Test 1 ⭐️ Flashcards
1
Q
What is homeostasis?
A
Conditions inside the body that are maintained at near constant conditions
Healthy balance to keep cells happy
2
Q
What is our internal environment?
A
Everything underneath our skin
3
Q
How many cells are in our body?
A
35 trillion cells
4
Q
How does the body maintain constant conditions?
A
Body has many different sensors to adapt to changing conditions
5
Q
Give examples of how the body maintains homeostasis:
A
If the body wants to maintain temperature, there needs to be sensors around that are measuring the body temperature so that it can detect a change and then feedback into system that will adjust for the change
6
Q
Give examples of how the body maintains homeostasis:
A
If the body wants to maintain temperature, there needs to be sensors around that are measuring the body temperature so that it can detect a change and then feedback into system that will adjust for the change
7
Q
Give another example of homeostasis:
A
Walking out into the snow temperature decreases the body senses a decrease, and then will send a signal to bring temp up.
I.e. shivering
8
Q
What is a key aspect of homeostasis?
A
What goes in must come out
Input yields output and waste products
Input: food and energy.
Output: work heat potential energy number of other things line
Waste products: CO2, H+, water, urea
9
Q
How does the body keep things constant inside?
A
Body has different control mechanisms to maintain homeostasis
Organ systems
10
Q
What happens to the body under anesthesia?
A
The control mechanisms normally present go off-line
Sensors that monitor blood gas, blood pressure and other things are impaired by the drugs
CRNA must do the work that the nervous system normally does to maintain the homeostasis
11
Q
What is physiology?
A
The study of all the processes that make life happen
12
Q
What is an example of an effect anesthesia has on the body?
A
When under anesthesia in the OR and paralyzed body temperature drops would need to rewarm/monitor with warming device because the nervous system is incapacitated
13
Q
What are some of the processes of homeostasis?
A
Metabolic processes.
Specialized processes
14
Q
What do cells need in their surroundings?
A
Energy compounds and chemicals
15
Q
What kind of energy compounds are needed in extracellular fluid
A
Oxygen sugars fats
16
Q
What are the chemicals used for in the extra cellular fluid?
A
They work to buffer the pH around the cells
17
Q
How does the kidney maintain homeostasis in the body?
A
Maintains blood pressure
extracellular fluid buffer (normal pH)—electrolytes
18
Q
How does G.I. system maintain homeostasis?
A
Replacing nutrients in the blood as they are being used by the cells
19
Q
How do the lungs aid in homeostasis?
A
Regulate blood gas
20
Q
Explain how cardiovascular system aids in homeostasis:
A
Think of “two hearts”
Right heart pump and left heart pump share a wall (septum)
Responsible for effective gas exchange in the lungs and supplying peripheral vascular with proper nutrients
21
Q
Describe ECF:
A
Extra cellular fluid: the fluid between the cells.
Lots of compounds helped to keep the values in the ECF constant
-electrolytes
-energy compounds
22
Q
Describe ICF
A
Intracellular fluid: fluid that is inside the cell
Fluid inside the cells, houses organelles and functions of the cell
Lots of compounds to help keep this fluid constant
23
Q
What is another term for intracellular fluid?
A
Cytoplasm
24
Q
How do peripheral circulatory beds, maintain homeostasis?
A
Use the controller, responsible for blood flow within the cardiovascular system
The amount of blood flow that goes through a tissue is determined by the metabolic demand of the tissue
Example: blood goes into the arterial, and then it has the opportunity to deliver nutrients that Cells will be using and also remove metabolic by products
25
How would metabolic byproducts be removed from the peripheral vascular system?
Veins
26
Explain what happens at peripheral circulatory beds if the cells are burning through oxygen and glucose:
Extracellular fluid composition would change because the cells are pulling those nutrients
ECF is deficient of nutrients
This deficiencies are picked up by sensors within the cardiovascular system
Cardiovascular system response by increasing blood flow to increase perfusion and bring the levels in the ECF back to normal
Venus blood flow also picks up to remove byproducts that are being produced faster because the metabolic demand are increased
27
If a cell has increased metabolism, how does it maintain homeostasis?
The organ systems respond just enough to meet the metabolic tissue requirements
If there is no increase metabolism, it’s difficult to get a response from the Organ systems
example: would be difficult to get prolong increase in blood flow without increasing metabolism to a peripheral circulatory bed
28
What is negative feedback?
Most common control system in the body
Sensor out in periphery can detect changes happen in the body, which is then sent to a controller
The controller perform tasks to counteract what’s happening in the body
Change is negative to the stimuli
29
Give some examples of negative feedback:
Blood pressure drops from 100 to 50:
body senses the drop, and it feeds that information to the nervous system the nervous system act to increase blood pressure
Increase CO2 in the blood:
Sensor notices increase and feeds information to the brainstem which can increase ventilation to bring it CO2 back to normal
Thermostat:
Thermometer within the thermostat senses an increase or decrease and turns on AC or heat to bring the level back to baseline
30
How does the body form a safety net for systems important for survival?
There are many sensors and systems involved with areas that are key to survival.
More than one change if change is detected in these areas
Example: blood pressure-very important so body has MANY mechanisms to regulate and help keep system functioning
31
What are some negative feedback mechanisms involved with low blood pressure?
BP drops:
1: Increase sympathetic nervous system outflow (increase norepinephrine in body increases MAP)
2: Decrease parasympathetic nervous system outflow: rest and digest limited so MAP increases
3: Circulatory compounds in the body
-Increase ADH/AVP: release from pituitary increase MAP (vasoconstriction and retain volume)
-Decrease ANP: (vasodilation)
32
What is a positive feedback?
Not as common
The sensor detects change in the body feeds back onto the controller and the change is amplified
Works well as long as the checkpoint is in place
33
What is an important aspect of positive feedback to prevent complications?
Checkpoint/safety valves to shut down process once goal is achieved
34
What happens if positive feedback doesn’t have a checkpoint?
The positive feedback would run out of control in a way it shouldn’t be occurring and creates a vicious cycle, causing major problems
35
How can you stop a vicious cycle from positive feedback?
Only thing to stop vicious cycle is usually once it reaches end organ damage or death
A mild degree of positive feedback can be overcome by the negative feedback control mechanisms and the vicious cycle fails to develop
36
Give examples of beneficial positive feedback:
1: oxytocin levels during labor and delivery
— uterus contracts to push the fetus to the cervix. cervix has pressure that will cause the cervix to stretch. Cervical stretch causes oxytocin to release from the brain, oxytocin acts on the smooth muscle in the uterus and causes more uterine contractions.
— checkpoint is birth: after birth, oxytocin levels should decrease and contraction stop
2: blood clotting pathways
— injury to blood vessels, endothelial cells release coagulation factors, and they promote platelet plug formation and coagulation
— checkpoint is bleeding has stopped
37
What is pathologic positive feedback?
