Exam 4: Renal & Endocrine Flashcards
What do the kidneys do to blood?
Filters it
What is the primary nitrogenous waste?
Urea
Where does the N in urea come from?
The breakdown of proteins (Amino acids, DNA, RNA)
What is the term used for the measure of nitrogenous waste in blood?
Blood Urine Nitrogen (BUN)
What is a normal BUN?
7-18 md/dL
What does BUN help measure? (What organ’s functioning does it test?)
Kidney function
Where does creatinine come from?
The breakdown of creatine phosphate
What is creatine phosphate used for?
Transferring a phosphate to ADP to make ATP
What is a normal creatinine level in humans?
0.7-1.2 mg/dL
What enzyme carries out the reaction where creatine phosphate + ADP –> creatinine + ATP?
Creatine kinase
What % of blood is protein?
7%
What % of urine is protein?
0.03%
Should there be a lot or a little protein in urine?
There should be VERY LITTLE protein in urine
How many liters of fluid do the kidneys filter daily?
180L
What % of fluid that the kidneys filter gets reabsorbed?
99.3%
What hormone does the kidneys produce that regulates the production of blood cells?
Erythropoietin
What hormone does the kidneys produce that increases intestinal absorption of Ca++ and PO4-3?
Vitamin D3
What does the body do with the increased Ca++ and PO4-3 absorption brought by vitamin D3?
Build bones
What hormone is produced in the juxtaglomerular apparatus?
Renin
Renin is produced when BP and sodium levels are high or low?
Low
Renin is produced when potassium levels are high or low?
High
What does renin split? What does it turn into?
Renin splits angiotensinogen into angiotensin 1
What splits angiotensin 1 into angiotensin 2?
Angiotensin-converting enzyme (ACE)
What does angiotensin 2 do to blood vessels?
Vasoconstricts, thus raising BP
What hormones does angiotensin 2 trigger the release of?
Aldosterone and vasopressin/antidiuretic hormone (ADH)
What do aldosterone and vasopressin/ADH do? (Retention or release)
Causes the kidneys to retain sodium and water
Does the retention of sodium and water raise or lower BP and blood volume?
Increases blood volume and blood pressure
What is the process of eliminating nitrogenous wastes?
Excretion
What do the kidneys do to the pH of blood?
Buffers the blood (maintains a stable level)
What do the kidneys do for blood volume and fluid osmolarity?
Balance fluid levels and electrolytes
What are the kidneys involved in detoxifying?
Reactive Oxygen Species (ROS) and free radicals
Where are the bladder and kidneys located anatomically?
Retroperitoneal (outside/below the peritoneum)
What are the basic filtering units of the kidneys?
Nephron
How many nephrons per kidney?
1 million
What level of nephron filtration is like “windows” or “holes” in the glomerular capillaries?
Fenestrae
What level of filtration in the nephron repels proteins that are smaller than the opening of fenestrae and podocytes?
Basement membrane
What type of charge does the basement membrane in nephrons have?
Negative charge
What level of filtration in the nephron are cells with filtration slits that cover the glomerular capillaries?
Podocytes
What are the two types of nephrons?
Cortical
Juxtamedullary
Where are cortical nephrons?
Superficial in the cortex
Where are juxtamedullary nephrons?
Deep in the cortex
Which nephron’s loop of Henle goes deeper into the medulla?
Juxtamedullary goes deep into the medulla
Cortical does NOT
Which arteriole brings unfiltered (dirty) blood to the corpuscle?
Afferent arteriole
Which arteriole brings filtered (clean) blood back to the circulatory system?
Efferent arteriole
What is the outer shell of the renal corpuscle?
Bowman’s capsule
What tissue is the Bowman’s capsule made of?
Simple squamous epi
Where is filtrate collected in the renal corpuscle?
Bowman’s space
What fills capillaries in the renal corpuscle with fenestrae?
Glomerular capillaries (glomerulus)
What are the cells with filtration slits in the renal corpuscle that cover glomerular capillaries?
Podocytes
What in the nephron takes filtrate from the corpuscle to the loop of Henle?
Proximal convoluted tubule
Which limb of the loop of Henle is where WATER leaves?
Thick descending limb
What is the concentrating limb in the loop of Henle? Why?
The thick descending limb, as water is leaving
Which limb of the loop of Henle is where SALT leaves?
Thick ascending limb
What is the diluting limb in the loop of Henle? Why?
Thick ascending limb, as salt is leaving
What in the nephron sends the message to the juxtaglomerular apparatus to release renin?
Macula densa
Where is the macula densa located?
Distal convoluted tubule
What % of water reabsorption is in the proximal convoluted tubules?
65%
What % of water reabsorption is in the loop of Henle?
15%
What % of water reabsorption is in the distal convoluted tubules?
10%
What % of water reabsorption is in the collecting duct?
9.3%
What % of water is left to eliminate after the rest is reabsorbed?
0.7%
Where does water go from the collecting duct?
Papilla
Where does water go from the papilla?
Minor calyx
Where does water go from the minor calyx?
Major calyx
Where does water go from the major calyx?
Renal pelvis
Where does water go from the renal pelvis?
Ureter
Where does water go from the ureter?
Urinary bladder
Where does water go from the urinary bladder?
Urethra
What mOSM is isotonic in the cortex?
~300 mOsm (280-296 mOsm)
Where is the water reabsorbed so that it can find its way back to the blood?
