Transcript Chapter 12 Transport in Organisms
When do Organisms need Transport Systems?
We need TRANSPORT when 2 cells are far from each other materials needed to be moved from one place to another huge sum of substances to be moved
Why do Organisms need Transport Systems?
ensure a continual supply of nutrients, oxygen and other useful materials for metabolism and removal of toxic waste products produced by metabolism
small animal can undergo this by diffusion but large animal cannot, they need a transport system
Blood Components
blood = plasma + (straw-coloured fluid) blood cells (corpuscles) blood cells include red blood cell (erythrocytes), white blood cells (leucocytes ) and blood platelets where red blood cells are the most numerous blood cells and give blood the red colour
Separation of blood
Blood components can be separated by centrifuge A Centrifuge for separation Plasma Blood cells
Composition of Mammalian Blood
Whole Blood Plasma (55% by volume) Blood Cell (45% by volume) 90 % Water 10% Dissolved Substances White Blood Cell Red Blood Cell Platelets Phagocytes Lymphocytes
Blood Plasma
Plasma is approximately 55% by volume and contains WATER (as a solvent) SOLUBLE SUBSTANCES protein mineral salts hormones gases dissolved food substances metabolic wastes
Blood Cells
Platelets White Blood Cell Red Blood Cell
Red Blood Cells (red corpuscles, erythrocytes)
form within bone marrow short life span with about 120 days old red blood cells are destroyed in liver & spleen
they have no nuclei when mature - it increases the space to carry haemoglobin they have biconcave disc shape - which provides large surface area to diffuse oxygen
possess of haemoglobin – haemoglobin is an iron-containing compound and its presence is responsible for the colour of red blood cell – enable red blood cell to carry oxygen from lungs to all parts of the body
Transport of Oxygen
haemoglobin has a high affinity for oxygen when the concentration of oxygen is high Oxygen + haemoglobin In lung In tissue oxyhaemoglobin change of haemoglobin to oxyhaemoglobin is accompanied by the colour change from purplish red to bright red
Transport of Carbon Dioxide
CO 2 (from tissue) CO 2 (in bloodstream) CO 2 + H 2 O enzyme H 2 CO 3 carbonic acid H + + HCO 3 hydrogen carbonate ion HCO 3 (In red blood cell) (in plasma)
To Test a Sample of Blood Plasma (chicken/pig/ox) for glucose
centrifuge supernatant Fehling’s solutions A and B boiling water chicken blood Name the supernatant obtained after centrifugation.
Ans: It is plasma.
centrifuge supernatant Fehling’s solutions A and B boiling water chicken blood What does the precipitate in the centrifuge tube consist of ?
Ans: The precipitate contains blood cells.
centrifuge supernatant Fehling’s solutions A and B boiling water chicken blood What happens to the supernatant when it is heated with Fehling’s solutions A and B ?
Ans: The supernatant forms an orange precipitate.
White Blood Cells (white corpuscles, leucocytes)
and irregular in shape prominent nucleus no haemoglobin kill germs, defend against disease
cells: phagocytes and lymphocytes
White Blood Cells - Phagocytes
made in bone marrow but different from the place where red blood cells are made irregularly shaped nucleus move like Amoeba can squeeze out through the walls of capillaries into the surrounding tissues engulf dead cells or pathogens
White Blood Cells - Lymphocytes
made in bone marrow, then migrate to lymph nodes large nucleus which nearly fills up the cells
produce antibodies to attack germs by reaction with their surfaces and often cause them to clump together produce antitoxins to neutralize the toxins secreted by germs
Platelets (thrombocytes)
platelets are not cells fragments budded off from specialized cells in bone marrow smaller than other blood cells life-span is about 5 to 9 days agent for initializing blood clotting
Blood Clotting
when platelets are damaged in an injury, it releases a chemical substance which starts a chain of reactions results: fibrinogen fibrin fibrin acts like a net, trapping blood cells and plugging the wound so bleeding stops
serum are yellowish fluid which is plasma without fibrinogen clot dries up and harden to form a scab when new skin formed under the scab, it loosens and comes off The clotting of blood ( plasma protein )
Functions of Blood
It acts as a transport medium for oxygen, carbon dioxide, food, urea, hormones, antibodies and heat It contains white blood cells and platelets for body defense against infection It helps in maintaining body temperature constant
In emergencies an injured person may die...
How can we
save
his life?
Blood Transfusion Any criteria for Blood Transfusion?
