�ݺ�ߣ

Chapter Overview Transport in Mammals 8.1 The Circulatory System - Introduction & Anatomy 8.2 The Blood & Blood vessels 8.3 The Hear t & Cardiac Cycle 8.4 Heart Diseases 8.1.1 The need for transport 8.1.2 Double Circulation 8.2.1 Components of the Tissue Fluid a) Blood Plasma b) Red Blood Cells c) White Blood Cells d) Platelets 8.2.2 Exchange of Substances and The Lymphatic System 8.2.3 Haemoglobin 8.2.4 Rejection and ABO Blood Group 8.2.5 Structure-function of blood vessels 8.4.1 Myocardial infarction 8.4.2 Causes of Heart Diseases 8.3.1. Structure and Function of heart 8.3.2 Heart valves, Systole and Diastole

(a) Explain the need for transport system in mammals (b) State the differences between single and double circulation, and the advantages (c) Identify the main blood vessels to and from the heart, lungs, liver and kidney. (d) State the functions of blood (e) List the different ABO blood groups and all possible combinations for the donor and recipient in blood transfusions. Objectives

Imagine you are an amoeba… (unicellular organism) Oxygen Food Carbon Dioxide Water Waste materials Cell is able to exchange substances DIRECTLY with the environment. Diffusion is enough

Multi -cellular organism Is diffusion enough? Do you know how many cells do we have in our body? How to transport materials into and out of Mr Bean efficiently?

Adapted from http://farm1.static.flickr.com/107/291667041_e1e590124a.jpg?v=0 Who will need a transport system? Unicellular organism (e.g amoeba) Adapted from http://www.akalaty.com/akalaty/wp-content/uploads/2007/05/extra-big-fat-cartoon.jpg Multi-cellular organism (e.g humans) Cells are too far from external environment. Organism needs transport system to ensure efficient exchange of substances. Organism does not need transport system. Cell is able to exchange substances directly with the environment.

The Need for Transport What makes simple diffusion a reliable mechanism in unicellular organisms? Here are two important factors: LARGE Surface Area to Volume Ratio Maintaining a Steep Diffusion gradient

The Need for Transport Multicellular organisms thus cannot depend on simple diffusion because they have: SMALL Surface Area to Volume Ratio DIFFICULTY in maintaining a STEEP Diffusion gradient How could they solve these problems?

The Need for Transport SMALL Surface Area to Volume Ratio  Increase surface area by having an internal system of channels or chambers. DIFFICULTY in maintaining a STEEP Diffusion gradient A diffusion gradient is difficult to maintain if they are bathed in static body fluid. Solution: Devise a pump to Actively circulate the body fluid

Transport system in mammals are subdivided into: Blood system carrying blood Lymphatic system carrying lymph

Blood Circulatory System What does the circulatory system consist of? What is the function of the circulatory system? How are the heart and blood vessels connected to allow circulation of blood? Heart, Blood Vessels, Blood Circulates blood around the body – Transports useful substances such as oxygen and food to all body cells and transports waste products such as carbon dioxide and urea to the sites of disposal.

Circulatory System Blood Blood Vessels Heart

3 Parts of the circulatory system Heart The muscular pump, that moves the fluid Causes your pulse Blood vessels The system of channels and tubes that are connected to all parts of the body Blood The fluid that has the capacity to carry the metabolites

Double Circulation For every organ, there will be at least one main artery which brings oxygenated blood from heart to the organ and one main vein which brings deoxygenated blood out of the organ to the heart. *take note of the main blood vessel Closed system

Double Circulation Blood passes through the heart twice in 1 complete circuit. Double circulation  Pulmonary circulation  Systemic circulation

Human Circulatory System Double circulation 1) Pulmonary circulation (low pressure) – circulation of blood from heart to lungs to heart 2) Systemic circulation (high pressure) – circulation of blood around the body except lungs One-way flow of blood

Advantages of Double Circulation (Pulmonary Circulation) Lower pressure to lungs, blood flows slower , allows sufficient time for gaseous exchange; (Systemic Circulation) Higher pressure to body , ensure efficient transportation of useful materials(e.g oxygen) to rest of body cells and allow cells to maintain a high metabolic rate .