Peritubular capillaries
What do Na+ and urea make the deep medulla compared to the cortex? (Hypo, hyper, isotonic)
Hypertonic
What is the medulla concentrated to in mOsm?
1200-1500 mOsm
What hormone makes the Na-K pump:
3 Na+ H2O goes back to blood
2 K+ excreted in urine
Aldosterone
Is this water retention or loss?
3 Na+ H2O goes back to blood
2 K+ excreted in urine
Water retention
What hormone makes the Na-K pump:
3 Na+ H2O excreted in urine
2 K+ back to blood
Atrial natriuretic peptide (ANP)
Is this water retention or loss?
3 Na+ H2O excreted in urine
2 K+ back to blood
Water loss
What hormone turns on genes that produce more water channel proteins?
Antidiuretic hormone (ADH)
What does producing more water channel proteins do? (Make you pee more or less?)
Make you pee LESS (ANTI-diuretic)
Does water passively or actively exit the urine to be returned to blood when more water channels are opened [thanks to ADH]? Why?
PASSIVE, because the medulla is so hypertonic
What does ADH do to urea?
Causes its reabsorption
Where do aldosterone, ANP, and ADH have their effects take place?
At the distal convoluted tubules and their collecting ducts
What is the last 0.7% of water that is filtered out regulated by?
Hormones
What hormone is associated with water retention?
Aldosterone
What hormone is associated with water loss?
Atrial natriuretic hormone (ANP)
What elemental levels can abnormal levels of aldosterone or ANP have clinical effects on?
K levels
What is an example effect from abnormal K levels caused by abnormal aldosterone/ANP?
Cardiac arrhythmias
Does ADH cause vasoconstriction or vasodilation?
Vasoconstriction
Where is ADH produced?
Hypothalamus
Where is ADH stored and released from?
Posterior pituitary gland (Neurohypophysis)
What is the primary hormone responsible for tonicity homeostasis and BP control?
ADH/vasopressin
What is the mOsm for hyperosmolarity?
> 280-296 mOsm
What states trigger ADH release to initiate water retention for dilution of conditions/bring it back to isotonicity?
Hyperosmolar states
What sort of diets/conditions would result in increased ADH secretion?
High salt diets and hypertension (high BP)
What does ADH do for arterial blood volume and pressure?
Increase effective arterial blood volume and increase blood pressure to maintain tissue perfusion
When BP drops or blood becomes hypertonic (hyperosmotic), what turns on protein synthesis to increase the # of water channels in the renal tubules to allow more water retention?
ADH
What hormone causes an increase in ADH release during times of a woman’s cycle? (This can be to the point of edema and BP rise)
Estrogen
What inhibits ADH when you drink?
Ethanol
What inhibits ADH in the sympathetic NS?
Epinephrine and norepinephrine
What kind of drug are epi and norepi?
Alpha-adrenergic agonists
What hormone released from the heart inhibits ADH?
Atrial natriuretic peptide (ANP)
What does GFR stand for?
Glomerular filtration rate
What does GFR measure?
Quantity of filtrate that passes through the glomerulus per unit time
What is a normal GFR? (in ml/min)
125 ml/min
What is a normal GFR? (in L/hour)
7.5 L/hour
What is a normal GFR? (in L/day)
180 L/day
What % of water is reabsorbed from the filtrate?
99.3%
What must the GFR be maintained at REGARDLESS of changes in overall BP?
125 ml/min
What would happen without the autoregulation mechanisms within the kidneys if there was a slight increase in renal BP?
A drastic increase in filtration
What would happen without the autoregulation mechanisms within the kidneys if there was a slight decrease in renal blood pressure (15%)?
Filtration would stop entirely
What is the glomerular (blood) hydrostatic pressure in mm Hg?
55 mmHg
What is the blood colloid osmotic pressure in mm Hg?
30 mmHg
What is the capsular hydrostatic pressure in mm Hg?
15 mmHg
What is the net filtration pressure in mm Hg?
10 mmHg
How do you calculate the net filtration pressure? (What values do you use)
Blood HP - (Blood CP + Bowman’s capsule HP)
55 - (30+15) = 10
Is hydrostatic pressure (HP) a pushing or pulling force?
Pushing
Is colloid pressure (CP) a pushing or pulling force?
Pulling
How much pressure pushes out the arteriole?
55 mmHg
How much pressure is pulled in the arteriole? (Total. Includes HP + CP)
45 mmHg
What goes with the 10mmHg pushing force out of the blood?
Urea, Na+, water
What forces increase GFR?
Plasma HP
Bowman capsule CP
What forces decrease GFR?
Plasma CP
Bowman capsule HP
What is another way of saying plasma/glomerular hydrostatic pressure?
BP in capillaries
What pressure is pushing out of blood?
Plasma/glomerular HP
What pressure is pulling back in the blood?
Plasma CP
What pressure is pushing back in towards the blood?
Bowman’s capsule HP
What pressure is pulling out of blood?
Bowman’s capsule CP
What is Bowman’s capsule CP in mmHg?
Near 0 mmHg
What is the filtering pressure of the kidneys? (in mmHg)
10 mmHg
Would this increase or decrease GFR?
Increase glomerular/plasma HP (AKA BP)
Increase
Would this increase or decrease GFR?
Decrease Bowman’s capsule HP
Increase
Would this increase or decrease GFR?