Donor’s blood and recipient’s blood must be compatible, otherwise, agglutination will occur which will block the blood vessels
Blood Grouping
a person’s blood group determined by the protein present on the surface of red blood cells called antigens there are two different antigens called antigen A and antigen B. For a person in group A contains antigen A
in human, there are mainly four different blood groups called A, B, AB and O in plasma, there may contain antibodies known as anti-A and anti-B. They will react with certain red blood cells which contain the wrong antigen
The ABO Blood Group
Type A Antigen A Type B Antigen B Type AB Antigens A and B Type O Neither antigen A or B Antibody B Antibody A Neither antibody A and B Antibodies A and B
Human Blood Groups
Blood Group A B AB O Antigen (RBC) A Antibodies (Plasma) Anti-B Recipient A & AB B Anti-A B & AB A & B NO NO Both anti-A & anti-B AB only ALL
Agglutination Reaction
A Type A blood of donor Type B antibody in type A blood of recipient No agglutination B Type A blood of donor Type A antibody in type B blood of recipient Agglutination
Human Blood Groups
Donor
A
Recipient B
Agglutination
AB O = universal recipient = universal donor
Blood Vessels
there are three main kinds of vessels: arteries, veins and capillaries arteries carry blood away from the heart while veins carry blood towards the heart
Vein
Blood Circulation
Heart Artery Venule Capillary Arteriole
Vein
Blood Vessels
Artery
Artery
wall of arteries are thick and supported with muscles and elastic fibres Artery
Vein
• Blood pressure is much lower in vein as blood has flowed slowly through the capillaries before entering the vein • vein has larger lumen and thinner walls than artery Vein
valves present to prevent backflow of blood and ensure that it flows towards the heart
Valve closed blood can’t flow back Valve open blood can flow
return of blood to heart is aided by contraction of body muscles as they squeeze the blood along the vein Blood squeezed towards heart Muscle contracted Valves closed Prevent back-flow
Direction of blood flow
Differences between Arteries and Veins
Arteries Veins carry blood away from the heart return blood to the heart thick wall made up of muscles and elastic fibres thin wall made up of muscles and elastic fibres
Differences between Arteries and Veins
Arteries Veins blood flows with pulse blood flows steadily with no pulse
Differences between Arteries and Veins
Arteries Veins Lumen small large
Differences between Arteries and Veins
Arteries Veins Location deep inside the body close to the surface
Demonstration of Venous Flow in the Fore Arm
A C vein elbow joint B D R S X Y finger X pressing down on R finger Y squeezing blood towards S finger Y removed finger X still pressing down on R both fingers are removed What structure in the vein is indicated by the appearance of the bulge at S shown in diagram C ?
Ans: The valve in the vein.
A C vein elbow joint B D R S X Y finger X pressing down on R finger Y squeezing blood towards S finger Y removed finger X still pressing down on R both fingers are removed What is the purpose of tying the arm with a piece of rubber tubing ?
Ans: This makes the vein more conspicuous.
A C vein elbow joint B D R S X Y finger X pressing down on R finger Y squeezing blood towards S finger Y removed finger X still pressing down on R both fingers are removed With reference to the steps shown, explain why the part of the vein between R and S has disappeared ?
Ans: Since there are valves at point S, blood is prevented from flowing back … along …
A C vein elbow joint B D R S X Y finger X pressing down on R finger Y squeezing blood towards S finger Y removed finger X still pressing down on R both fingers are removed Why is it necessary to take the rubber tubing away as soon as the demonstration has been completed ?
Ans: It is because we need to restore the normal blood flow for the arm as soon as possible.
Capillaries
It is the smallest blood vessels
It is the site of exchange (by diffusion) Thin wall (one cell) Nutrients
Diffusion
O 2 CO 2 Waste
Adaptation of Capillary
It has many branches to increase the surface area for diffusion of materials like glucose, amino acids, water, carbon dioxide, oxygen, mineral salts and metabolic wastes between blood and tissue cells
It has thin wall (only one-cell thick) to decrease the diffusion distance for exchange of materials between blood and tissue cells
Exchange of Materials
It is carried out by diffusion through the whole length of capillaries (B.P. > O.P.) substance pressed out to the tissue cells O.P.
O.P.= osmotic pressure B.P.= blood pressure B.P.
arteriole end blood flow (O.P. > B.P.) substances diffused into the blood capillary O.P.
