Blood

Functions of Blood

• Transports needed materials through body – Nutrients like glucose and amino acids– Oxygen

• Transports wastes through body to where they are eliminated– Carbon dioxide– Metabolic wastes

Functions of Blood

• Help body defend against infection – WBC and antibodies

• Help protect against injury through blood clotting

• Carry hormones to help regulate cell activities

• Help regulate body temp

• Help maintain body pH and water balance

Components of Blood

• Fluid – Plasma

• Cells– Red Blood Cells– White Blood Cells

• Fragments of cells– Platelets

Components of Blood

Where are Blood Cells Made?

– Blood Cells• Produced in the

bone marrow of ribs and long bones

Blood Plasma

• Fluid portion of blood (straw colored)• About 90% water• Has many things dissolved in it

– Proteins, vitamins, enzymes, glucose, amino acids, cellular wastes, hormones, dissolved gases and salts

• Has fibrinogen which is involved in blood clotting• Has antibodies which help fight infection

Red Blood Cells

• Carries oxygen from lungs to body tissues where it is released at the capillary

• Contain hemoglobin – Iron containing protein which carries oxygen

• Disc shaped• They do not have a nucleus and therefore have

a limited life span• Also called erythrocytes

Oxygen and Hemoglobin

• Oxygen Transport in the Body:• http://www.youtube.com/watch?v=WXOBJEXxNEo&safe=active

RBC Disorders

• Anemia: – too few normal RBC – not enough normal

hemoglobin

RBC Disorders

• Sickle Cell Anemia: – Abnormal form of hemoglobin causes

abnormal sickle shape – RBC doesn’t carry oxygen well and tend to

get stuck in capillaries causing pain

White Blood Cells• Defend the body against

disease & infection from bacteria, viruses and microbes.

• Help to provide immunity

• Only about 1% of blood• Also called leucocytes• Have a nucleus (unlike RBC)• Often larger than RBC• Produced in bone marrow and

lymphatic tissue

White Blood Cells

• Macrophages: – Type of WBC that can move to affected areas to engulf

antigens through phagocytosis– Engulf bacterial invaders, foreign substances and cancer

cells

• http://www.youtube.com/watch?v=JnlULOjUhSQ&safe=active

• During infection WBC count increases

• Pus = consists partly of dead WBC

• Leukemia: – Disease of the bone marrow– Uncontrolled production of WBCs that don’t function.– Considered to be a form of cancer

Platelets• Involved in helping to form

blood clots after an injury

• Small bits of cytoplasm without a nucleus

• Smaller than a RBC and WBC

• Produced in bone marrow• Only live about a week

Blood Clot Process

• Tear forms in blood vessel

• Platelets start to stick to wound’s edges and to each other at tear site

• Forms a “plug” that slows the loss of blood within three to five minutes.

• Release enzymes that help clotting factors adhere to plug and create a fibrous “clot”

• Clotting factors in blood reinforce platelet “plug”

• Forms fibrin web that binds clot together– Fibrin: protein fibers that form a sticky

network web over the wound

Blood Clot Formation

• http://www.youtube.com/watch?v=--bZUeb83uU&safe=active

• http://www.dnatube.com/video/29917/The-Process-of-Blood-Clotting

Lymphatic System• Lymph: portion of blood plasma that diffuses out

of capillaries.

– Surrounds the body cells as intercellular fluid (ICF) between the cells

– Helps to transport dissolved material from capillaries to cells

– Some reenters capillaries

– Some collects in lymph vessels

Lymphatic System• Lymph Nodes:

– Act as filters trapping microorganisms and stray cancer cells

– WBC in nodes destroy unwanted cellular material– Remove bacteria and dead cells from circulatory fluid– Can get swollen when you are fighting an infection

Blood Types

• A, B, AB, O

• Inherited from alleles from parents

– AA, AO– BB, BO– AB– OO

Antigens and Blood TypesAntigens and Blood Types– Red blood cells have specific proteins in their

membranes – Depending on your blood type, you have

different protein “antigens” present on your blood cells

• Antigen: – a normally foreign substance that stimulates an

immune response

• Antibodies:– Produced by WBCs (lymphocytes)– Recognize and attach to or “fit” specific antigens.

• Antibody/Antigen Response– Your body will produce antibodies in response

to foreign antigens– This is part of the “immune response”

Donating Blood

• You cannot give blood to or receive it from just anybody.

– Depending on blood type you have different antibodies in your bloodstream and different antigens on RBCs

• The antigens and antibodies will react!!

• You have to receive blood of the right type or it will agglutinate.

Blood Type Summary

Type A: Antigens on blood cells =Antibodies in plasma = Donates to = Receives from =

Type B: Antigens on blood cells =Antibodies in plasma = Donates to = Receives from =

Type ABAntigens on blood cells =Antibodies in plasma = Donates to = Receives from =

Type OAntigens on blood cells =Antibodies in plasma = Donates to = Receives from =

Rh Factor

• Rhesus Factor– Another protein present on the RBC– You can have it or not– Rh positive or Rh negative

Review

• Which will develop an antibody antigen reaction? Which will not?

– Type A person given type O– Type AB person given type A– Type O person given type B– Type B person given type A– Type A person given type AB