Download Circulatory System

Circulatory System Part 1
Begins
Hello there. I’m Mr. Heart
and I’m here to talk to you
about the circulatory system.
Cytoplasmic
streaming
moves materials
around in the
amoeba
Small organisms like the amoeba and
flatworm (planarian) do not need
circulatory systems. They simply move
substances through them by diffusion.
This is possible because of the amoeba
small size and the planarian’s thin
ribbon-like arrangement of cells.
I have a gastrovascular cavity like the
hydra with only a mouth. –no anus
that allows more diffusion with the
surrounding water
That’s right.
I’m very thin.
There are different types of circulatory systems.
OPEN CIRCULATORY SYSTEM
Blood circulates but is not always
contained within the blood
vessels, but rather bathes the
cells directly. Ex grasshopper
Heart arteries
maybe veins but
NO CAPILLARIES
Blood=interstitial fluid called hemolymph
CLOSED CIRCULATORY SYSTEM
Blood circulates around a body
within a continuous network of
blood vessels. Ex earthworm
Does the blood in open circulatory systems carry
oxygen?
That’s a very good question. Some Open
circulatory systems carry oxygen and others do
not. It depends on their gas exchange system.
Some invertebrates (like crabs)may use oxygen carrying
Hemocyanin is not
bound by blood cells.
It is based on Copper
not Iron as in
hemoglobin
Crabs use hemocyanin to circulate
oxygen from gills. Blood is BLUE
when oxygenated!
hemocyanin.......
Open
circulatory
system here
carries oxygen
in hemocyanin
Scorpion
But insects like grasshoppers do not carry
oxygen in their blood. It is called hemolymph.
No RESPIRATORY PIGMENTS in their hemolymph blood.
Air holes bring oxygen directly to the insect muscle.
You can see all the air holes in white on the diagram.
So then how do
they get their
oxygen?
RESPIRATORY PIGMENTS
proteins oxygen can bind
to- increasing oxygen
transport in the medium.
These open
circulatory systems
do not carry
oxygen.
Some spiders
and scorpions
(not insects) also
have
hemolymph.
They have a
similar gas
exchange system
to insects.
Did you know?
Horseshoe crabs are
not really crabs.
They are more
related to spiders
and scorpions
This horseshoe crab
uses hemocyanin to
circulate oxygen from
gills. Blood is BLUE!
Hemocyanin is not
bound by blood cells.
It is based on Copper
not Iron as in
hemoglobin
A horseshoe crab cannot right itself if
turned over.
The blood is used by medical labs to
detect bacterial toxins.
Horseshoe crabs are living fossilsvirtually unchanged for 445 million
years! They are the closest we can
get to a huge group of extinct
marine invertebrates called
trilobites.
single circulation
This is called
. The blood
travels through the heart only once during each
complete circuit.
Blood moves
slowly under
low pressure
and is
delivered to
body cells
Blood slows down in
the capillaries of the
gills and picks up
oxygen (red colour
code)
Slow blood
movement back to
heart
This is called DOUBLE CIRCULATION as
the blood travels though the heart twice each
circuit. Higher blood pressure delivers the
nutrients more effectively to the body cells.
High pressure blood to
lungs
Three camber heart has
only one ventricle.
Oxygenated and
deoxygenated blood mix
each time it pumps.
High pressure blood to
body cells
SYSTEMIC CIRCUIT
Double circulation also occurs here but the blood does
not mix. The heart acts like two hearts in one. The
right side pumps dexoygenated blood to the lungs and
the left pumps oxygenated blood to the body cells.
PULMONARY
CIRCUIT
SYSTEMIC
CIRCUIT
EVOLUTION WATCH
CONVERGENT EVOLUTION
Although birds and
mammals have the same
circulation model the bird
heart evolved from
different ancestors than
that of the mammal
Let’s talk about blood and blood cells now. Blood is
made of both solid and liquid components.
BLOOD CELLS AND CELL FRAGMENTS
–SOLID blood
BLOOD PLASMA
=LIQUID blood
RED BLOOD CELLS
ERYTHROCYTES
45% of blood
WHITE BLOOD CELLS
LEUKOCYTES
< 1% of blood
PLATELETS
55 % of
blood
Normally, blood appears as a red solution. CENTRIFUGE
to separate the blood components
Balance equivalent
samples opposite
each other
Close the top
Spin the samples – heavy
materials sink to bottom
Sample test tube centrifuged to separate
Red blood cells sink to bottom –heaviest
Make up 45% of the blood
Many needed to carry essential oxygen
White blood cells and platelets in middle
Make up less than 1%
Plasma forms liquid at the top.
Makes up 55%
Hello there Mr. Erythrocyte. Tell us a little
about yourself.
My main job is to carry oxygen to the cells. I use
hemoglobin found inside me to do this.
Hemoglobin is the molecule I use to form a weak
covalent bond with oxygen. It is weak because I
have to let oxygen go when I reach body cells.
Hemoglobin is made of IRON (makes me red) and 4
PROTEIN subunits.
The erythrocyte has a biconcave- shape. It is a little like a
doughnut but the hole does not go through ...... or a Certs
breath mint.
The diameter is 8 micrometers.
I have no nucleus- that is an exception to normal cells- and I
thus have a limited life -120 days. I am recycled in the liver.
I have no propulsion system so the heart provides my only push
One of the 4 subunits of
hemoglobin is shown
here. With 4 iron
molecules the
hemoglobin bonds 4
oxygen molecules
What about the carbon
dioxide. The blood has to
carry that away
Let me tell you about
my special
RESPIRATORY
PIGMENT -
Initially I take up 90% CO2, but I convert it into
bicarb and diffuse it to the plasma(I keep 23%
CO2) I carry the H+ from the carbonic acid to
prevent blood acidification. Note pH decrease
(acid) makes me dump more oxygen, so when
CO2 is made, acidifying the blood locally I direct
more O2 to that area. Called the
hemoglobin.