Increase plasma CP
Decrease
Would this increase or decrease GFR?
Decrease Bowman’s capsule CP
Decrease
How would liver failure affect GFR?
Decrease GFR
What mechanism within the loop of Henle creates a hypertonic medulla?
Counter current multiplier
What mechanism within the vasa recta helps maintain the hypertonic medulla?
Counter current exchanger
Does water go towards the hypertonic or hypotonic according to the rules of osmosis?
Water goes to the hypertonic (where there is more solute and less water)
What does the body change in order to maintain a steady filtration rate/GFR?
BP
What intrinsic controls (autoregulation) are used to regulate GFR?
Myogenic mechanism
Tubuloglomerular feedback mechanism
What does the myogenic mechanism do in response to an increase in BP?
An increase in BP stretches/dilates the afferent arteriole, so the muscles vasoconstrict to reduce filtration back to normal
What does the tubuloglomerular feedback mechanism do in response to an increase in BP?
The macula densa causes vasoconstriction of the afferent arteriole to reduce filtration
What does the tubuloglomerular feedback mechanism do in response to a decrease in BP?
The macula densa causes vasodilation of the afferent arteriole to increase filtration
How does the body use neural control to regulate GFR?
When your body has a fight or flight response, BP increases
What hormone/NT causes vasoconstriction of the afferent arteriole to regulate filtration?
Epinephrine
What system in the kidneys helps regulate the GFR if blood pressure drops?
Renin-angiotensin system
Where in the kidneys/what structure is where the renin-angiotensin system works?
Juxtaglomerular apparatus, specifically, the macula densa
What are the tubules in the kidney that monitors blood pressure through urine flow?
Macula densa
Does the macula densa monitor blood pressure directly or indirectly?
Indirectly, as it bases blood pressure off of the urine output
In what two situations might the macula densa activate means to control BP?
Increased flow or increased urine concentration signals the macula densa to get to work and do the opposite (decrease flow and decrease concentration)
What does the juxtaglomerular apparatus signal the release of?
Renin
Where is renin released from?
Granular cells in the afferent arteriole
Where does renin turn angiotensinogen into angiotensin 1?
The liver
What type of substance is renin?
An enzyme
Where does ACE turn angiotensin 1 into angiotensin 2?
The lungs
Does angiotensin 2 cause vasoconstriction or vasodilation? How does this affect BP?
Vasoconstriction, increases BP
What hormone is released by angiotensin 2?
Aldosterone
Where is aldosterone released from?
The adrenal cortex
What is the adrenal cortex?
The outer part of the kidney
What type of hormone is aldosterone?
A steroid
Where does aldosterone go after it is released from the adrenal cortex?
Into the kidney
What does aldosterone do in the kidney?
Turns on the Na-K pump
What goes on in the renal Na-K pump? Out/In from where specifically?
3 Na OUT of urine, into blood
2 K INto urine, out of blood
What follows Na to increase BP?
Water
What blocks ACE to lower BP?
ACE inhibitors
What is water loss that you’re generally unaware of?
Insensible water loss
What is water loss you are aware of?
Sensible water loss
Where does insensible water loss happen?
Exhaled from lungs
Perspiration from the skin (NOT sweating from exercise…casual sweat)
Excreted in feces
Where does sensible water loss happen?
Urine
Sweating from exercise
How much urine is excreted daily (in mL)?
1000-1500 mL/day
What is retained thanks to estrogen and what is released? (Think what might cause menstrual-related edema)
NaCl is retained
ADH is released
What drug causes Na resorption/retention resulting in water retention?
Prednisone
What sort of drug is prednisone?
A steroidal anti-inflammatory drug
What is it called when increased BP forces more fluid out of the glomerulus?
Pressure diuresis
What can cause water loss through pressure diuresis?
Hypertension (high BP) with loss of autoregulatory mechanisms
How might tissue damage result in edema?
Tissue damage releases “solute” particles into the interstitium
When solute particles are released into the interstitium due to tissue damage, does the interstitium become hypertonic, hypotonic, or stay isotonic?
It becomes hypertonic due to the increase of solute particles
What mechanism pertaining to the capillaries, along with tissue damage, results in edema?
Increased capillary permeability
As blood approaches the capillary, where does fluid go?
Fluid leaks out into the extracellular matrix (ECF)
As the remaining blood (that didn’t leak out) courses through the capillary, what does it become?
More concentrated, or hypertonic
What happens to fluid that is hypertonic in the capillary as it approaches the venous end?
It pulls fluid in from the ECF
What % of the ECF is drained by lymphatic vessels?
10%
What continuously happens to the interstitium, thanks to fluid being pushed in and out?
It is “washed” by fluid
What happens if the lymphatics are blocked by worms, tumors, etc.?
Massive swelling, such as in elephantiasis
If there is high HP, will fluid be pushed out, pulled in, pushed in, pulled out?
Pushed out
If there is low CP will fluid be pushed out, pulled in, pushed in, pulled out?
Pulled in
If there is low HP, will fluid be pushed out, pulled in, pushed in, pulled out?
Pushed in
If there is high CP, will fluid be pushed out, pulled in, pushed in, pulled out?
Pulled out
What is another name for the extracellular matrix?
Interstitium
What condition can be caused by hypotension due to post-surgical blood loss, sepsis, obstetric complications, burns, ROS?
