CH 13: Endocrine System Flashcards
The endocrine gland is made up of numerous glands that secrete:
hormones directly into the bloodstream
master gland consisting of anterior and posterior lobes with a section between called the pars intermedia.
pituitary gland
chemicals which affect the growth and/or function of other target tissues or organs
hormones
regulatory functions of hormones
metabolism
growth and development
muscle and fat distribution
fluid and electrolyte balance
sexual development
reproduction
stress response
control reproductive organ development, sperm production (testosterone), and secondary sec characteristics and growth
androgens (testes)
stimulates release of hormone from the adrenal cortex (ADH and cortisol)
adrenocorticotropic hormone (ACTH)
promotes water reabsorption (retention of fluids)
ADH/vasopressin (hypothalamus/post pit)
transmits neural impulses
epi and norepi (adrenal medulla)
stimulates glycogen breakdown in the liver to increase glucose in the blood
glucagon
affects metabolism of all nutrients; regulates blood glucose levels; has anti-inflammatory properties
glucocorticoids (cortisol)
stimulates growth, protein synthesis, and fat metabolism; inhibits carb metabolism
growth hormone
facilitates growth transport into muscles, adipose, or liver cells to use for energy and growth
insulin
stimulates release of oocytes and production of estrogen and progesterone; stimulates secretion of testosterone
luteinizing hormone
affects circadian rhythm, inhibits reproductive functions, protects against free radical damage
melatonin
stimulates contraction of the uterus during labor and milk release from breasts after childbirth
oxytocin
regulates calcium levels in the blood
parathyroid hormone
affects menstrual cycles; increase thickness of uterine wall; supports/ maintains pregnancy
progesterone
increase metabolic rate; needed for fetal and infant growth and development
thyroid hormone
endocrine glands
pancreas
thyroid
synthesize and release hormones
neurons
Neurotransmitter act ___ vs endocrine take ____
quickly vs hours to days
endocrine system chemical mediators
cytokines
leukotrienes
prostaglandins
important control center for many hormones
hypothalamic-pituitary axis
hormones exhibit predictable patterns of:
secretion, metabolism, and elimination
hormone two primary functions
- act on target tissues to achieve an effect
- act on glands to produce another hormone
triggers to the hypothalamus or pit gland to initiate hormone release
feedback mechanism
negative feedback (most common) description
internal thermostat. When the temperature gets too hot, the thermostat shuts down the heat source; when the temperature is too cool, the furnace is activated to release heat.
what happens with negative feedback when hormone levels rise above the expected range
the stimulation, production, or secretion of hormones is decreased.
effectors of hormones to the receptors
genetics
hormone levels
body fluid pH
factors affecting response to stressors
age
experience
general health
type of stressor
persistence of stressor
perception of stressor
social support
genetic influence
coordinates the actions of the autonomic nervous system, cerebral cortex, limbic system, and hypothalamus,
brainstem
produced so the body can quickly defend against stressor
epi and norepi
autonomic nervous system response to stress
HR, BP and RR increase
pupils dilate
sweating
gastric function decreased
altered blood flow
decreased oxygenation
prolonged cortisol exposure may result in
stress ulcers
regulates cognitive activities such as intense focus, planning, attention, and persistence
cerebral cortex
regulates emotions such as fear, anxiety, anger, and excitement
limbic system
intensifies sensory input related to the stressor such as vision, hearing, and smell
thalamus
release hormones to initiate the neuroendocrine response ;acts on ANS
hypothalamus
increases alertness and muscle tension and contributes to stimulation of ANS
reticular activating system
stress stimulates the release of
CRH and ultimate cortisol
cortisol actions
increased metabolism
regulates blood glucose for energy
catecholemines release action
heart rate increases
blood pressure increases
respiratory rate increases
person becomes much more alert
skeletal muscles also become activated for a rapid escape
Blood is shunted away from the skin and stomach. So, the person will look pale or ashen and digestion is decreased.
term used to describe this neuroendocrine response to a stressor and the corresponding physiologic changes.