Amplified change continues to occur past check point
If pathologic positive feedback continue, the system will not survive
38
Why do most control systems of the body operate by negative feedback rather than positive feedback?
Positive feedback leads to instability rather than stability and in some cases can cause death
39
What are some examples of pathologic positive feedback?
1: severe hemorrhage
— decrease blood pressure causes decrease coronary blood flow, which is insufficient to keep up demand of the heart decreases cardiac output further reduces blood pressure
2: sepsis/necrosis
— dying cells due to infection. Dying at a faster rate than body can manage. All of the toxins inside the cells are released to the environment where other cells are. Cell components can be toxic: potassium, metabolic byproducts. Healthy cells can be affected by that release and die as well
3: severe acidosis
— Severe acidosis, the CNS can be so affected that respiratory drive is reduced and further perpetuates acidosis.
4: diabetic renal insufficiency/hyper filtration
— 1 million nephron in each kidney. Nephron die with age do not regenerate in adults so as nephron die, the remaining nephron carry a larger load the larger load on the nephron makes it more likely to die keep dying. You eventually will be in renal failure.
5: athrosclerotic plaque clotting:
— clotting factors continue past checkpoint. Formation of unwanted clots. Lack of blood flow to vital organs. heart attack.
6: peripheral acidotic conditions
40
Describe compensated shock:
Negative feedback working
Example, hemorrhagic shock:
— can lose 20% of blood volume if totally healthy and be OK. 1 L of blood loss initial drop in blood pressure & drop in cardiac output but should be able to get cardiac put to normal within a few hours through negative feedback responses.
— Blood vessel constrict
— increase heart pumping
— massive fluid shifts
41
Describe decompensated shock:
Positive feedback running rampant
Example, hemorrhagic shock:2L loss
— Lose 40% blood volume difficult to survive despite defense of the body through negative feedback
— negative feedback is inadequate
— too many positive pathologic feedback cycles kick in and outweigh the negative feedback systems
42
How would response to anesthesia be different between healthy person and critically ill person?
Typical anesthetics will not behave the same in a sick patient compared to a healthy patient
circulation decrease in elderly person
Sick Patient has changes and physiologic systems
—ex: CHF
43
Describe a cell and its function:
Cells are the building blocks of the body
Smallest living unit
Capable of sustaining their own life with elements inside them: enzyme material to create energy
Cells are usually specialized for a specific task based on role and location
44
How many cells are in the body?
35 trillion
45
What type of cell is most abundant in the body?
Red blood cells – 25 trillion in the body
46
What is a tissue?
A group of cells – like-minded and organize together to perform a function
47
What is an organ?
A collection of tissues – organs maintain the internal environment of the body
48
What is necessary for Cells to replicate?
Most cells capable of replication – need to have DNA/normal machinery
49
What happens if a cell cannot replicate?
A nearby progenitor cell can aid with replication
50
What are some examples of cells that cannot replicate, and how do they reproduce.
1: Red blood cells: cannot replicate themselves, but bone marrow or progenitor stem cells can reproduce red blood cells
51
Why can’t red blood cells replicate themselves?
Red blood cells do not have genetic material (DNA)
No nucleus
52
Why is it important for cells to replicate?
Cells occasionally die so they need to be able to reproduce
53
Examples of cells that don’t replicate often:
1: neurons: problems replicating in CNS, do not replicate fast or often
2: heart cells: slow replication rate, only some new cardiac cells during lifespan
54
Describe the cell membrane, a.k.a. cell wall:
Keep inside components in and outside components out
Phospholipid bilayer
Lipid tails make up bulk of cell wall
Phospholipids create barrier so other charged particles can’t make it through cell wall
55
How does a phospholipid bilayer work?
Phosphate head—charged at cell wall, behave well in water
Lipid tail— uncharged, oily do not behave well in water
Phosphates and lipids aggregate to form bilayer if there are enough around in an aqueous solution
56
What is the major element inside the cell?
Water: 70 to 85%
Except for adipose cells
57
After water, what are the most abundant substances in the cell?
Proteins
58
What is cytoplasm and what occurs here in the cell?
Cytoplasm is the fluid part inside the cell
Lots of chemical reactions take place here — chemical reactions are very important to keep Cell alive
59
What is the nucleus and its function?
The nucleus is the control center of the cell
Holds DNA
Forms a barrier to keep DNA secure — out of reach of viruses and bacteria
Body is picky about what is allowed into the nucleus
60
How do allowed particles get into the nucleus?
Pores (opening in nuclear envelope)
61
What makes up the nuclear envelope?
Double phospholipid by layer
62
What is the purpose of the nuclear envelope?
Separate cytoplasm from nucleus
Prevent entry of random things into nucleus
VERY selective about what comes in
63
What is the endoplasmic reticulum and its function?
Extension of nuclear envelope
Important for fat and protein production
Important for calcium storage
Rough and smooth ER
64
What happens at the rough endoplasmic reticulum?
Takes info from the nucleus and makes proteins
Small dots on rough ER are ribosomes
Translate and packaged then sent for processing into the cytoplasm
65
What is the function of a ribosome? Where are they located?
Ribosomes translate instructions from the nucleus into proteins – stick amino acids together to make proteins
Located in rough ER
66
What happens at smooth endoplasmic reticulum?
Specialize for lipid production
No ribosomes here which is why it’s smooth
67
How do proteins travel around the cell?
Packaged into vesicles: transport vesicles or secretory vesicles
68
What is the Golgi apparatus and its function?
Protein modification
Area in cell that allows processing of proteins
Post translational processing— sent to Golgi apparatus after translated by the ribosome
It is common to have to alter proteins to work properly
69
Describe how a secretory vesicle works in the cell:
Used to carry a protein that is trying to go outside of the cell
Released from Golgi apparatus into cytosol
Vesicle moves to the cell wall and fuses with it, then dumps the contents into the area immediately outside Cell wall (ECF)
70
How can you get water soluble/charged compounds from one side of the cell to the other?
Need help of a protein: proteins can position themselves in the cell wall and permit the passage of charged compounds into cell
Working like a pore
example K+
71
What is cytosol?
The jelly like fluid portion of cytoplasm, where particles are dispersed
Surrounds organelles
72
Where does protein production occur?
95% in rough ER
5% outside rough ER in cytosol
73
Describe the process of protein production:
DNA instructions that encodes protein produce RNA
RNA is readily allowed out of the nucleus, comes into contact with ribosomes
Ribosomes Translate the message from the RNA and link amino acids together to form proteins
74
What is the purpose of ribosomes in the cytosol?
Not very concentrated
Don’t do heavy lifting
Usually don’t get packaged when made in the cytoplasm
75
Describe genetic translation:
Specific sequence of nucleotides (RNA) dictate which amino acids get stuck together in in which order
Ribosomes move the RNA along a sensor and grab amino acids from the cytosol, then attach them together to form a chain (protein)
76
What are the different organelles of a cell?
