Lesson 4 - Endocrine Pt 2 Flashcards
gigantism
hypersecretion of GH during childhood (before growth plates are depleted)
acromegaly
hypersecretion of GH during adulthood (after growth plates closed)
what happens with acromegaly?
thickening of the bones and soft tissues, especially hands, feet, and face
pituitary dwarfism
hyposecretion of GH during childhood
- rare because GH is now plentiful, made by genetically engineered bacteria
pineal gland
where is it located?
attached to the roof of the third ventricle beneath the posterior end of the corpus callosum
what happens to the pineal gland after age 7?
involution (shrinking)
pinealocytes synthesize _____ at night and fluctuates seasonally
melatonin
where are melatonin receptors in the body?
widespread
what are some functions of melatonin receptors? (4)
- circadian rhythm
- promotes sleep
- has antioxidant/anticancer properties
- slow maturation of sperm and egg cells
what has lack of melatonin been linked to?
premature puberty in humans
the thymus plays a role in three different systems:
endocrine, lymphoid, and immune
how many lobes does the thymus have?
two
where is the thymus located?
the mediastinum superior to the heart
what happens to the thymus after puberty?
involution
involution
shrinking
functions of the thymus (2)
- site of maturation of T cells
- secretes hormones that stimulate development of other lymphoid organs
what hormones does the thymus release? (3)
thymopoietin, thymosin, and thymulin
thyroid gland
what is special about this gland?
it is the largest gland that is purely endocrine
where is the thyroid gland located?
adjacent to the trachea, immediately below the larynx
structure of the thyroid gland (2)
- two lobes connected by a narrow bridge (isthmus)
- composed of sacs called thyroid follicles
isthmus
the narrow bridge connecting the two lobes of the thyroid
thyroid follicles
contain protein-rich colloid surrounded by simple cuboidal epithelium of follicular cells
what do follicular cells of the thyroid secrete?
thyroid hormone (TH)
T4 is also called
tetraiodothyronine because it has four iodine atoms
what does thyroid hormone collectively refer to?
T3 and T4
what form is 90% of thyroid hormone (TH)?
T4 or thyroxine
what form is 10% of thyroid hormone (TH)?
T3 or triiodothyronine
what is TH released in response to?
TSH release from the anterior pituitary
what do TSH levels influcence?
TRH release from the hypothalamus
TRH = thyrotropin-releasing hormone
parafollicular cells aka
clear (C) cells
what do clear cells secrete?
calcitonin in response to rising blood calcium
what does calcitonin do? (4)
- stimulate osteoblast activity
- inhibits osteoclast activity
- stimulates bone formation in children
- reduces blood calcium by stimulating calcium excretion by kidneys
what is essential for the production of T4/T3?
iodine
thyroid hormone is transported in the blood by what proteins?
- thyroid-binding globulins (TBG), a blood plasma protein
- transthyretin (thyroid binding prealbumin TBPA)
what does TH do? (6)
increases metabolic rate, O2 consumption, heat production, appetite, growth hormone secretion, and alertness
calorigenic effect
increase in heat production
what is TH needed for in children?
normal development of skeletal, muscular, and nervous system
effects of TH on peripheral tissue (7)
- elevated rates of O2 consumption/energy consumption
- increased heart rate/force of contraction (incres. blood pressure)
- increases sensitivity to sympathetic stimulation
- maintains normal sensitivity of respiratory centers to changes in [O2/CO2]
- stimulates RBC formation thus enhancing O2 delivery
- stimulates activity in other endocrine tissue
- accelerates turnover of minerals in bone
congenital hypothyroidism
what is it and what does it cause?
