A&P test 1 Flashcards
define homeostasis and summarize homeostasis
the conditions inside the body are maintained at near constant conditions by many different way
summary: body is constantly changing in order to maintain a constant internal environment regardless of the changes going on like metabolism, changes in food, or environment. changes in physiological systems can alter drugs (anesthesia) in unhealthy ppl. and drugs can alter physiological systems
for this class our healthy pt is 70kg, 30 year old male
internal environment
internal environment is everything under our skin. we have about 35 trillion cells and they have a constant condition in the fluid that surrounds it. in order for the cells to work the environment must be in homeostasis
snow storm example of homeostasis
our body wants to maintain the temperature around 37 C. so if you go out in a snow storm your internal body temp will start coming down and the body senses that and does mechanisms to bring it up aka shivering
homeostasis in anethesia
during anesthesia we take the homeostasis controls offline aka the sensors that regulate BP, blood gases, temperature, etc. so we have to do the work for the pt body in OR
cells in homeostasis and how they stay constant
describe input, output, and waste products
cells need energy compounds(sugar, oxygen, and fats) to buffer the pH and control the body’s constant condition
all in all homeostasis in cells involves many different processes and some are metabolic and some are more specialized
what goes in must come out
input(energy compounds)–> output(work or heat) and then waste products(CO2 is byproduct of metabolism, protons and water, urea)
role of kidneys, GI, lungs, heart in homeostasis
kidney- responsible for maintaining BP at normal level and extracellular buffering and electrolytes
GI- replaces nutrients in the blood consumed by cells
Lungs- regulate blood gases
Heart- 2 pumps separated by septum that are responsible for ensuring we get a decent amount of gas exchange at lungs and the peripheral part of CV system is supplied with proper nutrients
tissue example of homeostasis
the tissue is the controller responsible for the blood flow within the CV system. blood coming in through the artery into the tissue then that fluid is being brought in by the CV system is carrying nutrients that cells need to use and then the veins remove the metabolic byproducts. The AMOUNT OF BF that goes through a tissue is determined by the metabolic demands of the tissue.
so if cell actively burning through oxygen and glucose, the composition of the fluid surrounding will change causing a deficiency and the tissue senses increased metabolism and blood flow increases. so if increased rate of metabolism, environment will change, and CV system will respond by increasing perfusion and bringing that environment back to normal levels
tightly controlled so cannot increase blood flow easily if not increase in metabolism
simplify negative feedback
body keeps processes to maintain homeostasis in check through process called negative feedback. almost all systems are managed via NF. the more important of a function the more sensors and more counteracting mechanisms
sensor out in periphary detects changes such as ph changing, O2, CO2 levels changings, etc. and that info is fed to some kind of controller and that controller does things to counteract change
ex) BP drops–> sensors–> nervous system–> squeezes blood vessels–> BP increases
initial change–> sensors(periphary)–> controller(corrects/counteracts problem)–> solution is always NEGATIVE to original change. change is negative to stimuli.
example of negative feedback
thermostat, BP, CO2
1) thermostat
thermostat set to 70 and if environment goes above or below then the thermometer(sensor) senses this and signals to the thermostat to turn on AC or furnace to raise or lower temp and then it stops once temp back to normal
2) BP
DECREASED MAP–> INCREASED sympathetic outflow so releases norepi–> MAP back to normal
DECREASED MAP–> drop PARASYMPATHETIC outflow–> MAP back to normal
DECREASED MAP–> INCREASED AVP/ADH(vasopressin and antidiuretic hormone)–> increased MAP
DECREASED MAP–> DECREASED ANP-> increased MAP
3)CO2
if CO2 levels in the blood go up then brain cell going to increase ventilation to get it back to normal
explain/simplify positive feedback
explains oxytocin and blood clotting cascade example
sensors sees a change–> feeds back to controller–> controller amplifies the change it is seeing–> should stop at certain checkpoint
vicious cycles- when positive feedback has run completely out of control.the only thing thats going to stop it now is severe organ injury of death. normal positive feedback systems are not thought of as vicious cycles but when positive feedback system is ran out of control and its pathologic thats when its a vicious cycle.