Endoplasmic reticulum
Golgi apparatus
mitochondria
lysosomes
peroxisomes
77
Describe protein shape:
Strings of contorted and folded amino acids
3-D
78
What is the purpose of mitochondria?
Produce ATP from energy compounds and oxygen
79
What is a lysosome?
Digest by using acidic internal environment
Breakdown proteins that are malfunctioning
— amino acids are recycled
80
What is a peroxisome?
Known for breaking down toxins within a cell
Use oxidative stress to destroy things
Abundant and liver – ethanol digestion (catalase enzyme)
81
What is an enzyme?
Catalyzes chemical reactions
Typically a protein ending in – ACE
82
What are structural components of the cell?
Filaments or proteins to prop open, produced inside the cell to give shape
83
What are sugars used for in the cell?
1: energy – when floating cytoplasm
2: Glycoprotein: structure, ID tags, anchor cells together
84
Where are most sugars located in the cell? UNKNOWN
Many sugars are in the cell wall stuck to a protein a.k.a. glycoprotein
85
How do sugars function in identification?
They take on specific shapes.
Example: human shape, bacterial shape
—immune system can attack non-human cells
86
How do sugars play a role in structural function of cells?
Sugars are sticky— can anchor cells together that are next to each other
87
Which statement about feedback control systems are is incorrect?
A) most control systems of the body act by negative feedback
B) Positive feedback usually promotes stability in a system
C) Generation of nerve action potentials involves positive feedback
D) Feed-forward control is important in regulating muscle activity
B
88
Which on the following organelles is responsible for producing adenosine triphosphate (ATP), the energy currency of the cell?
A) ER
B) mitochondria
C) Lysosomes
D) golgi aparatus
E) peroxisomes
F) ribosomes
B
89
What role does the charge have on the sugar molecule?
Negative Charge.
Plays a role in repelling negatively charged proteins
90
What is special about external sugars?
Sugars that have a specific shape and charge
91
How do external sugars work in the kidney?
Limit protein filtration
92
What is glycolysis?
Sugars create ATP in cytoplasm using anaerobic metabolism
Glucose is being consumed to create ATP
93
Where does glycolysis typically occur?
Cytoplasm
94
What group are glyco– and carboxy– prefixes in?
Sugars
Generate ATP
95
What roles do proteins have in the cell?
Structural.
Enzymes
Functional
96
What dictates a cells specific task?
proteins expressed in the cell dictate what the cell will be good at
97
How is the specialized role of a cell dictated?
Genes expressed in the proteins dictate the specialized role of a cell
98
Do proteins function for generalized tasks?
No. Proteins have assigned tasks and are specialized for that task.
99
How do proteins function structurally?
Help the Cell hold shape
Can help something get across cell wall
force something in a way it may not want to go (pump)
100
What is an example of lipid soluble compound?
Cholesterol
101
What is a arachidonic acid and where is it found in the cell?
It is a long chain fatty acid found in the cell wall
102
What is cholesterol used for?
Used to generate signaling compounds
103
Where are fats primarily located?
Cell wall
104
What is an example of a task that a lipid has in the cell?
Metabolism to turn larger compounds into something more useful
105
What is flagella?
Moves a cell around it environment
106
What are examples of motility structures for the cell?
Flagella
Cilia
107
What is Cilia?
Small projections that come out of the cell
Moving environment around cells
Wave fluid or mucus example: the airway
108
What is the necessary step for protein and fat production?
RNA processing
109
Where is majority of genetic materials found in the cell?
The nucleus
110
What is a mitochondrial DNA?
Separate from human/host DNA
Inherit all mitochondrial DNA from mother
111
How many sets of mitochondrial DNA do we have?
12 to 20 different sets: lots of variability with bodies ability to inherit energy producing organelles that are super efficient
112
What is mitochondrial DNA used for?
Lineage and genetic testing
113
What would be a negative aspect if we were to only inherit one version of mitochondrial DNA?
Probably would not be enough variety to get all the jobs done in our cells
114
What is a part of the cell that is important for anesthesia?
The cell wall: how the cell turned itself off and on
Majority of anesthesia drugs dictate the function at the cell wall
When giving anesthesia may want to shut down part of particular system
115
Why are the ECF and ICF chemistries so important?
Chemistry dictates, how drugs are going to work
Example: if the fluid is not within normal pH won’t behave normally
116
How do cells maintain a normal internal pH?
Compounds for internal buffers – things in place to maintain pH within normal limits
Example: phosphate compounds are buffers in the intracellular
117
What is hydrophilic and an example?
Hydrophilic is a particle that behaves well in water
Charged particles are hydrophilic: sodium potassium chloride – they disassociate when put into water
118
What happens to charged compounds when put into water?
They fall apart (hydrophillic)
example sodium chloride: sodium disassociates from chloride leaving both in the solution. This happens because salt is charged and hydrophilic but needs enough water to be dissolved
119
What is hydrophobic and an example?
Particles that are water fearing
Uncharged particles, oils, usually fats
120
What are some example of water soluble things?
Ions
Proteins (somewhat)
Gases (some like CO2)
Buffers: found in all containers of the body where it’s important to manage pH
Some drugs
121
How can you tell if the drug is soluble or insoluble?
Can look at container the drug is in if it’s oily and slimy then it’s probably not water soluble
122
Why do insoluble drugs look oily?
There is probably a carrier protein or a lipid used to get these drugs into the cardiovascular system
123
How do we give drugs that are water insoluble?
Need to give the drug with a carrier to help it get around the cardiovascular system
- carrier protein
-carrier lipid
124
What is an example of an insoluble drug?
Propofol white color is due to lipids that help carry the drug through the cardiovascular system
Need carrier since cardiovascular system is mostly water
125
What are some insoluble compounds?
Cholesterol
Steroids
Lipids
Gases -nitrous
Some drugs
126
Where are majority of lipids found in the cell?
Cell wall
127
Describe ICF and relation to fluid concentration:
Largest of internal body fluid compartments
The sum some total of all the water that’s inside all the cells in the body
128
What percent of body mass is water in a healthy person?
60% of body mass is water in a 70 kg patient
129
What are the compartments that make up total body water?
ICF
Interstitial fluid
Plasma
130
What are the two compartments of ECF?
Plasma
Interstitial fluid
131
How much of total body water is in the ICF?
2/3 of total body water
132
How much of total body water is in the ECF?
1/3 of total body water in ECF
133
What is interstitial fluid?
Fluid that is outside the cell and outside the cardiovascular system
134
What percent of ECF water Content is in the interstitial fluid?
3/4 to 4/5 of ECF fluid is the interstitial fluid
135
What percentage of ECF is water in the plasma?
1/4 to 1/5 of ECS is water in the plasma
136
What is plasma?