B.P.
venule end
Heart
located inside the thorax, between the lungs enclosed by the pericardium the wall of heart is made of cardiac muscle and it works days and nights throughout one’s life
oxygen and nutrients are supplied to heart through coronary arteries while wastes are carried away by coronary veins
Structure of Heart
the heart is divided into right and left halves internally by a central wall or partition called septum heart is divided into four chambers with the two chambers at the top of heart are auricles and the two down at the bottom called ventricles
Heart-Auricles (Atrium)
walls are relatively thin right auricles receives deoxygenated blood from the venae cavae (superior vena cava and inferior vena cava) which collect blood from all parts of the body except lungs left auricle receives oxygenated blood from the pulmonary veins which come from the lungs
Direction of Blood Flow from Auricles to Ventricles
Right Superior vena cava Right auricle (atrium) Inferior vena cava Right ventricle Left Pulmonary veins Left auricle (atrium) Left ventricle
Heart-Ventricles
have thicker and more muscular walls than the auricles right ventricle pumps deoxygenated blood to the lungs via the pulmonary artery left ventricles pumps oxygenated blood into the aorta which takes the blood around the body
right ventricle pumps blood to the lungs, which lie very close to the heart but left ventricle needs to pump blood all around the body left ventricle has a thicker wall of muscles
Heart-Valves
prevent blood from flowing backwards, ensuring blood flows through the heart in only one direction there are three types of valve present in heart, they are : Tricuspid valve, Bicuspid valve and Semilunar valves
Tricuspid valve -valve on the right hand side lying between the right auricle and right ventricle has three parts Bicuspid valve - it situates at the left hand side lying between the left auricle and left ventricle is made up of two parts
REMARKS: chordae tendineae (heart tendon) are attached between the two valves above and the muscular walls of the ventricles to prevent the one-way valves from being turned inside out
Semilunar valves -situated at the entrances of the aorta and the pulmonary artery. They are pocket shaped valves to prevent the backflow of blood into the ventricles
Blood Flow from Ventricles to Other parts of the Body
To right lung To left lung To head Aorta To body Pulmonary arteries Venae cavae Pulmonary veins Articles Semilunar valves Tricuspid valve Septum Ventricles Bicuspid valve Heart tendon prevent valves to turn inside out Cardiac muscle
Examination of a Pig’s Heart
pulmonary artery first cut pulmonary artery second cut aorta right auricle left auricle third cut left auricle right auricle right ventricle left ventricle left auricle open heart tendon Why do the ventricles have thicker walls than the auricles ?
Ans: It is because ventricles need to pump blood to other parts of the body.
pulmonary artery first cut pulmonary artery second cut aorta right auricle left auricle third cut left auricle right auricle right ventricle left ventricle left auricle open heart tendon Which ventricle has a thicker wall than the other ? What is the reason for this difference ?
Ans: Left ventricle. As it needs to pump blood all around the body but right ventricle pumps blood to lungs which lie close to heart.
pulmonary artery first cut pulmonary artery second cut aorta right auricle left auricle third cut left auricle right auricle right ventricle left ventricle left auricle open heart tendon What are the structures separating the auricles and ventricles ?
Ans: It is septum.
pulmonary artery first cut pulmonary artery second cut aorta right auricle left auricle third cut left auricle right auricle right ventricle left ventricle left auricle open heart tendon Why is it necessary to have the chordae tendineae ?
Ans: It is used to prevent the one-way valves from being turned inside out.
pulmonary artery first cut pulmonary artery second cut aorta right auricle left auricle third cut left auricle right auricle right ventricle left ventricle left auricle open heart tendon What is the function of the coronary artery ?
Ans: It is used to supply nutrients and oxygen to the heart.
