BL103 CH18: Blood

Functions of blood

o   Transports substances throughout body (O2 & CO2, hormones, nutrients/waste)

o   Defense against external threats

What kind of things are dissolved in plasma?

water, proteins, nutrients, hormones

What do red blood cells, white blood cells, and platelets do?

• RBC: transports O2 -> body tissues; transport CO2 away

• WBC: defend against invading organism/abnormal cells

• Platelets: take part in blood clotting as body defense mech

Where are blood cells produced?

red bone marrow

What is hemoglobin? Where is it found?

protein which transports O2, found in RBC

What is erythropoietin?

Production controlled by hormone

When is erythropoietin released?

When low O2 levels are sensed

What releases erythropoietin?

Kidney

What does erythropoietin cause?

More RBCs

negative feedback mechanism for RBC production

o   Stimulus – too few RBCs, not enough O2

o   Sensor/receptor -- kidneys

o   Control center – kidneys -> release EPO (hormone)

o   Effector – EPO stimulates RBC

o   Response – more RBC / carry more O2

Function of this WBCs: Neutrophils

first on scene to fight infection by engulfing microorganism

Function of this WBCs: Monocytes

move out of bloodstream (become macrophages) and engulf microorganism

Function of this WBCs: Lymphocytes

recognize pathogens & remember them

How are blood types determined?

What antigens a person has

What is an antigen?

Proteins on surface of RBC (A antigens = A-blood type; B antigens = B-blood type; Rh antigens = (+) blood type, negative means no Rh)

What is an antibody?

Y-shaped protein circulating in blood that recognizes specific antigens

What would happen if a person with type B blood received a transfusion of Type O?

• Nothing, type O has no surface antigens (nothing to interact with)

• Type O = universal donor

What is Anemia?

too few RBCs/inadeq hemoglobin; caused by iron-deficiency, excessive blood loss, kidney failure

What is Leukemia?

Excessive production of WBCs