Chapter 17 part 1- Blood Flashcards
Blood
a fluid connective tissue
what is blood composed of?
- plasma
- formed elements
- erythrocytes
- leukocytes
- platelets
Hematocrit
percent of blood volume that is RBCs
- 47% for males
- 42% for females
what is an erythrocyte?
RBC
What is a leukocyte?
WBC
how much of your blood is plasma?
55% of whole blood, the least dense component
What are your formed elements made of?
~buffy coats
- leukocytes and platelets, <1% of whole blood
~Erythrocytes
- 45% of whole blood, most dense component
what are physical characteristics and volume of blood?
- sticky, opaque fluid
- color scarlet to dark red
- pH is 7.35-7.45
- 38 *C
- 8% of body weight
- average volume:
- 5-6 L for males
- 4-5 L for females
3 functions of blood
distribution, regulation, and protection
What does blood distribute?
- 02 and nutrients to body cells
- metabolic wastes to lungs and kidneys
- hormones from endocrine organs and transported to target organs
What des blood regulate?
- body temperature
- normal pH using buffers
- adequate fluid volume in the circulatory system (if not, lack of oxygen)
What does blood protect against?
- blood loss, plasma proteins and platelets initiate clot formation
- infection,
- antibodies
- complement proteins
- WBCs defend against foreign invaders
What is your blood plasma made of?
- 90% water
- proteins (are mostly produced in the liver)
- 60% albumin
- 36% globulins (proteins parts for antibodies)
- 4% fibrinogen (
formed elements?
- only WBCs are complete cells
- RBCs have no nuclei or organelles
- platelets are cell fragments
- most formed elements survive only survive a few days
- most originate in bone marrow and DONT divide
Erythrocytes
-biconcave discs, anucleate, no organelles
- filled w/ 9Hb) hemoglobulin for gas transport
- contain the plasma membrane protein spectrin (lets it change shape)
- major factor when contributing to blood viscosity
- O2 loading in the lungs
(produces oxyhemoglobulin (ruby red))
-O2 unloading in tissues
(produces deoxyhemoglbulin (dark red))
Hemaopoiesis
blood cell formation
- occurs in red bone marrow of axial skeleton, girdles, and proximal epiphyses of humerus and femur
where is red blood cell formation?
Occurs in red bone marrow of axial skeleton, girdles and proximal epiphyses of humerus and femur
Hemocytoblasts (hematopoietic stem cells)
- give rise to all formed elements
- hormones and growth factors push cell to a pathway of blood cell development
Erythropoiesis (red blood cell production)
- a hemocytoblast is transformed into a proerythroblast
- proerythroblasts develop into early erythroblasts and continue
RBC formation phases
- Stem cell (hemocytoblast)
- committed cell (proerythroblast)
- developmental pathway
- a. Phase 1, ribosome synthesis (early erythroblast)
- b Phase 2, hemoglobulin accumulation, (late erythroblast/normoblast)
- c. Phase 3, ejection of nucleus, (reticulocyte)
- erythrocyte
regulation of RBCs.
Too many RBCs?
Not enough RBCs?
too many cause increased blood viscosity
not enough can cause hypoxia
hormonal control of erythropoiesis by
erythropoietin (EPO)
Erythropoietin
direct stimulus for erythropoiesis
released by the kidney in response to hypoxia
What are some causes of hypoxia?