(a) State the functions of blood • red blood cells – haemoglobin and oxygen transport • plasma – transport of blood cells, ions, soluble food substances, hormones, carbon dioxide, urea, vitamins, plasma proteins white blood cells – phagocytosis, antibody formation and tissue rejection Objectives

Red Blood Cell White Blood Cell Platelets

Blood- A tissue fluid Composition of blood Plasma (Fluid) 55% Blood cells (corpuscles) 44% Platelets 1% Red blood cells White blood cells

Components of Blood Plasma – 55% total volume of blood  mostly liquid water (~90%)  soluble blood proteins (7%)  hormones  electrolytes  nutrients Cellular Component – 45% total volume of blood  White blood cells  Platelets  Red blood cells Only red blood cells and plasma transport materials! (2%)

Functions of Blood Transport Oxygen Carbon Dioxide (bicarbonate ions)  lungs Food Hormones Nitrogenous waste product  kidneys Protection Production of antibodies Phagocytosis of foreign bodies Clotting of blood (prevent loss of blood) Distribute body heat especially from muscles and liver, to maintain uniform body temperature

Transports substances such as: 1) Plasma proteins (fibrinogen,prothrombin and antibodies). 2) Dissolved mineral salts occurring as ions (Na+, +K,Ca2+, Cl-, hydrogencarbonates) . 3) Food substances (glucose, amino acids, fats, vitamins) 4) Excretory products (urea , uric acid,creatinine and CO 2 as hydrogencarbonate ions ) 5) Hormones (insulin, glucagon) 6) Blood cells (red and white blood cells) pale yellow liquid made up of 90% water and a mixture of dissolved substance Plasma Function Structure TB Pg 140

Plasma The amount of soluble proteins, mineral salts and glucose in the blood plasma are kept relatively constant  by the HOMEOSTASIS mechanism (Chapter 12) TB Pg 140

Components of Blood Red Blood Cells (Erythrocytes) Biconcave , circular, flattened discs  Increase surface area to volume ratio  Thinner central area facilitates rapid diffusion of oxygen in and out of the cell. No nucleus, DNA or mitochondria  Allows the RBC to carry more Haemoglobin , thus facilitating the binding and transport of more oxygen molecules. TB PG 141

Components of Blood Red Blood Cells (Erythrocytes) Small, Flexible and Elastic  To squeeze through narrow blood capillaries more easily Contains haemoglobin (Hb)  Allows the reversible binding of oxygen for oxygen transport . TB PG 141

Defenders of the body: WHITE BLOOD CELL What are the similarities between a COUNTER-TERRORIST unit and a WBC?

White Blood cell colourless (no haemoglobin) larger than red blood cells ratio of red blood cells: white blood cells = about 700:1 irregular in shape has nucleus can move and change shape (able to squeeze through walls of capillaries)

White Blood Cells (Leucocytes) Two groups of leucocytes: Lymphocytes  Formed in bone marrows and mature in lymph node  Typically round with rounded nucleus  Relatively small amount of non granular cytoplasm  Produces antibodies that fight against pathogens Phagocytes  Many types, shapes and sizes  Granular with lobed nucleus  Ingests foreign bodies by phagocytosis TB PG 142)

Test Yourself! (page 143) (a)  Red blood cells contain a red pigment and have a circular, biconcave shape.  White blood cells are round in shape.  Platelets are small fragments with irregular shapes. The diameter of the red blood cells is decreased so that they can pass easily through the lumen of capillaries; the red blood cells increase their surface area to speed of absorption or release of oxygen; the bell shape slows down the rate of blood flow, giving more time for gaseous exchange. (c) The cells of the body constantly require oxygen to provide energy by tissue respiration, whereas the white blood cells are required only at certain times.

Platelets (Thrombocytes) Platelets (Thrombocytes) Not true cells; cytoplasmic fragments Play Critical role in the clotting of blood (to be discussed later)

Functions of Blood Transport Oxygen Carbon Dioxide Digested Food from blood capillaries in small intestine Hormones Waste Protection Production of antibodies Phagocytosis of foreign bodies Clotting of blood (prevent loss of blood) Distribute body heat especially from muscles and liver, to maintain uniform body temperature Carried by plasma

How the Red blood cells transport O 2

Functions of Blood Transport Oxygen By Haemoglobin in RBC Haemoglobin A protein complex that contains 4 iron atoms Gives blood its red colour Able to bind to oxygen molecules In the unbound state, haemoglobin is a deep purplish red. When oxygen is bonded, haemoglobin turns into a bright red oxyhaemoglobin.

Functions of Blood Transport Oxygen – The Role of Haemoglobin Haemoglobin Unbound state  haemoglobin has HIGH AFFINITY for oxygen. Binds to oxygen easily. Reversible process. How is it reversible?