Fluid and cardiovascular system that doesn’t involve blood cells
137
What is the predicted plasma volume of a 70 kg patient?
3.5-2.8L
138
What is the predicted interstitial fluid volume of a 70 kg patient
10.5-11.2L
139
How would total body water differ in an obese patient compared to healthy patient?
Obese patient may have big cells with less water and more fat
So that would disrupt the normal water distribution
140
Why is it useful to have a larger portion of water in the interstitial fluid?
If there’s a loss of volume or blood from cardiovascular system, there can be a shift of interstitial fluid to make up for the volume loss
141
Why do the plasma and the interstitial fluid have similar fluid composition?
The capillary membrane that separates them is leaky so there’s not much difference between the two
Exception is protein
142
What is the function of the capillary membrane?
Barrier between the plasma and the interstitial fluid
143
How does a capillary membrane vary from the cell wall?
The cell wall is a tight barrier
Capillary membrane is endothelial cells that are more porous and permeable: all small charged ions can move between
— capillary membrane is tight enough to prevent proteins from leaking out of the plasma
144
What is an exception to normal capillary permeability?
The brain: capillaries are tight
145
What are some differences in ECF and ICF?
Different composition of fluid
Different processes happening
146
What is a steady state?
Sustained differences that are maintained that way in the body at rest
Differences, but they are tightly regulated
147
How is steady-state different than equilibrium?
Steady state doesn’t have to be equal.
Steady state contributes to homeostasis
EX: if sodium concentration was an equilibrium, the cell would be non-functioning
EX: if our body wasn’t equilibrium with the room temp that wouldn’t be good
148
ECF and ICF trends of protein
Highest in ICF
Five times higher in plasma, then in interstitial fluid
149
What are the protein concentrations in the plasma interstitial and intracellular?
Plasma protein: 1.2
Interstitial protein: 0.2
Intracellular protein: 4
150
Which organ produces plasma proteins?
Liver
151
What is the most major plasma protein?
Albumin
152
ECF and ICF trends of sodium
More sodium in ECF: 140-142 mOs/L
ICF sodium much lower: 1/10 ECF Na concentration 14mOs/L
153
What is the predominant cation in the ECF?
Sodium
154
How can we estimate overall osmolarity of the blood?
Double sodium to estimate osmolarity
155
ECF and ICF trends of potassium:
More potassium in the cell: 30x higher in cell
156
What is a normal level of potassium in ECF?
4mEq/L
157
Why are potassium levels much lower than sodium levels?
Due to the sodium potassium pump moves the two ions in different directions
158
Why is potassium important in the body?
Important for heart function
Potassium is out of wack electrical system in the heart is messed up
159
What are intracellular levels of potassium?
30 times higher than outside cell
120mEq/L (neurons)
160
What happens to potassium in unhealthy cells?
Potassium may leave the cell and can affect neighboring cells and cause issues
161
What is the function of calcium?
Important for turning cells on: opening calcium channels to turn cells on
162
Compare ECF and ICF trends of calcium
Hardly any calcium inside the cell
Calcium concentration outside the cell much higher than inside in a resting Cell
10,000:1 ratio
163
What do cells use calcium for?
As signal to turn themselves on
In order to be useful signals, you don’t want on all the time
When the cell is resting, calcium levels are low
When neurotransmitter hits, they may spike calcium levels for a little then calcium is removed and cell turns off quickly
164
How is calcium moved in the cell?
Calcium is moved by pumps
Transported out of cell after short period of time
165
If there is calcium in the cell, where would it be?
Tucked away in the endoplasmic reticulum
There are pumps that would send calcium back to the endoplasmic reticulum for storage
166
What are examples of systems that use calcium?
Neurons turn on cells with calcium
Muscle turns on cell with calcium for contraction
167
How is calcium moved in the cell?
Pumps
168
What is magnesium used for in the cell?
Magnesium is used as cofactor in some of the intracellular functions
Helps with chemical reactions
169
What are the ECF and ICF trends of magnesium?
Higher magnesium in ICF: cofactor for chemical reactions required in the cell
170
What are the ECF and ICF trends of chloride?
Chloride is the primary anion in ECF
High ECF: blood is salty due to increase concentration of sodium and chloride
Chloride follows distribution of sodium
171
Secondary anion in the blood
Bicarbonate
172
What are the ECF and ICF trends of bicarbonate?
Higher concentration in ECF
Most important ECF buffer
173
What is bicarbonate used for?
bicarbonate is a buffer
174
How are bicarbonate levels managed?
Levels are managed by the kidney
Adjust if acid base is off
175
What ions and electrolytes are looked at for anion gap?
Chloride and bicarbonate
176
What are the ECF and ICF trends of phosphate compounds?
Phosphates are intracellular buffers
Higher concentration in ICF
177
What are the three main functions of phosphate in the cell?
Intracellular buffer
On/off function in cell
Energy storage system
178
How do phosphates regulate cell activity?
Phosphates can be attached or detached from proteins to regulate activity
Phosphates stick to a target and turn the target either off or on
179
What is phosphorylation?
Phosphorylation of a target cell can either speed up process or shut it down
Phosphorylation regulates the speed of lots of different systems
180
What is an example of phosphorylation?
Muscle function: lots of phosphorylation that happens, and that typically turns on and off the different components path
181
How does phosphate work as an energy storage system?
ATP: useful because phosphates can be attached or pulled off depending if we need to burn energy or store energy for cellular reserves
To create ATP have to stick phosphates to adenosine: requires energy to attach each phosphate
As we consume ATP, we pull phosphates off: energy is released
182
What are ECF and ICF trends of amino acid concentration?
Higher concentration of amino acids in ICF: needed for protein synthesis
Also high concentration in the cell from breakdown of proteins: amino acids are liberated when a protein is broken down
183
What is creatine? What are the ECF/ICF trends of creatine?
Creatine is a high energy storage compound
Majority found on inside of skeletal muscles: higher concentration in ICF
184
How do muscles contract?
ATP is used for muscle contractility
Contraction is generated by pulling phosphate off ATP
Each phosphate pull off ATP we release energy energy can be harnessed to do work
185
Describe a creatine compound and how it can be useful in skeletal muscles:
Creatine can be phosphorylated: add a phosphate to creatine to create phosphocreatine
When under high exertion, some skeletal muscles pull phosphates from phosphocreatine first to generate skeletal muscle contraction
Creatine compound can give short term energy reserve (most of energy is still from ATP)
186
Why can’t phosphocreatine be used to generate muscle contractility instead of ATP?
Phosphocreatine is depleted quickly due to small amounts that are quickly burned
If phosphocreatine is present and the muscle is using a lot of energy it will pull the phosphates off creatine before breaking down ATP
187
What are the ECF/ICF trends of lactate?