Renal failure
What pathology is classified as “significant” loss of renal function?
Renal failure
At what mL/day urine output do you have anuria?
< 50 mL/day
What can low glomerular pressure or nephritis, transfusion reactions, and crush injuries cause?
Anuria
What pathology is classified as only 25% normal renal functioning?
Renal insufficiency
What does the GFR drop to in renal insufficiency?
25-30 mL/min
What pathology is when renal function drops to 10% of normal?
End stage renal failure (ESRF)
What causes azotemia?
Abnormal increase in BUN
Abnormal increase in creatinine
What is azotemia with neurological complications called?
Uremia
What is seen in uremia?
Edema, encephalopathy, nausea/vomiting, anorexia, ulcers, CHF
With uremia, what is retained?
Na…So also water!
Increased Na and water seen in uremia results in?
Increased renin, hypertension (fluid overload)
What pathology is where renal failure is so severe that there is glomerular damage, protein loss, edema?
Nephrotic syndrome
How much protein is lost in nephrotic syndrome? In g/day
3.5-10 g/day
Why is edema seen in nephrotic syndrome?
Due to the loss of plasma proteins
How much protein is lost in nephrotic syndrome? In %
Up to 20% loss
What is it called when the skin is pressed and a depression forms for some time after it is no longer depressed?
Pitting edema
Where is pitting edema seen?
Nephrotic syndrome
What system is activated in nephrotic syndrome?
Renin-angiotensin system
What is released in the nephrotic syndrome?
Increased ADH release
What is the urine output in diabetes mellitus?
Up to 12x normal
What diabetes is juvenile onset?
Type 1
What % of diabetes is type 1?
10%
What is destroyed in type 1 diabetes?
Autoimmune destruction of beta cells
What is there a deficiency of in type 1 diabetes?
Insulin
Is type 1 diabetes hyper- or hypo- glycemia?
Hyperglycemia, as the lack of insulin means glucose stays in plasma
What mg/dL is hyperglycemia?
> 200 mg/dL glucose in blood
What is hypervolemia?
Fluid overload
What causes hypervolemia/what disease is it associated with?
Hyperglycemia in type 1 diabetes
What does hypervolemia cause?
Hypertension
What is increased frequency of urination?
Polyuria
What is increased frequency of drinking?
Polydipsia
What is toxic production of ketones causing a “fruity” breath?
Ketoacidosis
What are pressure diuresis, polyuria, polydipsia, and ketoacidosis associated with?
Type 1 diabetes
Are people with type 1 diabetes overweight or underweight?
Underweight, due to loss of fat and proteins
What diabetes is adult onset or insulin resistant?
Type 2
What % of diabetes is type 2?
90%
What is destroyed in type 2 diabetes?
Insulin receptors (insulin is present, it just has little effect)
What is type 2 diabetes attributed to?
Obesity
What % of children born after 2000 will acquire type 2 diabetes?
1/3 (33%)
What is the most common cause of neuropathy in the western world?
Diabetes
What is the damage of capillaries throughout the body?
Microvascular disease
What is the destruction of vessels, associated with below the knee amputations?
Peripheral vascular disease
What is the clogging of capillaries of the retina?
Retinopathy
What is the most common cause of end-stage renal disease in the west?
Nephropathy
What is the urine output in diabetes insipidus?
24x normal
What is the difference between neurogenic and nephrogenic diabetes insipidus?
Neurogenic: Hypothalamus doesn’t produce enough ADH
Nephrogenic: There’s not enough ADH receptors in the collecting ducts
What is inflammation of the urinary bladder?
Cystitis
Is cystitis more common in males or females? How much more?
10x more common in females
What is inflammation of the glomeruli called?
Glomerulonephritis
What causes glomerulonephritis?
Immune problems, drugs/toxins, diabetes, vascular disease
What urine conditions are seen in glomerulonephritis?
Hematuria and proteinuria
What is blood in urine?
Hematuria
What is excessive protein in urine?
Proteinuria
What color is hematuria and why?
Brownish due to reactions with acid
How much protein is peed daily in proteinuria? What protein especially?
3-5 g/day, especially albumin
What is the inflammation of the renal pelvis and insterstitum?
Pyelonephritis
What causes pyelopnephritis?
Bacterial and fungal infections
What are symptoms of pyleonephritis?
Fever, chills, flank and groin pain
What is the most common cause of renal failure?
Acute tubular necrosis
What are the two forms of acute tubular necrosis?
Post ischemic (surgery, sepsis, burns)
Nephrotoxic
What is the most common kidney stone? What %?
Calcium oxylate 85%
What is the 2nd most common kidney stone? What %?
Struvic stones 15%
What molecules are associated with struvic stones?
Mg, NH4, P
What is the 3rd most common kidney stone? What %?
Uric acid 7%
What is the 4th (least) common kidney stone? What %?
Cystine <1%
What system do scientists sometimes combine the endocrine system with because they’re so closely related? What is this mega-system called?
The nervous system
Neuroendocrine system
What do neurons release? Do they need receptors?
Neurotransmitters DO need receptors
What do endocrine glands release? Do they need receptors?
Hormones DO need receptors
Is epinephrine from a neuron a hormone or NT?
Epinephrine from a neuron is a NT
Is epinephrine from the adrenal medulla a hormone or NT?
