Transport and Transport and Circulatory SystemsCirculatory Systems

Why are transport and circulation Why are transport and circulation different ?different ?

Transport is the movement of one molecule from one Transport is the movement of one molecule from one place to another. place to another.

Circulation is the continous flow of the materials.Circulation is the continous flow of the materials.

Why do we need?Why do we need? Transport and circulation are necessary for the Transport and circulation are necessary for the

movement of molecules that cells need for movement of molecules that cells need for metabolism and the molecules that are formed as a metabolism and the molecules that are formed as a result of metabolism. Also they may help regulation result of metabolism. Also they may help regulation of body temperature and hormonal control.of body temperature and hormonal control.

Simple organismsSimple organisms

Unicellular and simple organisms exchange Unicellular and simple organisms exchange materials by osmosis, diffusion and active materials by osmosis, diffusion and active transport .transport .

Transport in plantsTransport in plants

Primitive plants like liverworts, mosses don’t have Primitive plants like liverworts, mosses don’t have transport systems. Ferns have primitive vascular transport systems. Ferns have primitive vascular tissues. In higher plants transport occurs in two ways. tissues. In higher plants transport occurs in two ways. Water and minerals are taken by roots and Water and minerals are taken by roots and transported to the stem and leaves by xylem. But transported to the stem and leaves by xylem. But organic molecules like glucose are transported from organic molecules like glucose are transported from leaves to the roots and from roots to the leaves by leaves to the roots and from roots to the leaves by phloem.phloem.

Also stomata are important for the gas exchange and Also stomata are important for the gas exchange and for transpiration. for transpiration.

MonocotyledonesMonocotyledones Have closed vascular bundles. Have closed vascular bundles.

There is no cambium. Vascular There is no cambium. Vascular bundles are scattered in the bundles are scattered in the stem. stem.

DicotyledonesDicotyledones They have open vascular They have open vascular

bundles. bundles. Have cambium between Have cambium between

xylem and phloem.xylem and phloem. Vascular bundles are Vascular bundles are

arranged in a circle.arranged in a circle.

LEAF ADAPTATIONSLEAF ADAPTATIONS Leaves are the organs where photosynthesis, Leaves are the organs where photosynthesis,

transpiration and gas exchange occur. Palisade transpiration and gas exchange occur. Palisade paranchyma is the most important part in the paranchyma is the most important part in the photosynthesis. photosynthesis.

Stomata are the place where gas exchange Stomata are the place where gas exchange occurs ( CO2 intake- O2 release in occurs ( CO2 intake- O2 release in photosynthesis, O2 consumption - CO2 release photosynthesis, O2 consumption - CO2 release in cellular respiration)in cellular respiration)

Epidermal cells secrete waxy substance called Epidermal cells secrete waxy substance called cuticle to prevent water loss. cuticle to prevent water loss.

Structure of the stomaStructure of the stoma 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 Although stoma cells are epidermis, they are the only epidermal cells with are the only epidermal cells with chloroplasts. When cells do photosynthesis chloroplasts. When cells do photosynthesis , glucose level increases. Increase in the , glucose level increases. Increase in the Glucose level increases the osmotic Glucose level increases the osmotic pressure of the cell, this causes the cell to pressure of the cell, this causes the cell to take in water. Due to the unequal take in water. Due to the unequal thickening of the cell wall, cell swells and thickening of the cell wall, cell swells and stomatal openning enlarges. stomatal openning enlarges.

If the stoma cells lose water ( glucose is converted to starch, water If the stoma cells lose water ( glucose is converted to starch, water amount is increased, osmotic pressure is decreased), stomatal amount is increased, osmotic pressure is decreased), stomatal openning gets smaller. 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.

FACTORS EFFECTING THE OPENNING FACTORS EFFECTING THE OPENNING OF STOMAOF STOMA

Light: Light: Light causes the stomata of most plants to open, admitting CO2 for photosynthesis.

Amount of CO2: 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.Temperature: Plants close the stomata above 30 C. Wind: wind sweeps away the water vapor around the leaf and increases Wind: wind sweeps away the water vapor around the leaf and increases

the transpiration. the transpiration. Humidity: If there are enough water available, stomata open but Humidity: If there are enough water available, stomata open but

transpiration is low at humid air.transpiration is low at humid air.

TranspirationTranspiration Transpiration is the diffusion of the water vapor through the Transpiration is the diffusion of the water vapor through the

stomata. Transpiration:stomata. Transpiration: Increases the pulling force of the leaves on the water. In that way Increases the pulling force of the leaves on the water. In that way

more minerals can be taken with more water. more minerals can be taken with more water. Increases the resistance of plant to drought. Increases the resistance of plant to drought. Encourages the excretion of excess water. Encourages the excretion of excess water. Plants are adapted for different conditions. 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 consists of 2 processes:Water transport consists of 2 processes: Absorption of water from roots(root pressure)Absorption of water from roots(root pressure) Transport of water in xylem (in vessels and tracheids)Transport of water in xylem (in vessels and tracheids)

Within living tissues, the movement of water from cell to cell Within living tissues, the movement of water from cell to cell follows a gradient of water potentiafollows a gradient of water potential(osmotic pressure). l(osmotic pressure). Over Over longer distances, ilonger distances, inn xylem vessels and phloem sieve tubes, the xylem vessels and phloem sieve tubes, the flow of water and dissolved solutes is driven by a gradient of flow of water and dissolved solutes is driven by a gradient of concentrationconcentration. . ((bulk flowbulk flow))

Water transport Water transport

ABSORPTION OF WATERABSORPTION OF WATER 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.

