Transcript Transport and Circulatory Systems Why are transport

Transport and
Circulatory Systems
Why are transport and circulation
different ?
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Transport is the movement of one molecule from one
place to another.
Circulation is the continous flow of the materials.
Why do we need?
Transport and circulation are necessary for the
movement of molecules that cells need for
metabolism and the molecules that are formed as a
result of metabolism. Also they may help regulation
of body temperature and hormonal control.
Simple organisms
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Unicellular and simple organisms exchange
materials by osmosis, diffusion and active
transport .
Transport in plants
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Primitive plants like liverworts, mosses don’t have
transport systems. Ferns have primitive vascular
tissues. In higher plants transport occurs in two ways.
Water and minerals are taken by roots and
transported to the stem and leaves by xylem. But
organic molecules like glucose are transported from
leaves to the roots and from roots to the leaves by
phloem.
Also stomata are important for the gas exchange and
for transpiration.
Monocotyledones
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Have closed vascular bundles.
There is no cambium. Vascular
bundles are scattered in the
stem.
Dicotyledones
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They have open vascular
bundles.
Have cambium between
xylem and phloem.
Vascular bundles are
arranged in a circle.
LEAF ADAPTATIONS
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Leaves are the organs where photosynthesis,
transpiration and gas exchange occur. Palisade
paranchyma is the most important part in the
photosynthesis.
Stomata are the place where gas exchange
occurs ( CO2 intake- O2 release in
photosynthesis, O2 consumption - CO2 release
in cellular respiration)
Epidermal cells secrete waxy substance called
cuticle to prevent water loss.
Structure of the stoma
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A pair of specialized epidermal cells,
called guard cells, controls the opening
and closing of each stoma. When the
stomata are open, CO2 can enter the leaf
by diffusion—but water vapor is lost in the
same way. The inner side of the guard cell
wall is thicker than the outer part. This
structural detail enables the openning and
closing of the stoma.
Although stoma cells are epidermis, they
are the only epidermal cells with
chloroplasts. When cells do photosynthesis
, glucose level increases. Increase in the
Glucose level increases the osmotic
pressure of the cell, this causes the cell to
take in water. Due to the unequal
thickening of the cell wall, cell swells and
stomatal openning enlarges.
If the stoma cells lose water ( glucose is converted to starch, water
amount is increased, osmotic pressure is decreased), stomatal
openning gets smaller.
 K+ concentration in the guard cells also controls the openning of
the stoma. The increase in the concentration of K+, increases the
osmotic pressure of the cells.
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FACTORS EFFECTING THE OPENNING
OF STOMA
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Light: Light causes the stomata of most plants to open, admitting
CO2 for photosynthesis.
Amount of CO2: A low level favors opening of the stomata, thus
allowing the uptake of more CO2. When CO2 is low the pH is
basic, this encourages the conversion of starch to glucose. When
glucose is high, stoma opens.
Water stress is a common problem for plants, especially on hot,
sunny, windy days. Plants have a protective response to these
conditions, which uses the water potential of the mesophyll cells
as a cue. Even when the CO2 level is low and the sun is shining, if
the mesophyll is too dehydrated— plant closes the stomata and
prevent further drying of the leaf. This response reduces the rate of
photosynthesis, but it protects the plant.
Temperature: Plants close the stomata above 30 C.
Wind: wind sweeps away the water vapor around the leaf and
increases the transpiration.
Humidity: If there are enough water available, stomata open but
transpiration is low at humid air.
Transpiration
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Transpiration is the diffusion of the water vapor through the
stomata. Transpiration:
Increases the pulling force of the leaves on the water. In that way
more minerals can be taken with more water.
Increases the resistance of plant to drought.
Encourages the excretion of excess water.
Plants are adapted for different conditions.
