Homeostasis Flashcards
What is the science that is concerned with the
function of the living organism and its parts, and
of the physical and chemical processes involved?
Physiology
What is the study of disordered body
function
(i.e. disease), which is the basis for clinical
medicine?
Pathophysiology (“Path” means disease)
What is homeostasis?
Why is homeostasis important to proteins?
Why is homeostasis important to cells?
The maintenance of a stable internal environment
• Prevent denaturation of proteins (keeps them
from unraveling so they function properly)
• To keep cells under optimum conditions for
function and survival
• Claude Bernard
• Intracellular fluid compartment
• Extracellular fluid compartment
• Extracellular fluid compartment
Who coined the term “homeostasis”?
What are the two main body fluid compartments?
What body fluid compartment was Claude
Bernard referring to when he used the term
homeostasis?
What is the largest body fluid compartment?
What three compartments are contained within the
Extracellular fluid compartment?
What is interstitial fluid?
What is intracellular fluid?
What is transcellular fluid?
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What compartment within the extracellular fluid
compartment did Claude Bernard emphasize the
need for homeostasis?
Where does interstitial fluid (between cells) come
from
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When interstitial fluid returns to the plasma, what
does it bring with it?
What happens to these waste products?
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When plasma leaks out of the blood vessel and
becomes interstitial fluid, what does it bring with
it?
What needs to be within a stable range or
dysfunction will occur?
Should K+ be in high or low concentration inside
of the cell?
Should it be in high or low concentration outside
of the cell?
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Intercellular fluid
Interstitial fluid
Plasma
Transcellular
Fluid between cells
Fluid inside cells
Fluid elsewhere: joints, mucus, cerebrospinal
fluid around the brain, digestive juices, etc
Plasma
Plasma. The plasma leaks out of the blood
vessels and surrounds the cells. It is now
called interstitial fluid. Some of it enters the
cells and becomes intracellular fluid. When it
is reabsorbed back into the blood vessel, it is
called plasma again.
Carbon dioxide and other waste products
We exhale the CO2 and the other wastes are
excreted in the urine
Oxygen and nutrients, which is passed along
to the cells that need it.
Ions such as sodium (Na+), calcium (Ca++)
potassium (K+)
K+ should be high on the inside of a cell and
low on the outside
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Homeostasis Flashcards
Should Na+ be in high or low concentration inside
of the cell?
Should it be in high or low concentration outside
of the cell?
Which ion has to be strictly regulated so it stays
within a narrow range?
What converts glucose into usable energy?
What makes sure potassium concentrations stays
high inside of the cells?
What is responsible for replicating, transcribing,
and translating DNA?
What does the work of the body?
What are the monomers (building blocks) of
proteins?
What is the primary structure of a protein?
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Na+ should be high on the outside of a cell
and low on the inside
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Potassium (K+)
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Proteins
Proteins
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Proteins
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Proteins
Amino acids (AA)
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What is the secondary structure of a protein?
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What is the tertiary structure of a protein?
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What is the quaternary structure of a protein?
What does it mean when a proteins becomes
denatured?
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What denatures a protein?
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Why does our body temperature need to be kept
from overheating?
When proteins are too cold, do they function?
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The sequence of amino acids, like beads on a
necklace.
When this string folds into beta pleats (looks
like stairs).
When the protein folds onto itself and forms
links to keep it in that shape.
When two or more proteins link to each other.
When it loses its bonds that keep it in its
secondary, tertiary, and quaternary structure.
That will cause it to lose its function.
Mainly heat, but also pH disturbances (acids
and bases). Cold does NOT denature proteins
So our proteins do not become denatured.
What is a variable?
What are some examples of variables in the body
that can be measured by a doctor?
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What assures proper function of the body?
What is a set point?
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Is the set point one specific point?
What are two ways to correct deviations that are
outside of the acceptable range?
Which feedback mechanism promotes stability?
What is negative feedback?
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What is an example of negative feedback?
