endocrine system Flashcards
glands of the endocrine system
a gland is a specific type of organ that secretes
hormones into the blood to target and affect other organs
glands of the endocrine system
the major glands in the endocrine system
pineal
pituitary
thyroid
parathyroid
thymus
adrenal
glands of the endocrine system
organs contain endocrine tissue and produce hormones are the
pancreas and the ovaries or testes
glands of the endocrine system
the hypothalamus is a part of the
brain involved in the endocrine system and it controls the pituitary gland that is below it
glands of the endocrine system
the pineal gland is located in the middle of the
brain
glands of the endocrine system
the thyroid and parathyroid glands are found in the
neck
glands of the endocrine system
the adrenal glands are located on the top of each
kidney
functions of the endocrine system
the endocrine system regulates many body functions by controlling the amount of
hormones released
functions of the endocrine system
all body systems are regualted by the endocrine system in some way like
regualtion of blood production
appetite
reproduction
brain function
sleep cycle
electrolyte balance
growth
sexual development
response to stress and injury
functions of the endocrine system
glands and organs secrete
hormones into the blood to be transported to target organs and tissues to control their function
an ex the pancreas releases the hormone insulin which signals cells to uptake sugar
functions of the endocrine system
the pineal gland releases the hormone
melatonin which is involved in regulating sleep cycles
functions of the endocrine system
endocrine glands produces hormones that have different
chemical structures
functions of the endocrine system
lipid based hormones can enter a
cell and regulate DNA
functions of the endocrine system
some non-polar, fat-soluble hormones such as
estrogen and progesterone are released in a pattern set by age and development and their effects are long-lasting
functions of the endocrine system
reproductive hormones are responsible for
gamete production
for ex estrogen production increases at puberty and leads to the development of secondary sex characteristics
functions of the endocrine system
other polar, water-soluble hormones such as
epinephrine are released in response to stress and their actions are short, lived
functions of the endocrine system
hormone receptors on the cell membrane cause
cellular changes to regulate and control body functions
functions of the endocrine system
when the adrenal glands secrete
epinephrine into the bloodstream, heart rate
blood pressure
muscle strength
metabolism
increase
this response is called “the fight-or-flight” response
functions of the endocrine system
hormone imbalance can cause metabolic diseases like
diabetes
hyperthyroidism
gigantism
functions of the endocrine system
for ex in people with hyperthyroidism the thyroid gland releases too much
thyroxine
this can lead to an increase in both weight loss and heartbeat
to diagnose doctors look for elevated levels of thyroxine in the blood
functions of the endocrine system
gigantism occurs when the
pituitary gland makes too much growth hormone causing excessive growth
gigantism is too much GH in children, too much GH in adults is acromegaly
functions of the endocrine system
hormone levels are often measured to determine if an
endocrine-related disease is present
homeostasis
homeostasis is the maintenance of a constant
internal environment
it helps the cells to work as efficiently as possible
homeostasis
most homeostatic mechanisms work through
feedback systems and they are mainly controlled by endocrine glands
feedback systems bring about physiological and behavioral changes, which help maintain the internal constancy
homeostasis
ex of homeostasis
- maintaining the constant concentration of glucose in the blood, which is controlled by the hormones insulin and glucagon
- maintaining the right amount of water in the blood which is under the control of antidiuretic hormone (ADH) secreted by the pituitary gland
pos and neg feedback mechanisms
positive feedback causes an
increase in the secretion of a hormone
pos and neg feedback mechanisms
an ex of pos feedback is the secretion of the hormone
oxytocin
during childbirth the cervical stretching from fetal pressure triggers a release of oxytocin from the posterior pituitary
oxytocin stimulates uterine contractions that in turn cause the fetus to push against and stretch the cervix even more
this pos feedback continues until the fetus is expelled through the cervix
pos and neg feedback mechanisms
most hormone levels in the body are regulated through
neg feedback and are influenced by the production of a releasing hormone or an inhibiting hormone
pos and neg feedback mechanisms
neg feedback helps to maintain
homeostasis
the cells of the pancreas are able to adjust the amount of hormone they secrete in proportion to the amount of blood glucose they detect
when the blood sugar levels are too high the beta cells of the pancreas release the hormone insulin
this signals the cells to uptake sugar which lowers the blood sugar levels
when blood glucose levels are too low alpha cells secrete a different hormone glucagon
this hormone promotes the breakdown of glycogen which is stored in the liver and in muscle cells into glucose which raises blood sugar levels
the hormone secretion is stopped when a homeostatic level of blood glucose is detected
the central nervous system and the endocrine system
the nervous system is involved in rapid communication within the body as it detects
stimuli and coordinated responses quickly
the central nervous system and the endocrine system
the endocrine system is generally involved with comparatively slower and more long-lasting responses to stimuli than the
nervous system
the central nervous system and the endocrine system
the integration of the nervous system and the endocrine system is called the
activation of the neuroendocrine system
the central nervous system and the endocrine system
ex of activation of the neuroendocrine system
the hypothalamus of the brain directs the activities of the pituitary gland
certain biochemical levels send messages to the hypothalamus, which either stimilates or turns off messages to the pituitary gland which is located just below the brain
specialized cells in the hypthalamus secrete hormones called “releasing hormones” or “inhibiting hormones” to the pituitary
the pituitary gland then makes and sends specific hormones to target organs
for ex the pituitary gland secretes FSH which functions in egg development in the ovaries
the central nervous system and the endocrine system
another ex of activation of the neuroendocrine system
occurs in childbirth
during labor the pressure of the fetus on the cervix sends signals through the nervous system to the hypothalamus which results in oxytocin being secreted by the posterior pituitary gland
practice problems
which of the following best describes the kind of message sent in the endocrine system?
a. electrical signals between axons
b. chemical signals that travel through the bloodstream
c. physical sensory signals received through the integumentary system
d. audiovisual signals processed through the brain
b. chemical signals that travel through the bloodstream
practice problems
which of the following structures secretes releasing hormones?
a. hypothalamus
b. pituitary
c. pancreas
d. liver
a. hypothalamus
practice problems
which of the following is a function of the pineal gland?
a. releasing growth hormone
b. releasing melatonin
c. releasing insulin and glucagon
d. releasing luteinizing hormone
b. releasing melatonin
practice problems
which of the following glands releases epinephrine during stress?
a. hypothalamus
b. adrenal glands
c. pancreas
d. pituitary gland
b. adrenal glands
