form 5 biology chapter 1 transport (a).docx

8/18/2019 Form 5 Biology Chapter 1 Transport (a).docx

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Figure 10.2 The constituents of human blood

Water Dissolved Substances

Form 5 Biology Chapter 1 Transport (a

The Composition of Human Blood

1. Blood is a sticky, opaque fluid with a metallic taste. It is a connective tissue of

liquid plasma and cells.

2. Whole blood – blood from body with no constituent (plasma or platelets)

removed.

Figure 10.1 sin! a centrifu!e to separate blood components

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Blood cells

Erthroctes !"ed Blood Cells#

1. "eatures#

a) tiny biconcave disc$shaped cells (increase $%&' ratio) with elastic

membrane (to squeee throu!h narrow blood capillary).

b) no nucleus (more space for haemo!lobin), mitochondria or ribosomes so that it

can accommodate more haemo!lobin

c) full of haemoglobin (respiratory pi!ment containin! iron) to bind

o*y!en'carbon dio*ide

d) made in bone marro% and liver for about 12+ days

e# destroyed and recycled in the spleen and liver

&. Haemoglobin transport o'!en in the form of o'haemoglobin.

. -aemo!lobin also transport carbon dio*ide mainly in the form of hydro!en

carbonate, some (/1+0) in the form of carbaminohaemo!lobin.

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(eucoctes !White Blood Cells#

1. "eatures#

(a)colourless and no haemo!lobin

(b) has nucleus and no fi*ed shape

(c)lesser in number but lar!er in sie

(d) can change shapes and squeee throu!h the walls of capillaries into the

spaces amon! the tissue cells.

(e)important in body defense mechanisms a!ainst disease.

!f# divide into granuloctes and agranuloctes

)ranuloctes

a# *eutrophils

$he most common B, the neutrophils are the first to arrive at an infection site

to ingest bacteria, virus particles, fun!i, or protooa. 3eutrophil nuclei may have

t%o to five lobes. $he cytoplasmic !ranules are usually very fine and too faint to

observe.

"i!ure 1.+# 3eutrophils under li!ht microscope

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b# Eosinophil

omprisin! only about percent of the leucocytes, the eosinophils have bilobed

nuclei and uniformsied cytoplasmic !ranules. $hey moderate allergic

reactions (by releasin! enymes) and defend a!ainst parasitic %orm

infestations.

"i!ure 1.1# 4osinophil under li!ht microscope

c# Basophil

omprisin! less than 1 percent of the circulatin! white blood cells, the basophils

are smaller than other granuloctes. $hey are easy to identify because of the

numerous !ranules in the cytoplasm. $hey dischar!e their !ranules containin!

histamine and heparin into dama!ed tissue spaces to promote inflammation

and blood flow to dama!ed areas.

"i!ure 1.# Basophil

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+granuloctes

a# ,onoctes

omprisin! 2 to 5 percent of circulatin! B, monocytes are t%ice the si-e of

red blood cells. 6onocytes have oval$ or idne$bean$shaped nuclei. $hey

travel in the blood for about a day before e*itin!. $he mi!ratin! monocytes are

bi! eaters. $hey develop into macropha!es that pha!ocytise bacteria and debris in

the tissues.

"i!ure 1.7# 6onocytes

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b# (mphoctes

$hese cells of immunity are only sli!htly bi!!er than red blood cells. $hey are

easy to reco!nie due to the large nucleus that occupies most of the cell. $hese

cells may live for years and comprise 28 to percent of the B population. $

cells may directly attack forei!n and tumor cells. B cells produce antibodies to

attack forei!n cells or proteins. 3atural killer cells are important in cancer

prevention.

"i!ure 1.8# 9ymphocyte

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/uestion Identify the types of white blood cells in the dia!ram below.

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Thromboctes !latelets#

1. 3ot cells but are tiny fra!ments of other cells (me!akaryocytes) found in the

bone.

2. $hey are colourless, irre!ular in shape and no nucleus.

. 6ade in bone marrow and last for :; days.

7. -ave amoeboid movement.

8. "unction#

(a)Important in blood clotting

(b) Important in repairin! dama!ed tissues

(c)-elp to maintain the inte!rity of blood vessel wall

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lasma

1.& yellowish liquid in which the blood cell are suspended.

2.Blood serum is blood plasma with clottin! factors (such as fibrino!en).

