science 8th grade - 4th period

10
Science Fourth Period 2.015 1 Colegio Gimnasio Campestre San Sebastián NOMBRE:_______________________________________________ GRADO: 8TH GRADE PERIODO: FOURTH AREA: SCIENCE MISS SOPHIE CORZO PÉREZ The environment consists of numerous pathogens, which are agents, usually microorganisms that cause diseases in their hosts. A host is the organism that is invaded and often harmed by a pathogen. Pathogens include bacteria, protists, fungi and other infectious organisms. We are constantly exposed to pathogens in food and water, on surfaces, and in the air. Mammalian immune systems evolved for protection from such pathogens; they are composed of an extremely diverse array of specialized cells and soluble molecules that coordinate a rapid and flexible defense system capable of providing protection from a majority of these disease agents. Components of the immune system constantly search the body for signs of pathogens. When pathogens are found, immune factors are mobilized to the site of an infection. The immune factors identify the nature of the pathogen, strengthen the corresponding cells and molecules to combat it efficiently, and then halt the immune response after the infection is cleared to avoid unnecessary host cell damage. The immune system can remember pathogens to which it has been exposed to create a more efficient response upon re-exposure. This memory can last several decades. Features of the immune system, such as pathogen identification, specific response, amplification, retreat, and remembrance are essential for survival against pathogens. The immune response can be classified as either innate or active. The innate immune response is always present and attempts to defend against all pathogens rather than focusing on specific ones. Conversely, the adaptive immune response stores information about past infections and mounts pathogen-specific defenses.

Upload: sophie-corzo-perez

Post on 11-Feb-2016

186 views

Category:

Documents


0 download

DESCRIPTION

S

TRANSCRIPT

Page 1: Science 8th Grade - 4th Period

Science Fourth Period 2.015

1

Colegio Gimnasio Campestre San Sebastián

NOMBRE:_______________________________________________ GRADO: 8TH GRADE

PERIODO: FOURTH AREA: SCIENCE MISS SOPHIE CORZO PÉREZ

The environment consists of numerous

pathogens, which are agents, usually

microorganisms that cause diseases in their

hosts. A host is the organism that is invaded

and often harmed by a pathogen. Pathogens

include bacteria, protists, fungi and other

infectious organisms. We are constantly

exposed to pathogens in food and water, on

surfaces, and in the air. Mammalian immune

systems evolved for protection from such

pathogens; they are composed of an

extremely diverse array of specialized cells

and soluble molecules that coordinate a rapid

and flexible defense system capable of

providing protection from a majority of these

disease agents.

Components of the immune system constantly search the body for signs of pathogens. When pathogens

are found, immune factors are mobilized to the site of an infection. The immune factors identify the nature

of the pathogen, strengthen the corresponding cells and molecules to combat it efficiently, and then halt

the immune response after the infection is cleared to avoid unnecessary host cell damage.

The immune system can remember pathogens to which it has been exposed to create a more efficient

response upon re-exposure. This memory can last several decades. Features of the immune system,

such as pathogen identification, specific response, amplification, retreat, and remembrance are essential

for survival against pathogens. The immune response can be classified as either innate or active. The

innate immune response is always present and attempts to defend against all pathogens rather than

focusing on specific ones. Conversely, the adaptive immune response stores information about past

infections and mounts pathogen-specific defenses.

Page 2: Science 8th Grade - 4th Period

Science Fourth Period 2.015

2

Questionnaire # 1: THE IMMUNE SYSTEM

1. What the environment is made?

2. What is a host?

3. What are pathogens?

4. What is the function of the immune factors?

5. What is the function of the innate immune response?

6. What is the function of the adaptive response?

Quick Check # 1:

Draw the immune system with parts.

Immunisation - vaccination - injection?

Question: Do these words all mean the same thing?

Answer: Not quite.