TH hyposecretion present from birth; causes stunted bone growth, intellectual disabilities
what happens if TH levels decline before puberty?
normal skeletal muscle development with not continue
myexdema
severe or prolonged adult hypothyroidism
symptoms of myxedema (7)
- swelling of face
- slow heart rate
- low body temp
- sensitivity to cold
- dry skin/hair
- muscle weakness
- weight gain
how do they threat hypothyroidism?
oral thyroid hormone
endemic goiter (2)
what is it, and what is it due to?
pathological enlargement of the thyroid gland due to dietary iodine deficiency
- accumulation of colloid causes visible swelling in the neck
hyperthyroidism
excessive TH secretion
graves disease
autoimmune disorder; some of your body’s antibodies mimic the function of TSH, and the thyroid gland responds to the antibodies by secreting more TH
parathyroid glands
four small, ovoid glands partially embedded in the posterior surface of the thyroid gland
what do the parathyroid cells secrete?
parathyroid hormone (PTH)
what does PTH do?
increases blood calcium levels if blood levels are too low (antagonist to calcitonin)
functions of PTH: (3)
- promotes synthesis of calcitriol by the kidneys to enhance calcium and phosphate absorption in digestive system
- decreases urinary excretion of calcium through urinary systems
- increases bone resorption by by osteoclasts and inhibits osteoblasts
what do inadequate levels of PTH cause?
weak and flexible bones
adrenal (suprarenal) glands
sit on superior surface of each kidney; consists of medulla and cortex
adrenal medulla
what is the secretion controlled by?
inner core; hormone secretion is controlled by the sympathetic division of the autonomic nervous system
adrenal cortex
what is secretion controlled by?
thicker outer portion; hormone secretion is controlled by ATCH release from the anterior pituitar
adrenal medulla compostition
consists of modified POSTganglionic neurons called chromaffin cells
what is the adrenal medulla innervated by?
sympathetic PREganglionic fibers
what is the dual nature of the adrenal medulla?
acting as an endocrine gland and a ganglion of the sympathetic nervous system
when the adrenal medullae are stimulated they release what?
catecholamines like epinephrine and norepinephrine
catecholamines have what effects on the body? (3)
mobilize high-energy fuels, lactate, fatty acids, and glucose
increases blood pressure, heart rate, blood flow to muscles, pulmonary airflow, and metabolic rate
decreases digestion and urine production
epinephrine has what kind of effect?
glucose-sparing effect
glucose-sparing effect
muscles use fatty acids, saving glucose for brain neurons
glycogenolysis
breakdown of glucose
gluconeogenesis
conversion of fats, amino acids, and other carbs to glucose
adrenal cortex
what is it and what does it secrete?
surrounds medulla and secretes several corticosteroid or corticoids
mineralocorticoids
regulate electrolyte balance
what is an example of a mineralocorticoid?
aldosterone
what types of corticosteroid does the adrenal cortex secrete? (2)
mineralocorticoids and glucocorticoids
glucocorticoids (2)
what do they regulate?
regulate fuel metabolism and androgens
examples of glucocorticoids (2)
cortisol/hydrocortisone and corticosterone
aldosterone
what does it do?
increases taste bud sensitivity to sodium
what is aldosterone released in response to?
falling blood pressure
what is the most significant mineralocorticoid?
aldosterone
falling blood pressure causes the release of _____ from the kidneys, which stimulates _____ release from the adrenal cortex
angiotensin II, aldosterone
what does aldosterone cause the kidneys to do?
retain sodium in exchange for a loss in potassium, reabsorbing water along with the sodium
aldosteronism
what is it and what does it cause?
excess aldosterone released causing increase in body weight due to water retention and low blood K+
what is the most potent glucocorticoid?
cortisol
some circulating cortisol is converted to _____ by the liver
cortisone
what is cortisol secreted in response to what other hormones? (2)
A.C.
adrenocorticotropic hormone release from the anterior pituitary and corticotropin-releasing hormone from the hypothalamus
what does cortisol do? (3)
does not relate to Na or water
stimulates fat and protein catabolism, gluconeogenesis, and the release of fatty acids/glucose into the blood
what does the effects of cortisol help the body do?
adapt to stress and repair damaged tissues
cortisol has a _____ effect
anti-inflammatory
what does excessive secretion/medical use of cortisol do?
suppresses the immune system; do not use on open wounds
Addison’s disease (2)
hyposecretion of glucocorticoids and aldosterones
symptoms and signs of Addison’s disease (4)
t.l.l.h.
