Studied by 6 people
what is blood?
fluid that acts as a transport system for the body
functions of blood
transport, regulation, protection
transport of blood function
Delivering o2 and nutrients to body cells, transporting metabolic. transporting hormones from endocrine organs to target organs
what organs are part of transport of blood?
wastes to lungs and kidneys for elimination
which organs do hormones get transported to?
endocrine organs to target organs
regulation of blood function
maintaining body temperature by absorbing and distributing heat, maintaining normal pH using buffers; alkaline reserve of bicarbonate ions, maintaining adequate fluid volume in circulatory system
what instrument is used to normalize pH?
buffers
protection of blood
preventing blood loss, preventing infection
preventing blood loss
plasma proteins and platelets in blood initiate clot formation
preventing infection
agents of immunity are carried in blood (antibodies, complement proteins, white blood cells= leukocytes)
what agents are carried in blood
antibodies, complement proteins, and WBC’s
blood is the only tissue ______
that is fluid
blood is a mix of
matrix and cellular components
matrix is also?
plasma
cellular components is also?
formed elements
the color of blood varies with
\n o2 content
T/F: de-oxygenated blood is blue
false
what is the pH range of blood
\n 7.35-7.45
volume of blood in males
5-6L
volume of blood in females
4-5L
Red blood cells (RBC)
erythrocytes- 45% of whole blood
what is hematocrit?
percent of blood volume that is erythrocytes
what is buffy coat?
White blood cells and platelets (1%)
white blood cells (WBC)
leukocytes
how much blood is in plasma?
55% in blood
spun tube of blood yields three layers
plasma on top, buffy coat, erythrocytes on bottom
composition of plasma
\n straw-colored sticky fluid, about 90% water
most abundant solutes
plasma proteins
plasma proteins produced mostly by
liver
albumin
makes up 60% of plasma proteins, functions as carrier of other molecules as blood buffer and contributes to plasma osmotic pressure
formed elements
erythrocytes, leukocytes, platelets
leukocytes
complete cells
erythrocytes
no nuclei or organelles
platelets
cell fragments
most formed elements survive in bloodstream for
only a few days
most blood cells originate in
bone marrow and do not divide
what is an erythrocytes
small cells that contribute to gas transport
erythrocytes are filled with
hemoglobin (Hb) for gas transport
hemoglobin
red heme pigment bound to protein globin
globin
is composed of four polypeptide chains
heme pigment
is bonded to each globin chain
-gives blood red color
each heme's central iron atom
binds one o2
each Hb carries
four o2
cycle of Hb
Hb gets o2 in lungs, unloads o2 in tissues, picks up some co2 to release in lungs
hematopoiesis
formation of all blood cells, occurs in red bone marrow
hematopoiesis in adults
found in axial skeleton, girdles, and proximal epiphyses of humerus and femur
hematopoietic stem cells (hemocytoblasts)
stem cells that gives rise to all formed elements
producing erythrocytes takes
15 days
why do some athletes abuse artificial erythropoietin (EPO)
increases hematocrit which increase stamina and performance
dangers of abusing EPO
increasing hematocrit thickens blood which causes clotting, stroke, or heart failure
life span of erythrocytes
100-120 days
erythrocyte do not
grow, divide, make new proteins
when erythrocytes are aged
become fragile, Hb degenerates
macrophages in spleen
break down these RBCs
two erythrocyte disorders
anemia and polycythemia
anemia
blood does not carry enough o2
cause of anemia
blood loos, not enough RBCs produced, too many RBCs being destroyed
hemorrhagic anemia
rapid blood loss- trauma
chronic hemorrhagic anemia
slight but persistent blood loss
not enough RBCs produced
iron-deficiency anemia, low iron intake, poor absorption, kidney disfunction
too many RBCs destroyed
premature lysis of RBCs, incompatible transfusions or infections
sickle cell anemia
sickle cell anemia
RBCs become crescent shaped when o2 levels are low, misshape RBCs rupture easily and block small vessels
polycythemia
excess of RBCs; increases blood viscosity, causing blood flow
polycythemia vera
bone marrow cancer leading to excess RBCs, hematocrit may go as high as 80%
treatment for polycythemia vera
therapeutic phlebotomy
secondary polycythemia
caused by low o2 levels (example: high altitude) or increased EPO production
leukocytes
function in defense against disease
leukocytes increase in number
in response to infection
two major categories O leukocytes
granulocytes and agranulocytes
which contain visible cytoplasmic granules (granulocytes or agranulocytes)
granulocytes
granulocytes
larger and shorter lived than RBCs, contain lobed nuclei, all are phagocytic to some degree
life span of granulocytes
hours to days
three types of granulocytes
neutrophils, eosinophils, basophils
neutrophils
most numerous WBCs- 50-70%, kill microbes by process called respiratory burst
eosinophils
2-4% of all leukocytes, Red-staining granules contain digestive
enzymes• Release enzymes on large parasitic worms,
digesting their surface• Also play role in allergies and immune response
basophils
rarest WBCs, 0.5-1%, Nucleus deep purple with one to two
constrictions
Large, purplish black (basophilic) granules
contain histamine
histamine
inflammatory chemical that acts as vasodilator and attracts WBCs to inflamed sites
Agranulocytes
lack visible cytoplasmic granules, both have spherical or kidney shaped nuclei
life span of arganulocytes
hours to years
two types of agranulocytes
lymphocytes and monocytes
lymphocytes
found in lymph tissue
what are the two types of lymphocytes
T cells and B cells
T lymphocytes (T cells)
act against virus- infected cells and tumor cells
B lymphocytes (B cells)
give rise to plasma cells which produce antibodies
monocytes
abundant pale blue cytoplasm, dark purple-staining, U- or kidney-shaped nuclei, leave circulation, enter tissues, and differentiate into macrophages, actively phagocytic, activate lymphocytes to mount an immune response
leukocyte production
all originate from hemocytoblast stem cell that branches into two pathways
lymphoid stem cells
produces lymphocytes
myeloid stem cells
produce all other elements
leukemia
immature, nonfunctional WBCs flood bloodstream, cancerous cells fill red bone marrow, crowding out other cell lines, leads to anemia and bleeding
mononucleosis
highly contagious viral disease, usually seen in young adults, caused by Epstein-Barr virus, results in high numbers of typical aranuocytes,
platelets
cytoplasmic fragments of megakaryocytic
function of platelets
form temporary platelet plug that helps seal breaks in blood vessels
Platelets life span
age quickly and degenerate in about 10 days
hemostasis
processes that stop bleeding
first step of clot formation
vascular spasm- smooth muscle contracts causing vasoconstriction
second step of clot formation
platelet plug formation- injury to lining of vessel exposes collagen fibers; platelets adhere, platelets release chemicals that make nearby platelets sticky; plates plug forms
third step of clot formation
coagulation- fibrin forms a mesh that traps red blood cells and platelets forming the clot
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
