Endocrine system & Diabetes Flashcards
Which two systems regulate the function of the body?
nervous system and endocrine system
Nervous system
chemical and electrical communication; neurotransmitters
Endocrine system
chemical communication; hormones
Hormone
a chemical substance that is secreted into the internal body fluids by one cell or group of cells and has a physiological effect on other cells of the body
Local hormones
paracrine; exocrine glands
utilize ducts
local effects
Amylase
break down starch into glucose
Proteases
break down protein into amino acids
Lipases
Break down fats/triglycerides into glycerol and fatty acids
Amino acids and glycerol help to form?
glucose
Fatty acids can make ATP through
Beta oxidation reactions
RNAses
break down RNA into nucleotides
DNAses
break down DNA into nucleotides
General Hormones
endocrine glands; released into the blood, general broad effects
Steroid hormones
made from cholesterol
includes estrogen, progesterone, testosterone, cortisol, and aldosterone
What should you do to prevent hormone exposure?
wear gloves, masks and lab coats
Hormone Derivatives of Tyrosine
epinephrine, norepinephrine, triiodothyronine, and thyroxine
Protein hormones
FSH, LH, TSH, ACTH, Prolactin and GH
Peptide hormones
ADH and oxytocin
Polypeptide hormones
insulin, glucagon, parahormone, parathyroid hormone
Protein and peptide hormones administration, half life, and susceptibility
admin- injection
half-life- short
susceptibility- antigenic attack resulting in inactivation
Peptide hormones stored as?
preprohormones
Where are hormones activated?
Golgi apparatus
Physiological effects of hormones occurs at ?
1 pg to 1 ng per deciliter of blood
Why are proteins important for steroid hormones in the blood?
keeps hormones from accumulating in fat tissues
increases the half-life
When a hormone is bound to a blood protein it is? When it is unbound?
bound- inactive
unbound- active
Membrane Hormone Receptors
GPCRs
hydrophilic
Cytoplasmic and Nuclear hormone receptors
steroid based hormones
cholesterol based
lipophilic
Why do hydrophilic hormones usually have their receptors bound to the plasma membrane?
can’t cross lipid bilayer
need helper proteins or enzymes
Why are hydrophobic hormone receptors located in the cytoplasm and nucleus?
lipophilic
can easily transverse plasma and nuclear membranes
What does CREB stand for?
Cyclic AMP response element binding protein
Cyclic-AMP dependent pathway
- Hormone-receptor binding activates a Gprotein (Gi or Gs)
- G protein activates adenylyl cyclase
- adenylyl cyclase produces cAMP
- cAMP activates protein kinases
- protein kinases phosphoryate enzymes. This activates some enzymes and deactivates others
- Activated enzymes catalyze metabolic reactions with a wide range of possible effects on the cell
Common hormones of Cyclic-AMP dependent Pathway
ACTH
FSH
LH
PTH
TSH
Glucagon
Calcitonin
Catecholamines
Phosphoinositide Hydrolysis Pathway
- Hydrophilic hormone binds to Gq receptor
- Activated Gprotein binds to PLC, which splits PIP2 into IP3 and DAG
- DAG stimulates PKC which stimulates cell growth
- IP3 binds to Calcium channels and opens them, increasing intracellular concentration
Common Hormones in the Phosphoinositide Hydrolysis Pathway
ADH
TRH
OT
LHRH
Catecholamines
Why do hormone receptors decrease when hormone exposure is chronic?
protective mechanism against too much stimulation
tolerance
If tolerance occurs what might you have to do?
increase the dose
change to a different drug class
Agonist
activate receptors
causes receptors to down-regulate over time
Antagonists
block receptors
will cause receptors to up-regulate overtime
What are some ways to prevent undesired effects from agonists?
lower drug dose
minimize length of drug therapy
switch drug therapy
What are some ways to prevent undesired effects from antagonists?
use as needed
use minimum amount
switch drug classes
Hormone clearance
taken up and degraded by liver and kidneys, then excreted in bile or urine
Metabolic clearance rate (MCR)
rate of hormone removal
can be affected by disease, other drugs, and age
How would MCR change in the elderly? What would you have to do to the dose?
lower liver and renal function
increased half life of drugs
may have to lower the dose
Pituitary Gland
called the hypophysis, 1 cm, 0.5-1g
What does the the anterior pituitary gland secrete?