Lactate is a metabolic byproduct produced inside cells
So higher concentration of lactate intracellular
All metabolism is happening in the cell
188
What are the ECF/ICF trends of adenosine Triphosphate?
ATP is super valuable inside cell: high concentration in ICF
ATP is formed and used inside the cell
ATP Not found outside the cell at all
189
When would be an instance that all or part of ATP could leave the Cell?
Adenosine by itself can leak outside of the cell (all phosphates must be pulled off)
ATP—>ADP—>AMP—>adenosine
Adenosine is much smaller than ATP
190
How is adenosine useful in the cell?
Increase blood flow in an area that is highly metabolically active
Adenosine Opens up blood vessels: at active tissue, this will help perfuse the tissue and take care of metabolic requirements needed for tissue to do task
191
What are the ECF/ICF trends of glucose.
Glucose is lower in ICF compared to ECF
Most cells do not produce glucose
Glucose comes in from outside of cells
192
What are some functions of glucose?
Glucose can be turned into long-term energy storage compound
Glucose can be used for ATP production in short order
193
What is urea?
Uria is a byproduct of metabolism
Kidneys use recycling of urea to fine-tune water management
194
What are the ECF/ICF trends for total osmolarity?
Consistent between ECF and ICF: because water movement is not usually inhibited between fluid dividers (cell wall, capillary membrane)
If one container has a change in contents water should move to correct that change
Water moves into areas that are more concentrated with solute and the water movement should correct osmolarity differences
195
What is total osmolarity?
The number that tells us total dissolved compounds in a fluid sample
All solid numbers added up
196
How are osmolarity differences corrected by the cell?
Water movement into areas that are more concentrated with solute
197
How can osmolarity be predicted?
Plasma sodium concentration doubled
Predicted number close to 300
198
How is biological osmolarity different than predicted osmolarity and why?
Not all items will freely dissociate from one another
Electrolytes get close enough together they don’t freely dissociate: sodium may want to be close to chloride since they have opposite charges and the closer they are the less they behave like individual compounds
There are many charge particles in fluid and attraction between opposite charge compounds
Biologic osmolarity is less than predicted
199
What is the corrected estimate of total osmolarity?
280-282
200
What is an example of when total osmolarity is useful?
Useful when looking at fluid shift
Example, fluid shift in cranium: someone with increased ICP need to keep a close eye on sodium levels because they’re good indicators of total osmolarity
Total osmolarity governs how water moves from cardiovascular system to cranium
201
What is total osmotic pressure?
Molarity of solutions can generate large amounts of osmotic pressure (mmHg units)
All dissolved things in water can generate pressure greater than 5000mmHg
202
Why is it important to keep osmolarity within a normal range?
If we keep osmolarity in normal range, it will maintain the osmotic pressure and prevent complications to the brain from increased pressure
203
What are some items that are stuck in the cell wall?
Phospholipids
Protein
Glycoproteins
Glycolipids
204
What are glycolipids?
Sugars that are stuck to a phospholipid in the cell wall
205
What is the glycocalyx?
The sum of all external sugar structures that the body uses for immune system function
Grouping glycoproteins and glycolipids together
206
How does the body use the glycocalyx for immune response?
If the sugars do not look right, not in the right order orientation, then the immune system will investigate
207
How does uncontrolled diabetes affect the glycocalyx?
Glycocalyx no longer looks normal (extra sugars bound make look not human)
Extra sugars are stuck to the normal sugars if blood sugar is high for long periods of time
Uncontrolled diabetes creates a massive, inflammatory response mediated through the extra sugars, stuck to the normal sugars
208
Where are glycolproteins normally located?
Large proteins that span the entire width of the cell wall
209
Where are most of the precursor molecules located?
In the cell wall
Usually are large lipids and uncharged hydrophobic
Example cholesterol
210
What happens if too much cholesterol is stored in the cell wall
Cell Wall could become rigid and blood vessels less stretchy in the cardiovascular system
NOT GOOD
211
What is the tail of a phospholipid mostly made of?
Uncharged oily, mostly hydrogen and carbons
212
What is the structure of membrane cholesterol?
Planer molecule: flat and rigid
Increases stiffness of blood vessels
Reduces cell wall fluidity
213
What does cholesterol produce?
Sex hormones
Stress hormones
214
How is cholesterol used in our food?
Cholesterol is used to create a smooth texture at low temp
Cholesterol is easy to remove from food— but food without cholesterol would have a weird texture and not taste right
215
What is the chemical structure of a fat molecule?
Anytime just hydrogen is bound to a long string of carbons= fat molecule
No charge
-OH group on the end is how it orient itself to the cell wall
216
How does cholesterol arrange itself in the cell wall?
Sandwiches into the lipid tale of the cell wall: very lipid soluble
-OH group (only polar part) sticks out into the water so body can grab it if needed and change it into something else
217
How much of cholesterol is produced by the body (endogenous)?
80%: body usually makes more than what it needs
218
How much cholesterol is brought in by diet (exogenous)
20% cholesterol in the body
Trying to fix cholesterol with only diet will only get you so far
219
What is a drug that interferes with cholesterol synthesis pathway?
Statin: reduces the amount of cholesterol being produced by endogenous system
220
What does the body use to build cholesterol?
Acetyl-CoA
221
What is aceytl-CoA?
Generic big sugar compounds used as a substrate to build other things in the body
Widely available byproduct of metabolism
222
What are examples of compounds acetyl-CoA can assist in producing?
Cholesterol
ATP production from glucose and oxygen
223
How does acetyl-CoA produce ATP?
Need to have the right enzymes around
224
What are cholesterol metabolites?
Enzymatic actions that change the structure of cholesterol a little bit
Requires a lot of manipulation before turning into hormones
225
What are the sex hormones cholesterol can be turned into
Estradiol
Testosterone
Progesterone
Androstenedione
226
What is the third most active cholesterol driven sex hormone?
Progesterone
227
What is androstenedione?
Testosterone precursor
What was used by baseball players years ago to beef up
228
What are the stress hormones produced by cholesterol?
Cortisol
aldosterone
229
What are the six hormones derived from cholesterol?
Estradiol
Testosterone
Progesterone
Androstenedione
Cortisol
Aldosterone
230
Where are cortisol and aldosterone synthesized?
Adrenal glands: go through lots of cholesterol
231
Describe the structural variance between cortisol and aldosterone
Not a lot of variation and structure between the two
Cortisol has an -OH group
232
What would happen if cortisol OH group was oriented to the outside of the cell?
-OH group needs to be oriented inside the cell for the body to pull it for use?
if orientated to outside, would need to wait for orientation to change before it could be used (different isomer)
233
Are there similarities between the hormones produced by cholesterol?
Metabolites look very similar because from same parent compound
May have different bonds
Structural changes between the compounds create different effects on receptors they interact with
234
Are cholesterol metabolites receptor specific?
