(Circulatory System)

ORGAN SYSTEM FOR INTERNAL TRANSPORT

Overview: Transport and Exchange Every organism must exchange

materials with its environment Exchanges ultimately occur at the

cellular level In unicellular organisms, these

exchanges occur directly with the environment

For most cells making up multicellular organisms, direct exchange with the environment is not possible

Internal transport and gas exchange are functionally related in most animals

Open and Closed Circulatory Systems

In an open circulatory system, there is no distinction between blood and interstitial fluid, and this general body fluid is more correctly called hemolymph

In a closed circulatory system, blood is confined to vessels and is distinct from the interstitial fluid

Closed systems are more efficient at transporting circulatory fluids to tissues and cells

Heart

Hemolymph in sinusessurrounding organs

Heart

Interstitialfluid

Small branch vesselsIn each organ

Blood

Dorsal vessel(main heart)

Auxiliary hearts Ventral vessels

(b) A closed circulatory system(a) An open circulatory system

Tubular heart

Pores

CIRCULATORY SYSTEMDefiniton

It is a fluid-filled network of tubes (or vessels) through which materials move between the environment and the cells of a multicellular animal.

CIRCULATORY SYSTEMCharacteristic

It connects all parts of an organism in a way that allows individual cells to thrive as well as for organisms to function as a unit.

It is an entirely closed system.

CIRCULATORY SYSTEMFunctionTransport materials needed by cells

OxygenGlucose

Remove waste materials from cellsCarbon dioxideurea

CIRCULATORY SYSTEMMain Component

Pump (heart) Continuously circulates bloodNetwork of tubesArteries- blood away from heartVeins- blood back to the heartBloodFluid that fills the circulatory system

THE HEART

THE HEARTIt is the main organ of

the Circulatory System, which is located between lungs and diaphragm.

It is so powerful that it can pump blood

10, 000 liters of blood daily.

Parts of the Human HeartHeart is actually

made up of two pumps placed side by side:

- onto your right - onto your left

pericardium- protective membrane which surrounds the whole muscular organ

Heart Wall

Three layers of tissueEpicardium: This serous membrane of smooth outer surface of heart

Myocardium: Middle layer composed of cardiac muscle cell and responsibility for heart contracting

Endocardium: Smooth inner surface of heart chambers

Four Chambers of the Heart

1.Right and Left atria (sing.,atrium)- the upper thin walled chamber- collecting chambers of the heart

a. Right atrium(RA)- collects venous unoxygenated blood from your body

b. Left atrium(LA)- receives red oxygenated blood from your lungs

rightatrium

leftatrium

2. Right and Left ventricles - lower thick-walled chambers- the pumping chambers of your heart

a. Right ventricle(RV)- pumps blue venous blood out of your heart and into the lungs for oxygenation

b. Left ventricle(LV)- pumps oxygenated blood out of your heart to all parts of the body

rightventricle

leftventricle

Heart Valves1.Tricuspid

valve- between the right atrium and right ventricle

2. Bicuspid or mitral valve- between the left atrium and left ventricle

3. Pulmonary semilunar valve- between the right ventricle and the pulmonary artery

4. Aortic Semilunar Valve- between the left ventricle and aorta

A muscular wall, or septum, divides your heart into its right and left side.

Superior Vena Cava(SVC)- located at the upper part of your heart and brings blood from your head and arms.

Inferior Vena Cava(IVC)- located at the lower part of your heart and brings blood from the lower parts of your body.

Pulmonary Artery(PA)- carries deoxygenated blood from the right ventricle of your heart to the lungs.

Pulmonary Vein(PV)- brings back oxygenated blood from the lungs to the left atrium of your heart.

Aorta- it is the largest artery in the body. It brings oxygenated blood to all parts of the body.

Blood Flow Through Heart

From lungs

After passing through the capillaries of the lungs, the blood which is now oxygenated returns to the heart in the pulmonary veins.

The left atrium receives blood from the pulmonary vein.

Blood passes through the mitral valve into the left ventricle.

To rest of body

Contraction of the left ventricle pushes blood through the aortic semilunar valve into the aorta. Blood travels to all regions of the body where it feeds cells with oxygen picked up from the lungs and nutrients from the digestive tract.

Deoxygenated blood returns from the rest of the body through the superior and inferior vena cava.

The right atrium receives the deoxygenated blood.

Blood then enters the right ventricle through the tricuspid valve.

To lungs

Contraction of the right ventricle pushes blood through the pulmonary semilunar valve into the pulmonary arteries in which it travels to the lungs.