- tiredness
- loss of appetite
- low blood Na+
- high blood K+
Cushing syndrome
excess cortisol secretion
causes of Cushing syndrome (3)
A.A.A.
adrenocorticotropic hormone hypersecretion by pituitary, ACTH- secreting hormones, and hyperactivity of adrenal cortex
signs and symptoms of Cushing syndrome (6)
- hyperglycemia
- hypertension
- weakness
- edema
- rapid muscle/bone loss due to protein catabolism
- abnormal fat deposition (moon face/buffalo hump)
androgens
primary adrenal sex steroids, but also produce small amounts of estrogen
what are androgens secreted in response to?
A
ACTH secretion from the anterior pituitary
dehydroepiandrosterone (DHEA)
major androgen, converted to a more potent form (testosterone or dihydrotestosterone) in target tissues
what is DHEA responsible for? (3)
at puberty, it stimulates public/axillary hair growth, gland development, and libido
hypersecretion of androgens causes? (2)
virilization and amenorrhea (in females)
virilization
excessive hair growth
amenorrhea
loss of menstration
estradiol (2)
major adrenal estrogen; significant source of estrogen in females after menopause
pancreas
primarily and exocrine digestive gland (99% of function), but also contains scattered endocrine cell clusters called pancreatic islets
pancreatic islets/islets of Langerhans
scattered endocrine cell clusters within the pancreas
pancreatic hormones are very important in regulating _____
glycemia - blood glucose concentration
what hormones do pancreatic islets release? (3)
glucagon, insulin, and amylin
pancreas: alpha (a) cells (2)
aka glucagon cells
secrete glucagon between meals when blood glucose concentrations fall
what does glucagon stimulate in the liver? (3)
gluconeogenesis, glycogenolysis, and the release of glucose into circulation raising blood glucose levels
what does glucagon do in adipose tissue? (2)
stimulates fat catabolism and release of free fatty acids
what is glucagon also released in response to?
rising amino acid levels in the blood to promote their absorption, providing cells with raw material for gluconeogenesis
beta (B) cells
aka insulin cells
secrete insulin and amylin during and after a meal when glucose and amino acids blood levels are rising
insulin stimulates cells to do what?
absorb glucose and amino acids and store/metabolize them, lowering blood glucose levels
insulin promotes the synthesis of what? (3)
glycogen, fat, and protein
what does insulin suppress?
the use of already stored fuels in cells
what organs do not need insulin to absorb glucose? (4)
- brain
- liver
- kidneys
- RBCs
what is the cause of diabetes mellitus?
insulin insufficiency or inaction
what does amylin do? (5)
reduced glucose spikes by slowing the emptying of the stomach, modulating gastric secretions, inhibiting glucagon secretion and signalling satiety
diabetes mellitus (DM)
disruption of carbohydrate, fat, and protein metabolism due to hyposecretion or inaction of insulin
classic signs and symptoms of diabetes mellitus (6)
polyuria, polydipsia, polyphagia, hyperglycemia, glycosuria, and ketonuria
polyuria
excess urine output
polydipsia
intense thirst
polyphagia
hunger
hyperglycemia
elevated blood glucose
glycosuria
glucose in urine
ketonuria
ketones in urine
how do the signs and symptoms of diabetes mellitus interplay? (copy and pasted a paragraph)
Polyuria with thirst and dehydration occurs because glucose is filtered out of blood at the kidneys and not completely reabsorbed back into blood – too much glucose in blood for it to be reabsorbed back into blood during the filtration process at the kidneys. Water is lost via osmosis as it is “pulled” by the filtered glucose, resulting in high volume urine containing glucose
type 1 diabetes mellitus
insulin level is very low, no longer regulates glycemia and hyperglycemia results
hyperglycemia
abnormally high blood glucose levels
when does type 1 diabetes usually develop?
childhood
what does type 1 diabetes do to the body?
