Chapter 11: The Blood Flashcards
The blood represents ___ % of total body weight
8
- 5 liters in women
- 5.5 liters in men
Erythrocytes function
Red Blood Cells
- important in O2 and CO2 transport to body tissue
Leukocytes function
White Blood Cell
- immune systems mobile defence units
EXAMPLE: antibodies
Thrombocytes
platelets
- important in hemostasis (blood clotting)
Plasma represent __% of whole blood and its total weight
65
the buffy coat is made up of
- platelets and leukocytes
the buffy coat makes up __% of the whole blood
1
Erythrocytes make up __% of whole blood
45
Eosinophilis function
Leukocyte
- attack parasitic worms; important in alergric reactions
Monocytes function
Leukocytes
- in transit to become tissue macrophages
types of lymphocytes
- B Lymphocytes
- T Lymphocytes
B lymphocytes function
- produce antibodies
T lymphocytes function
- cell mediated immune responses
hematocrit values in females
42%
hematocrit values in men
45%
average pl. volume in blood females
58%
average pl. volume in males
55%
Plasma composition
- 90% water
- 1% inorganic molecules
- 6-8% plasma proteins
Albumins
- most abundant
- contribute to pl. colloid osmotic pressure
- transport many poorly soluable substances in the plasma
three plasma proteins
- albumins
- globulins
- Fibrinogens
Albumins examples
- bilirubin
- penicillin
- bile salts
Globulins
- exsists in three forms
- three units bind and transport many substances, such as TH, iron, and cholerstrol in the plasma
Alpha and Beta globulins
- transport many water- insoluble substances; clotting factors; inactive precursor molecules
Gamma Globulins
- antibodies
Alpha golbulin
- activates the conversion of angiotensinogen into angiotensin - II to regulate salt-water balance in the body
Fibronogens
- involved in clot formation
How many RBS’s are there
5 million
Erythrocyte structure
- contain no nucleus, orgenelles, or ribosomes
- flat, thin, disc-shaped, and slightly dented in the middle on both sides
Purpose of biconcave, flat, disc shape in Erythrocytes
- provides larger surface area
- thinnest promotes rapid O2 diffusion
Advantage of the flexiable membrane in RBC
- allows RBC’s to travel through the narrow capillaries without rupturing in the process
Role of Hemoglobin
- responsible for O2 and CO2 transportation
- only found in RBC
Hemoglobin pigement contains
iron
hemoglobin pigment color
- appears reddish when oxygenated
- appears bluish when deoxygenated
What are the two parts of hemoglobin
- globin portion
- Heme groups
Globin portion
- a protein composed of four highly folded polypeptide chains
Heme Groups
- four iron containing non protein groups
- each is bound to one of the polypeptides
How many Hb molecules does each erythrocyte contain
250 million
What does Hb transport
- O2
- CO2
- acidic H- ions
-CO - NO
what percent of the oxygen is transported through Hb
98.5
purpose of NO in tissues
- vasodilator to arterioles
- helps stabilize blood pressure by vasodilation and vasoconstriction
how many erythrocytes are contained in adult blood
25-30 trillion
How long do RBC’s last
120 days
WHY?? - not enough energy, only lasts that amount of time
what is the rate that RBC’s must be replaced at?
- 2-3 million cells/second
where do erythrocytes differentiate
- red bone marrrow
Erythropoietin
- is a hormone secreted by the kidneys that stimulate RBC production
- synthetic version is avaliable
Anemia
- refers to a below than normal o2 carrying cpacity of the blood, characterized by low hematocrit
Causes of Anemia
- decreased rate of erythropoiesis
- excessive loss of PBS
- deficiency in Hb content of RBC
Nutritional anemia
- causes by iron deficient diet
RBC are produced by contain less Hb than normal (they cannot transport as much o2)
Why is iron needed?