There is good evidence that root pressure There is good evidence that root pressure is is important and can be observed in important and can be observed in the the phenomenon of phenomenon of guttationguttation, in which liquid , in which liquid water is forced out through openings at the water is forced out through openings at the margins of leavesmargins of leaves. . Guttation occurs only Guttation occurs only under conditions of high atmospheric humidity under conditions of high atmospheric humidity and plentiful water in the soil, which occur and plentiful water in the soil, which occur most commonly at nightmost commonly at night. .

TThe key elements of he key elements of water transport in the water transport in the xylem arexylem are1. 1. Transpiration, Transpiration, the the evaporation of water evaporation of water from the leavesfrom the leaves2. 2. Tension Tension in the xylem in the xylem sap resulting from sap resulting from transpirationtranspiration3. 3. Cohesion Cohesion in the in the xylem sap from the xylem sap from the leaves to the rootsleaves to the roots

Transport of water in xylemTransport of water in xylem

The concentration of water vapor in the atmosphere is The concentration of water vapor in the atmosphere is lower than that in the leaf. Because of this difference, lower than that in the leaf. Because of this difference, water vapor diffuses from the intercellular spaces of water vapor diffuses from the intercellular spaces of the leaf, through openings called stomata, to the the leaf, through openings called stomata, to the outside air. This process is called outside air. This process is called transpirationtranspiration

The force generated by the evaporation of water from The force generated by the evaporation of water from the mesophyll cell walls creates a the mesophyll cell walls creates a tension tension that draws that draws more water into the cell walls, replacing thatmore water into the cell walls, replacing that which which was lostwas lost. . The removal of water from the The removal of water from the mesophyll mesophyll and and veins, establishes tension on the entire column of veins, establishes tension on the entire column of water within the xylem, so that the column is drawn water within the xylem, so that the column is drawn upward all the way from the roots.upward all the way from the roots.

The ability of water to be pulled upward The ability of water to be pulled upward through tiny tubes results from the through tiny tubes results from the cohesion cohesion of of water—the tendency of water molecules to stick water—the tendency of water molecules to stick to one another through hydrogen bonding. The to one another through hydrogen bonding. The narrower the tube, the greater the tension the narrower the tube, the greater the tension the water column can withstand without breaking. water column can withstand without breaking. The integrity of the column is also maintained The integrity of the column is also maintained by the adhesion of water to the xylem walls. by the adhesion of water to the xylem walls.

Adhesion: sticking together to the different Adhesion: sticking together to the different moleculesmolecules

Cohesion: sticking together to the same Cohesion: sticking together to the same moleculesmolecules

This transpiration-cohesion-tension 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 TRANSPORT OF ORGANIC MOLECULES (glucose, amino acids) IN PHLOEM(glucose, amino acids) IN PHLOEM

Substances in the phloem move from Substances in the phloem move from sources to sinks.sources to sinks. The flow can be in two The flow can be in two directions. directions. A A source source is an organ (such is an organ (such as a mature leaf or a storage root) that as a mature leaf or a storage root) that produces produces (by photosynthesis or by (by photosynthesis or by digestion of stored reserves) more digestion of stored reserves) more sugars than it requires. A sugars than it requires. A sink sink is an is an organ (such as a root, a flower, a organ (such as a root, a flower, a developing fruit or tuber, or an imma developing fruit or tuber, or an imma ture leaf) that ture leaf) that consumes consumes sugars for its sugars for its own growth and storage needs.own growth and storage needs.

Sugars (primarily sucrose), amino Sugars (primarily sucrose), amino acids, someacids, some minerals, and a variety of minerals, and a variety of other solutes are translocated between other solutes are translocated between sources and sinks in the phloemsources and sinks in the phloem. This . This translocation requires energy. translocation requires energy.

Translocation occurs by pressure flow. Translocation occurs by pressure flow. According to According to the the pressure flow model pressure flow model of translocation in the of translocation in the phloem, sucrose is actively transported into sieve tube phloem, sucrose is actively transported into sieve tube elements at a source, giving those cells a greater elements at a source, giving those cells a greater sucrose concentration than the surrounding cells. sucrose concentration than the surrounding cells. Water therefore enters the sieve tube elements by Water therefore enters the sieve tube elements by osmosis. The entry of this water causes a greater osmosis. The entry of this water causes a greater pressure potential at the source end of the sieve tube, pressure potential at the source end of the sieve tube, so that the entire fluid content of the sieve tube is so that the entire fluid content of the sieve tube is pushed toward the sink end of the tube— in other pushed toward the sink end of the tube— in other words, the sap moves by bulk flow in response to a words, the sap moves by bulk flow in response to a pressure gradientpressure gradient. . In the sink, the sucrose is unloaded In the sink, the sucrose is unloaded by active transportby active transport. .