Immunisation means putting a special type of substance (a vaccine) into your body so that your body can

learn how to fight an infection. That way, you will be protected (or immune) from getting sick if someone

around you has the germs for that infection.

There are immunisations for many different infections, including some rather nasty ones. Immunisation is

an easy and very safe way of protecting you.

Immunisations are usually given as an

injection (by a needle in your arm or leg) or

sometimes as a medicine that you drink.

Vaccination means pretty much the same

thing as immunisation - getting a vaccine

(usually by injection) that will help your body

to protect itself from an infection in the future.

Injection means the act of sticking a needle

into your body, usually just under the skin or

into a muscle, and squirting in a small

amount of liquid. Most immunisations involve

an injection given by a doctor or nurse in the

arm or leg, where there is plenty of flesh and

it won't hurt too much.

Page 3: Science 8th Grade - 4th Period

Science Fourth Period 2.015

3

Of course, injections are not just for immunizations - doctors give patients injections of other things, like

antibiotics, and some people give themselves medicines by injection (e.g. people with diabetes may inject

themselves with insulin several times each day).

A vaccine is a fluid that helps your body to become immune

to a disease caused by certain germs. The vaccine contains

some part of the germ or the poison that the germ makes,

but the vaccine does not make you sick - it helps your body

to protect itself from getting sick in the future.

Sometimes the vaccine contains a living virus that has been

changed so that you don't get sick (like the measles

vaccine), or it might contain parts of germs (like

meningococcal bacteria), or even bits of a poison (called a

toxin) like the toxin made by tetanus bacteria.

Your body's immune system will recognise that these vaccines do not belong in your body, and will work

out how to get rid of them. For some diseases, you will need a few doses of the vaccine - each time you

have the same vaccine, your immune system will get better at removing the germs or poisons.

Then later on, if you get exposed to the living germs for that disease, your immune system will be able to

kill them, and you won't get sick!

Questionnaire # 2: IMMUNISATION - VACCINATION - INJECTION?

1. What is immunization?

2. When immunization is given?

3. What is immunization?

4. What is an injection?

5. What is a vaccine?

6. What is the function of the vaccine?

7. What contains the vaccine?

8. What happens to the immune system with vaccines?

Quick Check # 2:

Answer some question about the reading

1. Is it important to know about immune system? Argue your answer

2. What are the elements that immune system need?

3. Where can the body obtain the vital elements for the immune system, from?

4. What are the kinds of defends of the body?

5. What are the most recognized defenders in the human body?

Page 4: Science 8th Grade - 4th Period

Science Fourth Period 2.015

4

Immune System

What is the immune system?

The immune system helps to protect us against diseases caused by tiny invaders (called pathogens) such

as viruses, bacteria, and parasites. The immune system is made up of specialized organs, cells, and

tissues that all work together to destroy these invaders. Some of the main organs involved in the immune

system include the spleen, lymph nodes, thymus, and bone marrow.

How does it work?

The immune system develops all kinds of cells that help to destroy disease causing microbes. Some of

these cells are specifically designed for a certain kind of disease. All throughout the body, disease fighting

cells are stored in the immune system waiting for the signal to go to battle. The immune system is able to

communicate throughout the entire body. When pathogens are detected, messages are sent out, warning

that the body is being attacked. The immune system then directs the correct attacking cells to the problem

area to destroy the invaders.

Antigens and Antibodies

Scientists call the invaders that can cause disease antigens. Antigens trigger an immune response in the

body. One of the main immune responses is the production of proteins that help to fight off the antigens.

These proteins are called antibodies.

How do the antibodies know which cells to attack?

In order to work properly, the immune system must know which cells are good cells and which are bad.

Antibodies are designed with specific binding sites that only bind with certain antigens. They ignore "good"

cells and only attack the bad ones. You can see from the picture below that the antibodies each have a

specially designed binding site. They will only bind with the antigen that has a "marker" that matches up

perfectly.