- essential for Hb production
Pernicious anemia
- failure to absorb B12
- deficiency in intrinsic factor (stomach)
- leads to the imparentment of RBC production and maturation
hemolytic anemia (sickle-cell) casues
- rupture of a excessive number of circulating RBC’s
- defects in RBC or ruptured induced external factors (malaria parasites)
- hereditary
- defective type of Hb polymerizes
- deformed RBCS clump (compromised blood flow)
- rate of RBC rupture exceeded erythropoiesis
Sickle cell disease effects (statistics)
1 in 650 people of african decent
Polycythemia
- characterized by too many circulating RBCs and elevated hematocrit
Primary polycythemia
- caused by the tumorlike condition of bone marrow
- eryhtropoisesis proceeds at an uncontrollable rate
Second polycythemia
- erthropoientin- induced adaptive mechanisms improves bloods oxygen carrying capacity in responce to prolonged reduced oxygen delivery
- occurs normally in people living in high altitudes
- sometimes called relative polycythemia
What are leukocytes
- mobile units of the bodies immune defence system
- recognizes and destroys materials within the body that are foreign
- colorless
- larger than erythrocytes
Where do leukocytes originate from
- the same undifferential multipoint stem cells in the red bone marrow
where are granulocytes and monocytes produced
- only in the bone marrrow
most leukocytes are produced by
- lymphocytes already in the lymphoid tissues
- EXAMPLE: lymph nodes and tonsils
Function of leukocytes
- defends against invading pathogens
- identifies and destroys cancer cells that arise in the body
- function as a “clean-up crew” that removes worn-out cells and tissue debris
Neurtrophils functions
- first defenders on the scene of bacterial invasion
- very important in inflammatory responces
- scavange to clean up debris
neurtrophilis release
- release web of extracellular fibers called neutrophil extracellular traps (NETs) that contain bacteria killing chemical
Basophils
- least numerous and most poorly understood leukocyte
- similar to mast cells
- synthesize and store histamine and heparin
Histamine
- release in important allergic reactions
Heparin
- speeds up the removal of fat particles from the blood after a fatty meal
- can also be uses to prevent clotting of blood samples (chemical analysis)
- used extensively as an anticoagulant drug
Monocytes
- emerge from bone marrow while still immature and circulate for a day or two before settiling down in various tissues in the body
Mature and enlargement of monocytes is know as
0 macrophages
B lymphocyte
humoral immunity
- produce antibodies
- responsiable for antibody-mediated immunity
T lymphocytes
cell mediates immunity
- do not produce antibodies
- directly destroy specific target cells by releasing chemicals that punch holes in the cells victim
- target cells include body cells invaded by viruses and cancer cells
Platelets
- cell fragments shed form megakaryocytic
- lack nuclei
- high concentrations of actin and myosin
- have organelles and cystolic enzymes for generating energy and synthesizing secretary products
how long to platelets remain functional for
10 days
the blood contains approximelty ___ platelets
250 million
Thromboprotein
- a hormone produced by the liver
- increases the number of megakaryotcytes (therefore increases platelet production)
Haemostasis
- prevents blood loss from a broken vessel
Causes of bleeding
- break in vessel
- difference in pressure in the inside and outside of the blood vessel
3 major steps of haemostasis
- vascular spasm
- formation of a platelet plug
- blood coagulation (clotting)
vascular spasm
- reduces blood flow through a damaged vessel
Formation of a Platelet plug
- platelets aggrulate on contact which exposes collagen in damaged vessel
- platelets release ADP –> surface of nerby platelets become sticky and adhear to aggregated platelets
Blood coagulation
- transformation of blood from a liquid into a solid gel
role of a platelet plug
- actin and myosin complexes contract to compact and strenghten the loose plug
- release powerful vasoconstrictors
- release other chemical which enhance blood coagulation
Vasoconstrictors released for platelet plug
- seratonin NE
- thromboxane A2
role of thrombin in clot formation
- converts fibrinogen to fibrin
- activates factor XIII to stabilize fibrin mesh
- acts as a positive-feedback fashion to facilitate its own formation
- enhances aggregation for the clotting process
clotting cascade
- plasma clotting factor
how many steps are involved in the intrinsic clotting pathway
- involves seven separate steps
when is the intrinsic clotting pathway initiated
- set off when factor XII (hageman factor) is activated by coming into contact with exposed collagen in a injured vessel of foreign surface such as a glass test tube
how many steps are required in the extrinsic blood clotting pathway
- four
extrinsic blood clotting pathway
- requires contact with tissue factors external to the blood
- tissue throbolastin is released from traumatized tissue directly actovates factor X
Clot retraction
- contraction of platelets shrinks fibrin mesh, squeezing fluid from the clot
Clot dissolution
- enzyme plasmin dissolves the clot
what is plasmin formed form
- plasminogen
what froms a scar
- fibroblast
vessel repair
- aggrevated platelets secrete a chemical that promotes the invasion of fibroblast from surrounding connective tissue
Cerebrovascular accident is also know as a
stroke
What is an cerebrovascular accident
- a abnormal or excessive clot formation within a blood vessel that can compromise blood flow to a vital organ
The bodys clotting and anicoagulant systems function in a _______________ manner
- check and balance manner
