TRANSPORTCIRCULATORY SYSTEM

IN BODY DEFENCE

MECHANISM

BODY DEFENCE MECHANISM

To protect body against pathogens (disease-causing MO) that may enter.

Transmission of pathogens: Air Contaminated food Animal vectors Contact

patho: diseasegens: agents

LINES OF NATURAL DEFENCE

First Line

Second Line

Third Line

FIRST LINE OF DEFENCE

Prevention of pathogens entering the body by mean of physical and chemical barriers. Skin

Sweat Sebum

Tears and saliva Mucous membranes

Skin A physical barrier It has dead keratinised

layer that is hard to penetrate

Continual shedding of dead skin cells prohibit growth of pathogens

If there is a cut, the blood clots quickly to seal the wound To prevent blood loss

and entry of pathogens

Sweat and Sebum

Produced by skin as chemical barrier

Protective film over skin Acidic sebum secreted

by sebaceous glands contain lysozymes, which destroy cell walls of certain bacteria

Tears and Saliva

Tears and saliva contain lysozymes, which destroy bacteria (protect eyes and mouth)

Mucous Membranes Lines trachea, respiratory passageways, digestive

and urogenital tracts.

Mucous Membranes: Methods of Defense Mucus secreted in the nasal cavity and

trachea traps dust particles and microbial spores contains lysozyme to destroy bacteria

The cilia in the respiratory tract sweep the trapped particles to the pharynx.

The hydrochloric acid in gastric juice can kill many microorganisms

SECOND LINE OF DEFENCE

The non-specific killing action by phagocytic WBC (e.g. neutrophil-blood, macrophages-IF; some dissolved e.g. venom and toxin).

They are attracted by chemicals produced at the sites of infection, engulf and ingest MO or other particles (like debris) by phagocytosis.

Some phagocytes may also be destroyed by toxins of pathogens.

THIRD LINE OF DEFENCE

Immune System System triggered in response to the presence

of foreign substance (antigen = proteins / polysaccharides usually found on cell membrane of MO or foreign tissues) in our body.

Specific / targeted response Immunity

The state which the body is resistant to infections by pathogens

Lymphocyte

Lymphocytes B Lymphocytes –

produce antibody T Lymphocytes –

attack infected cells or secrete certain chemicals to coordinate immune response

Antibody

Protein produced by lymphocytes in response to the entry of an antigen into the body.

Each type of antibody is specific to a particular antigen.

They help to destroy pathogens in different ways.

Types of Antibody Action Neutralisation – neutralizes toxins Agglutination – binds to surface of antigens and

cause clumping of bacteria cells Opsonisation – binds to surface of antigens to

stimulate phagocytosis by macrophages Lysis – binds to surface of antigens to form pores

on cell membrane, which leads to cell rupture

Memory Lymphocyte

After recovery, some lymphocytes remain for a period of time. Memory lymphocytes

Defend against future infection. Infection by the same type of antigen

Therefore, we are immune against particular diseases. Immunity – ability of organism to resist infection

by pathogens or their toxin effects.

Naturally Acquired Active Passive

Artificially acquired Active Passive

TYPES OF IMMUNITY

Types of immunity

Active natural immunity Active natural

acquired immunity: acquired after a person recovers from an infection.

Eg; measles or chickenpox.

Active artificial immunity Active artificial

acquired immunity: Eg; vaccine (contains

killed or weakened antigens).

Active because the a/bodies produced by the body itself

Artificial because it is obtained through vaccination. the process is known as immunisation.

Artifi

cial a

ctiv

e im

mun

ity

Passive immunity1. Passive natural immunity: when

a/bodies from the mother transported across the placenta to the foetus. Lasts for a few months.

2. Passive artificial immunity: injecting antiserum containing a specific a/bodies prepared from human/animal’s blood.

Passive artificial immunity Usually used to treat

patient with serious ill. Eg: rabies, tetanus or snake bites

Give temporary immunity.

Artificially acquired passive immunity

QUIZZES

Which of the following describes the first line of defence? Antara yang berikut, yang manakah menerangkan tentang barisan pertahanan pertama?

A. It involves lymphocytes in the blood Ia melibatkan limfosit dalam darah

B. It involves phagocytic white blood cells Ia melibatkan sel darah putih yang bersifat fagositik

C. It involves skin and mucous membranes Ia melibatkan kulit dan membrane mucus

D. It produces antibodies that destroy bacteria and viruses. Ia menghasilkan antibody yang memusnahkan bakteria dan virus

Which of the following substances is injected into the body to stimulate antibody production? Antara bahan berikut, yang manakah disuntik ke dalam badan se orang untuk merangsangkan penghasilan antibody? A. Serum B. Vaccine C. Antibody D. Antiserum

. Which of the following belong to the first line of defence? Antara yang berikut, yang manakah terlibat dalam barisan pertahanan yang pertama? A. Hydrochoric acid Asid hidroklorik B. Phagocytes Fagosit C. Antibodies Antibodi D. Macrophages Makrofaj

What is the antibody mechanism shown in Diagram 4? Apakah mekanisma antibody yang ditunjukkan di Rajah 4?1

1 Diagram 4/ Rajah 4

A. Lysis C. Opsonisation Lisis Opsonisasi B. Agglutination D. Neutralization Aglutinasi Peneutralan

Based on the diagram, what is the mechanism used by antibodies to destroy the antigen? Berdasarkan Rajah apakah mekanisme yang digunakan oleh antibody untuk memusnahkan antigen?

A. Lysis C. Opsonisation Lisis Opsonisasi B. Neutralization D. Agglutination Peneutralan Aglutinasi

Diagram 1 shows two microorganisms which enter the human body by chance. Rajah 1 menunjukkan dua mikroorgansma yang memasukki badan manusia secara kebetulan.

