The Circulatory and The Circulatory and Lymphatic systemsLymphatic systems

BloodBlood

BloodBlood is a is a fluid that circulates throughout the bodyfluid that circulates throughout the body..

It carries nutrients from digestive system to body cells.It carries nutrients from digestive system to body cells.

It carries oxygen taken up by respiratory systemIt carries oxygen taken up by respiratory system

It removes wastes produced by cell metabolism. *It removes wastes produced by cell metabolism. *

The human body contains approx 5-6L The human body contains approx 5-6L of blood.of blood.

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Blood consists of:Blood consists of:

A fluid component called A fluid component called plasma.

And formed elements :And formed elements :

– Red blood cells Red blood cells

– White blood cellsWhite blood cells

– PlateletsPlatelets

Function of blood Function of blood componentscomponents

PlasmaPlasma : :–Makes up 55% of whole bloodMakes up 55% of whole blood

– Is a Is a yellowish liquid yellowish liquid (mainly (mainly water) in which water) in which red blood cells, red blood cells, white blood cells and platelets white blood cells and platelets are in suspension.are in suspension.

–Also contains nutrients, Also contains nutrients, antibodies, hormones and antibodies, hormones and metabolic waste .*metabolic waste .*

Red blood cells:Red blood cells:– Are concave on both sides and lack a Are concave on both sides and lack a

nucleusnucleus– Contain Contain Hemoglobin (red pigment

that carries oxygen)– Are produced in the bone marrowAre produced in the bone marrow– 45% of blood volume 45% of blood volume

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Oxygenated bloodOxygenated blood carries oxygen carries oxygen and is bright redand is bright red

Deoxygenated bloodDeoxygenated blood depleted of depleted of oxygenoxygen, carrying carbon dioxide and , carrying carbon dioxide and is dark red (is dark red (notnot blue). blue).

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White blood cellsWhite blood cells::– Also called Also called LeucocytesLeucocytes– Are colourlessAre colourless– Larger than red blood cellsLarger than red blood cells

White blood cells protect the body by:White blood cells protect the body by:

– Engulfing and digesting dead or damaged cells, Engulfing and digesting dead or damaged cells,

old RBC’s, and microorganismsold RBC’s, and microorganisms

– Produce Produce antibodiesantibodies to to neutralize invading neutralize invading

organisms organisms * *

PlateletsPlatelets:: are are red blood cell fragmentsred blood cell fragments

Important in the clotting of blood Important in the clotting of blood ((clottingclotting –the process –the process where the where the platelets platelets clump together and start clump together and start the the formation of fibrin formation of fibrin filaments filaments to form a solid mass (a to form a solid mass (a clot) and stop the clot) and stop the bleeding) bleeding)

Fibrin filaments

Blood groupsBlood groups Red blood cells have Red blood cells have proteinsproteins on their surface, on their surface,

called called antigensantigens that that provoke a clotting reaction provoke a clotting reaction when they are introduced into another body.when they are introduced into another body.

Blood is grouped according to the type of antigen it Blood is grouped according to the type of antigen it contains and by the Rhesus factor.contains and by the Rhesus factor.

Blood typing is important for blood transfusionsBlood typing is important for blood transfusions

A A blood transfusion blood transfusion is the is the injection blood products injection blood products (usually red blood cells) from one person to (usually red blood cells) from one person to another.another.

Blood type A Blood type A -has the A antigen -has the A antigen (protein) (protein) on its surface on its surface

Blood type B Blood type B -has the B antigen on its -has the B antigen on its surface surface

Blood type AB Blood type AB -has both A and B -has both A and B antigen antigen on its on its surfacesurface

Blood type O Blood type O -has NO antigen on its -has NO antigen on its surface surface

Rhesus (Rh)factorRhesus (Rh)factor This This Rh factor Rh factor is another is another antigen antigen

determining the compatibilitydetermining the compatibility for blood for blood transfusionstransfusions

– Rh+ means the antigen is presentRh+ means the antigen is present– Rh - means the antigen is not presentRh - means the antigen is not present

