[احمد مرعي]

الثاني

Biology Chapter II : The transportation in the living organism
Definition
It is the entrance of the required material to the organism's body
Examples of transportation among iving organisms
In algae (primitive plants) H2O & CO2 & salts move from *
one cell to another by diffusion & active transport.
In primitive animals as protozoa & hydra, transportation occurs *
by diffusion
T.S. in Dicot. Stem
Epidermis *
Cortex ( Collenchyma - parenchyma - starch sheath ) *
Vascular cylinder : Pericycle - vascular bundles - Pith *
note : vascular bundles { Phloem - Cambium - Xylem } in

Phloem consists of sieve tubes, companion cells and phloem parenchyma *
It carry the high - energy food from the leaves to all the plant parts
Cambium is meristematic cells produce secondary phloem outwards and secondary xylem inwards
Xylem consistes of vessels , tracheides & xylem parenchyma
It carry water and salts from the root to the leaves and support the plant


The adaptation of xylem tissue to carry out its functions
1- The elongated cylindrical cells joined end to end to form vessels
2- The transverse walls disappear to facilitate the movement of H2O & salts.
3- The cells are hollow & devoid of protoplasm to carry H2O & salts.
4- Their walls are thickened with lignin to prevent the water to get out of the vessels and support the plant.
5- The unthickened Pits to allow the water to move at the two sides.
the factors that are responsible for the ascent of sap
1- Root pressure theory
G.R.F. The root pressure can not explain the ascent of sap along the xylem vessels
Ans. Because: 1- Root pressure does not exceed two atmospheric pressure.
2- Some plants as Pinus (Conifers) have no any root pressure.
3- The force of the root pressure is affected by the environmental factors.

2- Imbibition theory: G.R.F Imbibition can not explain the ascent of sap
Ans. Because the experiments prove that the sap ascends through the cavity of the xylem vessels & not along their lignified walls

3- The theory of capillary
G.R.F. Capillary can not explain the ascent of sap
Water rises inside the narrowest vessels more than 150 cm. So capillary is considered as weak and secondary force affecting the ascent of sap
4- Cohesive force, adhesive force and transpiration pulls theory
a- The cohesive force is due-to the strong attraction between the water molecules inside the vessels. This helps the water column to exist inside the vessel.
b- The adhesive force is due the strong attraction between water molecules & the walls of the vessels. This helps the water column to resist gravitational force.
c- the transpiration pull by which water rises inside the vessels. This helps the continues column of water to move upwards.
The conditions should be fulfilled in the xylem vessels in order to be capable for the transportation of the raw materials
1- The vessels must be capillary tubes.
2- The walls should have high adhesive force to water molecules.
3- The water column should be devoid of air bubbles, the air bubbles cuts, the water molecules, so that the water column falls down due to gravity.
G.R.F. The failure of transporting a cultivated plant part after being moved from the soil & left exposed to the sun rays for long time
Because water evaporates through stomata, then air enters through the cut surface to fill the xylem vessels breaking the water column. As a result the plant wilts & dies even after recultivation
Explain how does the sap rise inside the xylem vessels
1- Transpiration decreases the humidity in the air chambers ,so the cells around the air chambers evaporate water to replace the lost water from the chambers So that increase the concentration inside the cells .

2-The cells pull water from the neighbor cells, till the pulling water reaches the xylem vessels
3- Water inside the vessels are pulled up from stem & root xylem as they are connected
4- When water is pulled up in the root vessels until reach the vascular cylinder of the root and also pull water from the root hairs so the concentration inside the root hairs increase and increase the osmotic pressure thus water is absorbed from the soil.
Experiments to prove that manufactured food is transported along phloem

Rapidan & Bohr’s experiment: 1945 *
Leaves of bean plant were exposed to CO2 formed of radioactive C14 to carry out photosynthesis.
Radioactive carbon was then detected inside the phloem vessels up & down the stem
Mittler’s experiment *
By separating the body of the Aphid insect from the proboscis, during its feeding
on manufactured plant food & by ****yzing the contents of the insect’s stomach it was found that this solution is formed of sucrose & amino acids.
Miller found that the tip of the proboscis dip into the phloem sieve tubes which contains sucrose & amino acids..
The transportation of food by the phloem: cytoplasm streaming theory
Thain & Canny could see cytoplasm strands which carry food particles extending along the sieve tubes .
Transportation of food is due cytoplasm streaming inside the tubes moves up & down through the pores in the sieve plates by active transport which require energy (ATP). therefore it is affected by temperature & oxygen supply ,the transportation inside the phloem slows down in the conditions of low temperature or lack of oxygen Transport In Animals

