Blood and the Lymphatic System

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Blood and the Lymphatic SystemWhat is Blood?

• It is a type of CONNECTIVE tissue• Contains dissolved substances and

specialized cells• The human body contains about 5

liters (1.3 gal) of blood• 4 major components

PLASMARED BLOOD CELLSWHITE BLOOD CELLSPLATELETS

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PLASMA• 45% of blood is made up of cells

• 55% of blood is made up of a straw-colored fluid called PLASMA

• Plasma is 90% water and 10% dissolved gases, nutrients, proteins, salts, waste products

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Red Blood CellsErythrocytes

• Made from cells in the red bone marrow

• Shaped like discs with a thin center

• Contain the oxygen-carrying protein HEMOGLOBIN

• Mature red blood cells do not have nuclei

• There are 5 billion RBCs in a milliliter of blood

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White Blood Cells: The First Line of Defense• Made from cells in the bone

marrow; they contain nuclei• Function to fight INFECTION,

attack bacteria and parasites• Different types of white blood

cells. Some can “eat” the attacking agent in a process called phagocytosis.

• Lymphocytes are a type of WBC that helps create the antibody immune response.

• There are ~10 million WBCs in a milliliter of blood.

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Platelets• Fragments of cytoplasm

released from bone marrow with no nuclei

• Function is to plug up cuts in the blood vessel in the process known as blood clotting.

• Release proteins into the plasma that can produce fibrin, which holds the clot together.

• There are 300 million platelets in a milliliter of blood.

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Blood Clotting Thrombosis

Break in Capillary Wall

Blood vessels injured.

Clumping of Platelets

Platelets clump at the site and release thromboplastin. Thromboplastin converts prothrombin into thrombin..

Clot Forms

Thrombin converts fibrinogen into fibrin, which causes a clot. The clot prevents further loss of blood..

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ab

Immunohistological Staining of a Thrombus

Brown = platelets

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Blood TypesThe Blood Types: A, B, AB, O

• Blood typing requires matching two components: an antigen and an antibody. It is an immune system.

• An antigen (or carbohydrate) is a recognition marker

• Blood types are determined by the presence or absence of two antigens – A and B – on the surface of red blood cells

• An antibody is a defensive protein made by the

immune system and is present in the blood.

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Blood Typing

Rh Factor is another antigen present on red blood cells. People are either Rh positive or Rh negative.

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Blood Typing

Blood Type of Donor

A

B

AB

O

Blood Type of Recipient

A B AB O

Unsuccessful transfusion Successful transfusion

AB blood type is a UNIVERSAL ACCEPTOR

O blood type is a UNIVERSAL DONOR

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Lymphatic System• The lymphatic system is made up of three parts:

network of vessels nodes organs

Its function is to collect fluid lost by blood and return fluid to the circulatory system

• The fluid is known as LYMPH• Path: Lymphatic vessels to ducts to superior vena

cava• Lymph nodes are a filter system (bacteria)• Lymph is moved by contractions of skeletal muscle• Lymphatic system also moves nutrients into blood

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The Lymphatic System