Plants in dry conditions
Plants in humid
conditions
Leaf Surface area
narrow
Large
Stomata number
Few (embedded in deep)
More (on the surface)
Cuticle
thick
thin
Leaves
With hair
Without hair
Veins
few
more
Roots
ın deep layers
on the surface
Water transport
Water transport consists of 2 processes:
 Absorption of water from roots(root pressure)
 Transport of water in xylem (in vessels and tracheids)
Within living tissues, the movement of water from cell to cell
follows a gradient of water potential(osmotic pressure). Over
longer distances, in xylem vessels and phloem sieve tubes, the
flow of water and dissolved solutes is driven by a gradient of
concentration. (bulk flow)
ABSORPTION OF WATER
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Water moves into a root because the root has a
higher osmotic pressure than does the soil
solution. Water moves from the cortex of the
root into the stele (which is where the vascular
tissues are located) because the stele has a
more osmotic pressure than does the cortex.
The basis for root
pressure is a higher
solute concentration,
and accordingly a
more osmotic
pressure in the
xylem sap than in
the soil solution.
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There is good evidence that root pressure is
important and can be observed in the
phenomenon of guttation, in which liquid
water is forced out through openings at the
margins of leaves. Guttation occurs only
under conditions of high atmospheric humidity
and plentiful water in the soil, which occur
most commonly at night.
Transport of water in xylem
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The key elements of
water transport in the
xylem are
1. Transpiration, the
evaporation of water
from the leaves
2. Tension in the xylem
sap resulting from
transpiration
3. Cohesion in the
xylem sap from the
leaves to the roots
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The concentration of water vapor in the atmosphere is
lower than that in the leaf. Because of this difference,
water vapor diffuses from the intercellular spaces of
the leaf, through openings called stomata, to the
outside air. This process is called transpiration
The force generated by the evaporation of water from
the mesophyll cell walls creates a tension that draws
more water into the cell walls, replacing that which
was lost. The removal of water from the mesophyll
and veins, establishes tension on the entire column of
water within the xylem, so that the column is drawn
upward all the way from the roots.
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The ability of water to be pulled upward
through tiny tubes results from the cohesion of
water—the tendency of water molecules to
stick to one another through hydrogen
bonding. The narrower the tube, the greater the
tension the water column can withstand
without breaking. The integrity of the column
is also maintained by the adhesion of water to
the xylem walls.
Adhesion: sticking together to the different
molecules
Cohesion: sticking together to the same
molecules
This transpiration-cohesiontension mechanism requires no
work (that is, no expenditure of
energy) on the part of the plant.
(don’t forget that xylem cells are
nonliving). At each step between
soil and atmosphere, water
moves passively toward a region
with a more negative water
potential(high osmotic pressure).
In addition to promoting the
transport of minerals,
transpiration contributes to
temperature regulation.
TRANSPORT OF ORGANIC MOLECULES
(glucose, amino acids) IN PHLOEM
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Substances in the phloem move from
sources to sinks. The flow can be in two
directions. A source is an organ (such
as a mature leaf or a storage root) that
produces (by photosynthesis or by
digestion of stored reserves) more
sugars than it requires. A sink is an
organ (such as a root, a flower, a
developing fruit or tuber, or an immature leaf) that consumes sugars for its
own growth and storage needs.
Sugars (primarily sucrose), amino
acids, some minerals, and a variety of
other solutes are translocated between
sources and sinks in the phloem. This
translocation requires energy.
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Translocation occurs by pressure flow. According to
the pressure flow model of translocation in the
phloem, sucrose is actively transported into sieve tube
elements at a source, giving those cells a greater
sucrose concentration than the surrounding cells.
Water therefore enters the sieve tube elements by
osmosis. The entry of this water causes a greater
pressure potential at the source end of the sieve tube,
so that the entire fluid content of the sieve tube is
pushed toward the sink end of the tube— in other
words, the sap moves by bulk flow in response to a
pressure gradient. In the sink, the sucrose is unloaded
by active transport.
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http://www.whfreeman.com/thelifewire6e/con_index.htm?35 animasyon
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specific sugars and amino acids are actively
transported into cells of the phloem. In sink
regions, the solutes are actively transported out
of the sieve tube elements and into the
surrounding tissues.
CIRCULATORY SYSTEM IN
ANIMALS
The purpose of the circulatory system in
animals:
 Transport of food monomers and gases to the
body cells.