oxytocin) during labor the uterus contracts and pushes fetus towards cervix and when the cervix is exposed to this pressure from the fetus from the contraction it STRETCHES. the cervical stretch tells the brain to release oxytocin and oxytocin acts on smooth muscle in uterus to cause even more contractions on top of the already there contractions which stretches the cervix more which releases more oxytocin. so BASICALLY, contractions get stronger and stronger closer to birth until finally BIRTH and that is the checkpoint that shuts down whole system. cervix back to normal and oxytocin levels back to normal
blood clotting pathway) when endothelial cells in the blood vessels are harmed it starts bleeding and the coagulation factors are exposed which promote platelet plug formation. SO BLEEDING PROBLEM BUT PROBLEM RELEASES THINGS TO FIX IT. as the plug forms more and more platelets aggregate and make a clot and TXA2 vasospams etc. so when bleeding stops that is the checkpoint. this can get out of hand if the clotting doesnt stop then you get clotted blood vessel
Bad pathological positive feedback examples
1) severe hemorrhage
if we lose a lot of blood our BP is going to go down and coronary blood blood flow will decrease also. If coronary blood flow is insufficient for metabolic demand of heart then heart will drop CARDIAC OUTPUT which drops BP even more so then vicious cycle
2) sepsis
sepsis is widespread infection and cells are dying at faster rate than body can manage. when cells die they release their toxins(metabolic by products, potassium) into the environment and they come in contact with neighboring cells. so then these cells are dying bc of toxins on top of body fighting sepsis
3) severe acidosis
a little bit of acidosis the brainstem figures out whats going on and increases breathing but when we have severe acidosis, the central nervous system can be affected so much that that reduces respiratory drive. if respiratory drive is reduced then that accelerated acidosis and makes us even more acidotic
4)kidney failure
as we get older our million nephrons start to die(around 45-50) and with less nephrons this increases the load of the still living nephrons putting a heavier burden on them so then they die at faster rate. as more die the rate increases and increases. older and older you get the faster the rate the nephrons die bc of the burden the ones remaining have placed on them as the others die. results in renal failure
describe losing 1 liter of blood (20%) versus 2 liters(40%)
compensated shock negative feedback works well(in healthy person) bc our body can usually handle it. 1) our pump effectiveness is initially reduced when we lose 20% and BP will go down bc system is less full and bc less output. and the system should be back up in couple of hours bc our blood vessels will tighten and the heart will try to pump harder and we have massive fluid shifts to help our cardiovascular system out
decompensated shock positive feedback leads to death bc negative feedback insufficient; gain insufficient. if we lose 40% of our blood and not next to hospital then despite our BP controllers they are inadequate to deal with this. so then pathologic feedback kicks in and that outweighs negative feedback systems that are usually in charge of this. LOOK AT HEMORRHAGIC POSITIVE FEEDBACK RESPONSE
describe the cell, tissue, organ
-smallest living unit of the body and our body has 35 trillion human cells and 25 trillion are RBCs
-cells can sustain own lives with stuff inside them
-equipped with enzymatic machinery to put ATP together for energy
-most cells specialized aka INTERNAL CONTENTS DEFINES FUNCTION. ex) lung cells thin and narrow for gas exchange
-shield us from outside environment
-tissues are collection of cells that are like minded and work together to form function
-organs are collection of different type of tissues. responsible for maintaining internal environment of body
cell can move
-flagella–> move a cell around its environment. moves actual cell
-cilia–> move stuff around inside of cell
cell replication and RBC replication
most cells are capable of replication bc have DNA and normal machinery able to divide and replicate when cells die. if cant replicate then close to progenitor cell that can do task
ex) RBC does not have nucleus or genetic material to create copies of themselves so close to bone marrow with progenitor stem cells. RBCs last 90-120 days
neurons have hard time replicating. dont do it fast
cardiac cells are very slow to replicate
what are phospholipids
when enough phospholipids they aggregate to form bilayer to make themselves happy
hydrophillic head behaves well in water and is charged. Glycerol(carboxyl) and phosphate part
hydrophobic- anything that is uncharged is usually a fat. hydrogen and carbons together
specialized phospholipids are when something special is attached to phosphate head: cholesterol
point out organelles in cell
ribosomes
smooth ER
rough ER
golgi appartus
nucleus
1) smooth ER
2) rough ER
3) mitochondria
4) lysososome
5) nucleus
6) gogli apparratus
inside of cell
70-85% water except for adipose cells bc they are fatty and dont have high internal water content
cystoplasm: fluid part of cell where lot of chemical reactions take place
nucleus: barrier to keep DNA packed up and secure and out of reach of viruses and bacteria. where genes are stores
genes: can be turned on and off. carries instructions on how to make lipids or proteins
nuclear wall: separation btw cytoplasm and nucleus; double phospholipid bilayer. allows in steroids(through pores)to affect gene transcription and turn on stress response proteins.
