transport in organisms

8/2/2019 Transport in Organisms

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TRANSPORT IN ORGANISMS

Explain the need for transport systems in multi cellular organisms

Small organisms do not require an internal transport system as diffusion is a sufficient

enough process to get food and gases to their cell parts. This is common in organisms likeamoeba, paramecium (both of which are unicellular) and in flat worms and sea anemones

(multicellular animals belonging to the cnidarians). This is because these organisms

have a LARGE surface area to volume ratio. That is the surface area is large enough toallow all the gases to reach the cells by diffusion and once inside the cells the distances to

travel to other parts is small so once again diffusion is sufficient.

The opposite occurs in most multi cellular organisms that have tissues, organs and organ

systems. Humans for example cannot rely on diffusion as their surface area is small in

comparison with their volume. LARGE organisms have a SMALL surface area to

volume ratio. Additionally, most complex organisms have scales, skin, hair and or shells

which are not semi permeable to allow diffusion. Diffusion is thus not sufficient or fastenough to reach all cells to allow survival, hence the need for a transport system or

circulatory system.

http://www.biology-online.org/dictionary/Osmotic_Potential

http://www.bbc.co.uk/dna/h2g2/A686766

The above links discuss osmosis and osmotic potentials and how they relate to semipermeable membranes. Hence in large complex organisms with hair, shells, scales etc.,

osmosis will not be possible.

Identify the types of materials which need to be transported in animals and plants

The materials that are transported in animals and plants can be: useful, waste or harmful.

Useful ones are: oxygen, digested or manufactured food, water, mineral salts, hormones,

antibodies, plasma proteins etc.

Waste: carbondioxide, nitrogenous waste

Harmful: alcohol, drugs

Table 1 below shows examples of substances transported in blood of humans.
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Table 1: Substances transported in blood

Substance Transported from Transported to Why it needs to be

transported

Oxygen Lungs Body cells Respiration

Digested foods(fats, glucose,

amino acids)

Digestive organs(intestinal villi) and liver

Body cells Growth and cellmetabolism

Urea and other

nitrogenous waste

Liver and body cells Kidneys Excretion

Hormones Ductless endocrineglands

Various organs asneeded

Regulation of bodyfunctions

Heat Muscles, liver All tissues Regulation of bodytemperature

Carbon dioxide Body cells and tissues Lungs Excretion

http://biology.clc.uc.edu/Courses/bio105/kidney.htm

This link deals with various nitrogenous waste products from varying organisms and will

be useful in the future when excretion is done.

Describe the structure and function of the circulatory system in humans

The circulatory system in humans/the blood vascular system is made up of:1. a transporting medium (blood)

2. tubes through which the medium can travel (blood vessels)

3. a pump to push the medium through the tubes (heart)

DOUBLE CIRCULATION:

This is where the blood flows through the heart twice in one complete circulation. It existsin mammals in order to give blood the necessary increase in pressure required to take

oxygen to all of the bodys organs, give up carbon dioxide at the lungs and pick oxygen up

at the lungs. The increase in pressure is needed because blood loses a lot of pressure whenpassing through the lungs. Double circulation also allows the deoxygenated and

oxygenated blood to remain separate.

The double circulation consists of: pulmonary circulation and systemic (body)

circulation.

Pulmonary Circulation: This is where blood travels from the right side of the heart to the

lungs to be oxygenated, then back to the left side of the heart.

Systemic (body) circulation: This is where blood travels from the left side of the heart tothe body where it becomes deoxygenated and then back to the right side of the heart.