 Transport of unnecessary metabolites
 Regulation of body temperature
 Transport of hormones and homeostasis.
Open circulatory system
1. No capillaries and
veins
Closed circulatory
system
1. Capillaries and veins
are found.
2. Heart/s and artery can 2. Heart/s and artery can
be found.
be found.
3. Tissue fluid(blood3. Blood never travels
endolymph) travels out
aout of the blood
of the bood vessels
vessels.
and mixes with the
body fluid.
4. In molluscs,
4. Annelid(earthworm),
arthropoda, insects.
cephalopods, all
vertebrates.
ADVANTAGES OF CLOSED
CIRCULATORY SYSTEM
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Blood can flow more rapidly through vessels than through
intercellular spaces, and can therefore transport nutrients and
wastes to and from tissues more rapidly.
By changing resistance in the vessels, closed systems can be
more selective in directing blood to specific tissues.
Specialized cells and large molecules that aid in the transport
of hormones and nutrients can be kept within the vessels, but
can drop their cargo in the tissues where it is needed.
Overall, closed circulatory systems can support higher levels
of metabolic activity than open systems can, especially in
larger animals. How, then, do highly active insect species
achieve high levels of metabolic output with their open
circulatory systems? One way is by not depending on their
circulatory systems for respiratory gas exchange
A circulatory system is unnecessary if the cells of an organism are close
enough to the external environment that nutrients, respiratory gases, and
wastes can diffuse between the cells and the environment. Small aquatic
invertebrates have structures and body shapes that permit direct
exchanges between cells and environment. Many of these animals have
flattened body shapes that maximize the amount of surface area that is in
contact with the external environment .
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Large surface areas and branched internal
cavities cannot satisfy the needs of larger
animals with many layers of cells. The cells of
such animals are surrounded by an internal
environment of extracellular fluids, tissue
fluids.
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Insects have open circulatory system. The
contractions of the heart propel the tissue fluid
through vessels(small artery) leading to different
regions of the body, but the fluid leaves those
vessels to move through the tissues and
eventually return to the heart. The fluid returns to
the heart through valved openings called ostia. In
these organisms tissue fluid(blood-endolymph)
only carries nutrients. Respiratory gases are
carried by tracheal tubes.
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One large blood vessel on the ventral side of the earthworm carries blood
from its anterior end to its posterior end. Smaller vessels branch off and
transport the blood to even smaller vessels . In the capillaries respiratory
gases(mostly around skin), nutrients, and metabolic wastes diffuse
between the blood and the tissue fluid. The blood then flows from these
vessels into larger vessels that lead into one large vessel on the dorsal side
of the worm. The dorsal vessel carries the blood from the posterior to the
anterior end of the body.
Five pairs of vessels connect the large dorsal and ventral vessels in the
anterior end, thus completing the circuit. The dorsal vessel and the five
connecting vessels serve as hearts for the earthworm; their contractions
keep the blood circulating. The direction of circulation is determined by
oneway valves in the dorsal and connecting vessels.
Circulatory system in fish
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The fish heart has two chambers. An
atrium receives blood from the
body(deoxygenated) and pumps it into
a more muscular chamber, the
ventricle. The ventricle pumps the
blood to the gills, where gases are
exchanged. Blood leaving the gills
(oxygenated)collects in a large dorsal
artery, the aorta, which distributes
blood to smaller arteries and arterioles
leading to all the organs and tissues of
the body. In the tissues, blood flows
through beds of tiny capillaries,
collects in venules and veins, and
eventually returns to the atrium of the
heart.
Circulatory system in amphibia
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Pulmonary and systemic circulation are
partly separated in adult amphibians. A
single ventricle pumps blood to the
lungs and to the rest of the body. Two
atria receive blood returning to the
heart. One receives oxygenated blood
from the lungs, and the other receives
deoxygenated blood from the body.
Because both atria deliver blood to the
same ventricle, the oxygenated and
deoxygenated blood could mix, so that
blood going to the tissues would not
carry a full load of oxygen.