- growth hormone
- adrenocorticotropin hormone
- thyroid-stimulating hormone
- prolactin
- follicle-stimulating hormone
- luteinizing hormone
What does the posterior pituitary gland secrete?
antidiuretic hormone
oxytocin
Somatotrope
cell type in anterior pituitary gland
growth hormone, stain with acid dyes, acidophilus tumors
Corticotropes
cell type in anterior pituitary gland
secretes adrenocorticotropin hormone
Thyrotropes
cell type in anterior pituitary gland
secretes thyroid stimulating hormone
Gonadotropes
cell type in the anterior pituitary gland
secretes lutenizing hormone and follicle-stimulating hormone
Lactotropes
cell type in anterior pituitary gland
secretes prolactin
cells that secrete posterior pituitary hormones
not located in the posterior pituitary
large neurons located in the hypothalamus
Secretion by the pituitary gland is controlled by ?
- hormones: hypothalamic releasing/inhibitory factors— anterior
- nerve signals — posterior
Oxytocin causes smooth muscle to?
contract
Antidiuretic hormone
water retention, increased BP
Which electrolytes does the hypothalamus collect?
sodium, potassium, and hydrogen
Which nutrients does the hypothalamus collect?
glucose, oxygen, and carbon dioxide
In feedback inhibition, what do the hormones from the peripheral endocrine gland turn off?
the hypothalamus and anterior pituitary gland
Thyrotropic releasing hormone
triggered by low body temp
stimulates pituitary gland to release TSH
targets thyroid gland
grows the thyroid, secretes thyroid hormone, and has metabolic effects
Corticotropic releasing hormone
triggered by stress
stimulates pituitary gland to release ACTH
targets adrenal gland
simulates adrenal hormones aldosterone, cortisol, and weak androgens
regulates glucose, fat, and protein metabolism
Growth hormone releasing hormone
triggered by growth, puberty, or tissue injury
stimulates pituitary gland to release GH
targets all cells
causes widespread tissue growth
Gonadotropin releasing hormone
triggered by puberty
stimulates pituitary gland to release FSH and LH
targets gonads
causes egg and sperm production, ovulation, pregnancy, testosterone secretion
Dopamine
inhibits pituitary gland from releasing prolactin which targets the breast causing milk synthesis, testes more sensitive to LH
Pregnancy inhibits? increases?
dopamine
prolactin
How much ATP does glucose make?
30-32
glycogenesis
increases glycogen in the body
drops blood glucose levels
glycogenolysis
decreases glycogen
increases blood glucose levels
Fat source of energy
triglycerides
cholesterol
makes steroids and form plasma membranes
Phospholipids
form plasma membrane and create protective barriers
lipolysis
breakdown of triglycerides
increase in glycerol, fatty acids, and ATP
lipogenesis
formation of triglycerides
reduces glycerol and fatty acids
Proteolysis
breakdown of protein
amino acids
growth hormone functions
tissue growth and cellular proliferation
makes intermediates such as somatomedins or insulin-like growth factors
make ATP for IGF-1
IGF-1 hormone
increases bone length
stimulates osteoblasts
induces protein synthesis
Mechanisms for increased rate of protein synthesis
- increase transcription
- increase translation
- increase amino acid uptake into the cell
- decrease proteolysis
Humatrope, Norditropin, Neurotropin and Genotropin are all used in ?
children’s hormone replacement therapy
What does growth hormone not use as an energy source?
proteins and carbohydrates
If too much growth hormone is being made what could happen?
increase risk of cancer, atherosclerosis, and hyperglycemia
Is growth hormone tightly or loosely bond to blood proteins?
loosely
Factors for Growth Hormone secretion
starvation
hypoglycemia
exercise
excitement
trauma
sleep
What regulates growth hormone secretion?
GHRH and somatostatin
Decreased levels of growth hormone secretion can lead to ?
dwarfism
tumors causing hyposecretion of GH
thrombosis of the pituitary blood vessels
aging
Abnormal growth hormone secretion symptoms
hypothyroidism
decreased glucocorticoids
decreased gonadotropins
increased levels of growth hormone can lead to ?
giantism
acromegaly
cancer
The supraoptic nucleus secretes?
