A&P2 EXAM 2

University of Northern Iowa; Dr. Bird

Blood

the internal transport system of the body

viscous and opaque

metallic taste

8% of body weight

Functions of blood

transportation, regulation, protection

What does the blood transport?

O2 and nutrients, metabolic wastes to lungs and kidney, hormones

What does the blood regulate?

maintaining body temperature and distribution

pH

fluid volume in circulatory system

What are the protective functions of blood?

preventing blood loss (clotting), preventing infection (immune system)

What are the agents of immunity that are carried in the blood?

antibodies, complement proteins, white blood cells

How does the blood maintain normal pH?

using buffers, alkaline reserve of bicarbonate ions

What is Dr. Bird’s favorite hv pathology?

Hypovalemic shock

What type of tissue is blood?

connective

Parts of blood

RBC, platelets, WBC, plasma, fibrin

Erythrocytes

red blood cells

Leukocytes

white blood cells

What percent of blood is plasma?

55%

What percent of blood is formed elements?

45%

Tissue fibers (fibrin)

only appear when blood clots, the net

What are the three layers that form when you spin blood? (top to bottom)

plasma, buffy coat, hematocrit

Hematocrit

layer of only red blood cells

Buffy coat

thin middle layer consisting of WBC and platelets

What does bright red blood mean?

oxygen rich

What does dark red blood mean?

oxygen poor

How much blood do males have?

5 to 6 L

How much blood do females have?

4 to 5 L

Plasma

90% water

straw colored

sticky

albumin protein (60% of proteins)

not taken up by cells as fuel

***What is normal blood pH for humans?

7.35 to 7.45

Albumin

blood buffer in plasma

carries molecules

contributes to plasma osmotic pressure

Where are most plasma proteins produced?

the liver

What percentage of plasma proteins is globulin?

36%

What percentage of plasma proteins is intrinsic fibrinogen?

4%

List the plasma proteins

albumin, globulin, fibrinogen

Types of globulins

Alpha, Beta, Gamma, IgG, IgA

Alpha and Beta Globulin

produced by the liver, most are transport proteins that bind to lipids/metal ions/ fat soluable vitamins

Gamma globulin

antibodies released by plasma cells during immune response

Nonproteins nitrogenous substances

by product of cellular metabolisms such as urea, uric acid, creatine, and ammonium salts

List the formed elements of blood?

erythrocytes, leukocytes, platelets

Are RBS and platets true cells?

no, they lack nuclei and organelles

How are blood cells replaced?

stem cells in red bone marrow

Can RBCs divide?

no

What is the life expectancy for formed elements of blood?

only a few days

Granulocytes

neutrophil, basophil, eosinophil

Agranulocytes

monocytes, lymphocytes

Structural characteristics of RBCs

no nucleus or organelles, filled with hemoglobin (Hb), folding ability to get to capillaries that are smaller than 7.5 microns

What 3 features of RBCs make it ideal for gas exchange and transport?

biconcave disk shape, Hb, absence of mitochondria prevents cell from consuming the O2 it’s carrying (anaerobic ATP synthesis)

Bird’s favorite law

square surface law

Hemoglobin

reversibly binds to O2, made of heme pigment and globin protein in a 1:4 ratio

Why is carbon monoxide poisoning so fatal?

carbon monoxide irreversibly binds to hemoglobin…suffocating you

Where does oxygen bind to hemoglobin?

the iron in the middle of heme, each Hb molecules can transport 4 O2

Oxyhemoglobin

O2 loading in lungs (binding to hemoglobin), causes a bright red color

Deoxyhemoglobin

O2 unloading in tissues, reduces hemoglobin, dark red color

Carbaminohemoglobin

when CO2 binds to hemoglobin

Hematopoiesis

formation of blood cells in red bone marrow

Red bone marrow

reticular connective tissue with large capillaries, make blood cells

Where is red bone marrow located in adults?

axial skeleton, girdles, proximal epiphyses of humerus and femur

Hematopoeitic stem cells (hemocytoblasts)

cells that will become elements of blood

What causes hemocytoblasts to change?

hormones and growth factors

Can hemocytoblasts that have started to change into one cell type change to a different cell type?

no

What happens if too many RBCs is made?