Blood

Type can donate to can receive from

A+, A-, AB+, AB-

A-, O-

A+, AB+ A+, A-, O+, O-

B-, B+, AB-, AB+ B-, O-

B+, AB+ B+, B-, O+, O-

AB-, AB+ AB-, A-, B-, O-

AB+ Universal recipient

Universal donor O-

O+, A+, B+, AB+ O+, O-

+

-

+

+

+

-

-

-

Rh-

Rh-

Rh-

Rh-

Rh+

Rh+

Rh+

Rh+

The anatomy of the The anatomy of the Circulatory System Circulatory System

The HeartThe Heart

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the heart has 4 chambers:the heart has 4 chambers:– Right and left Right and left atriumatrium (1(1stst chambers that chambers that

blood enters in heart)blood enters in heart)– Right and left Right and left ventricle ventricle (last chamber before

blood leaves heart)

Left ventricle (very

muscular)

Left atrium

Right atrium

Right ventricle

Heart Valve movieHeart Valve movie

Major blood vessels of the Major blood vessels of the heart heart

Blood vessels are the plumbing of the Blood vessels are the plumbing of the body that assure the distribution of body that assure the distribution of blood to the entire body.blood to the entire body.

Two vessels leave the Two vessels leave the ventriclesventricles:: The Pulmonary artery The Pulmonary artery –blood is pumped –blood is pumped

to the lungs. to the lungs. The Aorta The Aorta – blood is pumped throughout – blood is pumped throughout

the body. the body.

Two vessels enter the Two vessels enter the atriaatria:: The Pulmonary veins The Pulmonary veins – bring blood back – bring blood back

from the lungs. from the lungs. The Venae Cavae The Venae Cavae – bring blood back from – bring blood back from

the body. the body.

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Aorta (blood to body)

Pulmonary artery(blood to the lungs)

Pulmonary vein(blood from the lungs)

Superior vena cava(blood from the upper body)

Inferior vena cava (blood from the lower body) Septum

Main blood vessels Main blood vessels

Blood VesselsBlood Vessels

ArteriesArteries ArteriesArteries carry carry blood blood awayaway from the heart from the heart to to

the organs of the body the organs of the body

have thick, muscular, elastic have thick, muscular, elastic walls to withstand high pressure. walls to withstand high pressure.

The The Aorta is the largest artery is the largest artery in the body. in the body.

These large arteries progressively branch and get These large arteries progressively branch and get smaller and smaller, becoming-smaller and smaller, becoming- arterioles, then arterioles, then capillaries. capillaries. * *

CapillariesCapillaries CapillariesCapillaries are are minute branches at the ends of minute branches at the ends of

the arteries and veinsthe arteries and veins..

They are permeable allowing the diffusion of They are permeable allowing the diffusion of substances into all body cells which are within substances into all body cells which are within 50µm of a capillary.50µm of a capillary. * *

VeinsVeins VeinsVeins –go –go to the heartto the heart and have and have

thinner walls and are less elastic than thinner walls and are less elastic than the arteries because there is the arteries because there is less pressure.less pressure.

to help the blood to flow up from the extremities (e.g. to help the blood to flow up from the extremities (e.g. legs), veins legs), veins have one way valveshave one way valves that prevent that prevent backflow. backflow.

Leg muscle contractions help “pump” the Leg muscle contractions help “pump” the blood back to the heart.blood back to the heart.

Capillaries turn into venules enlarging into veins Capillaries turn into venules enlarging into veins returning to left atrium via the large Vena Cava.returning to left atrium via the large Vena Cava.

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How it worksHow it works

When a heart beats it first When a heart beats it first contracts the atria and then contracts the atria and then the ventricles the ventricles

1.1. Deoxygenated blood returns Deoxygenated blood returns under pressure via the Vena under pressure via the Vena Cava into the relaxed right Cava into the relaxed right atrium.atrium.

2.2. Contraction of right atrium Contraction of right atrium forces blood into the right forces blood into the right ventricle.ventricle. **

3.3. Ventricular contraction forces Ventricular contraction forces blood through the Pulmonary blood through the Pulmonary artery into the lungs.artery into the lungs.

