Section 6 Exam Review 2 Flashcards
Cortisol has permissive effects on:
glucagon
When does cortisol secretion peak?
between early morning and noon
Cross-over effects are sometimes seen between:
steroid hormones
True or False? All the hormones secreted by the adrenal gland play a major role in growth and metabolism.
F
Pendrin is an anion transporter important in the production of:
thyroid hormone
Name an effect of thyroid hormone on peripheral tissue:
increased sensitivity to sympathetic stimulation
Iodine accumulation in thyroid cells involves symport with:
sodium
Excess secretion of growth hormone during adulthood will cause:
acromegaly
Somatostatin is another name for:
growth hormone-inhibiting hormone
Mature, less active bones:
osteocytes
Functions of PTH:
stimulate osteoclast activity, increases the rate of calcium absorption, decreases the rate of calcium excretion, raises the level of calcium ion in the blood
Excess growth hormone prior to puberty:
giantism
Calcium reabsorption at the kidneys is promoted by the hormone:
calcitriol
Functions of cortisol:
suppress the immune system and influence brain function
What are ACTH and MSH called?
melanocortins
Effect of hyperthroidism on protein in body?
increases protein catabolism
What does growth hormone bind?
plasma protein
PTH is:
a peptide and dissolved in plasma
Vitamin D is another name for:
calcitriol
Vitamin D is formed by:
sunlight
True or False? Vitamin D is bound to plasma protein for transport.
T
What disease results in hypercortisolism?
Cushing’s disease
What disease results in hyperthroidism?
Grave’s disease
What disease involves endocrine stimulation by antibodies?
Grave’s disease
Some symptoms of this disease mimic diabetes mellitus:
Cushing’s disease
This disease is associated with overactive osteoclasts:
Paget’s disease
Calcitonin may be the appropriate treatment for this disease:
Paget’s disease
This may be an autoimmune disease:
Addison’s disease
This disease may result from adrenal tumor:
Cushing’s disease
This disease may result from a pituitary tumor:
Cushing’s disease
This is associated with Grave’s disease:
exophthalmus (abnormal protrusion of the eyeballs)
This can be caused by growth hormone deficiency in childhood:
dwarfism
This is caused by growth hormone excess in adulthood:
acromegaly
This can lead to mental retardation associated with infantile hypothyroidism:
cretinism
This condition results from excess androgens in females:
adrenogenital syndrome
Hunchback appearance associated with osteoporosis:
kyphosis
Puffy appearance associated with hypothyroidism:
myxedema
Easily observable symptom of hypercortisolism:
moon face
Caused by elevation of TSH:
Goiter
The most importance metabolic effect of ___ is protecting against ___, crucial to surviving significant stress.
cortisol, hypoglycemia
What produce and store thyroid hormone?
thyroid follicles
____ is a result folicular deficient thyroid hormone secretion in infancy.
cretinism
What does calcium phosphate form in bone?
crystals of hydroxyapetite
Into what system is CRH released?
hypothalamic-hypophyseal portal system
Breakdown products of POMC:
ACTH, MSH and endorphins
Growth hormone stimulates secretion of what from the liver and other tissues?
insulin-like growth factor
True or False? Growth hormone has a positive feedback effect on growth hormone secretion.
F. negative
4 factors that affect normal body growth:
growth hormone and other hormones, adequate diet, absence of stress, genetic
4 physiological functions of calcium:
signalling molecule, helps hold cells together at tight junction, cofactor in coagulation cascade, excitability of neurons
2 endocrine cell types that make up the thyroid gland:
c cells and follicle cells
C cells secrete ___, while follicle cells secrete ___-.
calcitonin, thyroid hormones
What would damage to the zona fasciculata of the adrenal cortex result in?
decreased ability to convert lipids to glucose
A rise in cortisol would lead to:
Inc liver glucose and glycogen synthesis, higher fatty acids levels in blood, immune suppression
Premature closure of the epiphyseal plates could be caused by:
elevated levels of sex hormones
What effect will late start to puberty have on a boy?
probably be taller than if started sooner
Example of the permissive effect:
cortisol is required for glucagon to have its full effects, can’t adequately perform its role in glucose regulation and death results
How does cortisol suppress the immune system?
it prevents cytokine release and antibody production by WBC’s and decreases WBC mobility and migration (antibiotics-inflammatory and antibiotics-rejection drug for transplants)
True or False? Cortisol strengthens the skeleton.