structure- internal support needed to give and keep shape. structural components like filaments or proteins produced inside cell to prop it open and give it certain shape
organelles to know
mitochondria
lysosomes
peroxisomes
golgi apparatus
endoplasmic reticulum
describe ribosomes
-take amino acids and stick them together and use that structure to build proteins.
-located on rough ER. some are free floating
-where PROTEIN TRANSLATION OCCURS
describe the making of a protein and how vesicles are used
proteins that are formed at the RER are concentrated in storage vesicles and sent for processing and modification in GA. after processing, the proteins are typically active and ready to use so the modified proteins go around cell in vesicles
vesicles: specialized organelle that are storage places for proteins until ready to need
transport: move proteins within the cells
secretory: move active proteins outside of cell
1)nucleus contains DNA and transcribed into RNA 2) RNA leaves nucleus and interacts with ribosomes3) ribosomes translate the tRNA into mRNA to form proteins by linking AA(95% of this occurs in RER and 5% occurs in free floating ribosomes in cytoplasm but those dont get packaged) 4)go to GA for processing and packaged into VESICLES
RNA has some nucleotides in a certain sequence and that sequence dictates which AA get stuck together and in what order. SO ribosome moves RNA along its center and grabs AA from cytosol and attaches them to form a chain and typically folds. sometimes its modified at GA to fold more and be manipulated. the shape we get consists of strings of AA that are contorted and folded in a way that provides functional protein
describe ER
smooth and rough
ER: extension of nuclear wall. where fats and proteins are produced. a compartment within the cell that can used to store things like CALCIUM
rough: rough bc ribosomes(protein synthesis). takes infomation and forms proteins from it
smooth: does not have ribosomes. specializes in lipid production(cells need lipids to complete their day to day tasks)
golgi apparatus
close in proximity to ER and processes proteins created by rough ER. POST TRANSLATIONAL PROCESSING.
post translation: sometimes proteins modified so may fold differently, parts cut off. we normally alter proteins after making them and happens in GA
water inside cell(cytoplasm)
-70-85% water except for fat cell
-affects acid/base balance, electrolytes, and energy compounds
-all the processes happening al the time in the body keep these conditions fairly constant and if conditions change significantly then the chemistry doesnt work as predicted
mitochondria
-help us efficiently produce ATP from energy compounds and oxygen
-mitochondrial DNA separate from host DNA
- inherit all mito DNA from mother
-dozen or 20 sets of mito DNA which gives us variability with our body’s ability to inherit energy producing organelles that are super efficient bc if only inherited one set then might not be enough to get job done
lysosomes
-digestive organelle good at recycling bc…
-acidic environment that destroyes proteins and then that releases AA to be resused in cytoplasm
peroxisomes
-oxidizes
-can destroy proteins but better at processing toxins like ethanol
-liver contains peroxisomes that degrade alc and use oxidative stress to destroy and use oxidation reaction to destroy
-oxidation is what happens to iron if you put it out in oxygen for too long
-the cell can use oxidation reactions to destroy things that need to be broken down
-CATALASE–> enzyme present in peroxisomes that are used to oxidize compounds
sugars within cells
GLYCO=sugar group attached to something
CARBOXYL= starch(sugar)–> carboxylhemoglobin is example of sugar getting stuck on hemoglobin in blood–> the more sugar stuck to it the less functional it will be
-floating around cytoplasm to be used for ATP/energy. started in cytosol with anaerobic metabolism. GLYCOLYSIS typically happens within fluid and that means glucose being consumed to create ATP
-GLYCOPROTEINS–> sugars stuck onto proteins and sticking out of cell wall for IDENTIFICATION PURPOSES(specific shape) aka humans and bacteria produce ID tags that are different so sugars help cell identify self from non self and help immune system attack
-sugars also have specific NEGATIVE charge that repels proteins floating around that may also have negative charge
-GLYCOPROTEINS STRUCTURAL FUNCTION–> used to enable cells to attach to each other and hold cells together bc STICKY
-STICKY can be bad thing–> think hemoglobin example
-although sticky can also repel bc of negative charge
-kidneys use sugars to make sure we dont filter as much protein as we would–> look at Glut 1?