Heart Attack
cardiac muscle differs from other kinds of muscle as it is able to contract repeatedly without getting tired coronary arteries are branches from aorta which supply nutrients and oxygen to the cardiac muscle
coronary heart disease is the slow down of the flow of blood through coronary arteries which is caused by the deposition of a fatty substance called cholesterol on the inside wall of these arteries, making them narrower and rougher
heart attack is a result of blocking coronary arteries so cardiac muscle cannot obtain oxygen or nutrients from blood and die as a result, the person may die excess animal fat in the diet, smoking, high blood pressure, lack of exercise and stress may lead to heart attacks
Heart Beat
as cardiac muscle in its walls contracts and relaxes, heart beats systole is the time when cardiac muscle contracts and the heart becomes smaller which squeezes blood out
diastole is the time when cardiac muscle relaxes and the heart becomes larger which allow blood to flow into the auricles and ventricles it consists of auricular systole, ventricular systole and diastole
Auricular systole - it is about 0.1 second in duration - contraction of the two auricles, squeezing blood into the ventricles Ventricular systole it is about 0.3 second in duration - contraction of the two ventricles
- tricuspid and bicuspid valves are forced to close by the pressure of the blood, producing the first heart sound “lub” - semilunar valves are forced open by the pressure of the blood, so blood is forced out of the ventricles into the arteries
Diastole - it is about 0.4 second in duration - all four chambers relax blood pressure in the ventricles decreases and this causes the closure of the semilunar valves, producing the second heart sound “dup”
Cardiac cycle is the duration between one contraction of the auricles and the next and it is about 0.8 seconds
pulmonary circulation lungs heart systemic circulation body
Blood Circulation in Man
In one complete circulation, blood flows through heart twice but flow through the body once only consists of two circuits: pulmonary circulation and systemic circulation
Pulmonary Circulation
Tissue Venae cavae Deoxygenated blood Right auricle Pulmonary vein Right ventricle Left ventricle Left auricle Lung Oxygenated blood
Systemic Circulation
contraction of left ventricle pumps oxygenated blood out of the heart via aorta to all parts of the body (except lungs)
exchange of materials occurs when blood flows through the capillaries and become deoxygenated finally, blood is collected by the venae cavae which drains them into the right auricle of the heart
Lymphatic System
Tissue fluid - fluid formed when the high blood pressure at the arterial end of a capillary forces fluid out through it but red blood cells, platelets and plasma proteins stay back in the bloodstream
- used to bath the cells and keeps them in the right condition and provides a medium for exchange of materials between blood and cells
Lymph - excess tissue fluid which cannot be returned to the capillaries by osmosis but drained into lymph capillaries - lymph capillaries are colourless vessels present in the tissues and it will join up to form large lymph vessels
- lymph vessels carry lymph to subclavian veins which empty into the heart through the superior vena cava - lymphatic vessels contain valves, which help to keep the lymph flowing in the right direction - contraction of skeletal muscles also aids the flow of lymph
Lymph nodes (lymph glands) - situated on the way from the tissue to the subclavian veins
Lymph nodes
- made up of tiny spaces like a sponge and lymph is filtered through these spaces before it can continue to return to the bloodstream - contain large numbers of white blood cells to destroy bacteria and toxin in lymph
Functions of Lymphatic System
– to return excess tissue fluid to blood system – as a medium for material exchange between capillaries and tissue cells
- fats are absorbed by lacteals which join the lymphatic system so it transport absorbed fats - the lymph node filters the lymph, it also produce lymphocytes which make antibodies
Functions of Transport System in Angiosperms
carries water and mineral salts from the roots to the mesophyll cells of the leaves for photosynthesis by xylem
carries foods made in the leaves by photosynthesis to other cells of the plant by phloem xylem and phloem are together called vascular bundles
Arrangement of Conducting Tissues in Angiosperms
in root - close to central position in which xylem is found in the centre in a star-like arrangement and phloem lies between the radial arms of the xylem
to resist the strong pulling force from the wind blowing the shoot in stem - close to the epidermis where the conducting tissues are arranged in a ring near the outside edge, with phloem lying outside and xylem inside
- to resist the strong bending force produced by wind in leaves - vascular bundles are often called veins in which xylem lies above the phloem
Xylem
consists of long tubular vessels each vessel is made up of many dead cells which are hollow and joined end to end
the end walls of the cells have disappeared and so a long and open tube is formed xylem vessels run from the root, through the stem and finally branch out into every leaf of the plant
xylem vessels contain no cytoplasm or nuclei to prevent xylem from collapsing, they have thick cell walls made of cellulose and strengthened by rings of a woody substance called lignin
Phloem
made up of tube cells called sieve tubes which are living cells joined end to end by perforated horizontal walls called sieve plate the perforations allow dissolved substances to flow through them so food made in the leaves can be carried to other parts of the plant
sieve tubes contain cytoplasm but no nuclei and they do not have lignin in their cell walls each sieve tube has a companion cell next to it but this companion cell does not have nucleus and contain many other organelles
Comparison between Sieve Tubes and Vessels
Sieve Tubes Vessels living cells smaller diameter walls relatively thin, flexible, composed of cellulose dead cells larger diameter walls relatively thick, hard, strengthened by rings of lignin
Comparison between Sieve Tubes and Vessels
Sieve Tubes Vessels the lumens of mature cells are filled with cytoplasm end walls of adjacent sieve tubes from sieve plates the lumens of mature cells are empty end walls of adjacent vessels cells break down
Upward Transportation of Water and Mineral Salts
• root pressure • capillarity • by transpiration pull
Transpiration Pull
most of the water rising up in the xylem of the stem is pulled up by this during transpiration, water is continually removed from the top of xylem vessels to supply cells in the leaves so pressure at the top of xylem reduces and water flows up
Transport of Organic Nutrients
translocation is the process of transporting the manufactured carbohydrates in photosynthesis via phloem from the leaves to other parts of the plant