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specific sugars and amino acids are actively specific sugars and amino acids are actively transported into cells of the phloemtransported into cells of the phloem. . In sink In sink regions, the solutes are actively transported regions, the solutes are actively transported out out of the sieve tube elements and into the of the sieve tube elements and into the surrounding tissuessurrounding tissues. .

CIRCULATORY SYSTEM IN CIRCULATORY SYSTEM IN ANIMALSANIMALS

The purpose of the circulatory system in The purpose of the circulatory system in animals:animals:

Transport of food monomers and gases to the Transport of food monomers and gases to the body cells.body cells.

Transport of unnecessary metabolites Transport of unnecessary metabolites Regulation of body temperatureRegulation of body temperature Transport of hormones and homeostasis.Transport of hormones and homeostasis.

Open circulatory system Closed circulatory system

1. No capillaries and veins

1. Capillaries and veins are found.

2. Heart/s and artery can be found.

2. Heart/s and artery can be found.

3. Tissue fluid(blood-endolymph) travels out of the bood vessels and mixes with the body fluid.

3. Blood never travels aout of the blood vessels.

4. In molluscs, arthropoda, insects.

4. Annelid(earthworm), cephalopods, all vertebrates.

ADVANTAGES OF CLOSED ADVANTAGES OF CLOSED CIRCULATORY SYSTEMCIRCULATORY SYSTEM

Blood can flow more rapidly through vessels than through Blood can flow more rapidly through vessels than through intercellular spaces, and can therefore transport nutrients and intercellular spaces, and can therefore transport nutrients and wastes to and from tissues more rapidly.wastes to and from tissues more rapidly.

By changing resistance in the vessels, closed systems can be By changing resistance in the vessels, closed systems can be more selective in directing blood to specific tissues.more selective in directing blood to specific tissues.

Specialized cells and large molecules that aid in the transport Specialized cells and large molecules that aid in the transport of hormones and nutrients can be kept withinof hormones and nutrients can be kept within the vessels, but the vessels, but can drop their cargo in the tissues where it is needed.can drop their cargo in the tissues where it is needed.

Overall, closed circulatory systems can support higher levels Overall, closed circulatory systems can support higher levels of metabolic activity than open systems can, especially in of metabolic activity than open systems can, especially in larger animals. How, then, do highly active insect species larger animals. How, then, do highly active insect species achieve high levels of metabolic output with their open achieve high levels of metabolic output with their open circulatory systems? One way is by not depending on their circulatory systems? One way is by not depending on their circulatory systems for respiratory gas exchangecirculatory 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 struc tures 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 .

Large surface areas and branched internal Large surface areas and branched internal cavities cannot satisfy the needs of larger cavities cannot satisfy the needs of larger animals with many layers of cells. The cells of animals with many layers of cells. The cells of such animals are surrounded by an internal such animals are surrounded by an internal environment of extracellular fluids, environment of extracellular fluids, tissue tissue fluidsfluids. .

Insects have open circulatory system. Insects have open circulatory system. The The contractions of the heart propel the tissue fluid contractions of the heart propel the tissue fluid through vesselsthrough vessels(small artery)(small artery) leading to different leading to different regions of the body, but the fluid leaves those regions of the body, but the fluid leaves those vessels to vessels to movemove through the tissues and through the tissues and eventually return to the heart. eventually return to the heart. TThe fluid returns to he fluid returns to the heart through valved openings called the heart through valved openings called ostiaostia. . In In these organisms tissue fluid(blood-endolymph) these organisms tissue fluid(blood-endolymph) only carries nutrients. Respiratory gases are only carries nutrients. Respiratory gases are carried by tracheal tubes. carried by tracheal tubes.

One large blood vessel on the ventral side of the earthworm carries blood 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 from its anterior end to its posterior end. Smaller vessels branch off and transport the blood to even smaller vessels transport the blood to even smaller vessels .. In the In the capillaries capillaries respiratory respiratory gasesgases(mostly around skin)(mostly around skin), nutrients, and metabolic wastes diffuse between , nutrients, and metabolic wastes diffuse between the blood and the tissue fluid. The blood then flows from these vessels into 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. 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 dorsal vessel carries the blood from the posterior to the anterior end of the body. the body.

Five pairs of vessels connect the large dorsal and ventral vessels in the 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 anterior end, thus completing the circuit. The dorsal vessel and the five connecting vessels serve as connecting vessels serve as heartshearts for the earthworm; their contractions for the earthworm; their contractions keep the blood circulating. The direction of circulation is determined by one keep the blood circulating. The direction of circulation is determined by one way valves in the dorsal and connecting vessels.way valves in the dorsal and connecting vessels.