Cholesterol metabolites have some cross reactivity with their receptors because they all look very similar
Example: aldosterone receptor looks a lot like cortisol receptor so if you have a bunch of aldosterone and no cortisol aldosterone can interact with the cortisol receptors
235
How is cholesterol turned into different compounds?
Must have an enzyme to make changes to the parent compound
Enzymes are usually near the cell wall
Will not be able to produce cortisol if a single enzyme is missing
236
What is the structure of a specialized phospholipid?
An extra compound stuck to the polar head of phospholipid
237
How are specialized phospholipids named?
Phosphatidyl— + name of compound
238
What do phosphatidyl compound do in a cell?
They can be involved in signal transduction
Most play a role in surfactant production
239
What is surfactant made up of?
Combination of proteins and phosphatidyl compounds
240
What is the purpose of surfactant?
breaks surface tension of the fluid inside lungs and is important for normal lung function
Without surfactant lungs will not work right
Every lung disorder has some surfactant deficiency
241
What are the four main phosphatidyl compounds?
Phosphatidylinositol (PI)
Phosphatidylserine (cytosolic)
Phosphatidyl ethanolamine (PE)
Phosphatidylcholine (PCh)
242
What do you know about phosphatidylinositol?
Inositol is stuck to the phospholipid— in the cell wall for storage
IP3 makes smooth muscle contract
Can be used in smooth muscles to regulate contraction
243
What do you know about phosphatidylserine?
immunologic markers
Healthy cell should only have this on the internal part of the cell
If immune system sees serine in a place it shouldn’t be. It will destroy whatever it’s attached to.
244
What happens if phosphatidylserine moves to the outer side of the cell wall?
Flippase enzyme takes serines and flips them back into normal position in the cell
Flippase works quickly before immune system can catch
Flippase needs energy to move serine back (need good ATP amount)
245
What happens in regard to phosphatidylserine in a dying cell?
When a cell is dying, the inside runs out of ATP
Flippase Needs ATP so it stops working in these cells
Immune system will target serine outside the Cell to break down cell and recycle components
246
What causes a dying cell to be broken down by the immune system?
Destruction of the cell is mediated by energy deficiency that causes dysfunctional Flippase activity
247
What do you know about phosphatidylcholine?
Storage molecule useful in signaling transduction/ cell signaling
Used to stash choline for using the body: need Choline to assemble acetylcholine
248
What is sphingomyelin?
Compound stuck in the cell wall
Fatty compound used to construct myelin
249
Describe the characteristics of arachidonic acid
Poly unsaturated fatty acid
Long chain fatty acid
Found in cell wall
Manipulated by the body to accomplish many different tasks
Parent compound to lots of things
250
What are the three important compounds we looked at that are produced by arachidonic acid?
Prostaglandins and TXA2
Leukotrienes
HETEs/EETs
251
What is thromboxane A2?
Helps control blood vessel bleeding by initiating vasospasm
Works on blood vessels to tighten up and squeeze them when injured so coagulation factors can stop the bleeding
A Good thing for blood vessel to squeeze or Vasospasm to close and heal before reopening
252
What enzymes produce prostaglandins and TXA2?
COX1 and COX2 enzymes
COX1 and COX2 are cyclooxygenase enzymes
Manipulated by many different drugs
253
What is an example of common drug that work on Cox1 and COX2?
Aspirin/NSAIDs/Tylenol
254
What happens if we reduce activity of COX1 and COX2 enzymes?
Would reduce amount of prostaglandins in the body
255
What is another another name for PGI2?
Prostacyclin
256
What are prostaglandins?
Ramp up pain signals in the body
Increase pain sensitivity enough for us to notice the pain
257
What can we do in the prostaglandin pathway to treat pain
Knocked down prostaglandin synthesis by inhibiting COX1 and COX2 enzymes
258
How are prostaglandins formed?
COX1 and COX2 catalyze (speed up) two chemical reactions in a row
COX enzymes turn arachidonic acid into precursor compound PGG2
Then COX enzymes turn PGG2 into prostaglandin H2 (PGH2)
Specialized enzymes Direct compounds (PGE2, PGI2, PGF2alpha, TXA) into different pathways
259
What is an example an enzyme used to convert PGH2 into other specific prostaglandins?
Prostaglandin E2 is put together by enzyme prostaglandin E2 synthase
260
Tell me what you know about COX1 Enzyme:
Widespread in the body
Lots of tissues are capable of producing prostaglandins and TXA2 because of COX1
261
Tell me what you know about COX2 enzymes:
COX2 is more inducible form of cyclooxygenase: expressed in response to inflammatory stimuli
turned on to pain/ harmful stimuli in event something bad is happening
Drugs that affect COX2 are useful in treating pain
Drugs more specific for COX2 are more effective for pain management
262
Why were very specific COX2 inhibitors pulled off the market?
Very effective and strong pain meds
COX2 is also involved in keeping kidneys healthy and heart help make corrections after period of ischemia or infarction
Removed from market because of cardiovascular events
263
What is an example of a super specific COX2 inhibitor?
Vioxx: off market because cardiovascular events
264
What is the strongest over-the-counter painkiller?
Naproxen—more COX2 specific
265
What is the leukotriene arm in AA responsible for?
immune mediated inflammation
266
What is the enzyme responsible for turning AA into leukotrienes?
Lipoxygenase (LO)
267
What are HETEs and EETs used for?
Important mediators in acute inflammatory responses (acute renal failure)
- these drugs are hard to deal with because they're unstable
268
Arachidonic acid and HETE/EET are ___, while leukotrienes and prostaglandins are ___
hydrophobic; hydrophilic
269
What are some functions of proteins in the cell membrane?
Transport complexes, enzymes, receptors
270
What are some ways that water can get in and out of the cell?
They can sneak through electrolyte channels or through aquaporins that are dedicated for water
271
What is simple diffusion through the cell membrane?
It allows things to move across the cell wall without any help, and it does not require any ATP
272
What is something that can cross the cell wall through simple diffusion?
Gasses
273
What is a channel protein used for?
It is another form of simple diffusion that provides a conduit to allow a specific molecule or ion to cross the membrane
274
Why is a channel protein still considered simple diffusion?
It does not require energy;
does not require binding, conformational change and releasing
275
What dictates movement in simple diffusion?
concentration or electrical gradient of the cell/compound
276
What charge does a resting cell have?
Negative
277
What is movement across a cell membrane that requires energy called?
Active transport (pumps require energy)
278
What is facilitated diffusion?
It includes binding, conformational change, then releasing, but does not require energy
279
What is facilitated diffusion dependent on?
How many transporters you have and then concentration gradient
280
What is an example of facilitated diffusion?
GLUT transporters
281
What are GLUT 4 transporters used for?
They are insulin dependent
If you have more insulin in the body it pulls more transporters to the cell wall - this will pull more glucose into the cell and decrease your blood sugar
282
What percent of glucose movement across the membrane occurs through GLUT 4 transporters?