These animals supply their oxygen need
also by their skin.
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Turtles, snakes, and lizards are commonly said to have threechambered hearts, while crocodilians (crocodiles and alligators)
are said to have four-chambered hearts. But this statement is an
oversimplification. The hearts of all these animals have two
separate atria and a ventricle that is divided in a complex way so
that mixing of oxygenated and deoxygenated blood is minimized.
Amphibians and reptiles can not keep constant their body
temperature. They are called as poikilothermic animals.
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The four-chambered hearts of birds and mammals
completely separate their pulmonary and systemic
circuits. They kepp their body temp. Constant. They
are called as homeothermic animals.
Metabolic rate
Body temperature
poikilothermic
poikilothermic
homeothermic
homeothermi
c
Env. Temp.
Env. Temp.
Human circulatory system
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Heart always have deoxygenated blood in the right, oxygenated blood in the
left side.Deoxgenated blood from the body comes first to the right atrium by
veins. Blood then flows to the right ventricle through the tricuspid valve. This
valve prevents backflow of the blood rom ventricle to the atrium. Right
ventricle pumps the deoxygenated blood to the lung by pulmonary artery.
Arteries always carry blood from the ventricles. The right heart pumps blood
through the pulmonary circuit. The oxygenated blood from the lung returns
back to the left atrium of the heart. The vein who carries the oxygenated blood
from the lung to the heart is called as pulmonary vein.
The oxygenated blood in the left
atrium then flows to the left
ventricle through mitral(bicuspid)
valve. Then the oxygenated blood
is pumped rom the left ventricule
to the aorta. The left heart pumps
blood through the systemic circuit.
Also the arteries coming out of the
heart has valves at the beginning
part. This valve helps the one
directional flow of the blood.
Heart is composed of 3 layers. The inner layer is endocard, it is a very thin layer
which covers the inner surface of the heart. It contains epithelial cells and
connective tissue.
Myocard: is composed of cardiac muscle. It contains coronery blood vessels.
Pericard: is the outermost layer of the heart. It covers heart as an envelope. It
contains fluid inside this envelope. This layer reduces friction during
contractions.
Pulmonary and systemic circulation
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Pulmonary circulation is between the heart
and the lungs. Deoxygenated blood is
pumped out of the right ventricle through
the pulmonary artery to the lungs and in the
lung capillaries gas exchange occurs. After
oxygenated blood is collected by
pulmonary vein, it returns back to the left
atrium.
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Systemic circulation is between heart and
the body organs. Blood is pumped out of the
left ventricle through the aorta to the body
organ arteries. Material(gas, nutrients)
exchange occurs in the capillaries and blood
is collected back by veins to the vena cava
and flows to the right atrium.
Mechanism of heart contraction
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The contraction of the two atria, followed by
the contraction of the two ventricles and
then relaxation, is called the cardiac cycle.
Contraction of the ventricles is called
ventricular systole, and relaxation of the
ventricles called ventricular diastole.
Cardiac muscle has specific properties.
First, cardiac muscle cells are in electrical
contact with one another through gap
junctions, which enable action potentials to
spread rapidly from cell to cell. This
coordinated contraction is essential for
pumping blood effectively.
Second, some cardiac muscle cells are
pacemaker cells. These cells have the ability
to initiate action potentials without
stimulation from the nervous system.(but
speed of contraction can be controlled by
sympathic and parasympathic nerves)The
primary pacemaker of the heart is a nodule
of modified cardiac muscle cells, the
sinoatrial node, located at the junction of
the superior vena cava and right atrium.
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A normal heartbeat begins with an action
potential in the sinoatrial node. This action
potential spreads rapidly throughout the
electrically coupled cells of the atria,
causing them to contract. Situated at the
junction of the atria and the ventricles is a
nodule of modified cardiac muscle cells
called the atrioventricular node, which is
stimulated by the depolarization of the
atria. With a slight delay, it generates
action potentials that are conducted to the
ventricles by bundle of His. The short
delay in the spread of the action potential
imposed by the atrioventricular node
ensures that the atria contract before the
ventricles do, so that the blood passes
progressively from the atria to the
ventricles to the arteries.