F. weakens
How is the adrenal cortex affected during cortisol therapy?
it atrophies
Difference between hypertrophy and hyperplasia:
increase in cells size vs. increase in cell number
Hypertrophy and hyperplasia are both regulated by:
growth hormone, thyroid hormone, and insulin
3 causes of hypercoticolism:
adrenal tumor (primary), pituitary tumor (secondary), and iatrogenic
How does cortisol help protect against hypoglycemia?
via its catabolic effects
effects of cortisol:
gluconeogenesis, muscle protein breakdown, increased lipolysis, immune suppression, negative calcium balance, alteration of cerebral functions, and bone loss
Give an example of the permissive effect in children.
thyroid hormone is needed for full expression of growth hormone
List the trophic hormones:
FLAT
True or False? Endocrine cells are found in the posterior pituitary gland.
F. Anterior
Are the trophic producing cells part of the anterior or posterior pituitary gland?
anterior
Which releasing hormones have effects on more than one target?
TRH (TSH and prolactin) and GnRH (FSH and LH)
The renal actions of ADH are mediated by these receptors:
V(2) receptors, increase cAMP
How does ADH effect urea levels in the kidney?
increase urea reabsorption
Vascular effect of ADH are mediated by this receptor:
V(1) receptor (PIP(2) system)
How does ADH affect capillary and venue pressures?
decreases both
The osmoreptors in the kidney have ___ connections to the ________ nucleus.
neural, suproptic
Where are the stretch receptors located that sense high pressure?
carotid sinus and aortic arch
Where are the receptors located that sense low pressure?
cardiopulmonary, atria and thoracic veins
Which is sensed earlier, changes in plasma volume or osmolarity?
osmolarity
Lack of ADH leads to this disease:
diabetes insipidus
Excess ADH leads to this disease:
SIADH: Syndrome of Inappropriate ADH secretion
ACTH is aka:
endorphins
What is reticular activating substance involved in?
slep/wake cycle
What is the thalamus involved in?
pain
Functions of ACTH on the adrenal gland:
stimulate growth and function of gland
What hormone has inhibitory action on Tyrotropin?
Somatostatin
Which is involved in estrogen and progesterone synthesis, LH or FSH?
LH
Which is involved in follicular ovulation, LH or FSH?
LH
Which is involved in follicular growth, LH or FSH?
FSH
Effect of growth hormone on progesterone levels:
increases
Effect of progesterone on somatotrophs:
decreases the size and number of
Effect of progesterone on mammotrophs:
increases the size and number of
Prolactin inhibiting factor is aka:
GAP: GnRH Associated Peptide
True or False? Prolactin is involved in the up regulation of menstrual functions.
F. suppressed menstrual functions
The positive feedback loop involving oxytocin is continued as a result of
cervical stretch when baby pushes against cervix as a result of uterine contractions
How is ADH controlled?
osmoreceptors and volumes/ pressure receptors
Thyroxine is involved in the growth and development of what body systems/
CNS and skeletal system
True or False? Thyroxine is involved in temperature regulation.
T
True or False? Both Grave’s disease and Hashimoto’s disease are autoimmune diseases.
T
Are thyrotrophs found in the anterior or posterior pituitary gland/
anterior
What does T4 and T3 negatively feedback to in the thyroid axis control?
Thyrotroph
7 steps in the biosynthesis of thyroid hormones:
transport, Peroxidation (TPO), iodination (TPO), coupling, (TPO), reabsorption, proteolysis, secretion
How many steps in the biodynthsis of thyroid hormones is TPO involved in?
3; peroxidation, iodination, coupling
Functions of thyroid hormones:
transport, growth, metabolism, sympathetic nervous system, temperature regulation
How do thyroid hormones function in transported[orthodontic?