ADH
The paraventricular nucleus secretes?
oxytocin
Antidiuretic hormone (vasopressin)
used for water retention and to increase blood pressure
When blood becomes too concentrated what do ADH levels do?
increase
Stretch receptors
sense changes in blood pressure and volume
in heart and arteries
Functions of oxytocin
causes contraction of the uterus
involved in milk ejection
Where is the thyroid gland?
immediately below the larynx and anterior to the trachea
butterfly shape
what does the thyroid gland secrete ?
Triiodothyronine
Thyroxine
Calcitonin
Major constituent of the colloid?
thyroglobulin
How much iodine does someone need to ingest to have normal formation of thyroxine?
150 micrograms
isotope 131 I
iodotrope therapeutic
mCi
destroys the gland
isotope 123 I
microCi
used for diagnostic purposes
T3 and T4 formation
- formation and secretion of thyroglobulin by the thyroid cells
- oxidation of the iodide ion by peroxidase
- iodination of tyrosine and formation of thyroid hormones
- coupling of organified thyroglobulin molecules to form T3 and T4
- storage of thyroglobulin
- release of T3 and T4
When T4 is bound to albumin, what kind of bond is it and is albumin active?
tight bond
not active
When T3 is bound to albumin, what kind of bond is it and is albumin active?
loose bond
active
Why is the release of thyroxine slow? How slow?
tight binding to plasma proteins
6 days
Why is triiodothyronine rapidly released? How fast?
not tightly bound to plasma proteins
1 day
T3 acting at the thyroid hormone causes what of genes containing thyroid response elements?
derepression
activates transcription of genes
increases the MLCK and LDL receptors
How do thyroid hormones impact the mitochondria?
increases rate of ATP formation
excess- increase
deficient- decrease
How do thyroid hormones impact Na/K ATPase?
increase neuronal activity
increase in the transport of Na and K through the cell membrane
How do thyroid hormones impact growth?
complements effects of growth hormone; increases bone metabolism/growth
How do thyroid hormones impact carbohydrate metabolism?
increases absorption from the GI tract and this glucose is converted into ATP by increases in both glycolysis and gluconeogenesis
too much could cause cardiomyopathies and hyperglycemia
How do thyroid hormones impact fat metabolism?
increases the mobilization of fats form tissues, therefore it increases plasma levels of free fatty acids
too much- atherosclerosis
too little- decrease in ATP and energy
How do thyroid hormones impact plasma and liver fats?
decrease in cholesterol, phospholipids, and triglycerides
increases plasma free fatty acids
How do thyroid hormones impact vitamin metabolism?
excess- vitamin deficiencies
deficient- vitamin excess
How do thyroid hormones impact basal metabolic rate?
increase- increase rate by 60-100% above normal
decrease- decrease rates to about 50%
Dose range of thyroid hormone?
25-300 mg
Does thyroid hormone have abuse potential?
yes
How do thyroid hormones impact body weight?
excess- decreases weight in most
deficiencies- increase weight
How do thyroid hormones impact cardiovasculature?
increase blood flow, heart rate, respiration
excess- positive chronotropic and inotropic response
deficient- negative chronotropic and inotropoic response
How do thyroid hormones impact gastrointestinal tract?
increases neuronal firing and this increases GI motility and promotes LDL secretion into the feces
How do thyroid hormones impact the central nervous system?
increases neuronal firing and this increases CNS functioning
excess- extreme nervousness, psychoneurotic tendencies, paranoia, anxiety disorders, extreme worry
deficient: depression; dulled thinking;; difficulty concentrating
How do thyroid hormones impact the muscles?
increases neuronal firing and this increases neuronal action at the neuromuscular junction
How do thyroid hormones impact sleep?
regulates it
excess-cannot sleep so it results in constant fatigue
deficient- extreme somnolence/excessive sleepiness
How do thyroid hormones impact other endocrine glands?
excess- may increase rate of glucose metabolism, increase bone turnover, osteoporosis
Hyperthyroidism
autoimmune disease
makes thyroid stimulating immunoglobulin, an antibody that mimics the actions of TSH
Exopthalmos
extreme protrusion of the eyeballs
In Graves’ disease what do T4/T3 levels look like? TSH? TSI? Is there a goiter?