the individual generates immune cells that destroy pancreatic beta cells and thus destroying insulin production
T/F: type 1 diabetes is caused by diet issues
false, it is hereditary
signs and symptoms of type 1 diabetes mellitus (2)
glycosuria, and polyuria
glucose in the urine, and lots of urine
treatments for type 1 diabetes (3)
insulin injections, insulin pump, and dry insulin inhaler
what is also important for people with type 1 diabetes mellitus?
monitoring blood glucose levels and having a controlled diet
type 2 diabetes mellitus
problem is insulin resistance - unresponsiveness of target cells to insulin, but insulin production is normal
risk factors of type 2 diabetes mellitus (4)
heredity, age (40+), obesity, ethnicity (Native, Latin, or Asian descent)
what is type 2 diabetes treated with?
weight-loss program and exercise
why is type 2 diabetes treated with weight-loss and exercise? (3)
- loss of muscle mass causes difficulty with regulation of glycemia
- adipose signals interfere with glucose uptake into most cells
- if needed, also use glycemia-lowering medications (metformin)
pathogenesis of type 1 diabetes
calls can’t absorb glucose and must rely on fat and proteins for energy needs, thus weight loss, weakness, and an increase of free fatty acids/ketones in blood
ketonuria
ketones in urine
what negative effects does ketonuria promote? (4)
o.l.i.n.
- osmotic diuresis
- loss of Na+ and K+
- irregular heartbeat
- neurological issues
ketoacidosis
occurs as ketones decrease blood pH; deep gasping breathing and diabetic coma are terminal result
Kussmaul respiratoin
deep, gasping breathing
chronic diabetes pathology leads to… (3)
- neuropathy and cardiovascular damage
- arterial damage in retina and kidneys (type 1)
- atherosclerosis leads to heart failure (type 2)
diabetic nephropathy
kidney damage that can lead to kidney failed from diabetes
diabetic neuropathy (4)
what can it lead to?
nerve damage from impoverished flood flow can lead to erectile dysfunction, incontinence, poor wound healing, and loss of sensation from areas
diabetic retinopathy
retina damage as capillaries grow and leak out blood (hemorrhage) at the retina, may lead to partial or complete blindness
early myocardial infarction
heart attacks; degenerative blockages in cardiac circulation can lead to early heart attacks
peripheral tissue damage
blood flow to the distal portions of the limbs is reduced, and peripheral tissues can develop ulceration, infection, tissue death, loss of toes/feet
gonads
(ovaries and testes) have both endocrine and exocrine functions
exocrine product of gonads
eggs and sperm
endocrine product of gonads
gonadal hormones- mostly steroid
ovarian hormones (3)
E.P.I
estradiol, progesterone, and inhibin
testicular hormones (4)
testosterone, weaker androgens, estrogen, and inhibin
keratinocytes convert a cholesterol-like steroid into _____ using UV from the sun
cholecalciferol
the liver
what is it involved in?
involved in the production of at least five hormones
what does the liver convert?
cholecalciferol into calcidiol
what does the liver secrete? (4)
A.E.I.H.
angiotensinogen, erythropoietin, insulin-like growth factor 1, and hepcidin
angiotensinogen
a prohormone, and a precursor of angiotensin II a regulator of blood pressure
erythropoietin
stimulates bone marrow
insulin-like growth factor I
controls action of growth hormone
hepcidin
promotes what?
i
promotes intestinal absorption of iron
kidneys
what do they play a role in?
play a role in production of three hormones
what does the kidney convert?