TBG (thyroxine binding gobulin) and Albumin
These can lead to the enlargement of the thyroid gland:
thyroid stimulating immunoglobulins
True or False? T3 and T4 have a strong negative feedback to the hypothalamus in hypothyroidism.
F. Strong negative feedback to hypothalamus in Grave’s disease
Pendrin:
transports iodine into colloid
Does iodine get oxidized or reduced in the colloid?
oxidized, i- to i zero
Are a or b cells at the center of the islet?
beta
Insulin secretion:
plasma glucose increases, transported in via GLUT2 channels, oxidized to ATP, ATP closes K+ channel, cell depolarizes, voltage-sensitive calcium channel opens, calcium triggers the release of insulin
Pathway in which PKA increases the secretion of insulin:
adenylate cyclase/ glucagon receptor, ATP, to cAMP, to PKA
What type of adrenergic receptor is in the beta cell?
alpha-2-adrenergic receptor
What enzyme is used to make ADP + P from ATP in the beta cells?
Glucokinase
All weak androgens and glucocorticoids are synthesized from either:
pregnenolone or progesterone
The formation of mineralocorticoids, glucocorticoids, and weak androgens all start with the conversion of cholesterol to ___, via this enzyme:
pregnenolone, CSCC
Name 2 weak androgens:
DHEA and androstenedione
Aldosynthase converts what to what?
corticosterone to aldosterone
Which hormone is involved in long-loop negative feedback?
cortisol, on CRH and ACTH
2 factors that alter CRH release:
circadian rhythm and stress
True or False? Cortisol leads to protein anabolism.
F. catabolism (immune system suppression, gluconeogenesis, and lipolysis as well)
Extrahepatitc actions of glucocorticoids:
Break down protein from muscle and break down fat
Hepatic actions of glucocorticoids:
Synthesize glucose and glycogen
True or False? Glucocorticoids decreases sensitivity to insulin.
T
True or False? Glucocorticoids lead to an increase in liver glycogen storage.
T
How do glucocorticoids increase gluconeogenesis in the liver?
increase activity and amount of enzymes
True or False? Glucocorticoids lead to an increase in glucose sensitivity in adipose tissue.
F. decrease
True or False? epinephrine/ norepinephrine increase glycogenolysis and lipolysis.
T
Do epinephrine and norepinephrine both inhibit insulin release?
yes
What is the rate limiting step in the formation of pregnenelone?
cholesterol side chain cleavage (CSCC)
Main component of zona fasciculata and zona reticulata
cortisol, then corticosterone
Which group controls secretion, the renin-angiotensin system “RAS”?
mineralocorticoids
True or False? Aldosterone is involved in K+ excretion.
T, Na channel on luminal side, na/K ATPase on basal
What type of feedback control is there in the hypothalamic-pituitary-adrenal axis?
negative feedback
What hormone is involved in tissue integrity?
cortisol
Effect of cortisol on CNS:
decrease sensory acuity and promote sense of well being
Effect of cortisol on cardiovascular system:
decrease vascular permeability, helps maintain catecholamine effect on vasoconstriction and contractility
Effect of cortisol on kidney:
to concentrate urine
Effect of cortisol on GI tract:
increase acid secretion, inhibit calcium reabsorption
Effect of cortisol on bone:
increase resorption
Effect of excess cortisol on connective tissue:
decreases collagen synthesis
Excess glucocorticoids:
obesity, “moon face” (pie face), loss of bone mass, striations, muscle weakness
What causes Addison’s disease?
lack of both glucocorticoids and mineralocorticoids
Symptoms of Addison’s disease:
life threatening, loss appetite, malaise, lethargy
What is the adrenal medulla innervated by?
splanchnic nerves
Embryologic origin of the medulla:
neuroectodermal
Function of B-receptors:
increase cAMP (epinephrine>norepinephrine)
metabolic effects of B-receptors:
glycogenolysis, lipolysis, release of glucagon, calorigenisis
Cardiovascular effects of B-receptors:
increase heart rate and contractility, vascular dilation, u relaxation
alpha-receptors functions:
alpha-1: PIP(2) turnover, alpha-2: decrease cAMP epinephrine and norepinephrine bind equally well
metabolic effects of alpha-receptors:
decreased insulin secretion, increased glucagon and glucose release
Cardiovascular effects of alpha-receptors:
vasoconstriction
What is pheochromocytoma?