Arteries
Takes away the blood from
the heart
Veins
Capillaries
Brings the blood to the heart
Material exchange occurs
between blood and body
cells
Large arteries have many
Vein walls are not thick and
collagen, elastic fibers and
elastic as arteries. Thier
smooth muscle, which
diameter is large.
enable them to withstand
the high pressures of blood
flowing rapidly from the
heart
Capillary wall is very thin
consists of 1 layer of
epithelial cells. It is
semipermeable.
Blood moves by the pressure Blood pressure is the lowest Blood pressure is low
created by the beating of
in veins
the heart
Blood pressure drops as it
travels away from the
heart.
Valves within veins and
venules prevent backflow
Found between arterioles
and venules.
Blood flow speed is high.
Blood flow speed is low
Blood flow speed is the
lowest in the capillaries.
Contraction of skeletal
muscles and absorption
force of heart help blood
movement in the vein
Factors helping the movement of blood in the
arteries and arterioles.
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Pressure formed by the contraction of ventricles.
Contraction of smooth muscle cells in the wall of
arteries.
Pressure gradient
Pushing force of the blood
Factors helping the movement of blood in the
veins and venules
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One way valves
Contraction of the skeletal muscles around them
Pressure changes in the chest
Gravity
*pressure gradient
Absorption force formed by the diastole of the atrium
Blood pressure
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Blood exerts a pressure to the walls of the blood vessels. This pressure
is formed by the systole of the ventricles. Blood pressure decreases as
blood travels away from the heart. Blood pressure increases during
systole, decreases during diastole.
Velocity of the blood
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Velocity of the blood is affected from the diameter of the blood
vessels and the blood pressure. The velocity of the fluid decreases
as it passes from a narrow tube to a wide tube. The velocity is high
in arteries but it decreases as arteries branch into many arterioles.
The total cross-sectional area of the arterioles is bigger than the
AORTA, so the velocity is low in arterioles and in capillaries.
Material exchange between blood
and body cells
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Starling suggested that water balance in capillary beds is a result of
two opposing forces, which have come to be known as Starling’s
forces. One force is blood pressure, which squeezes water and small
solutes out of the capillaries, and the other is osmotic pressure
created by the large protein molecules that cannot leave the
capillaries. Starling called this second force colloidal osmotic
pressure. He hypothesized that blood pressure is high at the arterial
end of a capillary bed and drops steadily as blood flows to the
venous end.
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The colloidal osmotic pressure,
however, is constant along the
capillary. As long as the blood
pressure is above the osmotic
pressure, water leaves the capillary,
but when blood pressure falls below
the osmotic pressure, water returns
to the capillary. The actual numbers
for a normal capillary bed in a
resting person suggest that there
would be a slight net loss of water
to the intercellular spaces.
Basınç
Kan basıncı
Doku
sıvısı
Ozmotik
basınç
Atardamar
kılcalı
Toplardamar
kılcalı
Blood and blood clotting
Functions of the blood:
 Transport: brings glucose, aa, vitamin, mineral and oxygen to
the cells. Takes away the formed CO2, urea and excess water.
 Transport of hormones: Carries hormones to target organs.
 Regulation: in homeostasis within the body. Regulation of pH,
water, temperature.
 Immunity: White blood cells and antibodies fight against the
diseases.
 Coagulation: helps to keep the blood in the vessels during an
injury. )fibrinogen)
 Keep the osmotic pressure of the blood constant by blood
proteins like albumen, globulin.
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Blood proteins are formed in the liver.
Red blood cells are made in the red bone
marrow in spongy bones. Red blood cells don’t
have nucleus, mitochondria. They live for 120
days.Old red blood cells are broken down in
liver and the heme(ıron) molecules are used
again in the production of RBC. The
unnecessary hemes are converted into bilirubin
and passes to the bile and thrown out by feces.
plasma
Plasma is the liquid part of the blood which has
clotting proteins. But serum doesn’t have clotting
proteins.
