Endocrine Pt.2 Flashcards
small, round masses of tissue
attached to the posterior surface of the lateral lobes of
the thyroid gland
Parathyroid glands
usually____ parathyroid glands attached to each lobe of the thyroid, one superior and one inferior
two
made by the more
numerous chief (principal) cells of the gland..Stimulates
• osteoclastic activity in the bones
• Ca2+ reabsorption in the
kidneys
• (Indirectly) Ca2+ absorption
from the GI tract
Parathyroid hormone (PTH)
is made by the parafollicular (C-cells) of the thyroid gland and
when secreted____ the blood calcium level
Calcitonin (Thyrocalcitonin), lowers
An increase in blood calcium will stimulate the C-cells
of the thyroid to
secrete calcitonin
Steroid hormones like cortisol
the adrenal cortex
Catecholamines like norepinephrine
the adrenal medulla
The adrenal cortex is peripherally located.
The cortex has____ zones, each of which secretes a different group of____ hormones
three. steroid
Most superficial, mineralocorticoids
Zona glomerulosa
Middle, glucocorticoids,
primarily cortisol
Zona fasciculata
Deepest,
weak androgens
(masculinizing hormones)
Zona reticularis
regulate the concentrations of Na+ and K+ in the blood (affects blood volume/pressure)
Mineralocorticoids
is the major hormone in this group (Zona glomerulosa)
Aldosterone
influence glucose metabolism and the ability to resists the effects of stress
Glucocorticoids
is the major hormone in this group (Zona fasciculata)
Cortisol
Weak ____ (masculinizing sex hormones) have little effect in men, but play an important role in
promoting libido in women
androgens
important part of the renin-angiotensin-
aldosterone system (RAAS)
Aldosterone
Low BP (or blood volume)stimulates juxtaglomerular cells in the kidney to secrete the enzyme
renin
• Renin converts angiotensinogen (in the blood) into
angiotensin I
• Angiotensin I is converted to angiotensin II in the lungs
by angiotensin converting enzyme
(ACE)
stimulates the adrenal cortex to secrete aldosterone (salt and H20 resorption indirectly increases BP), and it is a
potent vasoconstrictor (which directly increases BP) and it is a
potent vasoconstrictor (which directly increases BP)
Angiotensin II
Glucocorticoids (mainly cortisol) regulate metabolism
promoting breakdown of proteins and fats to____
form glucose (gluconeogenesis)
(Reduce/Increase) inflammatory effects by inhibiting white blood cells.
glucocorticoids are very useful in the treatment of
chronic inflammatory disorders such as Lupus,
though long term side-effects are severe
Reduce
a modified sympathetic ganglion of the ANS
and is innervated by sympathetic preganglionic neurons
adrenal
medulla,
The catecholamines_____ (80%), and____4_ (20%),
epinephrine, norepinephrine
Response to emotional or physical threats, whether
actual or imagined
Can include events normally considered to be “good”, as well as bad
for instance, a marriage can be as stressful as a
divorce, a birth as stressful as a death, etc.
General adaptation syndrome (GAS) or stress response
If stress is extreme, unusual, or long lasting, the normal
mechanisms may not be enough, and they may elicit a
series of changes called the
stress response or GAS
Three stages to a prolonged stress response
alarm reaction, resistance reaction, and exhaustion
short-lived fight-or-flight response initiated by the hypothalamus and mediated by the sympathetic division of the ANS
it brings huge amounts of glucose and oxygen to the
brain, the lungs, and skeletal muscles
the RAAS is also activated to maintain blood volume
and BP
Alarm reaction:
initiated in by hypothalamic releasing hormones, longer-lasting response. release of high levels of cortisol and thyroid hormones assures that the body can sustain necessary metabolic needs
Resistance reaction
occurs when the body’s reserves become so depleted that they cannot sustain the resistance stage. Prolonged exposure to high levels of cortisol and other hormones causes wasting of muscle, suppression of the immune system, ulceration of the GI tract, and failure of pancreatic beta cells… disease often ensues
Exhaustion
Is the pancreas an endocrine or exocrine gland
Both
acini
exocrine cells
pancreatic islets
Endocrine
Each pancreatic islet contains four types of hormone-
secreting cells:
alpha (A), beta (B), delta (D), and F cells
Alpha cells secrete
Glucagon
Beta cells secrete
Insulin
increases blood glucose levels by acting
on hepatocytes to convert glycogen and other nutrients to glucose
Glucagon
decreases blood glucose
hepatocytes convert glucose to glycogen. facilitating diffusion of glucose into the cells for usage
Insulin
Insulin and glucagon are _____hormones in that
their actions act to balance one
another in terms of blood glucose
counter- regulatory
paracrine hormone inhibiting both insulin
and glucagon. also inhibits the secretion
of hGH • The interactions of
somatostatin and pancreatic polypeptides are complex and not well understood
Somatostatin
(enlargement of the breasts and widening of the hips) at puberty onward
female secondary sex characteristics
prepares the uterine lining for
implantation of a fertilized ovum
Progesterone