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No, but when they warm up, they will return
to function. When they are too hot, they will
never return to proper function.
anything that changes and can be measured
levels of calcium, glucose, hormones, liver
enzymes, blood pressure, force of heart
contraction, temperature
Maintaining variables within their set point
The optimum range for each variable in the
body
No, it is a range.
Negative feedback and positive feedback
• Negative feedback
When the variable deviates from the set point, the
correction is opposite in direction to the deviation to
return the variable toward the set point
When the deviation and correction go in opposite
directions. For example, if you are too hot, you need
to cool down. If your blood sugar is too high, it needs
to be pulled down with insulin.
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Homeostasis Flashcards
What does insulin do?
What does glucagon do?
What is the most common feedback mechanism in
the body: positive or negative feedback?
Which mechanism promotes instability and
disease, and is progressive?
How does positive feedback work?
How is positive feedback stopped?
What are three examples of positive feedback that
are normal?
Which feedback mechanism is rare?
Which feedback mechanism needs to be carefully
controlled?
How are deviation and compensation related?
What is a synergistic relationship?
What is an antagonistic relationship?
Are the body’s organs synergistic or antagonistic
to each other?
Which system works faster: the nervous system or
endocrine (hormone) system?
Which system’s effects last longer: the nervous
system or endocrine (hormone) system?
What is the cost of homeostasis?
How does equilibrium differ from homeostasis?
Is a reptile a poikilotherm or a homeotherm?
Which one is a human?
What is a poikilotherm and a homeotherm?
How does our body make heat?
What are the four main ways to lose heat?
Which method of heat loss is the most
predominant?
Pulls sugar from the blood and puts it into the cells. It
lowers blood sugar.
It is the storage form of glucose; stored in the liver.
When it is broken down (between meals, when blood
sugar gets too low), it raises blood sugar.
Negative feedback
Positive feedback
When the variable deviates from the set point, positive
feedback makes it deviate even farther from the set
point
Negative feedback has to kick in
Pregnancy
Blood clotting
Luteinizing hormone during ovulation
Positive feedback
Positive feedback
The greater the deviation, the greater the
compensation.
When one works with the other, both are trying to
accomplish the same thing
When one works against the goals of the other
They are synergistic at one moment and antagonistic
another moment. They are constantly trying to keep
homeostasis in the body
Nervous system starts to work faster
Endocrine system starts to work slower
Nervous system effects wear off fast
Hormones effects last longer
ATP (energy)
Equilibrium is when substances such as potassium, are
in equal proportions in two nearby areas. Equilibrium
of ions on the inside and outside of a cell membrane
would cause death.
a reptile is a poikilotherm
a human is a homeotherm
A homeotherm can regulate their own body
temperature, a poikilotherm needs sunlight to warm up
and shade to cool down.
It is a byproduct of metabolism. When we use food
and oxygen, heat is generated and must be eliminated
when it is in excess.
radiative, conductive, convective, and evaporative heat
losses
Radiative heat loss accounts for 60% of the way we
normally lose heat.
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Homeostasis Flashcards
What is radiative heat loss?
What is conductive heat loss?
What is convective heat loss?
What is evaporative heat loss?
When does evaporation occur?
What causes heat stroke?
When your body loses heat into the cooler
environment around you.
Heat loss from your body to a solid object that you
are touching.
Heat loss from your body to a fluid around your
body (humidity in air or if you are in water).
When water on skin surface becomes a gas; it leaves
the body and goes into the air, pulling off more water
off with it by cohesion. The result is that you become
cooler.
When the air temperature is high but humidity is low
(less than 10%).
When the air temperature is high AND humidity is
high. Because the air is humid, evaporation is less so
you cannot cool down, so your body gets too hot.
Most heat is lost from the body at room
temperature by which mechanism?
When the hypothalamic set-point temperature
is greater than the body temperature, what
happens to the body?
What mechanism causes heat loss from a
person when the environmental temperature is
hot (like 106F) and the relative humidity is
dry (like less than 10%)?
Radiation
When you are in a hot bath, do you lose or gain
heat?
What is the term for being too hot?
What is the term for being too cold?
What is the #1 environmental cause of
hyperthermia?