T4/T3- increase
TSH- decrease
(+) TSI
Goiter- yes
In Adenoma what does T4/T3 levels look like? TSH? TSI? Is there a goiter
T4/T3- increase
TSH- decrease
(-) TSI
Goiter- no
Hypothyroidism
deficiency in thyroid hormone; low T4, T3
Congenital Hypothyroidism
no thyroid gland at birth
symptoms include tongue swelling and yellowing and course skin
need replacement therapy within 6-8 weeks
Endemic Colloid Goiter
iodine deficiency related to where you live, life condition
Idiopathic Non-endemic goiter
hyposecreting tumor of the thyroid
unknown origin that’s not related to lifestyle
Hashimoto’s thyroiditis
autoimmune disease
antibody prevents T4, T3 formation and TSHr activation
How does PTH impact calcium absorption?
It increases its concentration in blood
How does Vit. D impact calcium absorption?
it increases calcium concentration in blood
leads to effects in GI tract
How does calcitonin impact calcium absorption?
decreases calcium concentration in blood
What percentage of calcium is lost in feces?
90%
What is the normal calcium concentration in plasma?
9-9.2 mg/dl
What are the 3 forms of calcium?
Ca^2+ (50% ionized state, active)
CaPO4 salts (inactive)
Hydroxyapatite (inactive)
How long of full body exposure to sunlight gives enough Vitamin D?
15 minutes
How does Vitamin D use the bone to impact Calcium absorption?
increases calcium absorption in blood through osteoblasts
How does Vitamin D use the kidneys to impact Calcium absorption?
increase calcium concentration in blood
How does Vitamin D use the GI tract to impact Calcium absorption?
increase calcium absorption by regulating transporters
Where does inhibition of PTH occur?
on the PTH gland once homeostasis is achieved
How long can Vit D3 be stored in the liver?
for months
Why is there such tight regulation over Vit. D3?
need to conserve it
some may not have access to foods rich in Vit. D3 or live in areas rich in sunlight
What does the increase in calcitriol do to calcium and phosphate levels and how does this occur?
increases calcium absorption by 40-60%
upregulation of calcium-phosphate cotransporters
When calcium falls below 9mg/dl what increases?
calcitriol
Hypocalcemia
excessive muscle contraction
impacts sodium and calcium counter transporter
low driving force leads to sodium buildup inside the cell
Hypercalcemia
depressed motor activity
huge driving force causes sodium decrease in cell resulting in a decrease in neuronal activity
High calcium binds with phosphate to form salts that can ppt into which 3 places?
joints causing pain
aveoli causing respiratory issues
kidneys causing renal failure
organic matrix of bone
95% collagen
5% gelatinous ground substance
secreted by osteoblasts and contribute to tensile strength
bone salts
calcium and phosphate
hydroxyapatite
Mechanism of bone calcification
- osteoblasts secrete collagen
- collagen polymerizes and makes osteoids
- osteoblasts get trapped in collagen and become osteocytes
- calcium salt ppt into bone
- salts are converted to hydroxyapatite
Osteoclasts
break down bone
osteoblasts
form bone
Why does bone remodel?
adjust to lifestyle/environment
Rate of bone deposition and fracture repair is enhanced by?
bone stress
push, pull, and hold exercises are beneficial
Blood alkaline phosphatase levels indicate?
rate of bone deposition/ extent of healing
The thyroid gland secretes what to decrease blood calcium concentration?
calcitonin
PTH activates osteoclasts. What happens in the rapid phase?
calcium increases in blood
secretion of calcium decreases in kidney
phosphate concentration in blood decreases
PTH activates osteoclasts. What happens in the slow phase?
new osteoclasts are formed
When calcium levels increase do the levels of PTH change?
no
calcitonin
decreases calcium concentration in blood
(-) osteoclasts, decrease bone resorption
treats osteoporosis
As calcium levels increase what does calcitonin do?