General adaptation syndrom
three major stages of general adaptation syndrome
(1) the alarm stage
(2) the resistance stage
(3) the exhaustion stage.
alarm stage of general adaptation syndrome
fight or flight
short term
returns to normal after stress
Catecholamines and cortisol released results is the body breaking down proteins, releasing lipids, and increasing circulating glucose.
resistance stage of general adaptation syndrome
result from persistent stress
Cortisol levels decrease – normally if stress continues hypercoritolism develops
exhausts inflammatory and immune response proteins and tissues begin to break down, and glucose tolerance develops
hypercortisolism
exhaustion stage of general adaptation syndrome
overwhelming stress
Energy depletion
Breakdown of cells, tissue and organs
Poor health
diagnosis of altered hormone function
hormone test of blood and urine
CT
MRI
genetic testing
condition of excessive production and release of ADH despite changes in serum osmolality and blood volume.
Syndrome of inappropriate antidiuretic hormone (SIADH)
high levels of ADH stimulate
water retention
low levels of AHD trigger
water loss through urination
most common cause of SIADH
tumor - paraneoplastic syndrome - lung cancer
symptoms of SIADH
oEdema UNCOMMON
oHyponatremia
oHypotonicity (plasma osmolality less than 280mOsm/kg)
oDecreased urine volume
oHighly concentrated urine with a high sodium content
oAbsence of renal, adrenal, or thyroid abnormalities
SIADH = ___ ADH
DI = ______ ADH
S = too much
DI = insufficient
inability of the body to retain water
DI
cause of DI
o Insufficient production of ADH by the hypothalamus or ineffective secretion by the posterior pituitary.
o Inadequate kidney response to the presence of ADH, also called nephrogenic DI. The collecting duct is unresponsive.
o Ingestion of extremely large volumes of fluids and decreasing ADH levels; water intoxication can sometimes be attributed to a psychiatric disturbance.
nephrogenic DI can be observed in those with:
chronic renal insufficiency
lithium (a drug used to treat manic-depressive disorder) toxicity
hypercalcemia
hypokalemia
with disease of the renal tubules.
DI symptoms
oPolyuria
oPolydipsia
oUrine low specific gravity
oSevere dehydration
excessive thyroid hormone
hyperthyroidism
causes of hyperthyroidism
oresult from excessive stimulation to the thyroid gland,
odiseases of the thyroid gland, or
oexcess production of TSH by a pituitary adenoma.
oCertain medications containing large amounts of iodine, such as cough expectorants, health food supplements that contain seaweed, and iodinated contrast dyes, can induce hyperthyroidism in thyroid-sensitive individuals.
elevated TSH indicates ___
decreased TSH indicates ___
hypothyroidism
hyperthyroidism
Functions of thyroid hormone
influences stimulating metabolism
facilitating the breakdown of carbohydrates, proteins, and fats for energy
stimulating heat and glucose production
producing structural proteins, enzymes, and other hormones
promoting growth and development in children.
thyroid hormone release leads to:
o Increased glucose absorption
o Release of lipids from adipose tissue
o Metabolism of proteins from muscle tissue
o Increased cholesterol breakdown in the liver
o Increased production of metabolic byproducts
o Increased oxygen consumption
o Increased body heat production
o Increased cardiac output
o Increased gastric motility
o Increased muscle tone and reactivity
o Increased cognitive processes
most common cause of hyperthyroidism
graves disease (autoimmune)
clinical manifestations of hyperthyroidism
o Goiter
o Increased metabolic rate
o Weight loss
o Agitation
o Restlessness, sweating,
o Heat intolerance
o Exophthalmos
diagnosis of hyperthyroidism
o History and physical
o Manifestations
o Low TSH
o high T3 and T4
causes of hypothyroidism
- Autoimmunity
- Iodine deficiency
- Medications
clinical manifestations of hypothyroidism
o Fatigue
o Cold intolerance
o Weakness
o Weight gain
o Dry skin
o Coarse hair
o Constipation (one of first clues)
o Lethargy
o Impaired memory
o Myxedema – swelling of skin and tissues
diagnosis of hypothyroidism
o History and physical
o Manifestations above
o HighTSH
o low T3 and T4
condition of prolonged exposure to elevated levels of either endogenous (from the adrenal cortex or cortisol-producing tumors) or exogenous glucocorticoids (as when taking glucocorticoid drugs).