Plasma contains important proteins. Blood
clotting proteins, antibody proteins, albumin
proteins for osmotic pressure.
Blood clotting
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Megakaryocytes are large cells that
remain in the bone marrow and
continually break off cell fragments
called platelets. A platelet is just a
tiny fragment of a cell without cell
organelles and function in clotting.
Blood clotting factors participate in a
cascade of chemical reactions that
activate other substances circulating
in the blood. The cascade begins with
cell damage and platelet activation
and leads to the conversion of an
inactive circulating enzyme,
prothrombin, to its active form,
thrombin. Thrombin causes
molecules of a plasma protein called
fibrinogen to polymer fibrin.
When thrombocytes react with
O2, they form an enzyme
thrombokinase. This enzyme
changes Prothrombin into
thrombin in the presence of Ca.
Thrombin converts fibrinogen into
fibrin. And fibrin fixes the injury.
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Lymphatic circulation
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Lymphatic circulation consists of lymph capillaries, lymph
vesses and lymph nodules. It is a separate system of vessels—
the lymphatic system—which returns tissue fluid to the blood.
Functions of the Lymphatic system
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Functions in material exchange. Collects extra fluid.
Absorbs triglycerides(fatty acids and glycerols) .
The lymph nodes also act as filters. Particles become
trapped there and are digested by phagocytes in the
nodes.
Lymph nodes are a major site of lymphocyte
production and of the phagocytic action that removes
microorganisms and other foreign materials from the
circulation
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After entering the lymphatic vessels, the tissue fluid
is called lymph. Fine lymphatic capillaries merge
progressively into larger and larger vessels and end in
two lymphatic vessels—the thoracic ducts—that
empty into large veins at the base of the neck . The
left thoracic duct carries most of the lymph from the
lower part of the body and is much larger than the
right thoracic duct. Thoracic duct mixes with blood
circulation from the left subclavian vein.
Lymph, like blood, is propelled toward the heart by
skeletal muscle contractions and breathing
movements, and lymphatic vessels, like veins, have
one-way valves that keep the lymph flowing toward
the thoracic duct.
Emilen maddelerin izlediği yol
Glikoz- aa
yağ ve ADEK
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İnce bağırsak toplar damarı
Kapı toplar damarı
Karaciğer
Karaciğer toplar damarı
Alt ana toplar damar
Sağ kulakçık
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Lenf damarı
Peke sarnıcı
Sol Köprücük altı toplar
damarı
Üst ana toplar damar
Sağ kulakçık
Immune system
Thymus, bone marrow, spleen, and
lymph nodes, are essential parts of the
defense system.
 Spleen : filters blood, produces
lymphocytes and monocytes. Destroy
old erythrocytes.
 lymph nodes : filter blood, holds
microbes
 tonsillite: produces lymphocytes.
 Bone marrow: Produces blood cells,
do phagocytosis, produces antibodies.
 Thymus: activates lymphocytes.
Defense types
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Nonspecific defenses, or innate defenses, are
inherited mechanisms that protect the body from
many pathogens. These can be chemical or cellular.
An example is the skin
Specific defenses are adaptive mechanisms aimed at
a specific target. The recognition and destruction of
specific nonself substances is an important function
of an animal’s immune system.
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The humoral immune response, which produces
antibodies,
the cellular immune response, which destroys infected
cells.
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In the humoral immune response (from the Latin
humor, “fluid”), antibodies react with antigenic
determinants on pathogens in blood, lymph, and
tissue fluids.
Some antibodies are soluble and travel free in the
blood and lymph; others exist as integral membrane
proteins on B cells. The first time a specific antigen
invades the body, it may be detected and bound by a
B cell whose membrane antibody recognizes one of
its antigenic determinants. This binding activates the
B cell, which makes multiple soluble copies of an
antibody with the same specificity as its membrane
antibody.
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The cellular immune response is carried out
by T cells within the lymph nodes, the
bloodstream, and the intercellular spaces.