increase
Hypoparathyrodism
decr PTH
symptoms: tetany, spasm of diaphragm, breathing difficulties
Hyperparathyroidism
increase PTH, increase calcium
symptoms: bone pain, hypercalcemia, decrease in neuronal firing, decrease in CNS function, breathing and muscle function
Rickets
in kids, Vit. D. and calcium deficiency
increase bone breakdown
Symptoms: tetany, respiratory depression, bowed legs, weak bones
Treatment: Vit. D; sun, Calcium PO
Osteoporosis
brittle bones; usually occurs in the elderly
can lead to pulmonary hypertension and increased thoracic pressure
Causes of Osteoporosis
lack of physical stress
inactive lifestyle
malnutrition
menopause
aging
cushing’s disease
hyperthyroidism
lifestyle
What does the adrenal medulla secrete?
epinephrine
What layer of the adrenal cortex secretes aldosterone?
zona glomerulosa
Which layers of the adrenal cortex secrete cortisol and androgens?
zona fasciculata
zona reticularis
Adrenocortical horomones are steroid compounds made from?
cholesterol
What are the precursors of androgens, cortisol and aldosterone?
cholesterol
pregnenolone
progesterone
Aldosterone Functions
maintain electrolyte and water balance
half life: 30 min
increases sodium absorption, potassium and hydrogen secretion into kidneys and small intestine
increase blood volume, blood pressure, blood pH and impacts neuronal function
What can excess aldosterone cause?
hypokalemia
muscle weakness
alkalosis
What can too little aldosterone cause?
hyperkalemia
cardiac toxicity
acidosis
When renal failure leads to hyperkalemia what follows?
CRH->ACTH->Aldosterone
increase potassium secretion into nephron
reduce potassium
When hypotension leads to increased activity of renin what follows?
CRH-> ACTH -> Aldosterone
increased sodium, water, and blood pressure
When renal failure leads to hyponatremia what follows?
increase CRH -> ACTH ->aldosterone
increased sodium
When a hyposecreting tumor develops in the anterior pituitary gland what follows?
increased ACTH
increased cortisol, aldosterone, weak androgens
hyperglycemia, hypertension, vivilization of body
What are the functions of glucocorticoids?
regulate inflammation and glucose concentration
Proteolysis and lipolysis stimulates?
gluconeogenesis
Excess cortisol and its impact on carbohydrate metabolism results in?
hyperglycemia -> insulin release -> insulin receptors desensitize -> T2D
Deficient cortisol and its impact on carbohydrate metabolism results in?
hypoglycemia -> fatigue/ lethargy
Excess cortisol and its impact on protein metabolism results in?
increase in proteolysis -> muscle deterioration -> lethargy/ mvmt issues/ congestive heart failure
Excess cortisol and its impact on fat metabolism results in?
increase fatty acids -> metabolization -> atherosclerosis, steatosis, accumulate in face, upper chest and back
Functions of cortisol in stress and inflammation
trauma
infection
intense heat/cold
sympathomimetic drugs
surgery
necrotizing substances
restraining
debilitating disease
5 steps to inflammation
- release of chemicals from damaged cells
- increased blood flow to damage area
- leakage of plasma out of capillaries into tissue
- infiltration of damaged area by leukocytes
- ingrowth of fibrous tissue = healing
Cortisol effects on transplantation surgeries
prevent rejection through immunosuppression
How does cortisol impact blood cells?
(+) RBC
(-) WBC
How does cortisol impact immunity in infectious diseases?
low/ susceptible to illness/ infection
Adrenal glands can secrete
weak androgens
dehydroepiandrosterone
adrostenedione
stimulate estrogen production
Hypoadrenalism (Addison’s disease)
vortices of adrenal glands fail to produce aldosterone and glucocorticoids
most likely due to an autoimmune disease
Mineralocorticoid deficiency
aldosterone
hypertension, hyperkalemia, high blood H+
Glucocorticoid deficiency
cortisol
hypoglycemia -> fatigue
Describe melanin pigmentation process
- autoimmune disorder attack decreases cortisol and aldosterone
- CRH increases
- ACTH increase
- MSH increases
Melanin Pigmentation Treatment
Replacement therapy
cortisol/glucorticoid and aldosterone/ mineralocorticoid
Addisonian Crisis
surgery -> trauma/ stressors to body -> their dose may have to increase by 10-25x their normal dose; to prevent cardiovascular collapse
Hyperadrenalism
cushing’s diseases
tumor of the adrenal glands causing excessive amounts of the hormones to be produced
rounding of face; puffiness to upper chest
Primary Aldosteronism
hypersecreting tumor of the zona glomerulosa
increase aldosterone, sodium
decreased potassium and H^+
Adreongenital system
increase in androgens and estrogen
acini
part of the pancreas that secretes digestive juices
Trypsinogen, chymotrypsinogen, and procarboxypeptidase
in pancreas; digests proteins
What would happen if you had an inflammation of the pancreas?