Types of Immunity Cells

The immune system has cells that perform specific functions. These cells are found in the blood stream

and are called white blood cells. B cells - B cells are also called B lymphocytes. These cells produce

antibodies that bind to antigens and neutralize them. Each B cell makes one specific type of antibody. For

example, there is a specific B cell that helps to fight off the flu.

T cells - T cells are also called T lymphocytes. These cells help to get rid of good cells that have

already been infected.

Helper T cells - Helper T cells tell B cells to start making antibodies or instruct killer T cells to

attack.

Killer T cells - Killer T cells destroy cells that have been infected by the invader.

Memory cells - Memory cells remember antigens that have already attacked the body. They help

the body to fight off any new attacks by a specific antigen.

Page 5: Science 8th Grade - 4th Period

Science Fourth Period 2.015

5

How do we get immunity?

The immune system is very smart and can adapt to new infections. Our bodies gain immunities in two

ways: natural and acquired. Natural - When we are born, our bodies already have some immunity. Babies

get antibodies from their mother as they are growing in the womb. They may also gain some antibodies

from their mother's milk. Acquired - Our bodies also learn immunities over time. When we get sick, our

body learns how to fight off the disease. The next time that disease invades, our body is ready for it and

can quickly produce antibodies to prevent infection. We can also gain immunity from vaccines.

How Vaccines Work

Vaccines introduce microbes that are already killed or modified so we don't get sick. However, the

immune system doesn't know this. It builds up defenses and antibodies against the disease. When the

real disease tries to attack, our body is ready and can quickly neutralize the antigens.

Interesting Facts about the Immune System

Some immunity eventually goes away, so we need a new vaccine after a period of time. Different people

have different levels of immunity to certain diseases. This is why some people get sick more often than

others. Sometimes the immune system can get confused and attack good cells. Type I diabetes is caused

when T cells attack insulin producing cells in the pancreas. T cells and B cells are stored in lymph nodes

throughout the body. They enter the blood stream when they are needed to defend against disease. Your

body responds much faster and stronger the second time it sees an antigen.

Questionnaire # 3: ANTIGENS AND ANTIBODIES

1. What is the function of the immune system?

2. How the immune system is composed?

3. How the immune system works?

4. What are antigens?

5. What are antibodies?

6. What is the function of T cells?

7. What is the function of helper T cells?

8. What is the role of killer T cells?

9. What is the role of memory cells?

10. How vaccines work?

Quick Check # 3:

What does mean disease?

How does the immune system work?

Page 6: Science 8th Grade - 4th Period

Science Fourth Period 2.015

6

Look for in the word search some words

Unscramble the words:

Page 7: Science 8th Grade - 4th Period

Science Fourth Period 2.015

7

1. Order these sentences

a. infections/ system/ is very/ The immune/ smart/ and can adapt/ to new/

_________________________

_________________________

b. our bodies/ we/ are born/ immunity/ already/ have/ When/ some/

_________________________

_________________________

c. the disease/ we get sick/ to fight off/ When/ learns/ how/ our body/

_________________________

_________________________

d. the disease/ builds up/ defenses/ Vaccines/ against/ and antibodies/

_________________________

_________________________

e. antigens/ call/ the invaders/ Scientists/ can cause/ disease/ that/

_________________________

_________________________

2. Draw these elements related with immune system

Vaccine Injection virus

Illness Flu Bacteria

Page 8: Science 8th Grade - 4th Period

Science Fourth Period 2.015

8

1. Select the corresponding answer

Page 9: Science 8th Grade - 4th Period

Science Fourth Period 2.015

9

Page 10: Science 8th Grade - 4th Period

Science Fourth Period 2.015

10

ASPECTS TO EVALUATE

YES

NO

I didn’t have any difficulty along the development of the worksheet.

I developed all the activities in order and dedication.

I felt myself comfortable doing all the activities.

I reinforced and acquired new knowledge to the activities planned in the

worksheet.