Diagram 1 / Rajah 1 Which parts of the these microorganisms are responsible in stimulating the immune response and produce antibodies against them? Bahagian mikroorganisma manakah yang bertanggungjawab untuk merangsang tindak balas keimunan dan menghasilkan antibody untuk menentang sesame sendiri?

A. P and R B. P and S C. Q and R D. Q and S

Diagram 2 is a graph which shows the amount of antibodies in the blood after two injections of compound X. Rajah 2 merupakan satu graf yang menunjukkan jumlah antibodi dalam darah selepas dua suntikan sebatian X.

Diagram 2/Rajah 2

Which of the following describes the compound X and the type of immunity in Diagram 2? Antara yang berikut, yang manakah menerangkan sebatian X dan jenis keimunan dalam Rajah 2?

Diagram 2 is a graph which shows the amount of antibodies in the blood after two injections of compound X. Rajah 2 merupakan satu graf yang menunjukkan jumlah antibodi dalam darah selepas dua suntikan sebatian X.

Diagram 2/Rajah 2

Which of the following describes the compound X and the type of immunity in Diagram 2? Antara yang berikut, yang manakah menerangkan sebatian X dan jenis keimunan dalam Rajah 2?

Which of the following graphs shows the immunity developed after vaccination? Antara graf berikut, yang manakah menunjukkan keimunan berlaku selepas pemvaksinan?

Which of the following graphs shows the immunity developed after vaccination? Antara graf berikut, yang manakah menunjukkan keimunan berlaku selepas pemvaksinan?

5 . Passive immunity against tetanus is acquired by injection with an anti-serum. Keimunan pasif terhadap tetanus didapati melalui suntikan dengan anti-serum. Which of the following reasons explain the statement? Antara sebab berikut,yang manakah menjelaskan pernyataan di atas? A. The anti-serum becomes effective immediately. Anti-serum member kesan dengan serta-merta B. The anti-serum kills many different kinds of bacteria Anti-serum membunuh berbagai jenis bakteria C. The effect of the immune serum is very long lasting Kesan sistem keimunan adalah berjangka panjang D. The immune system is stimulated to produce antibodies Sistem keimunan terangsang untuk menghasilkan antibody

Graph 1 shows a type of immunity. Graf 1 menunjukkan sejenis keimunan.

Which of the following statements is true about the graph? Antara pernyataan berikut, yang manakah benar tentang graf tersebut? A. Both injections contain serum that can raise antibody level. Kedua-dua suntikan mengandungi serum yang boleh meningkatkan aras antibody B. Second injection is required to boost level of immunity Suntikan kedua diperlukan untuk meningkatkan aras keimunan C. Both injections contain pathogens which can control production of antibody Kedua-dua suntikan mengandungi pathogen yang mengawal penghasilan antibodi D. Second injection contains higher level of antibody Suntikan kedua mengandungi aras antibody yang lebih tinggi

AIDS (acquired Immunodeficiency Syndrome)HIV virus

The effects of HIV Attacks the central nervous system & helper

T in the body’s immune system

Helper T are essential to activate other lymphocytes in antibody production.

Immune system become weakened & defenseless against pathogen

HIV Replication

Effects

Symptoms

“Some people get fever, headache, sore muscles and joints, stomach ache, swollen lymph glands, or a skin rash for one or two weeks. Most people think it's the flu. Some people have no symptoms” (AIDS.ORG 2003). In the later stages of HIV symptoms may include:   Persistent, unexplained fatigue Soaking night sweatsShaking chills or fever higher than 100 F for several weeks Swelling of lymph nodes for more than three months Chronic diarrhoea Persistent headaches

The patients does not die from AIDS itself but from other secondary infection such as: Pneumonia Meningitis bacterial infection of the membranes covering the brain and

spinal cord (meninges).

Tuberculosis Fungal infection Cancer like Kaposi’s sarcoma

Transmission

Salt Blood pressureHypertension Sedentary obesity

How can you avoid infection?

Avoid casual sexual relationship

Live a responsible and healthy lifestyle

Do not share needle and other personal item

Educational programme

World AIDS Day 1st Dec

Appreciating a healthy cardiovascular system

CV disorders (eg.) Anemia (ah-NEE-me-yah): Diseased condition in which there is a

deficiency of red blood cells or hemoglobin. Arteriosclerosis (ar-tir-ee-o-skle-ROW-sis): Diseased condition in which

the walls of arteries become thickened and hard, interfering with the circulation of blood.

Atherosclerosis (ath-a-row-skle-ROW-sis): Diseased condition in which fatty material accumulates on the interior walls of arteries, making them narrower.

Hemophilia (hee-muh-FILL-ee-ah): Inherited blood disease in which the blood lacks one or more of the clotting factors, making it difficult to stop bleeding.

Hypertension (hi-per-TEN-shun): High blood pressure. Leukemia (loo-KEE-mee-ah): Type of cancer that affects the blood-

forming tissues and organs, causing them to flood the bloodstream and lymphatic system with immature and abnormal white blood cells.

Sickle cell anemia (SICK-el cell ah-NEE-me-yah): Inherited blood disorder in which red blood cells are sickle-shaped instead of round because of defective hemoglobin molecules.

Appreciating a healthy CV system Stick to a nutritious, well-balanced diet. Control your blood pressure. Control blood cholesterol. Prevent and manage diabetes. Quit smoking. Minimize stress.

An electron micrograph scan of a human aortic valve. The aorta is the main artery of the systemic circulation. (Photograph by P. Motta. Reproduced by permission of Photo Researchers, Inc.)