Causes excess secretion of epinephrine and norepinephrine, leads to: hypertension, palpitations, late skin, headache, and anxiety
What negatively feeds back to the anterior pituitary gland in the growth and development pathway?
insulin-like growth factors
This food substrate up regulates the release of growth hormone while this one down regulates the release.
protein, carbohydrates
True or False? Growth hormone up regulates lypogenesis.
F. lipolysis
4 hormones related to growth:
thyroid hormones, glucocorticoids, androgens, and estrogens
Causes of retarded growth:
nutritional, excess cortisol, thyroxin deficient, precocious puberty, growth hormone responsive dwarfism, or growth hormone insensitive dwarfism
What type of growth are IGF’s involved in?
whole body growth
IGF-1 is aka:
Somatomedin-C
Function of IGF-1:
stimulate differentiation and proliferation
True or False? Thyroid hormones are involved in both neural and skeletal development.
T
True or False? Glucocorticoids are involved in growth, but not growth inhibition.
F. Vice versa
How do glucocorticoids exert their effects on a target tissue?
via direct action
This hormone has synergistic actions with growth hormone at target tissue:
androgens
Adrogens stimulate:
release of growth hormone, epiphyseal plate maturation, and muscle growth
True or False? Estrogens promote somatic cell growth.
F. inhibit somatic cell growth
Effect of estrogen on somatomedin C levels:
decreases somatomedin C levels
Effect of estrogen on growth hormone secretion:
increases growth hormone secretions
Intracellular functions of Ca:
contraction, motility, secretion, nerve function, growth, and differentiation
Extracelluar functions of Ca:
cell adhesion, aggregation of platelets, membrane integrity, blood coagulation
Functions of PO4:
cytosolic and blood pH buffer, energy exchange, component of membranes and nucleic acids, activation/inactivation of enzymes by kinases/phosphatases
14% of the PO4 in the body is here:
sequestered in the intracellular fluid
Extracellular fluid levels of Ca2+ and PO4:
0.1% Ca2+ and 0.03% of PO4
How are Ca and P stored?
in mito as crystal: Ca(3)(PO4)2
Where is most calcium reabsorbed?
duodenum
Calcium reabsorption is mediated by:
CaBP
PO(4) is reabsorbed most here:
jejunum, linear with diet
Bulk reabsorpion of calcium occurs here and regulated reabsorption occurs here:
poximal tubule, distal tubule
What % of the filtered load of PO(4) is reabsorbed in the poximal tubule?
90%
Reabsorption of PO(4) in the poximal tubule is ___ dependent.
Na+
Where is PTH synthesized?
chief cells of parathyroid gland (84 amino acids)
Action of PTH on the kidney:
increases reabsorption of Ca2+ and decreases PO(4) reabsorption
Where does PTH help in the formation of Vitamin D?
kidney, promotes formation of 1,25(OH)2
C cells are aka:
parafollicular cells, 32 amino acids
Action of calcitonin on kidney:
increase excretion of both Ca and P
True or False? Calcitonin has potent pharmacological actions.
T
The reaction of this converting to this requires sunlight.
7-dehyrocholesterol to cholecalciferol (Vitamin D3)
__ occurs in the liver to make Vitamin D.
hydroxylation, not regulated, vitamin D3 levels reflect dietary intake
Describe the biological activity and half life of 25(OH)-Vitamin D3:
weak biological activity, long half life (15 days)
True or False? 25(OH)-Vitamin D3 is the active form of Vitamin D.
F. activated in the kidney to 1,25(OH)-Vitamin D3
High plasma levels of what will increase the formation of 24, 25(OH)- Vitamin D3?
