Transcript Ch 19 Lab Student_CirBloodx

Chapter 19
The Blood
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Introduction
Circulatory system (cardiovascular)
• Consists of the heart, blood vessels and blood
• Functions of circulatory system
– Transport- O2, CO2, nutrients, wastes, hormones, and stem cells
– Protection- destroy microorganisms and cancer cells, neutralize
toxins, and initiates clotting to prevent blood loss; also vehicle for the
spread of infection, inflammation, and pathogens
– Regulation - fluid balance, stabilizes pH of ECF, produces ion
balance (Ca+, K+, Na+) and temperature control, absorbs and
neutralizes acids (ie: lactic acid)
The Blood
• Comprised of plasma, formed elements, plasma proteins
• Plasma – (47%-63% of blood volume) 92% water; 5xs MORE PROTEIN
in plasma than interstitial fluid
serum – identical to plasma except for the absence of fibrinogen
• Formed elements approximately 45% of blood volume. Erythrocytes
(RBC), leukocytes (WBC). platelets
• Plasma proteins account for 7% of plasma; 90% formed in the liver
• FIBRINOGEN (4%)
• Other elements- electrolytes, nutrients, blood gases, etc.
• Hematology – the study of blood
Components and Properties of Blood
7 kinds of formed elements
• erythrocytes - red blood
cells (RBCs)
– Ratio: 1000 RBCs to
every 1 WBC
• platelets
– cell fragments from
special cell in bone
marrow
• leukocytes - white blood cells (WBCs)
• 5 leukocyte types divided into 2 categories:
• granulocytes (with granules- contain enzymes)
– neutrophils, eosinophils, basophils
• agranulocytes (without granules)
– lymphocytes, monocytes
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Separating Plasma From Formed Elements
CENTRIFUGE
separates plasma
from formed
elements
HEMATOCRIT - % of blood volume
comprised of RED BLOOD CELLS
(RBC)
• Erythrocytes 37% to 52%
– Males: 40-54 – androgens stimulate
higher RBC production
– Females: 37-47
• white blood cells and platelets
– buffy coat- 1% total volume
• plasma
– 47% - 63% of total volume
– complex mixture of water, proteins,
nutrients (fatty acids, amino acids,
glucose, iron, cholesterol, vitamins),
electrolytes, nitrogenous wastes
(urea), hormones, and gases
Erythrocytes
1. 4.8 – 5.4 million RBC / cu mm of blood*
2. Biconcave; No nucleus,
mitochondria or other organelles- no
protein synthesis, ATP by anaerobic
respiration
3. Loss of organelles increases surface
area allowing for higher gas exchange
and cytoskeletal flexibility enabling
cells to stack on top of one another to
squeeze through small capillaries walls
4. Protein – hemoglobin- Transports
gases: most O2 (98.5%); some CO2
(23%)
– 280 million/per each RBC [WOW!]
– Anemia defined as insufficient RBCs
or hemoglobin
5. Plasma membrane has ABO and Rh
antigens/markers- for blood typing
* 0.000033814 fluid oz = 1cu/mm
Blood Antigens
Antigens – cell markers/receptor
 complex protein molecules ON SURFACE
OF CELL MEMBRANE unique to individual.
Used to provoke an immune response
 distinguishes self from foreign
 RBC antigens called agglutinogens - basis
for blood typing
 Two types of agglutinogens -antigen A &B
 type A person has A antigens ∎ type B person has B antigens
 type AB has both A and B antigens - rarest - type AB
 type O person has neither antigen - most common - type O
Antibodies (agglutinins - produce agglutination); Anti-A; Anti-B
– appear 2-8 mos. after birth; reach maximum concentration at age 10
– antibody-A and/or antibody-B (both or none) PRESENT IN THE
BLOOD PLASMA NOT ON THE CELLS
– **Antibodies recognize and bind to specific antigens  cause
clumping of cells  AGGLUTINATION
– do not form antibodies against your own antigens
Blood transfusion require compatibility between PLASMA antibody
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proteins and RBC- erythrocytes
“Antigen”
•
•
•
•
Blood type A has antibody B (anti-B) in its plasma
Blood type B has antibody A (anti-A) in its plasma
Blood type AB has NO antibodies in its plasma
Blood type O has both antibody A (anti-A) and antibody B (anti-B)
in its plasma
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ABO Blood Typing
ANTIBODIES
Anti A
Antibodies attack and
agglutinate foreign antigens
Anti B
• Antibodies called agglutinins found
IN PLASMA are anti-A and anti-B
Type A
• What blood type is anti-A going to
agglutinate?(A) What blood type is
anti-B going to agglutinate? (B)
Type AB
• AB blood type has neither A or B
antibodies or it would continually clot
itself. If you add antibodies to AB
blood it will clot.
Type O
• O Blood type has both antibodies
and can only receive O type blood.