The vascular circulatory system

Blood vascular system and lymphatic system are closely connected with each other *
Human circulatory system is a closed circulatory system because its blood *
. vessels form a complete circuit
The heart is surrounded by a double membrane Called pericardium to protect the *
. heart against Shocks & also to facilitate the hearts Pumping action
Tricuspid valve : it has 3 flaps
It allow the blood to pass from the right atrium to the right ventricle and prevent it to return back
Mitral valve Bicuspid valve : it has 2 flaps
It allows the blood to pass from the left atrium to the left ventricle and prevent it to return .
The Simi-lunar valve : It has 3 pockets
It allows the blood to pass from the right ventricle to the lunges through the *
Pulmonary artery or from the left ventricle to the body organs through the aorta artery and prevent it to return to the heart
Aortic Simi-lunar valve: It has 3 pockets
It allows the blood to pass and prevent it to return to the heart
The internal valves of vein can be observed in the arm veins when the arm is tied tightly with a bandage (tourniquet) {discovered by William Harvey}
3- Blood capillaries
microscopic blood vessels formed of one raw of thin epithelial cells connect between arterioles & venules its diameter is 7 : 10 microns the thickness of the wall is about 0.001 micron

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Comparison between Arteries and veins

Properties of the blood
1- It is a liquid tissue consists of plasma & cells (RBCs, WBCs & blood platelets)
2- It is a red viscous liquid due to the presence of hemoglobin.
3- It is weakly alkaline (pH=7.4)
4- The human’s body contains about 5 : 6 liters blood
The functions of the blood
1- It transports digested food,O2, CO2 ,Nitrogenous wastes, hormones &some enzymes
2- It regulates metabolic activities.
3- It regulates the body temperature.
4- It regulates the internal environment of the body, such as osmotic potential, & PH
5- It protects the body against microbes & by the lymphatic system.
6- It protects itself against bleeding by the formation of the blood clot.
Comparison between Erythrocytes and Leucocytes

Antibodies
They are chemical substance discover the harmful foreign materials and stop their action to be harmless.
The heart beating 1) The sino-atrial node (pace maker) S-A node
It is a specialized cardiac fibers buried in the right atrium between the two veins.
It sends impulses to the muscles of the 2 atria causing their contraction.
2) The atrio-ventricular node A-V node
It lies at the connection between the atria & the ventricles .
It receives electrical impulses from the sino-.atrjal node and send them through special fibers (named Hess & Perkinjs apparatus) to contract the ventricles .
It is connected to two nervous
a) The vagus nerve inhibits the rate of the heart beating.
The Heart sounds
Lubb-Dubb ….. Lubb-Dubb….. Lubb-Dubb…..
1- Lubb sound It is long & low pitched
It heard during the contraction of the ventricles due to the closure of the bicuspid & tricuspid valves.
2-Dubb sound It is short & high pitched
It heard during the contraction of the atria & relaxation of the ventricles due to the closure of the pulmonary & aortic Simi-lunar valves
Blood Pressure
Systolic blood pressure is the maximum blood pressure in the arteries that close to the heart during the contraction of the ventricles.
Diastolic blood pressure is the minimum blood pressure in the arteries that close to the heart during the relaxation of the ventricles.
Measuring the Blood Pressure
Sphygmomanometer is an instrument that used to measure the blood pressure
Sphygmomanometer give 2 numbers as 120/80 mm Hg in normal youth
The no.120 indicate Systolic blood pressure but 80 indicate the diastolic blood pressure.
Systolic blood pressure is the maximum blood pressure in the arteries that close to
the heart during the contraction of the ventricles 120 mm Hg but it decrease until reach 10 mm Hg in blood capillaries and veins therefore the presence of the internal valves of vein help the blood to return back to the heart .
The blood pressure increase gradually in old ages so, it needs to treat before it reaches the dangerous cases.
The Blood Circulation

1. Pulmonary circulation
It starts from right ventricle & ends at left atrium.
When the right ventricle contracts,
the deoxygenated blood rushes into the pulmonary artery
and the Simi-lunar valve is closed preventing the returning back
The pulmonary artery divide into two branches, each
branch divides again into small branches till it ends
at blood capillaries around alveoli.
Through the blood capillaries water vapour & CO2
come out the blood & O2 get into the blood
This is called exchange of gases so, the blood now become oxygenated.
The blood returns from the lungs to the left atrium through the 4 pulmonary veins.
The left atrium contracts pushing the blood down to the left ventricle through the bicuspid valve.
2- Systematic circulation


It starts from the left ventricle & ends at the right atrium.
When the left ventricle contracts the bicuspid valve shuts
& Oxygenated blood rushes into the aorta & does not go
back to the heart.GR
The aorta branches into arteries. Each artery enters to an
organ of the body and endat a network of blood capillaries
distributed between the body tissues & cells
Exchange of material between the blood & the cells takes
place where the cells receive O2 & foodstuffs from the
blood & the bloodn receives CO2 , H2O & wastes
Exchange of substance takes place by diffusion & active
transport through the walls of the blood capillaries
3- Hepatic portal circulation


The blood capillary of the villi, carrying digested food stuffs, collect to form larger venules, These venules form a large vein called hepatic portal vein that enters into the liver The hepatic portal vein also receives other veins coming from the pancreas, the spleen & the stomach.
The hepatic portal vein branches into smaller venules that end at blood capillaries distributed between the hepatic cells, Through the blood capillaries sugars & amino acids diffuse into the hepatic cells where some changes occur.
The blood leaves the liver through the hepatic vein to join the upper part of the inferior vena cava just before it opens at the right atrium