bio f5 subtopic 1.2

7/29/2019 bio f5 subtopic 1.2

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Subtopic 1.2

The Circulatory

System


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Circulatory system consists of a network

of tubes (vessels) that deliver useful

materials to all cells of the body and thentake away their waste products.

In mammals the circulatory system consists of thecardiovascular system and the lymphatic system.)


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Cardiovascular system consists of the

heart, blood vessels and blood.

Main components of blood


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Comparison three types of blood.Erythrocytes Leucocytes Platelets

Shape

Biconcave disc No nuclues

Granulocyte No fixed shape Granular cytoplasm Lobed nucleusAgranulocytes Spherical shape Cytoplasm has no

granules Spherical or bean

shaped nucleus

No fixed shape No nucleus

Size Diameter 8m Thickness 2m

Diameter 8-20m Diameter 2-3m

Number Approximately 5million/mm3 of blood

Approximately8000/mm3 of blood

Approximately250 000/mm3 of blood

Formed inBone marrow Bone marrow, lymph and

lymphatic systemBone marrow

Lifespan120 days A few days to a few

yearsA few hours to a fewdays

Function

Transport oxygen Transport carbon

dioxide

Neutrophils areinvolved in

phagocytosis Lymphocytesproduce antibodies

Monocytes areinvolved inphagocytosis

Secrete the enzymethrombokinase which

is involved in theblood clottingmechanism

Effect on animbalance in thenumber of cells

Decrease in number ofcells results in anaemia.

Large numbers of cellsresult in leukemia.

Deficiency in plateletsresults in the inability ofblood to clot.


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Functions Of Blood In Transport

Transport ofoxygen from the lungs to the

cells in all parts of the body.

Transport ofcarbon dioxide from the cells

to the lungs to be removed.

Transport ofabsorbed food materials

Transport ofexcretory waste products

Transport ofheat

Transport ofhormones

Transport ofwaterto tissues


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Structure Of Human Blood Vessels


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Differences between arteries,

capillaries and veins.

Arteries Capillaries Veinscarry blood away from the

heart

connect arterioles to venules Carry blood to the heart

Contain oxygenated blood

except the pulmonary artery

Acts as sites for exchange of

substances with the cells

Contain deoxygenated blood

except the pulmonary vein

Walls have thick layer of

muscles

Walls are thin, consisting of

only one layer of cells. No

muscles present.

Walls have a thinner layer of

muscles

No valves present except

semilunar valves at the base

of the aorta and pulmonaryartery

No valves present Valves present to prevent

backflow of blood

Blood is under high pressure Pressure is lower than in

arteries but higher than in

veins

Blood flows under lower

pressure than arteries

Blood flows in spurts or

pulses

Blood flows smoothly and not

in pulses

Blood flows smoothly and not

in pulses


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Structure Of The Human Heart


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Circulatory System In Insects, Fish,

Amphibians And Human

Insect FishAmphibians and

reptilesHumans

Open circulatory

system.

Haemolymphflows in spaces

known as

haemocoel.

Closed and

single circulatory

system.

Closed, double

and incomplete

circulatory

system.

Heart has three

compartments,

two atria and

one ventricle.

Closed, double

and complete

circulatory

system.

Heart has four

chamber, two

atria and two

ventricles.


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Circulatory System In Insects

Open circulatory system.

Haemolymph flows in spaces known as

haemocoel.


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Circulatory System In Fish

Closed and single

circulatory system.


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Circulatory System In Amphibians

Closed, double and

incomplete circulatory

system.

Heart has three

compartments, two

atria and one ventricle.


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Circulatory System In Human

Closed, double and completecirculatory system.

Heart has four chamber, two

atria and two ventricles.


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bio f5 subtopic 1.2