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>%B< 2+1?

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Function of Haemolmph in Transport

1. In many arthropods such as insects, a bloodlike nutritive fluid called the

haemolmph fills the entire body cavity or haemocoel and surrounds all the

cells.

2. -aemolymph helps to transport %ater4 hormones4 nutrients4 salts and

metabolic wastes around the body. It does not transport o*y!en and carbon

dio*ide in insects. $hese !ases are transported by the tracheal sstem.

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The 5tructure of Human Blood 6essels

+rter Capillar 6ein

$ransport blood away

from the heart

onnect arterioles to

venules

$ransport blood to the

heart

$ransport o*y!enated

blood (e*cept pulmonary

artery)

&ct as sites for the

e*chan!e of substances

with the cells

$ransport

deo*y!enated blood

(e*cept pulmonary

vein)

-ave small lumen -ave very small lumen -ave lar!e lumen

$hick and elastic

muscular wall

$hinnest wall, one cell in

thickness

$hinner, less muscular

and less elastic wall3o valves (e*cept the

semilunar valve)

3o valves alves are present

Blood flows in pulses

under hi!h pressure

3o pulses, the pressure is

lower than in the arteries

but hi!her than in the veins

3o pulses, blood flows

under low pressure

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The Circulation of Blood 7n Humans

$he structure and function of the human hearts

1. $he human heart contains four chambers# t%o atria and t%o ventricles.

2. $he atria receive blood returning to the heart while the ventricles pump

blood out of the heart.

. $he muscular wall of the left ventricle is thic @ needs to pump blood to all parts

of the bod at high pressure.

7. $he muscular wall of the ri!ht ventricle is thin@ needs to pump blood to the

lungs onl.

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8. $he heart has valves@ tricuspid valve, bicuspid valve and semilunar valves.

:. $he tricuspid valve and bicuspid valve prevent blood from flo%ing bac into

the atria

;. $he semi$lunar valves prevent blood from flo%ing bac into the ventricles

when the ventricles rela*.

5. hen the atria rela*, deo*y!enated blood from the body enters the ri!ht atrium

via vena cava and o*y!enated blood from the lun!s enters the left atrium via the

pulmonary veins.

A. hen the atria contract, blood is pushed into the ventricles.

1+. hen the ventricles contract, the bicuspid and tricuspid valve close, and thesemilunar valves open.

11. =eo*y!enated blood is pumped to the lun!s via the pulmonary artery and

o*y!enated blood is pumped to the rest of the body via the aorta

12.=urin! the closin! of the bicuspid and tricuspid valves, a lubbC sound is

produced and durin! the closin! of the semilunar valves, a dubbC sound is

produced. $he heart produces lubbdubbC sounds.

/uestion 1 4*plain the function of the tricuspid and bicuspid valvesD (2 marks)

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/uestion & 4*plain the function of the semilunar valvesD (2 marks)

/uestion 8 4*plain why the wall of left ventricle thicker than the wall of the

ri!ht ventricleD (2 marks)

/uestion 9 %tate the pathway of blood flow start from vena cava to aorta. (1

mark)

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>%B< 2+18?

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The umping of The Heart

1. $he heart is made up of cardiac muscles which are mogenic4 self$contract and

rela* rhthmicall.

2. $he cardiac muscle cells are interconnected to allow electrical si!nals to be

conducted rapidly throu!h the heart, and allow cardiac muscles to contract in a

coordinated way.

. $he contraction of the heart is initiated and coordinated by a pacemaer.

9. $he pacemaker is a cluster of specialied cells that set the rate of the heartCscontraction located in the wall of the right atrium.

/uestion : $he cardiac muscle is said to be mogenic. 4*plain. (1 mark)

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The se;uence of the contractions of the heart muscles %hich results in the

pumping of the heart

1. $he sinoatrial node !enerates electrical impulses which spread rapidly over the

walls of both atria4 causing the atria to contract.

2. 4lectrical impulses reach the atrioventricular node, at the floor of the ri!ht

atrium

. 4lectrical impulses move from the & node to the bundle of His fibres4 bundle

branches and then urin


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The "egulator ,echanism of Blood ressure

1. hen the blood flows alon! a vessel, it e*erts pressure a!ainst the walls of the

blood vessel.

2. $his pressure is called blood pressure.