Type B
Rh (Rhesus) Blood Group System
• Two types: Rh+ and Rh• Rh antigen (ANTIGEN D) “present” on RBC of Rh+ blood type
 (+) sign is an indication that antigen marker is “PRESENT”
on RBC
• Rh antigen is “ABSENT” on Rh- blood type
 (-) is indication that antigen marker is NOT present on RBC
• Anti-D antibody will be produced if a person with Rh- blood is
exposed Rh+ blood via transfusion or in the birthing process
– RESULT: the person starts making Rh antibody (anti-D).
• Ex: First pregnancy Rh- mother is carrying Rh+ fetus  if mixing of
blood occurs at birth, mother's body starts making Rh antibodies
– Anti-D is ONLY present in Rh negative blood
• universal donor Type O negative (–)
– lacks Red Blood Cell antigens so recipient’s antibodies will not
agglutinate
• universal recipient Type AB – rarest blood type
– lacks plasma antibodies; no anti- A or B; can receive A, B, AB, O
Leukocytes- White Blood Cells
1. Migrate in and out of the
blood
2. Mostly found in connective
tissues and lymphoid
organs
• Less than 1% of the
formed elements
• 5,000 – 10,000 WBC / cu
mm of blood
• Conspicuous nucleus
• DO NOT HAVE
HEMOGLOBIN
• Plasma membrane has
histocompatibility antigens
– used to match cells,
tissues and organs
during donation
procedures
• Protect the body from
infections
• A Differential Blood
Count determines the % of
the 5 times of WBC types
Types of Leukocytes
• Granulocytes- Specific granules that contain enzymes or
chemicals for DEFENSE against pathogens and stain
conspicuously distinguishing each cell from others
– neutrophils (60-70%)
• barely-visible granules in cytoplasm; 3 to 5 lobed nucleus
– eosinophils (2- 4%)
• large rosy-orange granules; bilobed nucleus
– basophils (<1%)
• large, abundant, violet granules (obscure a large S-shaped
nucleus)
• Agranulocytes - Non-specific granules (lysosomes containing
enzymes in the cytoplasm) are inconspicuous to the light
microscope and have relatively clear looking cytoplasm.
– lymphocytes (25-33%) [B and T]
• variable amounts of bluish cytoplasm (scanty to abundant);
ovoid/round, uniform dark violet nucleus
– monocytes (3-8%)
• largest WBC; ovoid, kidney or horseshoe shaped nucleus
Formed Elements of Blood
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Granulocyte Functions
• neutrophils - increased numbers in BACTERIAL INFECTIONS
• eosinophils - increased numbers in PARASITIC INFECTIONS,
collagen diseases, ALLERGIES, diseases of spleen and CNS
• basophils - stimulate ALLERGIC REACTIONS; increased
numbers in chicken pox, sinusitis, diabetes
– secrete histamine (vasodilator) – widens blood vessels
– secrete heparin (anticoagulant –blood thinner) – promotes the
mobility of other WBCs in the area by preventing blood clotting
– Stimulates release of neutrophils and eosinophils – for infections
– Become modified Mast Cells present in connective tissue
• lymphocytes - increased numbers in diverse infections and
immune responses
– Two types “T” and “B”(antibodies)
– destroy cells (cancer, foreign, and virally infected cells)
• monocytes - increased numbers in viral infections and
inflammation [no antibody for viral infection]
– transform into macrophages inside tissues
• “present” antigens to activate other immune cells - antigen
presenting cells (APCs)
Disorders
Leukocytosis (“cyto”=cell “sis”= process): increases ABOVE 10,000/cu mm
Leukopenia (“penia”=deficiency): decreases BELOW 5,000/cu mm of blood
Leukemia (“emia”= blood condition): CANCER OF LEUKOCYTES
• Reduces competency of immune system to infection
– myeloid leukemia – uncontrolled granulocyte (N,E,B) monocyte,
lymphoid leukemia - uncontrolled lymphocytes, crowd normal cells
• acute leukemia – appears suddenly, progresses rapidly, death
within months unless treated.
• chronic leukemia –undetected for months, slow progression,
survival time three years
• Opportunistic infections – pathogenic organisms develop that would not
usually mount an infection in a healthy immunocompetent individual
– Decrease RBC = anemia; Decrease platelets= hemorrhage
Normal and Leukemic Blood
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Platelets
 Thrombocytes- platelets - small cytoplasmic fragments of
megakaryocytes
 normal platelet count - 250,000 – 400,000 platelets/L
– secrete vasoconstrictors; stick together to form platelet plugs
to seal small breaks; secrete clotting factors
– attract neutrophils and monocytes; phagocytize and destroy
bacteria
 Circulate for 5-9 days in the blood stream
 Thrombocytosis: when # of platelets goes UP  excessive clots
 Thrombocytopenia: when # of platelets goes DOWN  excessive
internal bleeding
 megakaryoblast duplicates its DNA
repeatedly without dividing forming a
megakaryocyte
 megakaryocyte sprouts long tendrils
that protrude into the endothelium of
blood capillaries
 moving flow of blood breaks off the
tendrils into platelets that travel
through the blood
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