cholesterol
-lipid soluble not water soluble
-used to general all sorts of signaling compounds
-OH part is exposed to water to grab onto things
fats in cells
-related to cell function also; lipid soluble compounds also
-cholesterol and arachidonic acid
-hang out in cell wall bc thats where comfy bc non charged
soluble vs insoluble
soluble= electrolytes, proteins somewhat soluble, carbs bc charged, and gasses EXCEPT NITROUS, buffers
insoluble= cholesterol aka fat, steroid hormones, lipids, and nitrous gas
Body fluid compartments
TOTAL BODY WATER= 60%
ICF= intracellular; water inside of cells; largest internal body compartment. TWO THIRDS
ECF=water outside of cells so includes plasma and interstitial fluid(if see intercellular then thats ECF). ONE THIRD
-plasma= 1/4-1/5 of the ONE THIRD; fluid thats found within entire CV system(does not include volume of blood cells)
-interstitial= 3/4-4/5 of ONE THIRD; outside of cells but outside of CV system. useful when we lose bunch of blood and out body shifts fluid from interstitial to compensate
ex) take 60% of 70kg male and that gives us 42 kg of overall body content and 1L of water=1 kg. 2/3 is ICF and 2/3 of 42kg is 28. and then what if i ask you what the plasma volume then 1/3 of 42 is 14. 1/4 of 14 is 3.5 which is answer
steady state is the conditions are kept fairly constant but the steady state of ICF and ECF are different. much different from equilibrium
body fluid compartment math
write it out
electrolytes and ions ICF vs ECF
Left 2 columns plasma ECF and interstitial–> remember leaky barrier so not much difference
right column is ICF intracellular
difference of protein concentration ICF vs ECF
ECF- usually does not have difference btw plasma and interstitial but proteins do have difference bc not a lot of proteins interstitial but lots in plasma to keep blood in right places. plasma has 5x amount of proteins than interstitial
ICF vs ECF
the ICF has more protein concentration bc proteins made and used inside cells more than outside. major plasma protein is albumin(about 80%)
Amino acids build proteins so their concentration will be higher inside cell than outside cell and also when proteins are replaced and broken down this releases AA into cell
cholesterol in cell wall
-precursor molecule for stuff we need to synthesize
-stuck into cell wall and very lipid soluble(the carbons and hydrogen) except for OH groups(polar part sticking out for body to grab onto)
-lipid that doesnt like to hangout in water bc fatty and uncharged so hangout in cell wall so if body needs it it just grabs onto it(from OH group) and metabolize it
-dont want to go overboard with amount of cholesterol bc cholesterol is flat and RIGID and if too much can affect CV system bc blood vessels less stretchy
-reduces cell wall fluidity: stiff
-cholesterol rigid in normal temps (37C) but if frozen or lower temp then make it smoother like ice cream bc increase membrane fluidity
-if endothelial cells become rigid then atherosclerosis then heart problems bc blood vessels stiff
proteins in cell wall
1) GATEWAY of allowing stuff across cell wall
-channel, pumps, pores
2) SIGNALS to help COMMUNICATE to get stuff done
-usually receptors in cell wall can handle neurotransmission for message to get inside cell
3) ENZYMES
-catalyze reactions; sometimes apart of receptor and sometimes close
-G protein–> 7 transmembrane spanning receptor with outward portion and then inward portion in proximity to subunits. some kind of compound binds to receptor and that receptor changes a bit which will change the intracellular components and will turn something on or off
stuff in cell wall picture and performance of cell wall
-barrier to separate what inside of cell versus whats outside
-adhesion
-ID tags for immune system to regulate activity
-storing stuff(lipids, carbs, proteins, enzymes, precursor molecules) especially fatty molecules bc dont like to hangout in water