Blood travels through smaller Blood travels through smaller arteries then arterioles and arteries then arterioles and finally the capillaries in single file.finally the capillaries in single file.

The capillaries surround the minute air sacks The capillaries surround the minute air sacks (alveoli) and allow the exchange of gases (alveoli) and allow the exchange of gases (O(O22,CO,CO22) between blood and inhaled air. *) between blood and inhaled air. *

Oxygenated blood leaves the Oxygenated blood leaves the capillaries of the lungs, first capillaries of the lungs, first through the venules, then through the venules, then veins returning to the left veins returning to the left atrium via the pulmonary vein. atrium via the pulmonary vein.

Contraction of the left atrium Contraction of the left atrium forces the blood into the left forces the blood into the left ventricle.ventricle. **

4.4. Contraction of the left ventricle Contraction of the left ventricle forces the blood through the Aorta forces the blood through the Aorta throughout the body.throughout the body.

Arteries branch off the aorta and supply various organs and Arteries branch off the aorta and supply various organs and tissues with oxygenated blood. The blood follows this path:tissues with oxygenated blood. The blood follows this path:

ArteriolesArterioles Capillaries – exchange of gasesCapillaries – exchange of gases VenulesVenules VeinsVeins Vena cavaVena cava * *

Blood pressure Blood pressureBlood pressure is the is the force with which the blood is force with which the blood is

pushing against the arterial wallspushing against the arterial walls.. Bp is measured in mm of mercury (mm Hg)Bp is measured in mm of mercury (mm Hg) The The systolic pressure systolic pressure is when the ventricular is when the ventricular

pressure is at its maximum pressure is at its maximum and the vessels are and the vessels are expanded.expanded.

The The diastolic pressure diastolic pressure is when the is when the heart is at rest heart is at rest ( no contraction).( no contraction).

The pressure is given as a ratio of The pressure is given as a ratio of systolicsystolic 120120

diastolicdiastolic 8080(for adolescents normal bp is (for adolescents normal bp is 113113 mm Hg) mm Hg)

6565 * *

The lymphatic systemThe lymphatic system

Carries dissolved OCarries dissolved O22 and nutrients to the cells and nutrients to the cells

Collects cellular waste productsCollects cellular waste products

plays an important role in the immune system plays an important role in the immune system

LymphLymph is: is: A A fluid that fills the spaces between the blood fluid that fills the spaces between the blood

vessels and the body cellsvessels and the body cells

A fluid derived from the blood A fluid derived from the blood * *

Lymphatic vessels resemble blood vessels and Lymphatic vessels resemble blood vessels and are close to themare close to them

The lymph returns to the circulatory system via The lymph returns to the circulatory system via two veins near the heart.two veins near the heart.

The lymph relies on muscle movement for The lymph relies on muscle movement for circulation.circulation. **

The lymphatic system comprises of the followingThe lymphatic system comprises of the following

organs :organs : The thymus- found underneath the heartThe thymus- found underneath the heart The bone marrow- found in long bones The bone marrow- found in long bones

(femur)(femur) The spleen- found left of stomach under The spleen- found left of stomach under

diaphragmdiaphragm The tonsils- found in mouth bordering the The tonsils- found in mouth bordering the

pharynxpharynx **

The lymphatic vessels have lymph nodes The lymphatic vessels have lymph nodes throughout the body.throughout the body.

When an infection occurs these nodes When an infection occurs these nodes swell and harden (e.g. A cold or tonsillitis) swell and harden (e.g. A cold or tonsillitis) **

Tonsils

The immune systemThe immune system The The ability of the body to protect itself against ability of the body to protect itself against

antigensantigens is called is called immunityimmunity..

AntigensAntigens are are viruses, bacteria, abnormal cells viruses, bacteria, abnormal cells or other substances that produce an immune or other substances that produce an immune reaction. reaction.

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An An antibodyantibody is a is a substance produced by substance produced by certain white blood cells that can neutralize certain white blood cells that can neutralize specific antigens.specific antigens.

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