Circulatory system in fishCirculatory system in fish The fish heart has two chambers. An The fish heart has two chambers. An

atrium atrium receives blood from the receives blood from the bodybody(deoxygenated)(deoxygenated) and pumps it into and pumps it into a more muscular chamber, the a more muscular chamber, the ventricleventricle. The ventricle pumps the . The ventricle pumps the blood to the gills, where gases are blood to the gills, where gases are exchanged. Blood leaving the gills exchanged. Blood leaving the gills (oxygenated)(oxygenated)collects in a large dorsal collects in a large dorsal artery, the artery, the aortaaorta, which distributes , which distributes blood to smaller arteries and arterioles blood to smaller arteries and arterioles leading to all the organs and tissues of leading to all the organs and tissues of the body. In the tissues, blood flows the body. In the tissues, blood flows through bedsthrough beds of tiny capillaries, of tiny capillaries, collects in venules and veins, and collects in venules and veins, and eventually returns to the atrium of the eventually returns to the atrium of the heartheart..

Pulmonary and systemic circulation are Pulmonary and systemic circulation are partly separated in adult amphibians. A partly separated in adult amphibians. A single ventricle pumps blood to the single ventricle pumps blood to the lungs and to the rest of the body. Two lungs and to the rest of the body. Two atria receive blood returning to the atria receive blood returning to the heart. One receives oxygenated blood heart. One receives oxygenated blood from the lungs, and the other receives from the lungs, and the other receives deoxygenated blood from the body.deoxygenated blood from the body. Because both atria deliver blood to the Because both atria deliver blood to the same ventricle, the oxygenated and same ventricle, the oxygenated and deoxygenated blood could mix, so that deoxygenated blood could mix, so that blood going to the tissues would not blood going to the tissues would not carry a full load of oxygen. carry a full load of oxygen.

These animals supply their oxygen need These animals supply their oxygen need also by their skin. also by their skin.

Circulatory system in amphibia

Turtles, snakes, and lizards are commonly said to have three-Turtles, snakes, and lizards are commonly said to have three-chambered hearts, while crocodilians (crocodiles and alligators) chambered hearts, while crocodilians (crocodiles and alligators) are said to have four-chambered hearts. But this statement is an are said to have four-chambered hearts. But this statement is an oversimplification. The hearts of all these animals have two oversimplification. The hearts of all these animals have two separate atria and a ventricle that is divided in a complex way so separate atria and a ventricle that is divided in a complex way so that mixing of oxygenated and deoxygenated blood is minimized.that mixing of oxygenated and deoxygenated blood is minimized.

Amphibians and reptiles can not keep constant their body Amphibians and reptiles can not keep constant their body temperature. They are called as poikilothermic animals.temperature. They are called as poikilothermic animals.

The four-chambered hearts of birds and mammals The four-chambered hearts of birds and mammals completely separate their pulmonary and systemic completely separate their pulmonary and systemic circuits.circuits. They kepp their body temp. Constant. They They kepp their body temp. Constant. They are called as homeothermic animals. are called as homeothermic animals.

homeothermic

poikilothermic

Env. Temp.

Body temperaturepoikilothermic

homeothermic

Metabolic rate

Env. Temp.

Human circulatory systemHuman circulatory system Heart always have deoxygenated blood in the right, oxygenated blood in the 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 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 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 valve prevents backflow of the blood rom ventricle to the atrium. Right ventricle pumps the deoxygenated blood to the lung by pulmonary artery. ventricle pumps the deoxygenated blood to the lung by pulmonary artery. Arteries always carry blood from the ventricles. Arteries always carry blood from the ventricles. The right heart pumps blood The right heart pumps blood through the pulmonary circuitthrough the pulmonary circuit. The oxygenated blood from the lung returns . The oxygenated blood from the lung returns back to the left atrium of the heart. The vein who carries the oxygenated blood 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.from the lung to the heart is called as pulmonary vein.

The oxygenated blood in the left The oxygenated blood in the left atrium then flows to the left atrium then flows to the left ventricle through mitral(bicuspid) ventricle through mitral(bicuspid) valve. Then the oxygenated blood valve. Then the oxygenated blood is pumped rom the left ventricule is pumped rom the left ventricule to the aorta. The to the aorta. The left heart pumps left heart pumps blood through the systemic circuit.blood through the systemic circuit. Also the arteries coming out of the Also the arteries coming out of the heart has valves at the beginning heart has valves at the beginning part. This valve helps the one part. This valve helps the one directional flow of the blood.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 circulationPulmonary and systemic circulation Pulmonary circulation is between the heart Pulmonary circulation is between the heart

and the lungs. Deoxygenated blood is and the lungs. Deoxygenated blood is pumped out of the right ventricle through pumped out of the right ventricle through the pulmonary artery to the lungs and in the the pulmonary artery to the lungs and in the lung capillaries gas exchange occurs. After lung capillaries gas exchange occurs. After oxygenated blood is collected by oxygenated blood is collected by pulmonary vein, it returns back to the left pulmonary vein, it returns back to the left atrium. atrium.