Then cycle repeats again....

BLOOD VESSELS

BLOOD VESSELSAre hollow tubes that carry blood

through in a never ending stream.Responsible in carrying blood

between the heart, different tissues and organs of the body

Have the ability to expand to allow more blood to flow

Can also contract to help control blood flow

BLOOD VESSELS

Three types:ArteriesCapillariesVeins

BLOOD VESSELSArteries

Elastic, muscular tubes that carry the blood away from left ventricle to the capillaries

Have thicker walls3 layers thick:

Tunica intimaTunica mediaTunica externa

Arteries that connect to the capillaries are called arterioles

DID YOU KNOW THAT...•All arteries carries oxygenated blood except pulmonary arteries

BLOOD VESSELSCapillaries

Smallest working unit in the blood vessel that connects arterioles and venules

Walls are only one cell thick to facilitate exchange of nutrients and oxygen

Forms a network called capillary bedHave sphincters that regulates the flow of blood.

Fig. 42-15

Precapillary sphinctersThoroughfarechannel

Arteriole

Capillaries

Venule

(a) Sphincters relaxed

(b) Sphincters contracted

Arteriole Venule

Capillary Exchange

35

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venulearteriole

water

oxygenglucose

salt

water

wastes

osmotic pressureblood pressure

to heartfrom heart

Arterial endBlood pressure is higherthan osmotic pressure.Net pressure out. amino

acidscarbondioxide

Venous endOsmotic pressure is higherthan blood pressure.Net pressure in.

plasmaprotein

smoothmuscle fiber

Tissue fluid

BLOOD VESSELSVeins

Carry blood from capillaries to heart

Veins that connects to capillaries are called venules

Are not thick as arteriesHave also three wallsContains valve unlike arteries

Fig. 42-10Artery Vein

SEM100 µm

Endothelium

Artery

SmoothmuscleConnectivetissue Capillary

Basal lamina

Endothelium

Smoothmuscle

Connectivetissue

Valve

Vein

Arteriole Venule

Red blood cell

Capillary

15 µ

mLM

Circulation

CIRCULATIONPulmonary circulation

Carries the blood to and from the lungs

Right heart

Oxygen-depleted blood from the body leaves the systemic circulation when it enters the right heart, more specifically the right atrium through the superior (upper) vena cava and inferior (lower) vena cava. The blood is then pumped through the tricuspid valve (or right atrioventricular valve), into the right ventricle. Blood is then pumped through the semilunar valve and into the pulmonary artery.

ArteriesFrom the right ventricle, blood is pumped

through the pulmonary semilunar valve into the left and right pulmonary arteries (one for each lung) and travels through the lungs.

LungsThe pulmonary arteries carry deoxygenated

blood to the lungs, where it releases carbon dioxide and picks up oxygen during respiration. Arteries are further divided in to very fine branches called the capillaries.

VeinsThe oxygenated blood then leaves the lungs

through pulmonary veins, which return it to the left heart, completing the pulmonary cycle. This blood then enters the left atrium, which pumps it through the bicuspid valve, also called the mitral or left atrioventricular valve, into the left ventricle.

Left heartThe blood is then distributed to the

body through the systemic circulation before returning again to the pulmonary circulation.

CIRCULATIONSystemic Circulation

 refers to the part of the circulatory system in which the blood leaves the heart, services the body's cells, and then re-enters the heart

ArteriesOxygenated blood enters

the systemic circulation when leaving the left ventricle, through the aortic semilunar valve. The first part of the systemic circulation is the aorta, a massive and thick-walled artery. The aorta arches and branches into major arteries to the upper body before passing through the diaphragm, where it branches further into arteries which supply the lower parts of the body.

CapillariesArteries branch into

small passages called capillaries. The capillaries merge to bring blood into the veinous system.

VeinsAfter their passage

through body tissues, capillaries merge once again into venules, which continue to merge into veins. The venous system finally coalesces into two major veins: the superior vena cava (roughly speaking draining the areas above the heart) and theinferior vena cava (roughly speaking from areas below the heart). These two great vessels empty into the right atrium of the heart.

ArteriesOxygenated blood enters

the systemic circulation when leaving the left ventricle, through the aortic semilunar valve. The first part of the systemic circulation is the aorta, a massive and thick-walled artery. The aorta arches and branches into major arteries to the upper body before passing through the diaphragm, where it branches further into arteries which supply the lower parts of the body.