Epinephrine from the adrenal medulla is a hormone
Do hormones take effect near where they are released?
NO, they usually travel great distances
Do endocrine glands have ducts?
NO. They secrete directly into capillaries/blood
What is SIMILAR to the endocrine (but not part of it) where the molecule has its effects on the same cell that produces it?
Autocrine
What is SIMILAR to the endocrine (but not part of it) where the molecule has its effects near to the cell that produces it?
Paracrine
What system secretes products into the lumen of organs via ducts?
Exocrine
What are examples of exocrine products?
Digestive enzymes, tears, mucus, bicarb, sweat, oils, wax
What are the basic building blocks of polypeptide chains/proteins?
Amino acids
How many different amino acids are there?
20
What are the bonds that hold amino acids together?
Peptide bonds
Are peptide bonds held together by H bonds, covalent, ionic?
Covalent
What is a long chain (or polymer) of amino acids?
Peptide/polypeptide chain
What is a sequence of DNA nucleotides that carry the code/recipe for a polypeptide?
Gene
What is a SMALL chain of linked amino acids?
Peptide
What is a LONG chain of linked amino acids?
Polypeptide
What do functional/mature proteins consist of?
1 or more polypeptide chains
Are proteins 2D or 3D?
3D
How can proteins change shape?
Changes in heat and pH
What are amino acid or protein-based hormones made of?
Amino acids or peptides/polypeptides
Do amino acid/protein-based hormones cross cell membranes easily?
NO
Are amino acid/protein-based hormones water or lipid soluble?
Water
Are amino acid/protein-based hormones polar or nonpolar?
Polar
Are amino acid/protein-based hormones hydrophilic or hydrophobic?
Hydrophilic
Are amino acid/protein-based hormones lipophilic or lipophobic?
Lipophobic
Where are the receptors of amino acid/protein-based hormones usually?
On the cell membrane
What are amine hormones?
Modified amino acids
What are examples of amine hormones?
Dopamine, epinephrine, norepinephrine, melatonin
What are peptide/protein hormones made of?
Multiple amino acids connected by peptide bonds
What are examples of peptide hormones?
ADH, ANP
What are examples of protein hormones?
Growth H, FSH, Luteinizing hormone, human Chorionic Gonadotropin (hCG)
Are peptide hormones or protein hormones larger?
Protein hormones (they have multiple polypeptide chains)
What hormones are made of complex ringed lipid molecules?
Steroids
What are all steroid molecules derived from?
Cholesterol
Where are the receptors for steroids?
In the cytoplasm and nucleoplasm
Once steroids are bound to their receptors, where does the steroid-receptor complex bind to to turn genes on/off?
Directly on the DNA
Are steroids water or lipid soluble?
Lipid
Do steroids cross membranes easily?
Yes
Are steroids hydrophilic or hydropohobic?
Hydrophobic
What are examples of steroids?
Testosterone, cortisol, aldosterone, progesterone, estrogen
Where do arachidonic acid based hormones come from?
Special phospholipids in the cell membrane
What hormones are long, ringed fatty acids that are physiologically active?
Arachidonic acid based hormones
What are arachidonic acid based hormones precursor to?
Eicosanoids, leukotrienes, thromboxanes
What are eicosanoids made from?
Arachidonic acid
What enzyme converts arachidonic acid into prostaglandins and thromboxane?
Cyclooxygenase
What abbreviations are for cyclooxygenase?
COX 1 and COX 2
What are the functions of prostaglandins?
Inflammation, pain, uterine contraction, blood clotting…
Do prostaglandins vasodilate or vasoconstrict?
Vasodilate
What allergic reaction can prostaglandins help induce?
Anaphylaxis
What is produced by platelets causing them to aggregate and begin the clotting process?
Thromboxanes
Do thromboxanes cause vasodilation or vasoconstriction?
Vasoconstriction
What produces leukotrienes?
Leukocytes and mast cells
What do leukotrienes cause?
Inflammation, and the release of histamine and prostaglandins to increase inflammation
What does NSAIDS stand for?
Non-Steroidal Anti-Inflammatory Drugs
How do NSAIDS work?
Inhibit prostaglandin synthesis by inhibiting cyclooxygenase
What are examples of NSAIDS?
Ibuprofen, Asprin, naproxen, Indomethacin
What is the mechanism for Acetaminophen?
Unknown! It isn’t an NSAID though
What must hormones have for effects to take place?
Functioning receptors
What do steroidal hormones form in the nucleus?
Dimers
What are dimers?
Two hormone-receptor complexes
What do steroidal dimers do?
Bind directly to the two sides of DNA to activate/deactivate genes
Are hormone diseases caused by deficiency in the hormone, or the receptors?
Both
What is signal transduction?
The series of reactions when a hormone binds to its receptor on the cell membrane and genes are turned on/off
What are the “first messengers” in signal transduction?
The hormones
Where is the “second messenger”?
Near the cytoplasmic surface of the receptor (just inside the cell membrane)
What does the second messenger do?
Transmits the message of the hormone (first messenger) to the next set of chemical reactions
What does the Cyclic AMP (cAMP) System use?
A cyclic form of Adenosine Monophosphate
What happens after the hormone binds to its receptor in cAMP system?
The receptor activates the G protein on the membrane
What activates G protein?
Guanosine Triphosphate (GTP)
What deactivates G protein?