cholesterol metabolites
-usually used as primary feed compound to produce our sex hormones that look similar
-different enzymes to manipulate the compound and need each enzyme in order to produce it and if missing just one enzyme not able to make the metabolite
Stuff cholesterol can be turned into
1) sex hormones top of list
-estradiol and testosterone go through bunch of manipulation
-progesterone would be third most active sex hormone
-androstenedione is precursor to testosterone–> baseball players were using this
2) stress hormones
-made at adrenal gland which goes through a lot of cholesterol
-cortisol and aldosterone which look VERY similar just an OH group is different
CORTISOL- has OH group
-reason why matters? CROSS REACTIVITY–> look so similar there is no distinct activity aka activity isn’t regulated to just one receptor bc they can use each others. for example, if not enough cortisol around, aldosterone can be used to interact with receptors
-body needs regulation of this issue
arachindonic acid
-really really long fatty chain that hangs out in cell wall and our body manipulates it to accomplish different tasks and is parent compound to many different stuff
-just like cholesterol some parts are polar like the OH group and double O=O and thats probs the part that is sticking out of cell wall
prostaglandins, TXA2, leuokotrienes, HEETS and EETS
prostaglandins and leukotrienes happy hanging out with water so not just stuck in cell!!!!!!!!! bc dont look too much like arachindonic acid
Leukotriene part of AA pathway
-important effect on our immune response
-LTC4, LTD4, LTE4
-involved in immune mediated inflammation
-inflammation usually bad process bc makes lungs swell up and glands act goofy–> so if we can manipulate this pathway we can stay away from these problems
-ex) singulair is leukotriene receptor antagonist and the enzyme that drives it is LIPOXYGENASE(LO)
-LO takes Arachadonic acid and turns it into leukotrienes
simple diffusion
-the process of something moving across the cell without any help at all
-straight shot without using energy
-movement dictated by concentration(chemical) gradient or for electrolytes concentration gradient and also electrical gradient–> electrochemical gradient-> potential to move down chemical gradient or electrical gradient
GASSES
-can move across cell membrane without any help bc tend to be lipid soluble and small
CHANNEL PROTEINS
-can be ion specific and good for electrolytes to sneak through
-smaller charged particles need to get through
-going to be specific for an electrolyte or charge
-as long as no binding, releasing, or conformation change then simple diffusion
-allow water to cross cell wall bc water is permeable
WATER SPECIFIC CHANNELS AKA AQUAPORINS(AQP)
-area in body that needs to regulate its water permeability will probs going to have few ion channels bc make it hard to regulate water permeability
-want to regulate it by controlling number of aquaporins
-water can get specifically or nonspecifically
Active Transport
-either want to make transport go faster or want to put compounds where they don’t want to be
-requires energy
ex)Sodium Potassium ATPase pump which is enzyme and Calcium pumps and proton pumps
-FIRST DEGREE–> directly using ATP; being metabolized by pump
-secondary active transport
-pump does NOT USE ATP DIRECTLY; relies on ATP but that isn’t directly happening at pump
-NCX transporter/sodium calcium exchanger
-Na and glucose pump
Sodium Potassium ATPase pump
-enzyme that metabolizes ATP–> ATP harnessed or pulled from inside of cell and pump takes ONE ATP and RIPS OFF A PHOSPHATE–> ADP and PHOSPHATE FALLS OFF
-using the energy from when phosphate comes off the pump moves 5 IONS where they dont want to go
- 3 SODIUM OUT OF CELL AND 2 POTASSIUM INSIDE CELL
-SODIUM does not want to go to outside bc 1) it is positively charge 2) against its concentration gradient