What is the #1 environmental cause of
hypothermia?
You do not lose heat; you gain heat
Sweating
Evaporation
Hyperthermia
Hypothermia
prolonged exposure to heat and high humidity
prolonged immersion in cold water
When someone is in icy cold water, what
Hypothermia through convection heat loss
might they die from, and by what mechanism?
What do peripheral (skin) receptors detect?
What do central (brain) thermal receptors detect,
and what part of the brain are they in?
What does the brain tell the body to do when it is
too cold?
What does the brain tell the body to do when it is
too hot?
What does a fever-causing substance do to the
set point in the hypothalamus?
Why are high fevers dangerous, especially in
children?
What does the body do to compensate for
being too cold?
Changes in coldness only; they fire more when cold.
Changes in heat and cold
These receptors are in the hypothalamus portion of the
brain
Too cold: shiver
Too hot: sweat
Raises the set point so the body thinks it is too cold.
The body responds by shivering to warm up. The body
then heats up more, and a fever results.
High temperatures denature proteins in the brain.
Children’s brains are not fully developed.
Shivering (generates heat)
Vasoconstriction
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Homeostasis Flashcards
What effect does vasoconstriction (blood
vessels clamp down) have on temperature?
What does the body do to compensate for
being too hot?
How does a person die from heat stroke?
What is exercise-induced hyperthermia?
Does the hypothalamic set point change?
What is fever-induced hyperthermia?
Does the hypothalamic set point change?
In which hyperthermia condition does a person
sweat more: exercise or fever?
What is a pyrogen?
What is an antipyretic?
Do pyrogens (like bacteria) alter the hypothalamic
set point?
Do antipyretics (like Tylenol) alter the
hypothalamic set point?
It slows blood flow to the skin so less heat is lost.
Overall effect is to warm the core body temperature,
although fingers might feel cold.
Sweat (evaporation cools body)
Vasodilation (allows heat to escape
The person is too hot, so vasodilation occurs.
However, this causes blood pressure to drop.
That leads to hypoxia (low oxygen), then anoxia (no
oxygen), in the brain, heart, and kidneys. This leads to
organ failure and death
When your temperature goes up because you are
exercising. The set point does NOT change.
When your temperature goes up because you are
exposed to a bacteria or chemical that causes a fever.
The set point DOES change.
Exercise
Anything that resets the thermal set point to a higher
temperature (usually bacterial infection)
A medicine that returns an elevated set point back to
normal
Yes; they raise the set point so the body becomes
hotter.
Yes; they reduce the set point so the body becomes
cooler.
What are four examples of an antipyretic?
Aspirin
Acetaminophen (Tylenol)
Ibuprophen (Advil)
Naproxen (anti-inflammatory medicine)
How is a prostaglandin made?
Cell membranes are made of phospholipids. One
phospholipid is arachidonic acid. The enzyme called
COX cuts the arachidonic acid into pieces called
prostaglandins.
Decreases the synthesis of prostaglandins
What is the effect of a medicine that is a COX
inhibitor?
What effect does a prostaglandin have on body
temperature?
What effect do bacteria have on prostaglandin
(PG) synthesis?
What effect does Tylenol have on PG’s?
What is an NSAID?
It increases the set point so the body temperature
elevates
Bacteria increase PG synthesis. That is why we get a
fever during infection
Tylenol and other antipyretics are PG inhibitors.
That’s how they lower body temperature during a
fever
Non-steroidal anti-inflammatory drug. It is a group of
medicines that reduce inflammation (and therefore
pain) and reduce fever. There are also steroidal antiinflammatory drugs like cortisone.
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Homeostasis Flashcards
– Increased metabolism
– Increased vasodilation (more blood flow)
– Increased T-cell proliferation
Sweating and cutaneous vasodilation (blood vessels
When a fever has "broken" and the core
temperature is falling, what two effects does it open up in the skin and gives a red appearance)
What are three advantages of having a fever?
have on the body?
What happens in the body during the
induction phase of a fever when the core
temperature is rising?
Shivering and cutaneous vasoconstriction
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