prevents enzyme release; need supplements
Islets of Langerhan (alpha)
pancreatic cells that secrete glucagon
increase [glucose] in blood
Islets of Langerhan (Beta)
secrete insulin and amylin
decrease [glucose] in blood
Islets of Langerhan (Delta)
secrete somatostatin
inhibits glucagon and insulin release, and inhibits intestinal motility
C peptide levels are proportional to
active insulin levels
Pro-insulin
inactive form of insulin
What are 3 main process that decrease [glucose] in blood?
protein synthesis
lipogenesis
glycogenesis
Does insulin increase or decrease blood glucose levels?
decrease
Insulin brings glucose into the cell to be converted to ?
ATP or triglycerides
Insulin stores energy in the forms of?
glycogen
triglycerides
proteins
phosphorylase B kinase
enzyme in glycogenolysis
makes glucose
inhibited by insulin
glycogen synthase
enzyme involved in glycogenesis
makes glycogen
stimulated by insulin
Diabetes Mellitus 1
lack of insulin
fat can’t be stored so it undergoes extensive metabolism
Increases in fatty acids result in the formation of?
keto acids and acetoacetic acid
Consequences of Increased Fatty Acids
cause blood pH to decrease
increase risk of acid optic coma
increase risk of atherosclerosis
Protein synthesis increases the presence of?
insulin
Mechanisms by which insulin increases protein synthesis
increase gene transcription DNA -> mRNA
increase protein translation mRNA -> protein
increased amino acid transport into the cell
decreased proteolysis
decreased amino acid availability for gluconeogenesis
In diabetes mellitus one, an increase in protein metabolism occurs which causes>
skeletal muscle breakdown -> movement impairment/lethargy/ fatigue
cardiac muscle breakdown -> cardiac arrest
How fast is the release of glucose from the liver between meals?
slow
Rapid insulin release
occurs within 5 minutes due to the release of preformed insulin
Delayed insulin release
occurs 15 min to 3 hours due to the synthesis of new insulin
Why does an increase in digestion trigger an insulin release?
anticipating a rise in glucose
Why do the hormones glucagon, GH, cortisol, progesterone, estrogen and epinephrine also trigger insulin release?
all increase [glucose] in blood
With high glucose levels insulin x, lipolysis y, and lipogenesis z.
x- increase
y- decrease
z- increase
Glucagon ffects on Glucose metabolism
increase [glucose] in blood
causes glycogen breakdown; makes phosphorylase B Kinase
How would hypoglycemia effect glucagon levels and [glucose] in blood?
increase
How would decreased levels of amino acids impact glucagon levels, [amino acid] in blood, and [glucose]
increase
Exercise induces what type of glycemic?
hypoglycemia
Somatostatin
hormone release from hypothalamus; decreases GH secretion from anterior pituitary gland
released from delta cells
inhibits insulin release
regulates absorption of nutrients to prevent glucose spikes
Importance of blood glucose regulation
only nutrient used by brain, retina, and gonads
hyperglycemia could result in cellular/overall dehydration
diabetes mellitus
disease characterized by loss of insulin secretion/ loss of insulin receptor sensitivity
Type 1 diabetes mellitus
lack of insulin secretion from beta cells of the islets of langerhan
Type 2 diabetes mellitus
lack of insulin sensitivity in the tissues
What factors are involved in the development of diabetes
hereditary
autoimmune
obesity
pathological physiology of diabetes
decreased utilization of glucose
increased fat mobilization
protein depletion
cellular and overall dehydration
Polyuria
excessive urination
Polydipsia
extreme thirst
polyphasic
increased eating
Diagnosis of diabetes mellitus
urinary sugar
fasting blood glucose levels
glucose tolerance test
acetone breath
Hyperinsulinism
tumor in pancreas; over production of insulin
diagnose by increase in C peptide or low glucose levels
could lead to insulin shock/hypoglycemia
Hyperinsulinism Treatment
remove tumor
IV glucose
glucagon