Guanosine Diphosphate (GDP)
What does G protein activate (or deactivate) in cAMP?
Adenylate cyclase
What does the enzyme adenylate cyclase do?
Produces cAMP from ATP
What is the second messenger in the cAMP system?
cAMP, a cytoplasmic protein that turns reactions on/off
What enzyme does cAMP activate?
Protein Kinase A (PKA)
What does PKA do?
Phosphorylates another enzyme that phosphorylates another….etc.
What enzyme destroys cAMP (thus turning it off)?
Phosphodiesterase
What is another name for the PIP2 second messenger system?
Calcium signal system
What happens after the hormone binds to its receptor in PIP2 system?
The receptor activates the G protein (just like in cAMP)
What does the activated G protein bind to in PIP2?
The enzyme phospholipase C
What does phospholipase C do?
Splits PIP2 into DAG and IP3
What are the second messengers in PIP2?
DAG and IP3
What does DAG do?
Activates the enzyme protein kinase C
What does protein kinase C do?
Continues the signal transduction
What does IP3 do?
Causes the release of Ca ions
What do the Ca ions released by IP3 do?
- Activates more kinase enzymes, which can include cAMP and PKC
- Regulate ion channels
What is the protein activated by Ca ions which can itself activate other proteins?
Calmodulin
What is up-regulation?
Increasing the # of receptors in the cell membrane
Does up-regulation make the cell more or less sensitive to hormones? Does this increase or decrease the hormone’s effect?
More, increases the effect
Does down-regulation make the cell more or less sensitive to hormones? Does this increase or decrease the hormone’s effect?
Less, decreases the effect
What is down-regulation?
Decreasing the # of receptors in the cell membrane
What is it called when 2+ hormones (or drugs, toxins, etc.) produce an effect that is greater than the sum of their individual effects?
Synergistic effect
What is permissive action?
1 hormone makes the target organ much more sensitive to another hormone
Is permissive action up or down-regulation?
Up-regulation
What is an example of permissive action?
Estrogen causes an up-regulation of progesterone receptors in the uterus, making the uterus more sensitive to progesterone
What is it called when 2 hormones have opposite effects?
Antagonistic effect
What is this an example of:
Insulin lowers plasma glucose levels, while glucagon increases plasma glucose levels?
Antagonistic effect
What are hormones that stimulate the release of another hormone? They are often referred to as “stimulatory” or “excitatory” hormones?
Tropins
What are hormones that inhibit the release of another hormone? They are referred to as “inhibitory” hormones?
Statins
Where do most hormones produced by the hypothalamus have their effects on?
The Anterior pituitary gland
Gonadotropin Releasing Hormone in the hypothalamus causes the release of what where?
2 gonadotropins (follicle stimulating hormone FSH and Luteinizing hormone) released from the anterior pituitary gland
What does FSH do in females?
Females: Causes granulosa cells in the ovarian follicles to activate an enzyme to change testosterone into estrogen
What enzyme changes testosterone into estrogen?
Aromatase
What does FSH do in males?
Stimulates spermatogenesis (development of sperm)
What does Luteinizing hormone do in females?
Causes ovulation (release of oocyte from ovaries)
What does Luteinizing hormone do in males?
Stimulates cells to produce testosterone
What cells produce testosterone?
Leydig cells (interstitial cells) of the testes
What is the relationship called between the hypothalamus, pituitary gland, and the gonads?
Hypothalamic-hypophyseal-gonadal axis
What sort of feedback is involved when the hypo releases gonadotropin releasing hormone causing release of FSH & LH, which release testosterone that inhibits the hypo?
Negative feedback loop
Thyrotropin/Thyroid Releasing Hormone in the hypothalamus causes the release of what where?
Thyroid stimulating hormone released in anterior pituitary gland
What is another name for thyroid stimulating hormone?
Thyrotropin
What does thyrotropin do?
Causes the thyroid’s follicular cells to release T4
What is the name for T4?
Thyroxin
Is T3 or T4 inactive?
T4 is inactive
Where is thyroxine (T4) released from?
The colloid
Where does T4 go after it is released?
To the cells which will chop off an iodide to make T3
What is T3 called?
Triiodothyronine
What does T3 do?
Increases metabolism
What does estrogen regulate?
Secondary sexual characteristics and the uterus
What does calcitonin do?
Activates osteoblasts to make bone, thus decreasing blood Ca levels
Where is calcitonin released from?
Parafollicular cells
What does parathyroid hormone do?
Activates osteoclasts which resorb bone and increase plasma Ca
What produces parathyroid hormone?
Parathyroid glands
What causes reabsorption of Ca and excretion of P by the kidneys?
Parathyroid hormone
What vitamin does parathyroid hormone activate that causes an increase in Ca absorption?
Vitamin D
What does corticotropin releasing hormone in the hypo release from the anterior pituitary?
Pro-opiomelanocortin
What is pro-opiomelanocortin chopped up into?
Adrenocorticotropic hormone (ACTH)
Beta-Endorphin
Enkephalin
Melanocyte stimulating hormone
What does adrenocorticotropic hormone do?
Increase cortisol from the adrenal cortex
What does beta-endorphin do?
Causes runner’s high and reduces pain
What is beta-endorphin an example of?
Endogenous opiate
What is an example of an endogenous opiate other than beta-endorphin?
Enkephalin
What is another name for melanocyte stimulating hormone?
