Transcript File - Biology with Radjewski

Ch 29-31, 34 Unit 3 Review
Strive for a 5!
Radjewski 2013
Ch 29 #1 Define homeostasis and list
things that are important to maintain
• Homeostasis – maintenance of internal
conditions
• Important things to maintain:
– pH
– Ion concentrations
– Oxygen and carbon dioxide levels
– temperature
#2 Negative or Positive?
a. Increase in pepsin occurs, so this is positive
feedback Rather than returning the system to a set point, the process amplifies the response
that activates the
conversion of pepsinogen to pepsin. This increase in deviation from the set point is a process that typically
reaches a limit and then terminates rapidly. This is an appropriate response to ingested food.
b. Drinking response to low bp – negative feedback.
When low blood-pressure causes (un-stretched) sensory neurons to provide feedback information that blood
pressure has decreased, reflexes are activated to restore optimal blood pressure. The action required to
return blood pressure to “normal” in this example include the activation of thirst, stimulating water intake
(drinking) that ultimately restores optimal blood pressure as the ingested water moves into the blood.
c. More platelets are formed as a response – positive feedback
Clumped platelets at an injury site release a chemical signal that further enhances clumping of
more platelets, helping to seal the leak in the injured vessel and reduce the loss of precious blood.
#3 Ectotherms and Endotherms
Ectotherm
• If temperature goes up in
ectotherm, the organism’s
body temperature goes up
Endotherm
• If temperature goes up in
endotherm, the organism’s
body temperature stays the
same
#4 Steroid vs. protein hormones
Steroid Hormones
• Lipid soluble
• Readily pass through cell
membranes
• Do not dissolve in watery
blood plasma
• So they circulate bound to
carrier proteins
Protein Hormones
• Water soluble
• So they are easily
transported in the blood
• Cannot cross cell
membranes easily, so they
rely on signals on the
plasma membranes of
target cells
#5 Downregulation of insulin receptors
in diabetes type II
• Remember High concentrations of a hormone can cause a decrease
in the number of that hormone’s receptors – that’s downregulation.
Downregulation reduces the organism’s sensitivity to the hormone.
• In Type II diabetes, chronically high levels of
the hormone insulin (usually caused by
excessive carbohydrate intake) downregulate
production of insulin receptors throughout
the body, making the cells become less
sensitive to the hormone.
#6a Persons with hypothyroid goiters
have very high levels of thyroid
hormones in their blood
• False
• Hypothyroid goiter results when there is not
enough circulating thyroxine to turn off
thyroidstimulating hormone or TSH
production.
• This stimulates growth of the thyroid gland, to
the extent that is becomes the visible goiter.
#6b Persons with hypothyroid goiter
have very high levels of thyroidstimulating hormone in their blood
• True
• The levels of TSH are high in people with
hypothyroid goiter because there is not
enough thyroid hormone circulating to turn
off TSH production in the anterior pituitary
gland
• i.e., the negative feedback signal (thyroid
hormones) is at low levels or absent
#6c Persons with hypothyroid goiter
have very high levels of thyrotropin
releasing hormone in their blood
• True
• The levels of TRH are abnormally high for the
same reason as given in part B., above: lack of
• negative-feedback signals (low or absent
thyroid hormones).
• Remember TRH stimulates the release of TSH.
#7 ICE CREAM!
• Ingestion of excessive amounts of foods high
in calcium will cause calcium levels in the
bloodstream to rise.
• This, in turn, will inhibit the secretion of
parathyroid hormone (PTH). Therefore, the
PTH levels of “Uncle” will be low relative to a
person with a more normal (lower calcium)
diet.
Ch 31 #8 Innate or Adaptive
Nonspecific vs. specific
a)
b)
c)
d)
Stomach acid destroying bacteria –
T cell destroying a virus
Skin preventing a virus from entering
Defensins destroying invaders that have plasma
membranes
e) Interferons preventing viruses from spreading
between neighboring cells
f) Antibodies preventing reinfection by chicken pox
#9 Antibodies vs. MHC
Antibodies
• Bind specifically to non-self
antigens/pathogens
MHC
• Can bind to a variety of
different pathogens
#10. Phagocytes vs. Lymphocytes
Similarities
• Both are white blood cells
• Both originate in bone
marrow
• Both are part of the
immune system
Differences
• Phagocytes are non-specific
and destroy pathogens by
phagocytosis. They are
involved in innate and
adaptive immunity
• Lymphocytes are only
involved in adaptive
immunity. They are specific
to only one type of
pathogen. Examples are B
cells, T cells and natural
killer cells
#11 pathogen lands on skin
• skin is a physical barrier that bacteria can
rarely penetrate.
• the saltiness and acidityof the skin are not
hospitable to bacterial growth.
• Numerous bacteria and fungi that normally
reside on body surfaces without causing
disease compete with potential pathogens for
space and nutrients.
#11 b. Pathogen lands in your mouth
• saliva contains lysozyme that cleaves bonds in
the cell walls of many bacteria, causing them
to rupture.
• If bacteria move from the mouth to the nasal
passages, mucus provides a line of defense.
• If bacteria in the mouth are swallowed,
peristaltic and ciliary movement help move
them to the acidic stomach.
11c. Pathogen is ingested in water
• Gastric juice is deadly for many bacteria
because of the hydrochloric acid and
proteases that are secreted into it.
12. Antigens vs. antibodies
Antigens
• Foreign substance in the
body; “non-self”
• Produce an immune
response
Antibodies
• Proteins produced by B cells
• They specifically bind to
antigens
#13Older vs. Younger
• Older people have been exposed to more
pathogens over their lifespan, with more
opportunities to build up immunity, and thus
have a more diverse “arsenal” of antibody
capacity.
#14 T helper cells vs. cytotoxic T cells
Both have specific membrane receptors that bind to antigens. Response is different
T helper
Cytotoxic T cells
• Binding activates the
adaptive immune system
• Binding results in death of
antigen
15a. Cough of someone gets on arm,
you don’t get sick.
15b Ill, temperature then fine
Ch 34 #16 Afferent vs. Efferent
Neurons
Afferent
• Project to central nervous
system (brain and spinal
cord)
• Information from them
affects what happens next
in the central nervous
system
Efferent
• Project out of the central
nervous system
• Information from them
effect changes in the
periphery, such as muscles
and glands.
#17 Explain how neurons come to have more Na ions outside
the cell than in the cytosol, and more K ions inside the cell than
in the extracellular fluid.
• Sodium potassium pump
• It uses the energy of ATP hydrolysis to actively
expel Na+ from inside the cell, exchanging
them for K+ from the outside.
• This causes the concentration of Na+ to be
higher outside the cell, and the K+
concentration to be higher inside the cytosol
of cell, creating a concentration gradient for
both ions.
18. Draw neuron and label.