- hemorrhage or increased RBC destruction reduces RBC numbers
- insufficient hemoglobulin (ex: iron deficiency)
- reduced availability of O2 (ex: high altitudes)
Effects of EPO
- more rapid maturation of committed bone marrow cells
- increased circulatory reticulocyte in 1/2 days
- Testosterone also enhances EPO production, resulting in higher RBCs count in males
homeostasis of normal blood oxygen levels
- Stimulus; hypoxia, decreased RBC count, hemoglobulin, O2 availability
- Kidney (and liver to a smaller extent) releases erythropoietin
- erythropoietin stimulates red bone marrow
- Enhanced erythropoiesis increases RBCs
- O2 carrying ability of blood increases
Lifespan of RBCs
- 100-120 days
- old rbcs become fragile, Hb degenerates
- macrophages engulf dyings rbcs in the SPLEEN
- heme and globin are separated
- iron is salvaged for reuse
- heme is degraded to yeloow pigment bilirubin
- liver secretes bilirubin (in bile) into the intestines
- degraded pigments leave the body in feces as stercobilin (BROOWN POOP)
- globin is metabolized into amino acids
anemia:
=-blood has abnormally low O2 carrying capacity
- sign rather than a disease
- Blood O2 levels cant support normal metabolism
- accompanied by fatigue, paleness, shortness of breath, chills
- insufficient erythrocytes
- hemorrhagic anemia acute/chronic loss of blood
- hemolytic anemia: RBCs rupture prematurely
- Aplastic anemia: destruction or inhibition of red bone marrow
- low hemoglobin content
- iron deficiency anemia:
- 2ndary result of hemorrhagic anemia
- inadequate intake of iron-containing foods
- impaired iron absorption
- pernicious anemia:
- deficiency of vitamin b12
- lack of intrinsic factor (produced in tummy) needed for absorption of b12
- treated by instramuscular inection of b12 or nascobal
- abnormal hemoglobin
- thalassemias:
- faulty globin (protein) chain
- RBCS are thin. delicate, and deficient in Hb
- Sickle cell anemia:
- defective gene codes for abnormal HbS
- causes RBCs to become sickle shaped in low oxygen situations
Polycythemia
excess of RBCs that increase blood viscosity
polycythemia results from
- polycythemia vera - bone marrow cancer
- 2ndary polycythemia- when less O2 is available (high altitude) or wen EPO production increases
- Blood doping
RBCs membranes bear 30 types of _________ antigens that are
- glycoprotein
- perceived as foreign when blood is transfused and mismatched
- unique to each person
- promoters pf agglutination (agglutinogens)
presence or absence of each antigen is used to ________ blood cells into different groups
classify
antigens of the _____ and _____ blood groups cause vigorous transfusion reactions
ABO and Rh
ABO blood groups
A,B,AB,O
based on presence or absence of two __________ (A and B) on the surface of the RBCs
agglutinogens
Blood may contain Anti-A or Anti-B ________ that act against transfused RBCs with ABO antigens not normally present
antibodies
ANti-A or Anti- B form in the _______ at 2 months old
blood
AB blood cells has surface marker ____ and ____
A and B
B blood cells has surface marker _____ and anti-____
B and ant-A
A blood cells has surface marker ___ and Anti-___
A markers and anti-B
O blood type has no surface markers but has anti
A and B
there are 45 diff. Rh
aggultinogens (Rh factors)
C,D and E are the ______ common (Rh blood groups)
most
____ indicates presence of D
Rh+
Anti-Rh antibodies are not spontaneously formed in
Rh- individuals
Anti-Rh antibodies form if an _____ individual receives _____ blood
Rh-
Rh+
a second exposure to Rh+ blood will result in a
typical transfusion reaction
Homeostatic imbalance: hemolytic disease of the newborn
also called erythroblastosis fetalis
erythroblastosis fetalis
Rh- mother becomes sensitized when exposed to Rh+ blood cause her body to synthesize anti-Rh antibodies
Anti-Rh antibodies cross placenta and destroys RBCs of an Rh+ baby
erythroblastosis fetalis treatment
______ serum containing _____can prevent the Rh- mother from becoming sensitized
RhoGAM
Anti-Rh
When serum containing anti-A or Anti-B aggultinins is added to blood, agglutination (______) will occur between the agglutinin and the corresponding ________
clumping, agglutinogens
positive reactions indicate _____
agglutination
Type A blood (contain agglutinogen A; agglutinates with _____
Anti- A
Type B blood (contains agglutinogen B; agglutinates with _____
Anti-B
Type AB blood (contains aggltinogens A and B; agglutinates w ____)
both serums
diagnostic blood tests
- hematocrit
- blood glucose tests
- microscopic examination reveals variations in size and shape of RBCS, indications of anemias
- differential WBC count
- PROTHROMBIN time and platlet counts asses hemostasis
- SMAC, blood chemistry profile
- CBC