CIRCULATIONOther types of circulation:Coronary Circulation

Blood circulation in the heartRenal Circulation

 involves the blood flow through the kidneys

Portal circulationRefers to the blood flow involving the liver

BLOOD

Blood Composition and Function

In invertebrates with open circulation, blood (hemolymph) is not different from interstitial fluid

Blood in the circulatory systems of vertebrates is a specialized connective tissue

Blood consists of several kinds of cells suspended in a liquid matrix called plasma

The cellular elements occupy about 45% of the volume of blood

Blood: Homeostasis Functions

Transports substances to and from capillaries for exchange with tissue fluid

Guards against pathogen invasionRegulates body temperatureBuffers body pHMaintain osmotic pressureClots prevent blood/fluid loss

Plasma

Blood plasma is about 90% waterAmong its solutes are inorganic salts in

the form of dissolved ions, sometimes called electrolytes

Another important class of solutes is the plasma proteins, which influence blood pH, osmotic pressure, and viscosity

Various plasma proteins function in lipid transport, immunity, and blood clotting

Cellular Elements

Suspended in blood plasma are two types of cells:Red blood cells (erythrocytes) transport oxygenWhite blood cells (leukocytes) function in defense

Platelets, a third cellular element, are fragments of cells that are involved in clotting

Composition of Blood

56

Blood

Plasma 46-63% Formed Elements 37-54%

Plasma Protein 7% Water 92% Other Solutes 1% Platelets RBC 99.9% WBC

Albumin

Fibrinogen

Globulin

Regulatory Proteins

Eg. Electrolytes

Monocytes

Basophils

Eosinophils

Neatrophils

Lymphocytes

Fig. 42-17

Plasma 55%

Constituent Major functions

Water Solvent forcarrying othersubstances

Ions (blood electrolytes)

Osmotic balance,pH buffering, andregulation ofmembranepermeability

SodiumPotassiumCalciumMagnesiumChlorideBicarbonate

Osmotic balancepH buffering

Clotting

Defense

Plasma proteins

Albumin

Fibrinogen

Immunoglobulins(antibodies)

Substances transported by blood

Nutrients (such as glucose, fatty acids, vitamins)Waste products of metabolismRespiratory gases (O2 and CO2)Hormones

Separatedbloodelements

Cellular elements 45%

Cell type FunctionsNumberper µL (mm3) of blood

Erythrocytes(red blood cells)

5–6 million Transport oxygenand help transportcarbon dioxide

Leukocytes(white blood cells)

5,000–10,000 Defense andimmunity

Basophil

Neutrophil

Eosinophil

Lymphocyte

Monocyte

Platelets Blood clotting250,000–400,000

RED BLOOD CELLS

Red blood cells, or erythrocytes, are by far the most numerous blood cells

They transport oxygen throughout the body

They contain hemoglobin, the iron-containing protein that transports oxygen

Erythrocytes

WHITE BLOOD CELLS

There are five major types of white blood cells, or leukocytes: monocytes, neutrophils, basophils, eosinophils, and lymphocytes

They function in defense by phagocytizing bacteria and debris or by producing antibodies

They are found both in and outside of the circulatory system

PLATELETS

When the endothelium of a blood vessel is damaged, the clotting mechanism begins

A cascade of complex reactions converts fibrinogen to fibrin, forming a clot

A blood clot formed within a blood vessel is called a thrombus and can block blood flow

• Platelets are fragments of cells and function in blood clotting

Collagen fibersPlateletplug

Platelet releases chemicalsthat make nearby platelets sticky

Clotting factors from:PlateletsDamaged cellsPlasma (factors include calcium, vitamin K)

Prothrombin Thrombin

Fibrinogen Fibrin5 µm

Fibrin clot

Red blood cell

Fig. 42-18-4

Stem Cells and the Replacement of Cellular Elements

The cellular elements of blood wear out and are replaced constantly throughout a person’s life

Erythrocytes, leukocytes, and platelets all develop from a common source of stem cells in the red marrow of bones

The hormone erythropoietin (EPO) stimulates erythrocyte production when oxygen delivery is low

Fig. 42-19

Stem cells(in bone marrow)

Myeloidstem cells

Lymphoidstem cells

LymphocytesB cells T cells

Erythrocytes

Platelets

Neutrophils

BasophilsEosinophils

Monocytes

DISORDERS AND DISEASES OF THE

HUMAN CIRCULATORY

SYSTEM

ATHEROSCELEROSIS

ATHEROSCELEROSIS What is atherosclerosis?

