Chapter 20-Blood Flashcards
Introduction to blood
- ~5L of blood in body
- blood is connective tissue
- -cells=formed elements
- -matrix=plasma
basic functions of blood
- transport materials
- -nutrients, oxygen, metabolic wastes
- -specialized cells that defend tissues
- help maintain stable cellular environment
blood plasma
-55% of blood volume functions: -transport nutrients, gases and vitamins -regulate fluid and electrolytes -maintain pH
composition of blood plasma
- water: 92
- proteins: 7
- solutes: 1
blood plasma differs from interstitial fluid
- greater O2 concentration
- reduced CO2 concentration
- significantly more dissolved proteins
solutes
waste: -urea -ammonia electrolytes -Na+,K+, Mg+ etc organic nutrients: -lipids -glucose -amino acids
plasma proteins
albumin
globulin
fibrinogen
albumin
- 60%
- smallest
- maintains osmotic pressure of blood
- controls blood volume
- transports fatty materials in blood
- globulins
globulins
- 35%
- immunoglobulins: antibodies
- transport globulins:
- -transport compounds by binding to them
- -prevent filtering by kidneys
fibrinogen
4%
- blood clotting
- without these, plasma is known as serum
erythrocytes
red blood cells
40% of blood
-value known as hematocrit
-99.9% of all formed elements
erythrocyte structure
biconcave discs -thin central region -thick outer region -large surface area/volume ratio -anucleate: most organelles absent (no nucleus) allows passage through capillaries -forms rouleaux -flexible
hemoglobin
- 280 million molecules/cell
- 95% of RBC proteins
- structure:
- 4 polypeptide subunits
- one heme group per polypeptide
- one iron per heme group
- 1 molecule O2 per iron
function of hemoglobin
- each Fe carries one O2
- -oxyhemoglobin is bright red
- the reaction is easily reversed
- -deoxyhemogolbin is deep red/maroon color
- CO2 can also bind to hemoglobin
- -carbaminohemoglobin only accounts for 23% of blood CO2
leukocytes
white blood cells function: -defend against pathogens -remove toxins, wastes, damaged cells -do not function in circulatory system
how do leukocytes move
move into tissues from blood vessels
- diapedesis
- -squeezing out of the BV’s
- -going to different tissues
2 types of leukocytes
ganuloctyes
agranulocytes
granulocytes
-granular indusions in cytoplasm
agranulocytes
no visible granules
neutrophils
- granulocytes
- 60% of white blood cells
- lobed nucleus
- very mobile
- functions:
- -1st defense against microorganisms
- -phagocytic
- -attract more neutrophils
eosinophils
- granulocytes
- bi-lobed nucleus
- red granules
- functions
- -attracted to injuries
- -phagocytize compounds bonded with antibodies
- -increase during allergic reactions
basophils
- granulocytes
- 1% of WBCs
- s shaped nucleus
- blue granules
- functions
- -release histamine: inflammatory response, attracts other WBCs
- -release anticoagulants
monocytes
- agranulocytes
- 2-8% of WBCs
- largest cells in blood
- functions:
- -phagocytize foreign material
- -fuse to form osteroclasts
- –form free and fixed macrophages
- –recruit more monocytes
- -attract fibroblasts
lymphocytes
agranulocytes
- 20-305 of WBCs
- mature in lymph organs
- smalles
- non-phagocytic
- functions:
- specific immunity
- -focus on a single pathogen
- -produce antibodies
- -destroy abnormal tissue
3 types of lymophocytes
- t cells
- b cells
- NK cells
t cells
attack foreign cels directly
b cells
differentiate into plasmocytes that produce antibodies
NK cells
- immune surveillance
- destruction of abnormal cells
- -ex= cancer cells
thrombocytes
- platelet
- small, anucleate cell fragments
- from megakaryocytes
- produce proteins for blood clotting
- last for about 10-12 days
blood clotting
hemostasis --stopping flow of blood formation of clot involves --transport of important clotting agents --formation of a temporary patch --clot contraction
hemopoeisis
- all blood cells are derived from a pluripotent stemm cell
- -all cells except lymphocytes are derived from the resulting myeloid tissue
- in adults, all new blood cells are produced in the bone marrow
- -liver and spleen contribute while in utero, but eventually cease
erythropoiesis
- formation of RBCs
- RBCs have no nucleus of mitochondria
- wear and tear with no repair
- RBCs last for about 120 days
- replace about 1% per day
- 3 million RBCs replaced per second
leukopoiesis
- formation of WBCs
- granulocytes complete their development in the red marrow
- -neutrophils last for 12 hours, dyeing after they engulf an object
- monocytes do no complete development until they exit the circulatory system
- lymphocytes
- -immature cells can stay in bone marrow or move to thymus
- move to the spleen, tonsils, or lymph nodes where they mature
- can last for several years
blood type
RBC plasmalemma (cell membrane) has surface antigens
- these are usually glycoproteins or glycolipids
- are genetically determined (similar within ethnicities)
- A, B, and Rh are used to determine blood types
types of blood
A, B, AB, O
- people may have a antigens, b antigens, both (ab) and neither (o)
- you will produce antibody for all the antigens you dont have
- if foreign antigens are introduced into your bloodstream, you will produce antibodies to destroy them
Ab patient
can receive any blood, produces neither antibody
a patient
can receive blood from a and o, but produces B antibodies
b patients
can receive blood from b and o, but produces a antibodies
o patient
can receive blood from o only. produces a and b antibodies
Rh group
named after Rhesus macaque -if you have rh antigen --you are Rh+ -if you have no antigen --you are Rh- sometimes referred to as the D antigen
Rh group
Rh- people will only produce antibodies when exposed to the Rh antigen
- -usually occurs from:
- receive Rh+ transfusion
- pregnant with Rh+ baby
- -an Rh- mother may reject a second Rh+ baby