Melanotropin
What does the pro in pro-opiomelanocortin mean?
Because it is the first or pro-hormone to be made into other hormones
What does the opio in pro-opiomelanocortin mean?
Because it can be chopped into the endogenous opiates (beta endorphin and enkephalin)
What does the melano in pro-opiomelanocortin mean?
Because it can be chopped up into melanocyte stimulating hormone
What does the cortin in pro-opiomelanocortin mean?
Because it stimulates the release of cortisol from the adrenal cortex
What is the outer layer of the adrenal gland?
Adrenal cortex
What hormone class is the adrenal cortex part of?
Steroids
What is the outer 1/3 of the adrenal cortex called?
Zona glomerulosa
What subclass is found in the zona glomerulosa?
Mineralocorticoids
What is an example of a mineralocorticoid and its function?
Aldosterone (water retention)
What is the middle 1/3 of the adrenal cortex?
Zona fasciculata
What is the subclass in the zona fasciculata?
Glucocorticoids
What is an example of a glucocorticoid and its function?
Cortisol (anti-stress)
When are cortisol levels highest?
The morning
What is the deepest/inner 1/3 of the adrenal cortex?
Zona reticularis
What is the subclass for the zona reticularis?
Sex steroids
What are examples of sex steroids?
Androgens (like testosterone and estrogen)
Are estrogen and androgens stopped being produced after menopause?
Estrogen is stopped, but androgen continues. This can cause clinical manifestations
What is the inner layer of the adrenal cortex called?
Adrenal medulla
What subclass of hormones are in the adrenal medulla?
Sympathetic hormones
What are examples of sympathetic hormones?
Epi, norepi, dopamine, serotonin
When is cortisol released?
In response to stress (physical, pathological, emotional)
What effect does cortisol have on fats, proteins, and carbs? (Does it increase or decrease blood glucose levels?)
Increase
What is gluconeogenesis?
Producing glucose from non-carbs such as proteins and lipids
What is glycogenolysis?
Breaking down glycogen to release glucose into the blood
What does cortisol counteract? What might this do to the body?
Cortisol counteracts insulin, which may result in hyperglycemia
What can constantly high cortisol do to insulin?
Create insulin resistance
Does cortisol increase or decrease amino acid entry into muscles?
Decrease
Does cortisol increase or decrease hunger when high?
Increase
What does cortisol do to the immune system?
Cortisol is anti-inflammatory
What does cortisol reduce the release of as an anti-inflammatory?
Proinflammatory cytokines
Histamines
What does cortisol help control in the lymphatic system?
Control B lymphocyte functions and prevents T lymphocyte proliferations
Does cortisol down or up regulate epinephrine receptors?
Upregulate
Does cortisol cause vasoconstriction or vasodilation? What does this do to BP?
Vasoconstriction, raises BP
How does cortisol effect Na and P?
Has an anti-diuretic effect (increases Na retention and P loss)
How do high levels of cortisol affect the reproductive system?
Can cause infertility and miscarriage
How does cortisol affect: Ca absorption
Decrease
How does cortisol affect: bone formation
Decrease
How does cortisol affect: collagen formation
Decrease/inhibits
How does cortisol affect: Plasma amino acid levels
Increase
How does cortisol affect: gastric acid production
Increase
What does long-term cortisol levels do to the brain?
Damages hippocampus, impairing learning and memory retrieval
Can high levels of cortisol interfere with the negative feedback loop controlling the amount of cortisol?
Yes
Where are catecholamines/adrenergic hormones produced?
Adrenal medulla
What are the fight or flight sympathetic hormones?
Catecholamines/adrenergic hormones
What is the body’s main source of catecholamines?
Epinephrine
Does epinephrine and norepi cause vasodilation or vasoconstriction? What does this do to BP?
Vasoconstriction, raising BP
What do epi and norepi tend to do to insulin?
Reduces its release
What does prolactin releasing hormone in the hypo effect in the anterior pituitary?
Prolactin
What does prolactin do?
Stimulates lactation (production of milk)
What is prolactin inhibited by?
Dopamine
What does growth hormone releasing hormone in the hypo effect in the anterior pituitary?
Growth hormone and Insulin-like growth factor
What does insulin-like growth factor do?
Stimulates mitosis
What does somatostatin in the hypo affect in the anterior pituitary?
DECREASES growth hormone
What hormones are made by the hypo but are stored and released from the POSTERIOR pituitary?
ADH and oxytocin
What does oxytocin do?
Causes uterine contraction (as seen in labor) and causes milk let down
What sort of states release ADH release?
Hyperosmolar (high concentration)
What dietary choices might increase secretion of ADH?
High salt diets
What hormone inhibits appetite?
Leptin
What produces leptin?
Adipocytes
What do alpha cells in the islets of langerhans produce?
Glucagon
What do beta cells in the islets of langerhans produce?
Insulin
What do delta cells in the islets of langerhans produce?
Somatostatin
Are the acinar cells of the pancreas endocrine?
NO, they’re exocrine.
What do acinar cells produce?
Digestive enzymes and bicarb ions
What is prominent in the anterior, superior mediastinum (above the heart) of juveniles?
Thymus
What does the thymus do?
Supports T-lymphocyte maturation
What do T-lymphocytes do?
Help the immune system
What is the thymus replaced by in adults?
Adipose
What are gonads?
Primary reproductive organs
What cells produce testosterone in females?
