSH, TSH, ACTH, LH, GH
Which hormones increase glucose levels?
GH, cortisol, glucagon EP and NE
Promotes cartilage and bone growth and increases protein synthesis
What homeostatic imbalance occurs with hypersecretion of GH at epiphyseal plate?
What homeostatic imbalance occurs due to hypersecretion after epiphyseal plate closure?
What homeostatic imbalance occurs due to hyposecretion of GH prior to epiphyseal plate closer?
Prolactin. stimulates milk production
Thyroid stimulating. stimulates normal development and secretory activity of thyroid
Adrenocorticotropic. stimulates adrenal cortex to release glucocorticoid hormone
FSH & LH
Regulate function of gonads
Which two hormones does the thyroid secrete?
TH and calcitonin
Which type of cells synthesize thyroglobulin?
Which type of cells synthesize calcitonin?
Which two compounds comprise TH?
thyroxine and triiodthronine
Increase metabolic rate and body heat production. Plays important role in regulating development and maturation of skeletal, nervous, and reproductive systems
What is the role of I-
1. Iodide is trapped then converted to iodine.
2. I- is attached to Tyr in the colloid then linked together to form T4
What hormone does the hypothalamus secrete to to promote TH?
TRH: Thyrotropin-releasing hormone
What hormone does the ant. pituitary secrete to promote TH?
What is myxdemia?
hypothyroidism in adults
How can myxdemia lease to a goiter?
if there is a lack of I-
What is cretinism?
hypothyroidism in infants
What is Graves' disease?
hyperthyroidism due to abnormal Abs that mimic TSH and that secrete TH
lowers Ca2+ levels
increase Ca2+ levels, increase reabsorption of Ca2+ in kidneys
What are the two parts of the adrenal glands?
adrenal medulla and adrenal cortex
Which part of the adrenal glands produce corticosteroids?
Which part of the adrenal gland takes part in the sympathetic division
stimulates NA+ and a mineralocorticoid
promotes gluconeogensis, mobilizes fas from adipose, stimulates breakdown of stored proteins and a glucocorticoid
What occurs when cortisol is at high concentrations?
inhibits inflammation and depresses the immune system
What is Cushing's syndrome?
excess of glucocorticoid, elevated blood glucose, facial swelling, and "buffalo hump"
Which two hormones does the adrenal medulla secrete?
NE and EP
How does the adrenal medulla and adrenal cortex respond to stress?
Adrenal medulla: short-term stress
Adrenal cortex- long-term stress
What hormone does the pineal gland secrete?
Influence rhythmic variations in physiological processes
What classifies the pancreas as a "mixed gland?"
It consists of both endo- and exo- gland cells
What component contribute to the endo-?
Which cell typed produce insulin and glucagon?
increase blood glucose by targeting liver cells
lowers blood glucose