Route of blood: body heart lungs heart body
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http://www.rkm.com.au/ANIMATIONS/animation-double-circulation-blood.html

http://www.s-cool.co.uk/gcse/biology/heart-and-circulation.html
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BLOOD VESSELS SUPPLYING MAJOR ORGANS:

Those carrying oxygenated blood are:

Name of blood vessel Organ or Region in the body

Carotid artery Head

Pulmonary vein LungHepatic artery Liver

Mesenteric artery Intestines

Aorta Heart

Renal artery Kidney

Subclavian artery Arms

Coronary artery Heart

Iliac artery Legs
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Those carrying deoxygenated blood are:

Name of blood vessel Organ or Region in the body

Jugular vein Head

Anterior and posterior vena cava Heart

Hepatic vein Liver Mesenteric vein Intestines

Pulmonary artery Heart

Renal vein Kidney

Subclavian vein Arms

Iliac vein Legs

Hepatic portal vein Intestines

STRUCTURE AND FUNCTION OF THE HEART

The heart is hollow but its walls are made of cardiac muscle which contracts and relaxesrhythmically throughout life. The cardiac muscle gets oxygen and nutrients from coronaryvessels that spread over the heart walls. Efficient exchange of food, oxygen, carbon dioxide

and other dissolved substances between blood and tissues comes from an efficient heart. It

contracts approximately 70 times a minute throughout our lives and the muscle is special asit does not get tired.

The heart is found in the chest cavity and it is surrounded by the pericardium. This is amembrane which along with the rib cage protects the heart.

Valves are found in the heart and prevent the backflow of blood.

When the heart contracts, blood is pumped out of it into the arteries, when it relaxes blood

is sucked into it via the veins.

Contraction= blood leaves via arteries

Relaxation=blood enters via veins

The heart beats to a pulse wave which is caused by a wave of pressure travelling along the

arteries. This pulse can be felt along different parts of the body and it can be heard using astethoscope.

The heart is divided into two parts by the septum. This prevents the blood from the rightside from mixing with the left side of the heart. The right side of the heart receives

deoxygenated blood from the body and pumps it to the lungs where it is oxygenated; theleft side receives oxygenated blood from the lungs and pumps it throughout the body.

The heart also consists of four chambers: two top thin- walled ones called atria (singular is

called atrium) and two lower ones that are larger, thicker and called ventricles.

BLOOD FLOW THROUGH THE HEART:

The heart has two actions: diastoleand systole.
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Diastole-This is when the heart muscle relaxes. Deoxygenated blood from the head and

body enter the right atrium through each vena cava. At the same time, oxygenated bloodfrom the lungs enters the left ventricle through the pulmonary veins. The atria fill with

blood.

Systole- Following the filling of atria, they contract. There is an increase in pressure from

the contraction which opens the tricuspid and bicuspid valves and forces blood into the

ventricles. When the ventricles become full, the pressure is high and they contract. Thetricuspid and bicuspid valves close because of the pressure and blood is forced to the semi-

lunar valves. (These secure the openings of the pulmonary artery and the aorta.)

The right ventricle pumps blood into the pulmonary artery to be taken to the lungs whilethe left ventricle pumps blood to the aorta to be taken to the rest of the body.

NOTE: The left ventricle walls are thicker than the right ventricle walls because the left

ventricle has to pump harder to move the blood over a longer distance. Refer back to thediagram to see that the distance travelled to take blood to the head and body is further than

blood that goes to the lungs.

IT IS A GOOD IDEA TO STUDY THIS SECTION ABOVE USING THE DIAGRAMS

BELOW, AND ALSO WRITE OUT A FLOW DIAGRAM.
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Describe the composition and functions of blood in transport.

Blood consists of plasma and blood cells.

PLASMA: This is a sticky, yellowish liquid made of 90% water and 10% substances in

solution. The 10% substances in solution may be: sugars, amino acids, vitamins, minerals,

carbon dioxide, urea, hormones and proteins like antibodies, albumen, globulin, andfibrinogen. Hydrogen carbonate ions may also be found in plasma.

-------Albumen- makes the blood thick and viscous-------Globulin-Produced by the lymph cells to help make antibodies. Some types may help

in blood clotting.

--------Fibrinogen- this helps in blood clotting.