Thecal cells
What hormone made by the small intestines and stomach causes HCl production?
Gastrin
What hormone made by small intestines causes the pancreas to release bicarb and proteases?
Secretin
What hormone is made by the small intestines and causes the gallbladder to contract? (Thus forcing bile into the duodenum)
Cholecystokinin
What hormone is an endogenous opioid with an unknown function?
Endorphin
What hormones are released by the pineal gland?
Serotonin and melatonin
What is associated with reduced melatonin levels?
Seasonal affective disorder (SAD) and premenstrual syndrome (PMS)
What contains adipocytes, connective tissue matrix, nerve tissue, vascular cells, and immune cells?
Adipose tissue
Where are proifnlammatory cytokines found?
Adipose
What does adipose tissue act on in obesity?
Appetite and energy balance, immunity, insulin sensitivity, BP, cardiovascular disease…
What are examples of proinflammatory cytokines?
Tumor necrosis factor and interleukin 6
What do tumor necrosis factor and interleukin 6 cause?
Inflammation, obesity-related insulin resistance
What condition is angiotensinogen and angiotensin implicated in?
Hypertension
What does plasminogen activating inhibitor (PAI-1) impair?
Fibrinolysis
What is fibrinolysis?
Breakdown of blood clots
What do adiponectin and leptin do?
Stimulate beta oxidation of fatty acids in skeletal muscles
What might adiponectin and leptin do in regards to insulin?
May improve body’s sensitivity to insulin and protect against diabetes type 2
What pathology is an overactive thyroid that results in elevated thyroid hormones?
Hyperthyroidism
What disease is a type of hyperthyroidism?
Grave’s disease
Is metabolic rate increased or decreased in hyperthyroidism?
Increased
Is increased metabolic rate anabolic or catabolic?
Catabolic
What causes hyperthyroidism?
Autoimmune issues…Antibodies are produced that stimulate TSH
What are signs of hyperthyroidism?
Goiter, nervousness, rapid pulse, bulging eyes, weight loss, sweating
What can hyperparathyroidism be caused by?
Hyperthyroidism
What levels are increased in hyperparathyroidism?
Blood Ca levels due to increased PTH
In hyperparathyroidism, do you see bone thinning or bone thickening?
Bone thinning
What is bone thinning called?
Osteoporosis
What is an underactive thyroid called?
Hypothyroidism
What is the most common type of hypothyroidism in the US?
Hashimoto thyroiditis
What is Hashimoto thyroiditis strongly associated with?
Lymphoma
What do hypothyroidism symptoms range from?
Asymptomatic to myxedema coma
What happens in primary hypothyroidism?
Thyroid gland can’t produce hormones
What happens in secondary hypothyroidism?
The thyroid is normal, but the hypothalamus or pituitary glands are affected
Is T4 increased or decreased in hypothyroidism? Why?
Decreased, due to increased TSH
How do you diagnose hypothyroidism?
Elevated serum TSH and decreased T4…Sometimes patients can have an elevated TSH and a normal T4
What disease alters the T3/T4 negative feedback loop on TRH and TSH?
Hypothyroidism
What are signs of hypothyroidism?
Goiter, weight gain, pallor, fatigue, slowed speech/movement, dull facial expression
What is hypercortisolism also called?
Cushing’s disease
What is cushing’s disease often due to?
Increased ACTH from a pituitary adenoma
What are characteristic signs of cushings?
Weight gain in face and trunk (“moon face” and “buffalo hump”)
What is the skin like with cushings?
Fragile, with acne and facial hair growth
What is hirsutism?
Abnormal facial hair growth
What is hair like in cushings?
Brittle or bald
Do people with cushings fail to bruise or bruise easily? Why?
Bruise easily due to decreased collagen
Why do people with Cushings have insulin resistance?
Due to increased cortisol
Do people with cushings have hypotension or hypertension?
Hypertension
When are cushings symptoms often seen?
Prolonged use of corticosteroids like prednisone
What is another name for hypocortisolism?
Addison’s disease or adrenal insufficiency
What is rare, reduced cortisol (and often aldosterone) production by the adrenal cortex?
Addison’s disease
What kind of disease is Addison’s?
Autoimmune
What are signs of Addison’s?
Weight loss, fever, hypoglycemia, dehydration, fatigue
What causes rickets/osteomalacia?
Reduced vitamin D
What is osteomalacia in kids?
Rickets
What is rickets in adults?
Osteomalacia
What is an abnormal increase in growth hormone from childhood?
Giantism
What is an abnormal increase in growth hormone from adulthood?
Acromegaly
What is an abnormal decrease in growth hormone?
Drawfism
What is postmenopausal osteoporosis due to?
Loss of estrogen
What are other names for estrogen?
Estradiol
Estradio-17 beta
Estradiol-17 beta
In hypoparathyroidism is there more or less Ca in the blood?
Way too little Ca in blood
In what disease is there increased neuromuscular irritability (i.e., myalgias, twitching, spasms) due to decreased threshold?
Hypoparathyroidism
Is macroglossia (enlarged tongue) in hypothyroidism or hyperthyroidism?
Hypothyroidism
What disease can have a “fruity” breath from ketoacidosis?
Type 1 diabetes
What’s the way to distinguish between diabetes mellitus and diabetes insipidus?
Mellitus: Insulin
Insipidus: ADH
