what is the function of the endocrine system?
interacts with nervous system to coordinate and integrate activity ofbody cells
how does the endocrine influence metabolic activity?
hormones
describe Hormones
chemical messengers released into blood for transport throughout body to regulate metabolic function of other cells
List 5 things the Endocrine System Controls
Mobilization of body defenses
Cellular metabolism
Reproduction
Electroyle, water, and nutrient balance
Growth and development
endocrine glands are _______
ductless
what cells are influenced by hormones?
target cells
where is the thymus located?
deep to sternum
where is the pineal gland located?
hangs from roof of third ventricle
where is the thyroid gland located?
anterior trachea
where is the parathyroid gland located?
posterior trachea
where are the adrenal glands located?
triangular organ on top of kidneys
where is the pancreas located?
partly behind stomach
Degree of target cell activation depends on what three things?
Blood level of hormones
Relative number of receptors
Affinity of the binding
what is up-regulation?
Persistently low levels of a hormone can cause target cells to form additional receptors for that hormone
what is down-regulation?
Prolonged exposure to high hormone concentrations can decrease the number of receptors for that hormone
what is permissiveness?
Situation in which one hormone can not exert its full effects without another hormone being present
what is synergism
occurs when more than one hormone produces the same effects at the target cell and their combined effects are amplified
what is Anatagonism?
Occurs when one hormone opposes the action of another
Synthesis and release of most hormones are regulated by some type of __________________________________
negative feedback mechanism
what is a humoral stimuli?
Endocrine glands that secrete their hormones in direct response to changing blood levels of certain critical ions and nutrients
what is a neural stimuli?
Nerve fibers that stimulate hormone release
what is a hormonal stimuli?
Endocrine glands that release their hormones in response to hormones produced by other endocrine organs
The nervous system makes these adjustments to maintain homeostasis by _____________________________________
overriding normal endocrine controls
where is the pituitary gland located?
sella turcia of the sphenoid bone
what is the posterior pituitary gland made of?
neural tissue and nerve fibers
what does the posterior pituitary gland release?
is it considered a true gland that manufactures hormones?
neurohormones
no
Posterior pituitary lobe and infundibulum is the region called the ____________
neurohypophysis
what is the anterior pituitary gland composed of?
glandular tissue
what regulates anterior pituitary secretion?
Hypothalamic hormones
Growth Hormone (GH) is secreted by what?
what is its function?
anterior pituitary gland
Anabolic hormone
stimulates somatic growth
Mobilizes fats
Spares glucose
Thyroid stimulating hormone (TSH) is secreted by what?
what is its function?
anterior pituitary gland
stimulate thyroid gland to release thyroid hormones
Adrenocorticotropic hormone (ACTH) is secreted by what?
what is its function?
anterior pituitary gland
Promotes release of glucocorticoids and androgens
Follicle-Stimulating Hormone (FSH) is secreted by what?
what is its function?
anterior pituitary gland
In females, stimulates ovarian follicle maturation
In males, stimulates sperm production
Luteinizing hormone (LH) is secreted by what?
what is its function?
anterior pituitary gland
In females, triggers ovulation and stimulates ovarian production
In males, promotes testosterone production
Prolactin (PRL) is secreted by what?
what is its function?
anterior pituitary gland
Promotes lactation
Oxytocin is secreted by what?
what is its function?
posterior pituitary gland
stimulates uterine contractions
Antidiuretic hormone (ADH) is secreted by what?
what is its function?
Posterior Pituitary gland
Stimulate kidney tubule cells to reabsorb water from urine back into blood
what are the hormones produced by the thyroid gland?
Thyroxine (T4)
Triiodothyronine (T3)
what is the function of parathyroid hormone?
stimulates osteoclasts to digest the bony matrix to release ionic calcium and phosphates to the blood
mineralocorticoids are produced by what?
what is its function?
adrenal gland
elevates blood volume and blood pressure by increasing sodium levels
glucocorticoids are produced by what?
their effects include
Promotes __________ and _________
Mobilizes fats for energy metabolism
Stimulate protein catabolism
Assists body to resist _____
Depress __________ and ____________
adrenal gland
gluconeogenesis and hyperglycemia
stressors
inflammatory and immune responses
gonadocorticoids are produced by what?
what effect does it have?
adrenal gland
source of estrogens after menopause
catecholamines are produced by what?
Effects
Mimic ___________________
Increase _________
Increase __________
Increase ____________ via _________
adrenal gland
sympathetic nervous system activation
heart rate
metabolic rate
blood pressure
vasoconstriction
glucagon is produced by what?
_____________
Breakdown of ________ to __________
Release of _______ to the blood by liver cells
Causes ___________ levels to rise
pancreas
Glycogenolysis
glycogen to glucose
glucose
blood glucose
Insulin is produced by what?
Effects
Enhances ___________________ into most body cells, especially muscle and fat cells
__________________ of glycogen to glucose
pancreas
membrane transport of glucose
Inhibits the breakdown
These hormones are thought to be involved in the normal development of T Lymphocytes and the immune response, what are they and what are they secreted by?
peptide hormones secreted by the thymus