FUNCTIONS OF PLASMA:

To transport:

--dissolved food from the ileum to tissues--CO2 as the HCO3

- ion from tissues to lungs

--other waste from tissues to excretory organs

--hormones from endocrine glands to target organs--heat from muscles and liver to all body parts

--ions and water to maintain the correct concentration of body fluids

--white blood cells and antibodies to sites of infection--platelets and plasma proteins to cuts

BLOOD CELLS:

These are made in the bone marrow, the three main groups are: red blood cells, white blood

cells and platelets.

Red blood cells: These contain the red pigment haemoglobin and they have no nuclei so

they are not able to survive for approximately more than 3 months. Old red blood cells are

destroyed in the liver or spleen. Haemoglobin combines with oxygen readily to formOXYHAEMOGLOBIN. When the amount of oxygen in the body is low (low

concentration), it breaks down to release oxygen.

HAEMOGLOBIN + OXYGEN OXYHAEMOGLOBIN

TAKE NOTE THAT YOU MUST RESEARCH THE ABILITY OF CARBON

MONOXIDE TO COMBINE WITH HAEMOGLOBIN AND WHY IT IS BAD.
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White blood cells: These are of two types: lymphocytes and phagocytes. These havenuclei but each has its own characteristic shape. They have no haemoglobin and look

translucent under a microscope. The lymphocytes produce antibodies to start destroying

antigens (foreign bodies). Phagocytes then complete the destruction by swallowing,digesting and killing the antigens, a process known as phagocytosis.

***Research what are venules and arterioles.

Platelets/thrombocytes : Fragments of cells made in the bone marrow. Approximately 3

micro meters in size and important in blood clotting.

---Blood clotting: As a cut occurs, the tissue and platelets that are damaged produce

thromboplastin as they are exposed to air. Thromboplastin along with Ca2+ ions then begin

reactions which turn soluble fibrinogen (a type of plasma protein) into insoluble fibrin.

This fibrin forms fibres over the cut which traps the blood cells forming a clot. When thisdries a scab forms.

CutThromboplastin + Ca 2+ fibrinogen fibrin clot scab

TABLE COMPARING STRUCTURE AND FUNCTION OF ARTERIES, CAPILLARIES

AND VEINS

ARTERIES CAPILLARIES VEINS

Carry blood away fromheart Carry blood throughout alltissues

Link arteries to veins

Carry blood towards heart

Carry high pressure blood Pressure decreases along length

of capillaries

Carry low pressure blood

Blood moves in pulses

created by ventricle

contractions

Blood flow is smooth Blood flow is smooth

Blood flow is rapid Blood flow slows along length

of capillaries

Blood flow is slow

Carry oxygenated blood

(except pulmonary artery)

Blood becomes deoxygenated

along the length of capillaries

Carry deoxygenated blood

(except pulmonary vein)Most lie deep within body

where they are protected

Run throughout all tissues Many lie close to body

surface

****I will be sending you another table with comparisons of the white and red bloodcells and another with some diagrams for the blood vessels. This will be copied and

given to you.
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THE LYMPHATIC SYSTEM:

This is made oflymph and lymphatic vessels. The vessels start inside tissues and have

swellings along their length which are called lymph nodes (found most commonly in theneck and groin). Valves are present in the vessels to prevent backflow oflowpressure

lymph.

Lymph is formed from tissue fluid found in body tissues which in turn is made from

plasma. Lymph flows in one direction only, from tissues to blood. Lymph rejoins plasma

in the subclavian veins just before joining the anterior vena cava in the shoulder region.

FUNCTIONS OF THE LYMPHATIC SYSTEM:

1. Provides a rapid way of returning cell waste to the blood.2. Adds lymphocytes to the blood: these are made in lymph nodes.

3. Stationary phagocytes in lymph nodes filter bacteria from the lymph.4. Absorbs fatty products of digestion: these are absorbed into the lacteals of villi

and the lymph carries them to the blood.
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transport in organisms

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