98%
283
What is GLUT 1 transporters used for?
Red blood cells
284
How does the sodium/potassium ATP ase pump work?
It takes one ATP, rips off a phosphorus to make it ADP and this energy is used to move 5 ions in a direction they don't want to go
285
What 5 ions are moved in the Na/K pump and which direction do they go?
3 sodium move out of the cell and 2 potassium move into the cell
286
What percent of the cells energy goes to the Na/K pump?
60-70%
This is the most energy consuming process in the body
287
What are some examples of active transport?
Na/K pump
Calcium specific pump
Proton pump
Sodium calcium exchanger
Sodium glucose channels
288
What is the sodium concentration ratio of ECF:ICF?
10:1
289
What is the potassium concentration ratio of ECF:ICF?
1:30
290
What are the two types of active transport and what is the difference?
First degree: directly uses ATP by the pump itself
Second degree: uses energy from another process that burns ATP
291
What is the calcium concentration ratio of ECF:ICF?
10,000:1
292
What type of transport is a calcium pump that moves Ca ion outside of the cell and requires energy?
First degree active transport
293
How does a proton pump work?
Uses ATP directly to take a proton (hydrogen ion) and move it to the outside of the cell to create a more acidic environment
294
How does a sodium calcium exchanger work?
a transport protein in the membrane pushes calcium out of the cell against it's electrochemical gradient in exchange for 3 sodium to come into the cell
295
Give examples of first degree and second degree active transport
First degree: Na/K ATPase pump, Calcium pump, Proton pump
Second degree: NCX, Sodium glucose transporters
296
How does the sodium glucose transporters work?
If we want to move glucose into the cell faster than it wants to go, then it can hitch a ride with sodium because sodium is already traveling down it's gradient
not found throughout body: specific to kidneys to reabsorb glucose after its been filtered
297
Where are GLUT 4 transporters typically found?
Muscle and fat: large systems that can impact the rest of the body if increased glucose transport: using all the glucose in the blood
298
What is Vmax?
maximal speed conformation change can occur in transporters for facilitated diffusion
once at max rate and max amount of transporters cant really transport any faster
299
What is total osmotic pressure?
Amount of physical hydraulic pressure generated via osmosis
OR
amount of force we would have to exert to prevent movement d/t osmosis
300
What is the difference between osmolality and osmolarity?
Osmolality: quantity of "stuff" dissolved in 1kg of water
Osmolarity: Quantity of "stuff" dissolved in 1L of solution
1L of solution is less water than 1L of water
301
Specific cells Tylenol targets in COX pathway:
Neurons: useful pain control and stays away from bleeding aspect because it specifically acts in nervous system
302
Primary way Ca2+ is removed from cells:
NCX: sodium calcium exchanger
303
At sea level, what offsets osmotic pressure?
increased weight
304
List some factors that contribute to rate at which items move across cell wall:
Concentration: if bigger difference moves faster
Lipid solubility: more lipid soluble moves faster
Size: smaller=faster
Pores: more pores=faster movement
Temp: higher temp faster movement
Physical pressure: pushing something through cell wall (pumps)
Charges: increased rate with opposite charge
305
How does Na/K pump maintain osmolarity?
Gets rid of excess Na+ in cell
Water follows when Na+ is pumped out
Helps maintain intracellular volume
306
What would happen to the cell if Na/K pump stopped working?
Na+ would build up in cell
Water would build up in cell
Intracellular edema :(
307
Why can't we just give lasix to deal with intracellular edema?
It wont work on the cellular level
Very difficult to fix intacellular edema: would need to fix Na/K ATPase
308
Patient is septic in ICU and not meeting energy requirements body needs: what is happening inside the body?
Na/K pump is not pumping as fast because there is not a good source of ATP
intracellular edema
309
Where does the Na+ inside the cell come from?
1) Secondary active transport processes: NCX
2) Cell wall is somewhat leaky to Na+ at rest
3) Na+ comes into cells during action potentials
310
What contributes to resting membrane potential in a cell?
1) Na/K pump
2) Protein distribution within cell wall
3) Electrolyte gradients
311
What is typical membrane potential of a resting cell?
-80mV
312
What happens to membrane potential when a cell is activated?
Briefly flips positive then goes back to resting state so it can be excited again
313
What does negative membrane potential indicate?
A resting cell that is ready to go
314
How do proteins contribute to membrane potential?
Proteins usually have negative charge (amino acids are majority negative)
Proteins make inside of cell negative
315
What is the typical process of generating an action potential?
Na+ floods cell, membrane potential becomes more positive
316
How does Na/K pump contribute to resting membrane potential?
Moving one positive charge out on each cycle of the pump
Sets up all electrolyte gradients in cell
317
Vrm:
Resting membrane potential (mV)
318
What is voltage?
Potential difference between 2 places
319
Nernst Potential AKA Equilibrium Potential equation:
320
What is the nernst potential used for?
Formula that tells us what charge the cell would be if it were only permeable to ONE ion
Good estimate of overall membrane potential
321
What would we expect membrane potential to be if cell is only permeable to Na+?
+61mV
322
What would we expect membrane potential to be if cell is only permeable to K+?
-90mV
323
What happens when K+ concentrations are changed ?
Heart problems related to membrane potential (impact on electrical system of heart)
Messes with underlying membrane potentials of all excitable cells
324
What dictates overall charge of the cell?
Everything the cell is permeable to that is charged
325
What is a cell permeable to at rest?
Very permeable to K+
Slightly permeable to Na+
10X more permeable to K+ than Na+
326
What is a cell permeable to when active?
Could become more permeable to Na+ or Ca2+
327
What is the dominant electrolyte that determines resting membrane potential?
K+
328
Goldman Equation
Combination of equilibrium potentials for each ion in same equation
Looks at concentration gradient of each ion with relative permeability factor
329
What does EMF stand for?
Membrane potential
Electromagnetic Force
Electromagnetic flux
Motive force
330
What heavily influences membrane potential and whether a cell will be + or - ?
Ion with the highest permeability
331
Why is the predicted osmolarity higher than the biological osmolarity (corrected osmolarity)?
Not all ions freely disassociate so they don't behave as individual --> which is what predicted osmolarity is showing
332
How is osmotic pressure calculated?
osmolality (osmolarity) x 19.3 mmhg
333
How do drugs interact with electronegativity of the cell?
All drugs interact with membrane potentials of cell
Membrane potential is manipulated by many drugs
334
What characteristics determine how electrolytes affect electrical activity of the cell?
Concentration gradients
Charge of ion
335
How does Chloride permeability alter membrane potential of neurons?
inhibits action potentials
336
what is important to look at when trying to figure out membrane permeability of a cell?
chemical gradient
cell wall permeability to electrolytes
337
Why is it beneficial to know equilibrium potential of individual ions?