Systemic circulation is between heart and Systemic circulation is between heart and the body organs. Blood is pumped out of the the body organs. Blood is pumped out of the left ventricle through the aorta to the body left ventricle through the aorta to the body organ arteries. Material(gas, nutrients) organ arteries. Material(gas, nutrients) exchange occurs in the capillaries and blood exchange occurs in the capillaries and blood is collected back by veins to the vena cava is collected back by veins to the vena cava and flows to the right atrium. and flows to the right atrium.

Mechanism of heart contractionMechanism of heart contraction The contraction of the two atria, followed The contraction of the two atria, followed

by the contraction of the two ventricles and by the contraction of the two ventricles and then relaxation, is called the cardiac cycle. then relaxation, is called the cardiac cycle. Contraction of the ventricles is called Contraction of the ventricles is called ventricular systole, and relaxation of the ventricular systole, and relaxation of the ventricles called ventricular diastoleventricles called ventricular diastole..

Cardiac muscle has specific properties. Cardiac muscle has specific properties. First, cFirst, cardiac muscle cells are in electrical ardiac muscle cells are in electrical contact with one another through gap contact with one another through gap junctions, which enable action potentials to junctions, which enable action potentials to spread rapidly from cell to cellspread rapidly from cell to cell. . This This coordinated contraction is essential for coordinated contraction is essential for pumping blood effectively.pumping blood effectively.

Second, some cardiac muscle cells are Second, some cardiac muscle cells are pacemaker cellspacemaker cells. These cells have the ability . These cells have the ability to initiate action potentials without to initiate action potentials without stimulation from the nervous system.stimulation from the nervous system.(but (but speed of contraction can be controlled by speed of contraction can be controlled by sympathic and parasympathic nerves)sympathic and parasympathic nerves)The The primary pacemaker of the heart is a nodule primary pacemaker of the heart is a nodule of modified cardiac muscle cells, the of modified cardiac muscle cells, the sinoatrial nodesinoatrial node, located at the junction of , located at the junction of the superior vena cava and right atrium. the superior vena cava and right atrium.

A normal heartbeat begins with an action A normal heartbeat begins with an action potential in the sinoatrial nodepotential in the sinoatrial node. . This action This action potential spreads rapidly throughout the potential spreads rapidly throughout the electrically coupled cells of the atria, electrically coupled cells of the atria, causing them to contractcausing them to contract. . Situated at the Situated at the junction of the atria and the ventricles is a junction of the atria and the ventricles is a nodule of modified cardiac muscle cells nodule of modified cardiac muscle cells called the atrioventricular node, which is called the atrioventricular node, which is stimulated by the depolarization of the stimulated by the depolarization of the atria. With a slight delay, it generates atria. With a slight delay, it generates action potentials that are conducted to the action potentials that are conducted to the ventricles ventricles byby bundle bundle oof Hisf His. . The short The short delay in the spread of the action potential delay in the spread of the action potential imposed by the atrioventricular node imposed by the atrioventricular node ensures that the atria contract before the ensures that the atria contract before the ventricles do, so that the blood passes ventricles do, so that the blood passes progressively from the atria to the progressively from the atria to the ventricles to the arteries.ventricles to the arteries.

Arteries Veins Capillaries

Takes away the blood from the heart

Brings the blood to the heart Material exchange occurs between blood and body cells

Large arteries have many collagen, elastic fibers and smooth muscle, which enable them to withstand the high pressures of blood flowing rapidly from the heart

Vein walls are not thick and elastic as arteries. Thier diameter is large.

Capillary wall is very thin consists of 1 layer of epithelial cells. It is semipermeable.

Blood moves by the pressure created by the beating of the heart

Blood pressure is the lowest in veins

Blood pressure is low

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 Factors helping the movement of blood in the arteries and arterioles.arteries and arterioles.

Pressure formed by the contraction of ventricles. Pressure formed by the contraction of ventricles. Contraction of smooth muscle cells in the wall of Contraction of smooth muscle cells in the wall of

arteries. arteries. Pressure gradient Pressure gradient Pushing force of the bloodPushing force of the blood

Factors helping the movement of blood in the Factors helping the movement of blood in the veins and venulesveins and venules

One way valvesOne way valves Contraction of the skeletal muscles around them Contraction of the skeletal muscles around them Pressure changes in the chest Pressure changes in the chest Gravity *pressure gradient Gravity *pressure gradient Absorption force formed by the diastole of the atriumAbsorption force formed by the diastole of the atrium

Blood pressureBlood pressure Blood exerts a pressure to the walls of the blood vessels. This Blood exerts a pressure to the walls of the blood vessels. This

pressure is formed by the systole of the ventricles. Blood pressure pressure is formed by the systole of the ventricles. Blood pressure decreases as blood travels away from the heart. Blood pressure decreases as blood travels away from the heart. Blood pressure increases during systole, decreases during diastole. increases during systole, decreases during diastole.