These cells have integral membrane proteins—
T cell receptors—that recognize and bind to
antigenic determinants. Once a T cell is bound
to an antigenic determinant, it initiates an
immune response that typically results in the
total destruction of a nonself or altered self
cell.
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The first time a vertebrate animal is exposed to a
particular antigen, there is a time lag (usually several
days) before the number of antibody molecules and T
cells slowly increases But for years afterward—
sometimes for life—the immune system “remembers”
that particular antigen. The secondary immune
response is characterized by a shorter lag time, a
greater rate of antibody production, and a larger
production of total antibody or T cells than the
primary response.
Antibodies
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Antibodies are proteins called
immunoglobulins. There are several types of
immunoglobulins, but all contain a tetramer
consisting of four polypeptide chains. In each
immunoglobulin molecule, two of these
polypeptides are identical light chains, and two
are identical heavy chains. Disulfide bonds
hold the chains together. Each polypeptide
chain consists of a constant region and a
variable region.
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interferon: virüs bir canlıya girdiğinde , canlı interferon üretir ve
canlıyı korur. İnterferon hücrelere bağlanarak özel enzimler
üretmelerine sebep olur, bu enzimler virüs için gerekli proteinlerin
yapımına engel olur.
İltihaplanma:zararı maddeler sonucu ortaya çıkan bir dizi olaydır.
İltihaplanma sırasında histamin salınır ve bu madde yaralı bölgeye
kan akışını hızlandırır. Kılcaldan doku sıvısına geçiş artar.
Akyuvarlar bu bölgeye gelerek yabancı maddeleri fagositozla yok
etmeye çalışırlar. Bu durum yaralı bölgede şiş ve kızarıklık
oluşturur. Bölgede irin oluşması ise akyuvar ölüleri ve mikrop
kalıntılarını içerir.
http://highered.mcgraw-hill.com/sites/0072437316/student_view0/chapter48/animations.html immune
Spesifik bağışıklık

Vücuda giren moleküller algılanarak planlı bir
engelleme ise spesifik bağışıklıkla olur.
Vücuda giren yabancı maddelerin(antijen) yok
edilebilmesi için antikor denilen özel bir
Antikor: Bu maddeler protein
madde üretilir.
yapıdadır.
Değişken kısımları vardır bu
bölgelerden
molekülleri(antijen)
tanırlar ve onlara bağlanarak onları
etkisiz hale getirirler.
Antijen vücuda girdikten sonra
antikorun kanda görülmesi 1 hafta
süre alabilir. İkinci defa aynı antijen
ile karşılaşırsa daha hızlı antikor
üretilir.
Antikor
yoğunluğu
İkinci tepki
Birinci tepki
hafta
Salgısal-Humoral bağışıklık



B lenfositleri tarafından oluşturulur. İnsanda barsakta
lenfoid doku B lenfositlerinin olgunlaştığı yerdir.
B lenfositleri antijenle karşılaştıklarında hemen
bölünürler ve plazma hücresini oluştururular. Plazma
hücreleri antijene göre antikor üretmeye başlarlar.
Antikorlar antijenleri etkisiz hale getirir.Bu işlem
kanda veya lenfte gerçekleşir.
Bazı B hücreleri hafız hücreleri olurlar ve aynı antijen
vücuda girdiğinde daha hızlı olarak cevap yaratırlar.
Hücresel bağışıklık:

Timüste olgunlaşan T lenfositleri görev yaparlar. Bu
hücreler doğrudan antijenle savaşırlar. Antijen
makrofaj tarafından tutulur. Bilgi yardımcı T
hücresine aktarılır. Yardımcı T hücresi aktifleşir ve
bölünür. Yardımcı T hücreleri Humoral bağışıklığı da
tetiklerler. Mikropların fagositozu hızlanır.


AŞILAR
Aşıda amaç denetimli bir enfeksiyon yaratarak
mikrobun organizma tarafından tanınmasını
sağlamaktır. Aşı aktif bağışıklık sağlar etkisi
uzun sürelidir.
Serum aşılarda ise hazır antikorlar
bulunmaktadır