Functions of Blood Transport Oxygen – The Role of Haemoglobin Hb(O 2 ) 4 ( oxyhaemoglobin ) high oxygen concentration (lungs) low oxygen concentration ( in body tissues) Bright red Hb + 4O 2 (haemoglobin) Purplish red

Functions of Blood As blood passes through oxygen-poor tissues, oxyhaemoglobin releases its oxygen . Oxygen then diffuses in solution into tissue cells. Body Tissues Red Blood Cell

Adapted from http://www.3dscience.com/img/Products/Images/clip_art/respiratory_alveoli_web.jpg Adapted fromhttp://www1.bellevuepublicschools.org/curriculum/k6web/fifthgrade/bodysys/alveoli2.jpg Alveoli in lungs Deoxygenated blood is brought back to the lungs through pulmonary arteries. Oxygenated blood is brought out of the lungs through pulmonary veins. Transport function Pulmonary artery Pulmonary vein

Adapted from http://www.3dscience.com/img/Products/Images/clip_art/respiratory_alveoli_web.jpg Adapted fromhttp://www1.bellevuepublicschools.org/curriculum/k6web/fifthgrade/bodysys/alveoli2.jpg Alveoli in lungs Oxygen diffuses from the alveoli (higher concentration of oxygen) to blood capillaries (lower concentration of oxygen), down a concentration gradient. Carbon dioxide diffuses from the blood capillaries (higher concentration of oxygen) to alveoli (lower concentration of oxygen). Transport function Pulmonary artery Pulmonary vein O 2 O 2 O 2 O 2 O 2 O 2

Adapted from http://www.3dscience.com/img/Products/Images/clip_art/respiratory_alveoli_web.jpg Adapted fromhttp://www1.bellevuepublicschools.org/curriculum/k6web/fifthgrade/bodysys/alveoli2.jpg Alveoli in lungs Oxygen diffuses from the alveoli (higher concentration of oxygen) to blood capillaries (lower concentration of oxygen), down a concentration gradient. Carbon dioxide diffuses from the blood capillaries (higher concentration of oxygen) to alveoli (lower concentration of oxygen). Transport function Pulmonary artery Pulmonary vein CO 2 CO 2 CO 2 CO 2 CO 2 CO 2

Carbon Monoxide = Carboxyhaemoglobin formation Carbon Monoxide Poisoning

Haemoglobin combines even more readily with carbon monoxide than with oxygen to form a bright pink compound called carboxyhaemoglobin . Unlike oxyhaemoglobin, carboxyhaemoglobin does not readily give up its carbon monoxide, so the haemoglobin becomes useless . This is why people can be poisoned by the fumes of gas or car exhausts in a confined space. Carbon Monoxide Poisoning How does it happen? TB Pg 147

by placing face masks on the patients and supplying them with air containing a much higher proportion of oxygen than usual. Carbon Monoxide Poisoning How is it treated?

Transport function How is a molecule of oxygen being transported from lungs to the liver cell? As RBC moves through the capillaries in the lungs, oxygen diffuses from the alveoli (higher concentration) into RBC (lower concentration). Haemoglobin in RBC binds with oxygen to form oxyhaemoglobin . Blood transports oxyhaemoglobin to all tissues in the body. Oxyhaemoglobin releases its oxygen to tissues containing very little oxygen by diffusion. Rearrange! 1 2 3 4

Thinking time… How do humans adapt to living at high altitude? What makes their cheeks so red?

At high altitudes, oxygen is low . to compensate for the low concentration of oxygen body produces more red blood cells (acclimatisation)  rosy cheeks. Increasing the proportion of RBC increases haemoglobin content  more oxygen can be transported to tissue cells per unit time. For the same reason, long distance runners often train at high altitudes before a big race hence when they run at lower altitudes, body can carry oxygen more efficiently, run longer.

Functions of Blood Transport Carbon dioxide

Functions of Blood Transport Food Hormones Waste Examples Glucose Amino Acids Vitamins Chemical messengers that control many metabolic processes. Examples Insulin Glucagon Adrenalin Excretory products delivered to the kidneys for removal. Examples Urea Uric Acid Creatinine

Functions of Blood Transport Oxygen Carbon Dioxide Food Hormones Waste Protection Production of antibodies Phagocytosis of foreign bodies Clotting of blood (reduce loss of blood) Distribute body heat especiallly from liver and muscles Protection Production of antibodies So we have seen how blood transports metabolic substances and the important role played by haemoglobin…. Next, we shall look at the protective functions of blood.

Protective function Phagocytosis Antibody production Blood Clotting/Coagulation By platelets By phagocytes By lymphocytes

Protective function Blood Clotting 2) Damaged tissues and blood platelets release thrombokinase (enzyme). 4) In the presence of calcium ions , thrombokinase catalyses conversion of inactive prothrombin to active thrombin (enzyme). 3) Thrombokinase neutralises action of heparin (anti-clotting substance in blood). 5) Thrombin catalyses conversion of soluble fibrinogen to insoluble fibrin threads . 6) Insoluble fibrin threads entangle blood cells. A clot and scab is formed. A yellow-ish liquid serum is left behind 1) Platelets adhere to the cut edges. Platelets release chemicals to attract more platelets. Formation of platelet plug prevents external bleeding. When blood vessels are damaged,

Function of Blood Clotting Clotting seals wound, preventing excessive loss of blood Clotting of blood by platelets prevent further entry of bacteria/ foreign particles  reduce infection by pathogens

What if some microbes get into the wound?