the blood will become too viscous

Erythopeitin (EPO)

stimulates erythropoeisis (blood cell formation)

What organ releases signals to trigger erythropoesis?

kidneys

What causes hypoxia?

decreased RBCs from hemorrhage or excessive destruction, insufficient hemoglobin (iron deficiency), reduced O2 availability

What hormone enhances EPO production

testosterone

Hormonal control of Erythropoiesis

erythropoietin

causes hypoxia

excess RBCs or high oxygen levels in blood inhibit EPO production

EPO targets cells committed to erythropoiesis and accelerates their maturation

Dietary requirements for erythropoiesis

nutrients (amino acids, lipids, carbohydrates), Two B complex vitamins (B12 and folic acid), Iron

What does iron do for erythropoiesis?

hemoglobin synthesis

intestinal absorption

bind to proteins because iron ions are toxic

How is iron stored in cells?

ferritin and hemosiderin (protein to iron complexes)

RBC life span

100 to 120 days

What breaks down old blood?

macrophages in spleen

Bilirubin

degraded heme

What is globin metabolized into?

amino acids

How is bilirubin broken down?

in intestine becomes urobilinogen then broken down more into brown pigment stercobilin

How are most erythrocyte disorders classified?

anemia or polycythemia

Characteristics of anemia

blood has low oxygen carrying capacity, a sign of a disorder rather than disease itself, individuals are fatigued/pale/short of breath/ chilled

What are the causes of anemia?

blood loss, not enough RBCs produced, too many RBCs being destroyed

Hemorrhagic anemia

blood loss anemia, acute or chronic

Acute hemorrhagic anemia

rapid blood loss, treated by blood replacement

Chronic hemorrhagic anemia

blood loss is slight but persistent, treated by solving primary problem

Iron deficiency anemia

result of hemorrhagic anemia/low iron intake

causes microcytes

treated with increasing iron

Microcytes

RBCs are small and pale due to limited Hb synthesis

Pernicicous anemia

an autoimmune disease that destroys stomach cells that produce intrinsic factor

results in macrocytes

treated with B12 injections/nasal gel

Intrinsic factor

needed to absorb vitamin B12

Macrocytes

enlarged RBCs that don’t divide

Renal anemia

caused by a lack of EPO, accompanies renal disease, treated with synthetic EPO

Aplastic anemia

may result from destruction or inhibition of red bone marrow, cause unknown, affects all formed elements (anemia plus clotting and immune issues), treated short term with transfusion and long term with transplanted stem cells

Hemolytic anemia

RBCs lyse prematurely, caused by blood transfusion reactions/certain bacterial or parasitic infections/ hemoglobin abnormalities

Thalassemias

typically occur in people of Mediterranean ancestry

one globin chain absent or faulty

RBCs are thin/delicate and deficient in hemoglobin

some forms require monthly blood transfusions

Sickle cell anemia

caused by mutated hemoglobin (called Hemoglobin S), less O2 bound causes a RBC to fold into a sickle shape, sickling increases during exercise, deformed RBCs rupture easily and block vessels, occurs more often in malarial belf of Africa

Possible benefit of sickle cell anemia

sickle cells increase rate at which macrophages destry them and the parasites inside (if infected with malaria)

Treatments for sickle cell

transfusion

pain management

hydroxyurea

gene editing

Hydroxyurea

switches on gene for fetal hemoglobin (which is not sickle)

Polycythemia

too many blood cells

increases blood viscosity

Polycythemia vera

bone marrow cencer leading to excess RBCs, treated with therapeutic phlebotomy (blood draws)

Secondary polycythemia

caused by any condition or medication that stimulates EPO production (the doping that cyclists do)

Leukocytes

aka WBCs

form a mobile army that protects the body from harmful bacteria, viruses, parasites, toxins, and tumor cells

Diapedesis

when leukocytes cross capillary walls to leave the blood stream to cause inflammatory response

How do leukocytes move?

amoeboid motion and positive chemotaxis

What percent of blood volume is WBCs?

Leukocytosis

a normal response to infection from WBCs

What is the normal WBC count for an infection?

11,000/ microliter

What are the two types of leukocytes?

granulocytes and agranulocytes

Granulocytes

contain obvious cytoplasmic granules

List the granulocytes

neutrophils

eosinophils

basophils