-sets up almost all the electrical gradients in our body bc of the sodium and potassium movement–> most of the other gradients are related to this pump
-uses 60-70% of energy in a cell so most energy requiring process in body
LOPSIDED PUMPING–> bc losing 3Na and gaining 2K so LOSE ONE POSITIVE CHARGE AKA MAKING THE CELL EVEN MORE NEGATIVE
DIURETIC EFFECT
-cells have a way for water to move across cell wall
-keeps OSMOLARITY of cell in check bc as cleans out excess sodium the water follows it out of cell
-maintains INTRACELLULAR VOLUME of cells
-if shut pump off then Na builds up and cell SWELLS UP aka CELLULAR EDEMA
-unhealthy ppl with less ATP so less ATPase so cell swells up and hard to fix bc fluid inside cell-> only way to fix is to give more ATP
indirectly affects lots of other electrolyte gradients like calcium which dictate charge of cell
osmolarity vs osmolality
-we will use OSMOLARITY in this class
-small difference btw the two bc IL of solution is little bit less than 1L of pure water bc blood(solution) has more stuff than just water in it. about 1% difference of the two
-units of millimoles (mOsm)
Osmolality
-quantity of stuff dissolved in 1kg of water
-1kg of pure H2O=1L of H2O
-so if we take 1 mOsm in 1L of water then osmolality is 1 and then take that number and multiply it by constant 19.3 then get OSMOTIC PRESSURE that solution has potential to be
-IMPRACTICAL to use bc would have to pull out 1L of pure solution from the blood
osmolarity
-looking at quantity of stuff dissolved in 1L of solution
-mOsm and mEQ are units of quantity
describe the normal test tube and then what happens when you had solute to it
-the U shape test tube is filled with just water separated by a semi permeable membrane–> restricts movement of the SOLUTE but not solvent so water is distributed evenly
WHEN YOU ADD THE SOLUTE to ONE SIDE
1) increases the saltiness or osmolarity of the left side
2) bc of this has also messed with the water concentration on the LEFT side bc adding the solute DECREASES water concentration of the LEFT side
3) RIGHT side still high water concentration bc did not add solutes to that side
4) water wants to move down its concentration gradient so water will go from RIGHT TO LEFT which will push the LEFT SIDE VOLUME high but will never completely even out both sides
-if measure the height at which we pushed the column up then we could quantify the osmotic pressure in units of mmHg(mercury is liquid at room temp)
-remember 1 mOsm is 19.3mmHg in 1L so if 1 mOsm of solute in L side then L side will move up 19.3 mm
-dissolving 280 mOsm will have enough osmotic pressure to push column up 5000 mmHg
-only thing keeping the column from going all the way up is gravity and when increase the weight of the left side and gravity pulling it down.
-SO as the column of mercury goes up and up the osmotic pressure is being OFFSETTED BY GRAVITY BC OF THE INCREASE IN WEIGHT
-done at sea level bc in space the water would just go up and up
-so in theory 1 little electrolyte would make the water keep going up and up bc no matter what will never even out concentration of water bc LEFT will always be lower than right
-can also quantify osmotic pressure via applied pressure aka can be defined as amount of pressure needed to keep the left side from not going up in height at all aka stopping osmosis
explain kinetics
Vmax is maximum speed at which the conformational changes can occur(if not transporter dont have to deal with this)
facilitated diffusion
-conformation change so rate of diffusion increases with increased gradient BUT HAS Vmax when those transporters get saturated
-so speed dependent on concentration gradient AND speed of conformation change
-only way to speed up diffusion at this point is to increase number of transporters around
simple diffusion
-rate of diffusion increases LINEARLY with increase in gradient–> speed determined by concentration of substances
-does not have Vmax bc doesnt have transporter
