blood clotting: a three step program

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blood clotting a three step program
1. plug it up 2. slow the flow 3. seal the
slice site
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1. plug it up
this is accomplished by the platelets, those
small blood cells we talked about earlier they
undergo a drastic change in shape when
they contact collagen and other compounds not
encountered in the blood vessel wall, but found
on the outside of the vessels. why do they
encounter the outside of the vessel?
skin
collagen
blood vessel wall
blood vessel
before after
Texas AM-Kingsville, Dr. J.C. Pérez
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2. slow the flow
signals released from clumped platelets (including
serotonin) cause the blood vessels to
constrict this slows the flow of blood to the
cut site
clumped platelets
after
before
Texas AM-Kingsville, Dr. J.C. Pérez
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3. seal the slice site
floating around in your bloodstream are blood
clotting proteins in their inactive
form contact with the wound site, collagen, and
possibly other factors start a cascading process
where these proteins are transformed into their
active forms at the end of this complex cascade
is the production of a fibrous protein called
"fibrin" which first forms a soft
clot eventually, through cross-linking, the
fibrin proteins form a hard clot (a "scab")
Texas AM-Kingsville, Dr. J.C. Pérez
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Hemophilia
a genetic disease effecting mostly males at a
rate of about 1 in several thousand hemophiliacs
have problems with blood clotting they also can
start to bleed internally with light trauma in
their joints and muscles without treatment, this
can lead to severe pain, joint damage,
disability and early death it is caused by
alterations in the DNA sequence of either
factor VIII, factor IX or (more rarely) factor
XI
Texas AM-Kingsville, Dr. J.C. Pérez
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so how do the blood clots form that cause strokes?
it's not known entirely, but experiments with
mice have suggested that a product of fat cells
in the body - leptin - somehow causes platelets
to clump together improperly, leading to blood
clots. ...so people with excess fat cells
presumably have higher levels of leptin in the
blood than normal, which could explain the
increased blood clotting in overweight
people the resulting stoppage or decrease in
blood flow can lead to a stroke recent studies
suggest, though, that what may be happening is
that leptin buildup leads to "plaques" - fatty
deposits on the walls of blood vessels. If these
plaques burst, then the body initiates a blood
clotting reaction, and this can lead to a stroke
or heart attack
thanks Beth!
centers for disease control
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blood types
determined by "antigens" on the surfaces of red
blood cells these antigens are proteins produced
from genes for our purposes, there are two
classes of these antigens (there are actually
many more than that) 1) ABO 2) Rh factor
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ABO blood types
ABO refers to the three types of antigens in this
class "A" "B" and "O" ("O" means no antigen at
all) Since you inherited one antigen from your
mother one from your father, then different
people have one of the following 6
combinations AA, AO, BB, BO, AB, OO AA and AO
are "type A" BB and BO are "type B" AB is "type
AB" OO is type "type O"
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Rh factor blood types this is easier, since
there are only two possibilities either you
inherited, (from each parent) an Rh antigen or
you didnt "" means that you inherited an Rh
antigen "-" means that you didn't again, there
are three possibilities, since you inherited one
Rh gene from your mother and one from your
father , -, and -- and - are "Rh" --
is "Rh-"
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what are the universal donor and universal
acceptor blood types and why?
people who have one of the blood antigen types on
their red blood cells have the other type of
antibody in their blood so...if you are blood
type A then you have antibodies in your
blood and if you are blood type B then you have
antibodies in your blood and if you are
blood type O then you have
antibodies in your blood and if you are blood
type AB then you have antibody in
your blood and if you are blood type Rh- then
you have antibodies in your blood and
if you are blood type Rh then you
have antibodies in your blood
B
A
A and B
neither
Rh
these antibodies will react to blood cells that
have an antigen of the same type. so if you
receive such blood, then your body will reject
it! that would be bad!
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so......
if you are type AB, then you have no A,B, or Rh
antibodies so you are a "universal blood
acceptor" - your immune system will reject no
blood (lucky you!) and if you are type O-,
then you have all the antibodies, so you can
only accept O- blood. BUT, since, you have no A,
B, or Rh antigens you are a "universal blood
donor" - since no one will reject your blood!
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what are hormones, and what are they good for?
substances produced in one part of the body that
are carried in the bloodstream and have effects
on other parts of the body
a way for one part of the body to communicate
with other parts of the body a way for the body
to coordinate responses in multiple parts of the
body at the same time a way to control a process
that needs to vary over time
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endocrine system
hormone(s)
(examples)
body function
insulin, noradrenaline, thyroid hormone,
digestion, basal metabolism, etc.
corticosteroids
vasopressin, prolactin
water and salt regulation, excretion, etc.
calcitonin
calcium metabolism
growth hormone, thyroid hormone
growth and development
FSH, LH, estrogen, prolactin, testosterone progest
erone
reproductive organs reproduction
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types of hormones
steroid hormones - derived from cholesterol
peptide hormones - transcribed from genes
(e.g. insulin, melatonin, adrenaline)
modified amino acids (e.g. thyroid
hormone)
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control of levels of hormones
1) via both positive and negative control (e.g.
oxytocin) 2) negative feedback systems e.g.
corticotropin - corticosteroid thyroid
stimulating hormone - thyroid hormone follicle-st
imulating hormone - sex steroids
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some endocrine glands (and examples of hormones
produced there)
pituitary gland (in the brain) (thyroid
stimulating hormone, growth hormone,
prolactin) thyroid (in the throat) (thyroid
hormones) adrenal (on top of the
kidney) (aldosterone, glucocorticoids) pancreas
(accessory digestive organ) (insulin,
glucagon) kidney (erythropoietin) reproductive
(ovaries/testes) (LH, FSH, sex steroids)
Kidney
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