Protective function Phagocytosis Phagocyte engulfs foreign particle. Destroy pathogens by phagocytosis and ingest foreign particles like bacteria that gain entry into blood Phagocyte flows over to the foreign particle. Adapted from http://www.cutiegadget.com/pict/pacman-plush.jpg

Protective function Antibody production This stimulate Lymphocyte releases antibodies . Antibodies can - rupture bacteria - agglutinate bacteria such that they will be easily digested by phagocytes - neutralise harmful products (e.g toxins) produced by bacteria/foreign particle. - prevent viruses from attaching to host cells by attaching to them Disease causing micro-organisms in blood stream.

Functions of Blood Antibodies are soluble proteins… Mostly produced by lymphocytes. Capable of recognizing foreign objects… Then binds to them… Foreign objects with antibodies bounded to them are destined for destruction by immune system. Protection Production of antibodies

* Hexa (Six-in-One) includes Diphtheria/Tetanus/Pertussis (DTaP) Haemophilus Influenza type B (Hib) Inactivated Polio (IPV) Hepatitis B ** Diphtheria/Pertussis/Tetanus (DTaP), Haemophilus Influenzae type B (Hib) & Polio (IPV) Vaccination : Injection of dead foreign bodies into humans to stimulate lymphocytes into secreting antibodies Adapted from http://1.bp.blogspot.com/_lm2JI7sGwYI/SZUGTvIT7RI/AAAAAAAAEkQ/14mCG1Y2RX0/s400/vaccination(5).jpg Age Vaccine At birth BCG (for tuberculosis) Hepatitis B - 1st dose 2 month *Hexa (Six-in-One) 4 months ** DTaP/ IPV/ Hib 6 months Hexa (Six-in-One) 12 months Hepatitis B Booster for children of Hepatitis B carrier mothers only 15 months MMR (Measles/Mumps/Rubella) 18 months DTaP/ IPV/ Hib - 1st booster 6 yearsDT 2nd booster Oral Sabin - 2nd booster (oral polio vaccine) 12 yearsDT 3rd booster Oral Sabin - 3rd booster MMR - 2nd dose

Amount of antibodies in blood 2 nd exposure to the same foreign bodies 1 st exposure to foreign bodies Graph (1 st exposure to foreign bodies): Lymphocytes respond to foreign bodies by producing antibodies. Graph (2 nd exposure to foreign bodies): - More antibodies - Response is faster

Protective function Phagocytosis Antibody production Blood Clotting What will happen when tissue or organ transplant occur?

Organ transplant or tissue rejection In 2002, Ms De Cruz became the first person in Singapore to receive an organ transplant from an unrelated living donor. "Taking medication every day has become ordinary...The only thing I'm fearful about is becoming immune to the anti-rejection drugs I'm on and the possibility of renal failure."

Red Blood Cells (Erythrocytes) Circular, flattened, biconcave shape No nucleus Contain haemoglobin Elastic.Able to turn bell shape Transport oxygen from lungs to cells around body Plasma Pale yellowish liquid Contains 90% water Transports substances such as soluble proteins (e.g. fibrinogen, prothrombin, antibodies), dissolved mineral salts (e.g. calcium), food (e.g. glucose, amino acids), excretory products (e.g. urea, carbon dioxide), hormones (e.g. insulin) around body White Blood Cells (Leucocytes) Irregular in shape Presence of nucleus Colourless. No haemoglobin Elastic. Defense body against diseases Platelets (Thrombocytes) Membrane-bound fragments of cytoplasm (not true cells) Blood clotting Transport function Protective function Structure Function

Test Yourself! (page 151) (a) To produce antibodies against disease-causing microorganisms. (b) To ingest and destroy foreign particles like bacteria. (c) To carry oxygen to all parts of the body. (d) To bring about blood clotting when tissue is damaged. 2 Any organ from another person may be treated as a foreign body by the recipient’s immune system. The recipient’s lymphocytes may respond by producing antibodies to destroy the transplanted organ. 3 By matching the tissue of the donor and recipient as closely as possible, e.g. using tissue donated from a relative, or by using immuno-suppressive drugs. 4 Blood may be infected with disease-causing microorganisms such as bacteria. The patient’s body produces more white blood cells to combat the bacteria e.g. more phagocytes to ingest bacteria and more lymphocytes to produce antibodies.

�ݺ�ߣ

Transport in humans part i 301_28th june

More Related Content

Transport in humans part i 301_28th june

Editor's Notes