BOHR EFFECT
Oxygen loading and unloading “dump truck” action. When one
oxygen unloads, due to partial pressure differences, they all
unload due to changes in the protein structure. The same idea
applies when oxygen attaches to hemoglobin. See curve below.
Sigmoidal
curve
I carry about
70% of CO2 as
bicarb. and 7%
in plasma. Sorry
but O2 and CO2
don’t dissolve
well in water.
We are dumping more Carbon dioxide into
the bloodstream than usual due to exercise.
CO2
CO2
Hey, we are getting more oxygen. That’s
exactly what we need. Thanks Mr.
Erythrocyte. But how did he know?
CO2
O2
I take 90% of
CO2 and
convert it to
carbonic acid
and bicarb
More carbon
dioxide in the blood
is causing a local
excess carbonic
acid overload.
O2
O2
A pH decrease
automatically causes
me to dump more
oxygen in these
tissues
What is this
process called?
BOHR EFFECT
Did you know?
The porphyrin ring structure is
common to hemoglobin.
Chlorophyll and retinal use this
type of structure for light
absorption
Hemoglobin and red blood is not limited to the vertebrates.
The earthworm is an annelid and it has red blood -hemoglobin
Here’s a real exotic annelid – the giant tube worm that only
lives at the depths of the ocean near volcanic vents. It has a
brilliant red colour at the tip due to the presence of a
special type of hemoglobin that absorbs both oxygen in the
presence of hydrogen sulfide.
Mr. Leukocyte, could you tell us a
little about yourself now?
Bein’ a white blood cell, I am responsible for
protectin’ the body. I actually spend most of my
time huntin’ down the bad guys in the interstitial
fluid and the lymphatic system. See that little
purple thing in the blood. That’s a white blood cell.
White blood cells (leukocytes) are larger than red blood
cells and are clear
Leukocytes have a nucleus
Leukocytes use amoeboid motion to move on their own in
the blood stream
Lymphocytes can squeeze out of the circulatory system
and into the interstitial fluid surrounding cells.
Here you can see some of the various types of white blood
cells. There are two type of leukocytes- granulocytes and
agranulocytes. Lymphocytes include both B and T cells which
are involved in the immune response.
I happen to be a B
cell( a type of
lymphocyte) capable
of producing the
antibodies. When I
am like this I can be
called an activated B
cell or plasma cell. I
have the license to
kill the bad invaders
with my antibodies.
Gun. My ammo has
the criminal’s name
on it as it will only
attach to him.
These antibodies are
trapping me. I can’t do
any harm now!
This is my gun. It fires antibodies and disables the bad guys. The antibodies are
specifically designed to attach to the cell markers of the invaders.
The antibodies have a Y shape
and the ends have an antigen
binding site that is specific to
each different type of microbe.
The antibody only binds one
antigen and must be “custom
made” by B cells each time you
get a new infection.
You can’t use
those
antibodies
on me I’m
different
than that
other
bacteria.
Platelets(thrombocytes) are involved in blood clotting
Platelets combine with fibrinogen to
form a net-like plug where there is
damage to the circulatory system
FIBRINOGEN
Platelets shown becoming activated
FIBRIN
Platelets have no nucleus
and are considered to be
cell fragments.
Platelets only last
about 8 days.
Destroyed in the
liver + spleen
FIBRIN NET
Blood clot
formed
Although I can live off
siphoning plant juice for
energy, I need to suck
blood to obtain protein
for the development of
my eggs. I inject a
salivary anticoagulent
so that the
thrombocytes are not
able to stop me from
siphoning away the
blood.
Hey what are you doing here Mrs.
Mosquito?
Hey I
require
fresh blood
also.
Vampire
bats
need it
too.
Sometimes the saliva with the anticoagulant includes other
parasites like the protozoa that cause MALARIA
(Plasmodium) or the viruses that cause West Nile disease.
Too bad for you.
When you bite the
victim and inject the
anticoagulent, it causes
a local inflammation
that we see a the
mosquito bite bump! It
is caused by the
injected antigens
causing mast cells to
release histamine. This
also causes the itch.
We leeches
like to suck
your blood
too.
All the blood cells are produced in the red bone
marrow of long bones.
Hey it’s Zack Nephron from the kidneys. Why are you here Zack?
All blood cells
from
PLURIPOTENT
STEM CELLS in
red marrow
Kidneys produce
ERYTHROPOIETIN (EPO)
hormone that initiates more
erythrocyte production. It’s
done when tissues do not
receive enough O2. EPO
levels drop when blood
delivers more O2 than the
tissues use. Ex of NEGATIVE
FEEDBACK
Hi there, I’m Mr Plasma, not to be confused
with my brother Mr. Serum.
You know, there is just no way I could ever carry
enough oxygen to the tissues Up to 2L of O2 is
needed per minute. I can provide only 4.5 mL of
that if I don’t have Mr. Erythrocyte
I’m 90 % water and I dissolve the following, giving
me this straw- like colour
dissolved proteins
glucose
clotting factors-fibrinogen
eletrolytes
hormones
antibodies
bicarbionate
Carbon
dioxide
I’m serum and I have the clotting
factors(FIBRINOGENS) removed.
DID YOU KNOW?
EPO is used in blood doping to improve athletic
performance. It is banned in the Olympics.
EPO can be used to treat people with anemia.
Leukemia is cancer of the blood – One
cure is to kill all the pluripotent stem cells
and replacing them with noncancerous
stem cells from a donor. Here you can see
the stem cell injection in to the patient.
I’m so weak. I
need more O2
in my blood.
Circulatory System Part 1
end