Hardening and narrowing of the arteries due to growing plaques

These plaques can behave in three different ways:•They can stay wihin the artery wall•They can grow in a slow manner eventually causing significant blokage•They can rupture, allowing blood to clot.

ATHEROSCELEROSIS What are its

causes? Smoking High cholesterol High blood pressure

Diabetes Abdominal obesity

Stress

Not eating fruits and

Vegetables

Excess alcohol intake

Not exercising regularly

ATHEROSCELEROSIS What are the treatments for

atherosclerosis? Lifestyle changes Medication Bypass surgery

ATHEROSCELEROSIS How can we prevent

atherosclerosis? Avoid Smoking Avoid stress and depression Eat fruits and Vegetables Exercise regularly

HEART FAILURE

HEART FAILURE What is heart failure?

Condition wherein the heart is unable to to provide sufficient pump action to maintain blood flow required by the body

HEART FAILURE What are its symptoms?

Heart failure on the left side of the body Breathlessness Frothy spit with cough

Heart failure n the left side of the body Swollen ankles Swollen legs Enlarged liver Enlarged stomach

HEART FAILURE What are its symptoms?

Heart failure on both sides of the body Dizziness and/or confusion Nausea Constipation Loss of appetite

HEART FAILURE What are its

causes? Diabetes Obesity Smoking Hypertension Heart attack Depression among heart disease patients

Inherited heart disease

Congenital heart defects

Anemia Faulty heart valves

Heart arrhythmias

HEART FAILURE What are the treatment for heart

failure? Medications

ACE inhibitors Diuretics Digoxin

Surgery Pacemaker that uses heartbeat Surgery that reshapes scarred left ventricle

Exercise training

HEART FAILURE How can we prevent heart failure?

Give up smoking Eat sensibly Exercise regularly Consume alcohol within recommended level

Get at least 7 hours of sleep Avoid mental stress

SEPSIS

SEPSISWhat is sepsis?

Condition when the body is fighting a severe infection

SEPSISWhat are its symptoms?

Chills and severe shakingVery fast heartbeatLow blood pressureDizziness and decresaed urination

Skin rashesFeverMay develop pain in the joints of the wrists, elbows, back, hips, knees and ankles

SEPSISWhat are the causes of sepsis?

BacteriaViruses and fungiPneumoniaUrinary tract infectionAppendicitisInfection that develop after surgery

SEPSISWhat are the treatment for this?

Medications given intravenouslyIV salt solutionIf result show an infection in the abdomen, either drainage of the infection by the placement of tubes or surgery may be necessary

SEPSIS How can we prevent sepsis?

Following recommended immunization schedules may reduce risk in children

Hospital-related infections leading to sepsis may be decreased by strictly following hand washing and hygiene protocol.

ANEMIA

ANEMIAWhat is anemia?

Condition wherein the blood does not carry sufficient amount of oxygen due to iron defficiency

ANEMIAWhat are the causes of anemia?

Blood lossDecreased or faulty red blood cell production

Destruction of red blood cells

ANEMIAWhat are its symptoms?

Easy fatigue and loss of energyRapid heartbeatDizzinessLeg crampsInsomnia

ANEMIAWhat are the treatments for

anemia?Creating a check-up schedule with doctor

Follow doctor’s medicationSupplement your oxygenSchedule blood transfusion at the advice of your doctor

ANEMIAHow can we prevent anemia?

Check if your at riskEat a diet rich in iron and vitamin C

Take iron supplement to make sure your getting enough

Avoid excessive dieting and over-exercising

Avoid donating blood

STROKE

STROKEWhat is a stroke?

happens when blood flow to a part of the brain stops. A stroke is sometimes called a "brain attack."

If blood flow is stopped for longer than a few seconds, the brain cannot get blood and oxygen. Brain cells can die, causing permanent damage.

STROKEWhat are the causes of stroke?

Blood supply to brain is interrupted or reduced

A blocked artery (ischemic stroke) or a leaking or burst blood vessel (hemorrhagic stroke)

STROKEWhat are the treatment for stroke?

Medical treatmentAspirinStroke recovery and rehabilitation

STROKEHow can we prevent stroke?

Healthy dietAntiplatelet therapyControl of sugarAvoid smokingManagement of high blood pressure

STROKEWhat are its symptoms?

Sudden numbness of the face, arm or leg, especially on one side of the body

Sudden trouble seeing in one or both eyes

Sudden trouble walking, dizziness, or loss of balance and coordination

Sudden severe headache with no known cause

Sudden confusion or trouble in speaking and understanding