Lectura 3: Blood

BLOOD

Blood isn't everyone's favorite topic.  But so many people either lose blood through surgery, injury, or because their bodies cannot manufacture blood components because of a disease that blood transfusions are a life-saving measure. In fact, about 5 million people each year in the United States get blood transfusions.

A Bit about Blood 

Blood is the body's transportation system; it is always busy making deliveries and pickups. As blood circulates throughout the body, it delivers oxygen and nutrients to all the places they're needed. Blood also collects waste products, such as carbon dioxide, and carries them to the body's organs responsible for making sure the wastes leave the body. 

• Red blood cells carry oxygen to and remove carbon dioxide from all of the body's tissues.
• White blood cells are part of the immune system. Their job is to fight infection.
• Platelets are cell fragments that clot, which helps to prevent and control bleeding.
• Plasma is a yellowish liquid that contains substances that help clotting, along with other important blood components.

Blood is a mixture of these three types of blood cells and plasma. Each component has a specific task.

What Are Transfusions?

When blood or one of its components, such as red blood cells or platelets, is delivered into a person's bloodstream, it is called a blood transfusion. Transfusions are usually given through a tiny tube that is inserted into a vein with a small needle. The whole procedure usually takes about 1 to 3 hours. It's vital that the blood of a person receiving a transfusion is compatible with the donor's blood. Blood is classified into different types: A, B, AB, and O. You inherit your blood type from your parents. Blood types are also classified as either Rh positive or negative. You'll typically hear blood types described according to both of these characteristics - for example, "A positive" or "AB negative." In emergencies, there are certain exceptions to the rule that the donor's blood type must match the recipient's exactly. Type O Rh-negative blood, which is called "O negative" or the "universal" blood type, is often given in emergencies because it's the only type that people with all other blood types can safely receive. O negative donors are called "universal donors." People who have type AB blood are called "universal recipients" because they can safely receive any type of blood.

Why Do People Need Transfusions?

People need transfusions for many different reasons. Some people have medical conditions; others may need a blood transfusion because they've had life-threatening blood loss from a serious accident or surgery. For example, some people need blood transfusions because they're receiving chemotherapy treatment for cancer. People who have hemophilia, a disease that affects their blood's ability to clot, need plasma.

Where Does the Blood Come From?

In the United States, the blood supply comes from people who volunteer to donate their blood at local blood banks, at community centers or through the American Red Cross. Many people's lives depend on other people who donate blood. People can also donate blood for a specific person with the same blood type, such as a child or parent. 

Do People Get Sick From Transfusions?

Some people worry about diseases from infected blood.  Donated blood is carefully tested for viruses and other agents that cause diseases like HIV, hepatitis, syphilis, and West Nile virus. If any of these things are found, the blood is discarded. Although the blood supply today is extremely safe, some people still decide to ask people they know to donate blood if they need it.   Like any medical procedure, there are a few risks involved with a blood transfusion. When a patient receives a blood transfusion, there's a possibility of certain reactions. Some examples:

• Allergic reaction. This is quite common and usually mild. Often the only symptom is a skin rash. Allergic reactions to blood transfusions occur when antibodies in the patient's blood react to proteins in the plasma of the donated blood. Allergic reactions are usually treated with antihistamines.
• Fever. This is also very common and usually mild. Fever can be accompanied by headache, nausea, and chills. 
• Hemolytic reaction. Hemolysis means the destruction of red blood cells. This is the most serious type of immediate reaction, and it can be life threatening. It occurs when the patient's blood and the donated blood do not match. 

What Are the Risks of Donating Blood?

A person can't get an infection or disease from donating blood. Needles and other equipment used are sterile and they're used only on one person and then thrown away. There are, virtually, no health risks associated with donating blood, according to the American Association of Blood Banks. 

Who Can Donate Blood?

To donate blood, the American Red Cross requires that people be at least 17 years old and weigh more than 110 pounds (50 kilos). Donors must be in good health. Despite the age requirements, the Red Cross estimates that 15% of all blood donors in the United States are high school or college students.

  Your time and effort could save a person's life.

Activities

1.    Find one adjective in the superlative degree.

2.    Find an example of Infinitive of Purpose in the text.

3.    Find an example of Possessive Case in the text.

4.    Find an example of a noun-noun structure in the text.

5.    Find an example of a relative clause in the text and underline its pronoun.

6.    Find some modal verbs and explain their uses in Spanish.

7.    Find two examples of Passive Voice from the text (English).

8.     Who does the action? Is the agent mentioned in the text?

Example 1:

Example 2:

9.    When is the passive voice used? (Spanish)

10. Complete the table

TENSES	Example (English)	Uses (Spanish)
Simple Present
Present Continuous
Present Perfect
Simple Past
Past Continuous	Form:
Past Perfect	Form:
Future Simple

A.   READING COMPREHENSION

Complete the table with information related to the text in Spanish:

WHAT?
WHEN?
WHERE?
WHY?
WHO?
HOW?
HOW OFTEN?

Adapted from: www.teenshealth.org