cushing syndrome
function of glucocorticoids (cortisol)
oStimulate glucose production
oDecrease tissue glucose utilization
oIncrease breakdown and circulation of plasma proteins
oIncrease fat mobilization
oPrevent the release of chemical mediators that trigger the inflammatory response
oDecrease capillary permeability and inhibit edema formation
oInhibit the immune response
oInhibit bone formation
oStimulate gastric acid secretions
oContribute to emotional behavior
oContribute to an effective stress response
causes of cushing syndrome
long term use of corticosteroids
tumors
clinical manifestations of Cushing’s Syndrome
*obesity of the trunk, face, and upper back.
*Obesity of the face and posterior neck and back (“moon face” and “buffalo hump”)
*Striae, or stretch marks, can develop from central obesity.
*extremity weakness and muscle wasting.
*The skin becomes atrophic and thin.
*Bones exhibit osteoporosis.
*increased infections, skin ulcerations, and poor wound healing.
*Glucose intolerance, from excess circulating glucose and loss of tissue utilization, can lead to diabetes mellitus.
*Changes in behavior can range from euphoria to minor emotional disturbances to psychosis.
*Hirtsutism = development of excessive body and facial hair
diagnosis of Cushing’s
24 hour urine collection
(cortisol spillage)
considered one of the most serious endocrine disorders because it can lead to severe hypotension, shock, and death.
acute ACTH deficiency
occurs as a result of insufficient production of cortisol and aldosterone from the adrenal cortex.
addisons disease
most common cause of addisons disease
Autoimmune destruction of the layers of the adrenal cortex
clinical manifestations of addisons disease if glucocorticoids are deficient
hypoglycemia
weakness
poor stress response
fatigue
anorexia
nausea
vomiting
weight loss
personality changes
clinical manifestations of addisons disease if mineralocorticoids are deficient
dehydration
hyponatremia
hyperkalemia
hypotension
weakness
fatigue
shock
clinical manifestations of addisons disease if androgens are deficient
sparse axillary and pubic hair
diagnosis of addisons disease
electrolyte levels (hyponatremia and hyperkalemia)
serum corticosteroid levels
neurotransmitter of the endocrine system
epi
norepi
dopamine
serotonin
paraneoplastic syndrome
tumor diagnosis from finding of extra secretion of a certain hormone
posterior pituitary glands
ADH
oxytocin
anterior pituitary glands
FSH and LH
TSH
ACTH
Prolactin
GH
receptor binding
*Receptor binding allows for selectivity and specificity
*The number of receptors on a cell affects the amount of response
*Affinity or attraction for the hormone to the receptor can be reduced
*genetics, hormone levels, and body fluid pH affect the affinity of hormones to receptors.
stress
body’s reaction to harmful forces (stressors) capable of disturbing homeostasis.
An inadequate or even excessive response to stress can result in
destruction of body tissues.
adrenal cortex increased cortisol
alteration in glucose, fat, protein metabolism
suppression of inflammatory and immune response
autonomic nervous system response to stress
increased HR and BP
pupil dilation
dry mouth
increased sweating
increased coagulability
immune system response to stress
decreased resistance to inection
alterations in immune response
adrenal hormones from adrenal medulla
epinephrine and norepinephrine
adrenal cortex steroid hormones
mineralocorticoids
glucocorticoids
sex hormone