PO(4) or 1,25(OH)2
Function of 1,25(OH)2-Vitamin D3:
increases calcium and PO(4) absorption in gut
Function of 1,25(OH)2-Vitamin D3 in gut is inhibited by:
glucocorticoids
Osteoblasts secrete:
collagen, alkalin phosphatase, and other proteins and amorphous CaPO(4) to form osteoid
What is osteoid:
cartilage-like material, calcium salts can precipitate
Osteoblasts arise from osteoprogenitor cells in:
marrow, periosteum, or periodontal ligament
There are inactive osteoblasts:
surface cells
What are surface cells connected to?
osteocytes via gap junctions
What do surface cells separate?
bone fluid from plasma
Where do osetocytes reside?
bone interior, in lacuna connected via cannuliculi
Osteocytes arise from:
encapsulated osteoblasts
True or False? Osteocytes destroy bone matrix.
F. They mobilize Ca and P from immature CaPO(4) crystals by osteolysis without destruction
From what cells do osteoclasts arise?
monocytes/ macrophages
True or False? Osteoclasts are mononucleated.
F. multinucleated
How do osteoclasts resorb bone?
secretion of acid hydrolases, acidification of resorbing surfaces
How are osteoblast and osteoclast activity coupled?
various paracrine factors scubas PGE(2), secreted cytokines, and factors from osteoid degradation
True or False? Calcitonin and Vitamin D both lead to the absorption of Ca and P from the plasma.
F. Calcitonin does, vitamin d leads to release of Ca and P into the plasma
Where are PTH receptors found?
osteoblasts and osteocytes
What signals for the formation of new osteoclasts?
paracrine release of factors from osteoblasts.
How are osteoblasts activated?
release of factors (from degraded osteoid?)
Where are calcitonin receptors found?
osteoclasts
How does decreased activity of active osteoclasts affect osteoblasts via coupling?
decreases osteoblastic activity leading to decreased bone turnover
Are Vitamin D receptors found on osteoblasts, osteocytes, or osteoclasts?
osteoblasts and osteocytes
True or False? Vitamin D directly activates osteoclasts.
F. indirectly, like PTH
Actions of Vitamin D:
direct: permissive action, indirect: positive systemic Ca2+ and PO(4) balance
Do glucocorticoids decrease bone formation and degradation via direct or indirect actions?
both
What does prolonged exposure of glucocorticoids lead to?
osteoporosis
What sex steroids help maintain bone mass?
testosterone and estradiol
PTH acts to reabsorb Ca here and P here:
Distal tubule, poximal tubule (with Na)
Body locations on which PTH acts:
Kidney, bone, and intestines
Osteocytes around encapsulated ____.
osteoblasts
True or False? PTH and Vitamin D have receptors on the same cells types.
T
Aromatase is involved in the conversion of:
androgens to estrogens
True or False? PTH and Vitamin D have receptors on the same cells types.
T
All amino acid derived hormones are derived from:
tyrosine
Primary source of calcitonin:
thyroid
Primary source of melatonin:
pineal gland
Primary source of melatonin:
pineal gland
A hormone that controls the secretion of another hormone:
trophic hormone
Primary pathologies arise in the _____ endocrine gland in a reflex.
last
What is a secondary pathology?
a problem with one of the tissues producing trophic hormones
What type of hormone triggers an increase in the activity of G proteins in the membrane?
peptide hormones
What happens to a hormone after it exerts its effects?
inactivated or remove from blood
Difference between hormones and cytokines:
hormones are made in advance and stored
In a simple endocrine reflex, the endocrine cell is the:
sensor and the integrating center
Which produce a faster response, hormones acting through signal transduction pathways or those that produce genomic effects?
signal transduction pathways
2 ways hormones affect their target:
2nd messenger systems activated by peptide hormones modify existing proteins or activate gene transcription to make new proteins. Steroid hormones activate gene transcription to make new proteins and some steroid have nongenomic responses
Example of synergistic hormones:
epinephrine potentiates the effects folicular glucagon in elevating blood glucose levels
Example of permissive effect involving reproductive hormones:
reproductive hormones, along with adequate thyroid hormone have a permissive effect on the reproductive system birth control both are required for normal development
Example of antagonistic hormones:
glucagon and insulin
Benefit to portal system:
ensures direct delivery of hormone to target cell, hormone not diluted by passing through generation circulation, smaller amounts necessary
True or False? The hypophyseal portal system is the only endocrine portal systems.
T
The hormones from the posterior pituitary gland are secreted as:
neurohormones