Velocity of the bloodVelocity of the blood Velocity of the blood is affected from the diameter of the blood Velocity of the blood is affected from the diameter of the blood

vessels and the blood pressure. The velocity of the fluid decreases 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 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. in arteries but it decreases as arteries branch into many arterioles. The total cross-sectional area of the arterioles is bigger than the The total cross-sectional area of the arterioles is bigger than the AORTA, so the velocity is low in arterioles and in capillaries. AORTA, so the velocity is low in arterioles and in capillaries.

Material exchange between blood Material exchange between blood and body cells and body cells

Starling suggested that water balance in capillary beds is a result of Starling suggested that water balance in capillary beds is a result of two opposing forces, which have come to be known as Starling’s two opposing forces, which have come to be known as Starling’s forcesforces. . One force is One force is blood pressureblood pressure, which squeezes water and small , which squeezes water and small solutes out of the capillaries, and the other is solutes out of the capillaries, and the other is osmotic pressureosmotic pressure created by the large protein molecules that cannot leave the created by the large protein molecules that cannot leave the capillaries. Starling called this second force capillaries. Starling called this second force colloidal osmotic colloidal osmotic pressure. pressure. He hypothesized that blood pressure is high at the arterial He hypothesized that blood pressure is high at the arterial end of a capillary bed and drops steadily as blood flows to the end of a capillary bed and drops steadily as blood flows to the venous endvenous end..

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The colloidal osmotic pressure, The colloidal osmotic pressure, however, is constant along the however, is constant along the capillary. As long as the blood capillary. As long as the blood pressure is above the osmotic pressure is above the osmotic pressure, water leaves the capillary, pressure, water leaves the capillary, but when blood pressure falls below but when blood pressure falls below the osmotic pressure, water returns the osmotic pressure, water returns to the capillary. The actual numbers to the capillary. The actual numbers for a normal capillary bed in a for a normal capillary bed in a resting person suggest that there resting person suggest that there would be a would be a slight slight net loss of water net loss of water to the intercellular spaces.to the intercellular spaces.

Basınç Kan basıncı

Ozmotik basınç

Doku sıvısı

Atardamar kılcalı

Toplardamar kılcalı

Blood and blood clottingBlood and blood clotting

Functions of the blood:Functions of the blood: Transport: brings glucose, aa, vitamin, mineral and oxygen to Transport: brings glucose, aa, vitamin, mineral and oxygen to

the cells. Takes away the formed CO2, urea and excess water.the cells. Takes away the formed CO2, urea and excess water. Transport of hormones: Carries hormones to target organs. Transport of hormones: Carries hormones to target organs. Regulation: in homeostasis within the body. Regulation of Regulation: in homeostasis within the body. Regulation of

pH, water, temperature.pH, water, temperature. Immunity: White blood cells and antibodies fight against the Immunity: White blood cells and antibodies fight against the

diseases.diseases. Coagulation: helps to keep the blood in the vessels during an Coagulation: helps to keep the blood in the vessels during an

injury. )fibrinogen)injury. )fibrinogen) Keep the osmotic pressure of the blood constant by blood Keep the osmotic pressure of the blood constant by blood

proteins like albumen, globulin.proteins like albumen, globulin.

Blood proteins are formed in the liver. Blood proteins are formed in the liver. Red blood cells are made in the red bone Red blood cells are made in the red bone

marrow in spongy bones. Red blood cells marrow in spongy bones. Red blood cells don’t have nucleus, mitochondria. They live don’t have nucleus, mitochondria. They live for 120 days.Old red blood cells are broken for 120 days.Old red blood cells are broken down in liver and the heme(ıron) molecules down in liver and the heme(ıron) molecules are used again in the production of RBC. The are used again in the production of RBC. The unnecessary hemes are converted into bilirubin unnecessary hemes are converted into bilirubin and passes to the bile and thrown out by feces. and passes to the bile and thrown out by feces.

plasma

Plasma is the liquid part of the blood which has Plasma is the liquid part of the blood which has clotting proteins. But serum doesn’t have clotting proteins. But serum doesn’t have clotting proteins. clotting proteins. Plasma contains important proteins. Blood Plasma contains important proteins. Blood clotting proteins, antibody proteins, albumin clotting proteins, antibody proteins, albumin proteins for osmotic pressure. proteins for osmotic pressure.

Blood clottingBlood clotting Megakaryocytes are large cells that Megakaryocytes are large cells that

remain in the bone mar row and remain in the bone mar row and continually break off cell fragments continually break off cell fragments called platelets. A platelet is just a called platelets. A platelet is just a tiny fragment of a cell without cell tiny fragment of a cell without cell organellesorganelles and function in clotting. and function in clotting.

