ch 17 blood (bio163)

plasma

(not living fluid matrix)

55% of whole blood

least dense component

cardiovascular system

supplies all tissues with enough blood to meet energy demands

buffy coat

leukocytes and plates

<1% of whole blood

erythrocytes

45% of whole blood (hematocrit)

most dense components

formed elements

living blood cells suspended in plasma

contains-

erythrocytes: RBC

leukocytes- WBC

platelets

hematocrit

percent of blood volume that is RBC

47% ± 5% for males; 42% ± 5% for females

blood description

sticky opaque fluid with metallic taste (iron in hemoglobin in RBC)

has salty taste because of NaCl in plasma

color of blood

varies with oxygen content (red w/ oxygen and dark red (scarlet) without)

normal pH

7.35-7.45

average total blood volume

5 liters

hematopoiesis

forming blood (hematopoietic stem cells in red bone marrow)

erythropoiesis

forming RBC’s( increased by EPO from kidney in response to hypoxia: too few RBC)

leukopoiesis

forming WBCS

RBC definition

mature cell is biconcave disc ( decreased diffusion distance for oxygen),

full of hemoglobin (carries oxygen)

reticulocyte

immature RBC (# indicates the level of hematopoiesis)

hemoglobin

found in rbcs and is made out of:

heme and globin

heme

broken down in the body and turned into bilirubin, a yellow pigment that the liver usually gets rid of by sending it into the intestines as part of bile.

hyperbilirubinemia

too much bilirubin in the blood.

• Can happen from liver failure or too much red blood cell (RBC) breakdown.

• Causes jaundice (yellow skin and eyes).

• Bilirubin goes to the intestines and turns into stercobilin, which makes poop brown.

• contains iron that binds to oxygen (4 hemoglobin molecule)

globin

a protein that gets broken down into amino acids when recycled

spleen

where old rbcs are recycled

ex) RBC graveyard

anemia

decreased blood has abnormally low oxygen carrying capacity

-oxygen lvls are too low to support normal metabolism (body function)

-symptoms of fatigue, pale skin (pallor), shortness of breath and chills

causes of anemia

• Blood Loss

• Low Red Blood Cell (RBC) Production

• High RBC Destruction

• Increased Blood Plasma Volume
  

sudden blood loss in anemia

leads to hemorrhagic anemia

ex) stab wound

ongoing blood loss in anemia

leads to like chronic hemorrhagic anemia

ex) like a bleeding ulcer

low iron anemia

makes fewer, smaller and pale RBCS

low vitamin b12

occurs when you aren’t eating enough animal products

causes fewer and larger RBCs to be made

pernicious anemia

autoimmune disease where the stomach doesn’t make intrinsic factor, so the body can’t absorb B12

hemolytic anemia

when rbcs are being destroyed faster than the body can make them

ex) sickle cell disease

increased blood plasma volume

blood has more liquid than cells, making it watery

dilutes rbcs which makes it seem like there are fewer

ex) pregnancy: to support the baby

2 things that are normally not permeable thru a capillary

RBC and protein (mostly albumin)

hydrostatic

pushes fluid out of capillaries

too much hydrostatic pressure

pushes out too much fluid → edema (swelling)

too little hydrostatic pressure

pulls in too much fluid → lowers fluid in tissues, may increase blood volume

colloid osmotic pressure

pulls in plasma in a capillary

too little colloid pressure

not enough fluid pulled back in → edema (swelling)

too much colloid pressure

pulls in too much fluid → lowers fluid in tissues, may increase blood volume

white blood cells function

leukocytes fight infection/ disease

leukocytosis

WBC count over 11,000/mm3 which indicates infection

3 types of granulocytes

neutrophils

eosinophils

basophils

neutrophils

most numerous

is a bacteria slayer

eosinophils

digests parasitic worms

basophils

contains histamine

histamine

an inflammatory chemical that causes vasodilation (blood vessels widen) to attract wbcs to inflamed sites but also in allergies

what are the 2 agranulocytes?

lymphocytes (b and t) and monocytes (in blood)

lymphocytes (b and t cells)

crucial to immunity

monocytes (in blood)

become macrophages in tissues

leukopenia

abnormally low wbc count (often drug induced)

leukemia

is a cancer

overproduction of abnormal wbcs

cancer leukocytes fill red bone marrow

other lines crowded out→ anemia & bleeding

platelets

cytoplasmic fragments of megakaryocytes

act in clotting process

hemostasis

stopping of bleeding

vascular spasm

smooth muscle contracts which causes vasoconstriction

platelet plug formation

injury to lining of vessel exposes collagen fibers, platelets stick here

platelets release chemicals that make nearby platelets sticky

platelet plug forms

required von willebrand factors

coagulation

fibrin forms a mesh that traps rbcs and platelets

forming the clots

series of rxns using clotting factors (procoagulants) that converts soluble plasma protein (fibrinogen) into a insoluble fibrous protein (fibrin)

vitamin k needed to synthesizes 4 of them

pic on reveiw

write it

intrinsic pathway

triggered by negatively charged surfaces ( activated platelets, collagen, glass)

– Uses factors present within blood (intrinsic)

extrinsic pathway

triggered by exposure to tissue factor (an extrinsic factor) present on the surface of damaged tissues

bypasses several steps of intrinsic pathway so faster

vessel repairs

.

platelet derived growth factor

stimulates division of smooth muscles and fibroblasts to rebuild blood vessel wall

vascular endothelial growth factor

stimulates endothelial cells to multiply and restore endothelial lining.

plasminogen

clot is converted to plasmin by tissue plasminogen activator (tPA) factor XII (12) and thrombin (negative feedback)

plasmin

is a fibrin digesting enzyme

what are the two mechanisms that limit clot size?

1) swift removal and dilution of clotting factors

2) inhibition of activated clotting factors

thrombin bounds onto?

fibrin threads

antithrombin III inactivates…

unbound thrombin

heparin in basophil and mast cells…

inhibits thrombin by enhancing antithrombin III

thromboembolic disorders

undesirable clot formation

thrombus

clot that develops and persists in unbroken blood vessel

may block circulation leading to tissue death

embolus

thrombus freely floating in bloodstream

embolism

embolus obstructing a vessel

ex) pulmonary and cerebral emboli

risk factors for thromboembolic disorders

atherosclerosis

inflammation

slowly flowing blood or blood stasis from immobility

bleeding disorders

abnormalities that prevent normal clot formation

thrombocytopenia

deficient number of circulating platelets

petechiae

apreas due to spontaneous widespread hemorrhage

impaired liver function affects ability for blood to coagulate

inability to synthesize procoagulants

hemophilia a

most common type (77% of all cases); factor VIII (8) deficiency (intrinsic pathway)

disseminated intravascular coagulation (dic)

involved both types of disorders

occurs as a pregnancy complication, in septicemia or incompatible blood transfusions

widespread clotting blocks intact vessels and causes ischemia and uses up clotting factors which results in bleeding

aspirin

inhibits thromboxane a2 (released by activated platelets for spasm and clotting)

often suggested to prevent strokes, heart attacks

heparin

anticoagulant used clinically for pre and post op cardiac care

warfarin (coumadin)

used for those prone to atrial fibrillation due to increased clot formation in blood pooling in atria> risk of stroke

interferes with action of vitamin k (required for formation of clotting factors)

what hemoglobin does the fetus form

hemoglobin f

-has a higher affinity for o2 than hemoglobin a (adult) formed after birth

helps fetus obtain oxygen from mom’s blood thru placenta