C–> C
calcidiol (from the liver) to calcitriol (vitamin D3)
what does calcitriol do? (2)
c
increased calcium absorption by intestines and inhibits calcium loss in urine
what does the kidney secrete?
renin
what does renin do?
converts angiotensinogen to angiotensin 1
angiotensin-converting enzyme
converts angiotensin 1 to angiotensin 2
where is angiotensin-converting enzyme found?
in the lungs
what does angiotensin 2 do?(4)
- constricts blood vessels
- stimulates the release of aldosterone from the adrenal cortex
- stimulates antidiuretic hormone from the posterior pituitary
- leading to water reabsorption in the kidneys increasing blood pressure
what is the main source of erythropoietin?
the kidney
what does the heart’s atrial muscle secrete?
atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) in response to increasing blood pressure
what do ANP and BNP do?
decrease what?
decrease blood volume and pressure by decreasing sodium and water output by the kidneys and opposes the action of angiotensin II
the stomach and small intestine secrete at least 10 _____ _____ secreted by enteroendocrine cells
enteric hormones
what do enteric hormones do?
coordinate digestive motility and glandular secretion, some are gut-brain peptides
enteric hormones (4)
C.G.G.P.
cholecystokinin, gastrin, ghrelin, and peptide YY
what does adipose tissue secrete?
leptin
when does adipose tissue secrete leptin?
as tissue absorbs glucose and lipis
what does leptin do?
acts as a negative feedback mechanism to reduce appetite
synergistic effects
multiple hormones act together for greater effect
example of a synergistic effects
follicle stimulating hormone and testosterone on sperm production
permissive effects
one hormone enhances the target organ’s response to a second, later hormone
example of permissive effects
estrogen prepares uterus for action of progesterone
antagonistic effects
one hormone opposes the action of another
example of antagonistic effects
insulin lowers blood fgucose while glucogon raises it
integrative effects
hormones produce different but complementary effects
example of integrative effects
calcitriol and parathyroid hormone both increase blood calcium levels
stress
situation that upsets homeostasis and threatens one’s physical or emotional well-being
stressors include (8)
injury, surgery, infection, intense exercise, pain, grief, depression, anger
how does the body respond to stress?
stress response - general adaptation syndrome (GAS)
three stages of the stress response
- alarm reaction
- stage of resistance
- stage of exhaustion
what does the stress response typically include?
elevated levels of what hormones?
elevated levels of epinephrine and glucocorticoids (especially cortisol)
alarm reaction (2)
initial response to stress, releases norepinephrine and epinephrine from the sympathetic nervous system via the adrenal medulla
what does the alarm response prepare the body for?
fight or flight
what is the dominant hormone in the alarm reaction of the stress response?
epinephrine
hormones of the alarm reaction (2)
norepinephrine and epinephrine
what hormones increase during the alarm reaction? (2)
what do they promote?
aldosterone and angiotensin to help raise blood pressure, and promote sodium and water conservation
stage of resistance
providing alternative fuels for metabolism
what is the dominant hormone in the stage of resistance?
cortisol
stage of resistance: what happens after a few hours or the stressor not being resolved?
glycogen reserves are gone and dietary intake cannot maintain pace with the body’s demand
stage of resistance: the hypothalamus and pituitary secrete…
C.A.
hypothalamus: corticotropin-releasing hormone (CRH)
pituitary: adrenocorticotropic hormone (ACTH)
cortisol has a _____-_____ effect
glucose-sparing
what is a glucose-sparing effect?
inhibits protein synthesis leaving free amino acids for gluconeogenesis to produce glucose for neural tissue
what adverse effects come from the glucose-sparing effect? (3)
- depresses immune function
- increases susceptibility to infection and ulcers
- lymphoid tissues atrophy, antibody levels drop, and wounds heal poorly
stage of exhaustion
stress overwhelms homeostasis, may lead to rapid decline and death
stage of exhaustion: what happens when stress continues for several months?
fat reserves are gone and the body cannot maintain homeostasis, protein breakdown and muscle wasting occurs
stage of exhaustion: why does loss of glucose homeostasis occur?
_____ stops producing _____
the adrenal cortex stops producing glucocorticoids
stage of exhaustion: aldosterone
what does it promote?
promotes water retention and hypertension by conserving Na+, hastening elimination of K+ and H+
stage of exhaustion: hypokalemia and alkalosis
los potassium and high pH
death occurs from what after the stage of exhaustion? (4)
hypokalemia, alkalosis, heart/kidney failure, and/or overwhelming infection