Blood clotting factors participate in a Blood clotting factors participate in a cascade of chemical reactions that cascade of chemical reactions that activate other substances circulating activate other substances circulating in the blood. The cascade begins with in the blood. The cascade begins with cell damage and platelet activation cell damage and platelet activation and leads to the conversion of an and leads to the conversion of an inactive circulating enzyme, inactive circulating enzyme, prothrombin, to its active form, prothrombin, to its active form, thrombin. Thrombin causes thrombin. Thrombin causes molecules of a plasma protein called molecules of a plasma protein called fibrinogen to polymerfibrinogen to polymer fibrin. fibrin.

When thrombocytes react with When thrombocytes react with O2, they form an enzyme O2, they form an enzyme thrombokinase. This enzyme thrombokinase. This enzyme changes Prothrombin into changes Prothrombin into thrombin in the presence of Ca. thrombin in the presence of Ca. Thrombin converts fibrinogen Thrombin converts fibrinogen into fibrin. And fibrin fixes the into fibrin. And fibrin fixes the injury. injury.

Lymphatic circulationLymphatic circulation

Lymphatic circulation consists of lymph capillaries, lymph Lymphatic circulation consists of lymph capillaries, lymph vesses and lymph nodules. It is avesses and lymph nodules. It is a separate system of vessels— separate system of vessels—the the lymphatic systemlymphatic system——which which returns tissue fluid to the blood.returns tissue fluid to the blood.

Functions of the Lymphatic systemFunctions of the Lymphatic system

Functions in material exchange. Collects extra fluid.Functions in material exchange. Collects extra fluid. Absorbs triglycerides(fatty acids and glycerols) .Absorbs triglycerides(fatty acids and glycerols) . The lymph nodes also act as filters. Particles become The lymph nodes also act as filters. Particles become

trapped there and are digested by phagocytes in the trapped there and are digested by phagocytes in the nodes.nodes.

Lymph nodes are a major site of lymphocyte Lymph nodes are a major site of lymphocyte production and of the phagocytic action that removes production and of the phagocytic action that removes microorganisms and other foreign materials from the microorganisms and other foreign materials from the circulationcirculation

After entering the lymphatic vessels, the tissue fluid After entering the lymphatic vessels, the tissue fluid is called is called lymphlymph. Fine lymphatic capillaries merge . Fine lymphatic capillaries merge progressively into larger and larger vessels and end in progressively into larger and larger vessels and end in two lymphatic vessels—the two lymphatic vessels—the thoracic ductsthoracic ducts—that —that empty into large veins at the base of the neck . The empty into large veins at the base of the neck . The left thoracic duct carries most of the lymph from the left thoracic duct carries most of the lymph from the lower part of the body and is much larger than the lower part of the body and is much larger than the right thoracic duct.right thoracic duct. Thoracic duct mixes with blood Thoracic duct mixes with blood circulation from the left subclavian vein. circulation from the left subclavian vein.

Lymph, like blood, is propelled toward the heart by Lymph, like blood, is propelled toward the heart by skeletal muscle contractions and breathing skeletal muscle contractions and breathing movements, and lymphatic vessels, like veins, have movements, and lymphatic vessels, like veins, have one-way valves that keep the lymph flowing toward one-way valves that keep the lymph flowing toward the thoracic duct.the thoracic duct.

Emilen maddelerin izlediği yolEmilen maddelerin izlediği yolGlikoz- aa yağ ve ADEKGlikoz- aa yağ ve ADEK

İnce bağırsak toplar damarıİnce bağırsak toplar damarı Kapı toplar damarıKapı toplar damarı KaraciğerKaraciğer Karaciğer toplar damarıKaraciğer toplar damarı Alt ana toplar damarAlt ana toplar damar Sağ kulakçıkSağ kulakçık

Lenf damarıLenf damarı Peke sarnıcıPeke sarnıcı Sol Köprücük altı toplar Sol Köprücük altı toplar

damarıdamarı Üst ana toplar damarÜst ana toplar damar Sağ kulakçıkSağ kulakçık

Immune systemImmune system

TThymus, bone marrow, spleen, and hymus, bone marrow, spleen, and lymph nodes, are essential parts of the lymph nodes, are essential parts of the defense systemdefense system..

Spleen : filters blood, produces Spleen : filters blood, produces lymphocytes and monocytes. Destroy lymphocytes and monocytes. Destroy old erythrocytes.old erythrocytes.

lymph nodeslymph nodes : filter blood, holds : filter blood, holds microbesmicrobes

tonsillite: produces lymphocytes.tonsillite: produces lymphocytes. Bone marrow: Produces blood cells, Bone marrow: Produces blood cells,

do phagocytosis, produces antibodies. do phagocytosis, produces antibodies. Thymus: activates lymphocytes. Thymus: activates lymphocytes.

Defense typesDefense types 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. The humoral immune response, which produces

antibodies, the cellular immune response, which destroys infected

cells.

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.

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.

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.