Equilibrium potential is the charge required on inside of the cell to prevent an electrolyte from moving down its concentration gradient
338
If cell is only permeable to one ion, what would the membrane potential be?
membrane potential of that cell would be dictated by nernst potential of that ion
339
What would the membrane potential be of a cell that is only permeable to Na+?
+61mV
340
What are the permeability trends of K+ and Na+ for a cell at rest?
A cell at rest is VERY permeable to K+ and permeable to Na+
10x more permeable to K+ than Na+
341
What happens to membrane permeability during an action potential?
cell is more permeable to Na+
342
What 3 things determine an ions driving force?
- charge of the ion
- the concentration gradient
- charge of the inside of the cell
343
If a cell at rest (-80mV) was permeable to sodium, potassium, and calcium, which would have the greatest driving force?
Calcium
- it has two positive charges
- it has a greater concentration gradient (10,000:1) than potassium and sodium
344
What is typical membrane potential during an action potential?
>0mV
345
What would slow down the driving force of sodium and calcium going into the cell?
If the cell is depolarized during an action potential and has a positive charge of +35
346
What is another way to define equilibrium potential?
The charge on the inside of the cell that's required to prevent an electrolyte from moving down it's concentration gradient
347
What charge would the cell need to keep potassium parked inside the cell?
-90 mV
348
What charge would the cell need to keep sodium from coming into the cell?
+61 mV
349
What are leak channels?
Most cells have leak channels
They are channels that are always open and "leaking" electrolytes
350
Why is the movement of potassium out of the cell blunted?
Because the cell normally has a net negative charge, the potassium is pretty happy staying in the negative charge
351
What type of leak channels are usually seen in a cell at rest?
Lots of K+ leak channels
a few Na+ leak channels (some resting Na+ permeability)
352
Why don't we have to actually have any current?
All we need is the POTENTIAL to have current
353
What drugs have an effect on voltage-gated sodium channels?
Drugs that end in -caine
Lidocaine, bupivacaine, etc.
354
Do Na+ leak channels cause action potentials?
Not by themselves--would need help from voltage gated Na+ channels
355
What causes the voltage gated channels to open?
when there is a change in voltage
356
What are some characteristics of voltage-gated sodium channels?
- very fast to open and close
- highly selective for sodium
357
What happens to K+ concentration gradient in a patient with hyperkalemia?
Concentration gradient would decrease
K+ no longer wants to leave cell as fast as normal
358
Describe how a voltage-gated sodium channel opens and closes
- Under resting conditions the activation gate (outside) is closed and the inactivation (inside) gate is open
- With stimulus the activation gate swings open to allow sodium into the cell
- The inactivation gate slams shut
- During repolarization, the gates are reset
359
What happens to K+ equilibrium potential in a patient with hyperkalemia?
Equilibrium potential becomes more positive
360
What would happen to membrane potential in cell that has normal Na+ concentration and decreased K+ concentration gradient?
There would be new range for Vrm
would be more positive but still close to equilibrium potential of K+
361
Why is repolarization so important for VG sodium channels?
If repolarization doesn't happen and the cell doesn't go back to it's resting state, the cell might not be able to perform another action potential
362
How do VG potassium channels differ from VG sodium channels?
Potassium VG gates are slower to open and close so they're not acting at the same time as the sodium gates
363
Why is it bad when K+ is out of whack?
Messing with prime determinant of resting membrane potential
364
Describe hyperpolarization in regards to the VG potassium channels -
Because the gates are slower to close, it lets a little more potassium come in than what's needed
365
Why is it bad if Vrm is at an abnormal level?
Cell will not function normally and may be more or less difficult to excite
366
What is a cardiac issue involved with higher than normal Vrm?
EKG issues
Cell not able to rest and not able to work properly
V-fib when K+ is high enough
367
What is Polarization?
charge difference between inside and outside cell
normal resting polarity is negatively charged
368
How long is typical action potential?
About 3 milliseconds
369
What is depolarization?
Cell is excited and becomes more positively charged
membrane potential increases
Na+ or Ca2+ floods cell from action potential
370
What is repolarization?
Returning cell back to resting state
from depolarized to repolarized
From peak of action potential back to normal--voltage gated K+ channels open
371
What is hyperpolarization?
happens in the process of repolarizing cell--overshoot
dip below normal resting (-80mV) more difficult to excite
can happen naturally when cell is at rest
372
What is conductance?
The ease at which an ion can get across cell wall
how much ion flow there is
inverse to resistance
373
Why wont action potential ever reach +60mV?
That would require all K+ channels to be closed which will never happen
374
How do we send messages throughout body?
action potentials
375
Give example of how actions potentials can differ depending on where they are located:
action potentials have different shapes depending on which channels are involved:
fast action potential in heart, plateau phase
376
Why is the plateau phase important for cardiac action potentials?
action potential is sustained for longer amount of time
useful because that time in action potential defines how well heart muscle will pump
377
How does hyperkalemia affect action potential?
Hyperkalemia makes the membrane potential more positive and doesn't allow the sodium channels to reset and could either prevent more action potentials or limit the amount of action potentials the cell has
378
How does hyperkalemia affect your heart in relation to action potential?
Because the hyperkalemia could slow/shut down the sodium channels and could lead to a slower heart rate/arrhythmia
- the pause in the action potential is what controls how well the heart muscle pumps
379
How is osmotic pressure corrected if out of whack?
Vasopressin
380
What is Dr. Schmidts hometown?
Milwaukee, Wisconsin
381
Where did Dr. Schmidt get his undergrad degree?
University of Wisconsin (Milwaukee campus)
382
Where did Dr. Schmidt go to grad school?
Medical college of Wisconsin - graduated in '08
383
What are Dr. Schmidt's degrees?
Undergrad: Biological Science
Grad: PhD in Physiology
384
Regarding transport of substances through the cell membrane, what characterizes active transport ?
A. It is mediated by a carrier protein.
B. It is selective of specific substances.
C. It relies on a concentration gradient.
D. It requires an additional source of energy.
D
385
This organelle functions to be the intracellular digestive system containing hydrolase enzyme granules…
A. Agranular endoplasmic reticulum
B. Lysosomes
C. Peroxisomes
D. Ribosomes
B
386
Translation is the process by which:
A. RNA is formed using DNA as a pattern within the cell nucleus
B. Water soluble substances are transported across a phospholipid membrane
C. Chromosomes are condensed during mitosis
D. Proteins are synthesized using RNA as a template
D
387
Higher in extracellular or intracellular fluid:| Amino acids, bicarbonate, chloride, fatty acids, glucose, magnesium, oxygen, phosphate, potassium, sodium
Intracellular - potassium, magnesium, phosphate, amino acids
Extracellular - sodium, chloride, bicarbonate, oxygen, glucose, fatty acids
388
Define transcription and translation:
Transcription - DNA => RNA
Translation - RNA => protein