. Blood pressure is the force that pumps blood along the arteries and the

capillaries.

7. Blood pressure is !reater in arteries than in veins. Blood flows from area of hi!h

pressure to areas of lower pressure.

8. =urin! the contraction of ventricles (known as the systole sta!e), blood pressure

is the hi!hest in the aorta and lar!e arteries when blood is pumped into the aorta

and pulmonary arteries.

:. &t rest, a healthy adult has a blood pressure of 12+'5+ mm -!.

;. $he first number is the sstolic pressure, the hi!hest recorded pressure in an

artery when the ventricles contract. $he second number, the diastolic pressure, is

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the lowest recorded pressure durin! the rela*ation phase of the heartbeats (the

diastole sta!e).

5. Blood pressure is re!ulated by a ne!ative feedback mechanism.

A. Baroreceptors or pressure receptors located in the arch of the aorta and carotid

arteries (arteries in the neck that supply blood to the brain detect the pressure of

the blood flowin! throu!h them.

+. $hese receptors send nerve impulses continuously to the cardiovascular centre in

the medulla oblongata to help re!ulate the blood pressure.

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@pen Circulator 5stem

1. $he open circulator sstem is found in insects such as the !rasshopper.

&. $he !rasshopper has more than one heart to pump the haemolymph throu!h

blood vessels and into the haemocoel when the heart contracts.

8. Chemical e'change occurs between the haemolymph and body cells

9. hen the heart rela*es, the haemolmph is dra%n bac into the hearts.

>. $he open circulatory of the insects is very efficient because the haemolymph is in

direct contact with the body cells.

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The Closed Circulator 5stem

The circulator sstem of fish

1. & fish has a heart consistin! of t%o separate chambers, an atrium and a

ventricle.

2. $he deo*y!enated blood enters the atrium and then the ventricle. $he ventricle

pumps the blood to the capillaries in the gills where !aseous e*chan!e occurs.

. $he pressure drops as the o*y!enated blood flows out from the !ills directly to

the body tissues. $he deo*y!enated blood then flows back to the heart.

7. $he blood flows throu!h the heart only once. & fish has a single closed

circulator sstem.

8. $ransportation of o*y!en is not efficient because the blood which carries o*y!en

flows from the !ill capillaries slowly to the systemic capillaries. $his is because

the blood pressure drops as it flow away from the heart.

:. $he e*chan!e of substances between the capillaries and the body cells is very

slow.!&


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The circulator sstem of amphibians

1. &mphibians use the buccal cavity, moist skin and lun!s to carry out !aseous

e*chan!e.

&. $hey have an incomplete double closed circulator sstem consistin! of a

pulmocutaneous and a sstemic circulator sstem.

8. In the pulmonary system, the blood flows from the heart to the lun!s and then

back to the heart.

9. In the systemic circulatory system, the blood flows from the heart to other parts

of the body and back to the heart.

>. &mphibians have a three$chambered heart with two atria and one ventriclewhich are not separated by a septum. $his results in the mi*in! of o*y!enated

with deo*y!enated blood in the sin!le ventricle.

A. $he blood contains lower levels of o*y!en but is sufficient to meet the cellular

requirements of amphibians.

!'

Systemic

circulatio

)ulmocutaneo

us circulation

*ung and s+in

capillaries


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The circulator sstem of mammals

1. 6ammals have a hi!h metabolic rate. $hey need a rich supply of nutrients ando*y!en to the tissues.

2. $hey have a four$chambered heart separated b a septum. $he heart acts as

two separate pumps. 6ammals have a double closed circulatory system

consistin! of the pulmonary and systemic circulation. $he blood enters the heart

twice durin! one complete cycle.

. $he fourchambered heart prevents the mi'ing of the o'genated and

deo'genated blood. It supplies adequate blood rich in o*y!en and nutrient

rapidly to the body tissues.

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7. Blood can be maintained at a relatively hi!her pressure by the contraction of the

thick muscular left ventricle. It allows animals with a fourchambered heart to

attain lar!er sies.

8. $he separation of the ri!ht and left chambers of the heart also prevents the high

blood pressure from damaging the fine blood capillaries of the lungs.

ompared to the left ventricle, the ri!ht ventricle is smaller and its wall is less

muscular as it only has to !enerate a lower pressure to pump blood a short

distance to the lun!s.

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form 5 biology chapter 1 transport (a).docx

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