AntibodiesAntibodies 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.

interferon: virüs bir canlıya girdiğinde , canlı interferon üretir ve canlıyı interferon: virüs bir canlıya girdiğinde , canlı interferon üretir ve canlıyı korur. İnterferon hücrelere bağlanarak özel enzimler üretmelerine sebep korur. İnterferon hücrelere bağlanarak özel enzimler üretmelerine sebep olur, bu enzimler virüs için gerekli proteinlerin yapımına engel olur. olur, bu enzimler virüs için gerekli proteinlerin yapımına engel olur.

İltihaplanma:zararı maddeler sonucu ortaya çıkan bir dizi olaydır. İltihaplanma:zararı maddeler sonucu ortaya çıkan bir dizi olaydır. İltihaplanma sırasında histamin salınır ve bu madde yaralı bölgeye kan İltihaplanma sırasında histamin salınır ve bu madde yaralı bölgeye kan akışını hızlandırır. Kılcaldan doku sıvısına geçiş artar. Akyuvarlar bu akışını hızlandırır. Kılcaldan doku sıvısına geçiş artar. Akyuvarlar bu bölgeye gelerek yabancı maddeleri fagositozla yok etmeye çalışırlar. Bu bölgeye gelerek yabancı maddeleri fagositozla yok etmeye çalışırlar. Bu durum yaralı bölgede şiş ve kızarıklık oluşturur. Bölgede irin oluşması durum yaralı bölgede şiş ve kızarıklık oluşturur. Bölgede irin oluşması ise akyuvar ölüleri ve mikrop kalıntılarını içerir.ise akyuvar ölüleri ve mikrop kalıntılarını içerir.

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Spesifik bağışıklıkSpesifik bağışıklık Vücuda giren moleküller algılanarak planlı bir Vücuda giren moleküller algılanarak planlı bir

engelleme ise spesifik bağışıklıkla olur. engelleme ise spesifik bağışıklıkla olur. Vücuda giren yabancı maddelerin(antijen) yok Vücuda giren yabancı maddelerin(antijen) yok edilebilmesi için antikor denilen özel bir edilebilmesi için antikor denilen özel bir madde üretilir.madde üretilir. Antikor: Bu maddeler protein

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.

Birinci tepki

İkinci tepki

hafta

Antikor yoğunluğu

Salgısal-Humoral bağışıklıkSalgısal-Humoral bağışıklık

B lenfositleri tarafından oluşturulur. İnsanda barsakta B lenfositleri tarafından oluşturulur. İnsanda barsakta lenfoid doku B lenfositlerinin olgunlaştığı yerdir. lenfoid doku B lenfositlerinin olgunlaştığı yerdir.

B lenfositleri antijenle karşılaştıklarında hemen B lenfositleri antijenle karşılaştıklarında hemen bölünürler ve plazma hücresini oluştururular. Plazma bölünürler ve plazma hücresini oluştururular. Plazma hücreleri antijene göre antikor üretmeye başlarlar. hücreleri antijene göre antikor üretmeye başlarlar. Antikorlar antijenleri etkisiz hale getirir.Bu işlem Antikorlar antijenleri etkisiz hale getirir.Bu işlem kanda veya lenfte gerçekleşir.kanda veya lenfte gerçekleşir.

Bazı B hücreleri hafız hücreleri olurlar ve aynı antijen Bazı B hücreleri hafız hücreleri olurlar ve aynı antijen vücuda girdiğinde daha hızlı olarak cevap yaratırlar.vücuda girdiğinde daha hızlı olarak cevap yaratırlar.

Hücresel bağışıklık: Hücresel bağışıklık: Timüste olgunlaşan T lenfositleri görev yaparlar. Bu Timüste olgunlaşan T lenfositleri görev yaparlar. Bu

hücreler doğrudan antijenle savaşırlar. Antijen hücreler doğrudan antijenle savaşırlar. Antijen makrofaj tarafından tutulur. Bilgi yardımcı T makrofaj tarafından tutulur. Bilgi yardımcı T hücresine aktarılır. Yardımcı T hücresi aktifleşir ve hücresine aktarılır. Yardımcı T hücresi aktifleşir ve bölünür. Yardımcı T hücreleri Humoral bağışıklığı da bölünür. Yardımcı T hücreleri Humoral bağışıklığı da tetiklerler. Mikropların fagositozu hızlanır.tetiklerler. Mikropların fagositozu hızlanır.

AŞILARAŞILAR Aşıda amaç denetimli bir enfeksiyon yaratarak Aşıda amaç denetimli bir enfeksiyon yaratarak

mikrobun organizma tarafından tanınmasını mikrobun organizma tarafından tanınmasını sağlamaktır. Aşı aktif bağışıklık sağlar etkisi sağlamaktır. Aşı aktif bağışıklık sağlar etkisi uzun sürelidir.uzun sürelidir.

Serum aşılarda ise hazır antikorlar Serum aşılarda ise hazır antikorlar bulunmaktadır bulunmaktadır