Transcript Case #2: Brave new world or Rave new world?

Agenda
• Chapter 19: Blood
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Major functions
Major Components
Structure of RBCs and WBCs
ABO Blood Types, and Rh Factor
• Lab 34.1 and “Blood Typing”
Blood: General functions
• Transport of dissolved gases, nutrients,
hormones, and metabolic wastes
• Regulation of pH, ion composition of
interstitial fluids
• Restriction of fluid loss at injury site
• Defense against toxins and pathogens
• Regulation of body temperature
Blood is Fluid Connective Tissue
• Recall that connective tissues are comprised
of: specialized cells, extracellular protein
fibers and fluid (ground substance)
• Matrix is a combo of the non-celluar
components
• The matrix of blood is called plasma
Components of blood
• Plasma
~ 90% water
~ 10% dissolved (soluble) proteins
most made by the liver
• Formed elements (cells and cell fragments)
1. RBCs
2. WBCs
3. Platelets
Plasma proteins
• Albumins (60%)
-major component of osmotic pressure of
plasma
• Globulins (35%)
-antibodies and transport proteins
• Fibrinogens (4%)
-functions in blood clotting
Formed Elements: Hematocrit
• Percent of blood volume contributed to
formed elements (cells)
Centrifuge:
separate
components by
density
Hematocrit
• Males ~ 46, Females ~ 42
• What can effect hematocrit?
– : Dehydration and EPO (erythropoietin),
testosterone
– : Internal bleeding, or defect in RBC
formation
When you look at a smear of
blood, which cells predominate??
20 m
RBCs Characteristics
• Function primarily to carry oxygen and CO2
-contain hemoglobin (33% of cell weight)
• Lack a nucleus
• Contain few organelles (no mitochondria)
– Can they generate ATP?? Make new protein?
• Shaped like biconcave discs
-increases surface area for gas exchange
• Life span approx. 120 days
• FYI: 1 L of blood = ~ 5 million RBCs
1 drop of blood = ~ 260 million RBCs
Red Blood Cells
~ 0.8 m
~ 2.6 m
7.2 - 8.4 m
Increased surface area, stackable, and
flexible (can fit through 4 m capillaries)
Hemoglobin
Composed of globin (protein) and pigment
(heme)
-Protein portion: 2  and 2  chains
-Four heme units: contain iron and
bind oxygen
Hemoglobin
Quaternary Structure
Hematopoiesis
• Rate of RBC production
controlled by erythropoietin
(EPO)
• EPO produced by kidneys
(upon exposure to low O2)
• EPO acts on stem cells of red
bone marrow, and rate of
maturation
• What is necessary for healthy
RBCs?
Myeloid
stem
cell
Fate of RBCs
• Life span of 100-120 days
• In 1 min: travel from periphery, are squeezed
through capillaries, sent to heart and back!
• Become trapped in the spleen (eaten by
macrophage)
-heme degraded to biliverdin (green)
-biliverdin converted to bilirubin (orange-yellow)
-bilirubin binds to albumin, transported to liver for
excretion in BILE
• At large intestine, bacteria convert bilirubin to
urobilinogens and stercobilinogens
• urobilins and stercobilins
ABO Blood Types
• ABO system refers to the presence of
surface antigens on the RBCs AND the
antibodies in the plasma
• Antigens also called agglutinogens
• Antibodies called agglutinins
ABO Blood Types
Type A
Type B
Type AB
Type O
• For a person with type A blood, the A antigens (surface
proteins) inform the body’s defense system that “A” is “self”.
• For a persone with type A blood, which antigen(s) would
alert the body as “non-self” or foreign?
ABO Blood Types
Type A
Type B
Type AB
Type O
When the body encounters “foreign” material, it generates
antibodies against the surface antigens.
When foreign RBC antigens are covered with antibodies, they
clump and lyse (agglutination and hemolysis).
What antibodies will each blood type have in the plasma?
Blood Types
Rh Factor and Hemolytic Disease of
the Newborn
Fetal cells enter mother’s circulation
Second pregnancy is attacked by
maternal antibodies
White Blood Cells (Leukocytes)
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Complete cells with nuclei and all organelles
Fewer than RBCs (6000-9000/ul)
Critical to the body’s defense (immune system)
Special features
- Can migrate out of bloodstream
- Capable of amoeboid movement
-Atracted to specific chemical stimuli
(respond by positive chemotaxis)
-Capable of phagocytosis (Neutrophils,
Eosinophils, Monocytes)
Types of WBCs
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Neutrophils
Eosinophils
Basophils
Monocytes
Lymphocytes
granulocytes
agranulocytes
Note that many of these cells have names that reflect the way these cells look when under
the scope, when stained with certain dyes
Neutrophils
• Account for 50-70% of
circulating WBCs
• Dense segmented nucleus
with 2-5 lobes
• Highly mobile, often the
‘first to arrive on the
scene’following injury
• Attack bacteria coated with
antibodies
• While active, release
prostaglandins and
leukotrienes
Eosinophil
• 2-4% of WBCs
• Stain red, 2 lobed
nucleus
• Attack cells coated with
antibodies
• Importantly, protect
against parasites via
exocytosis of toxic
compounds
Basophils
• Less than 1%
• Granules contain
histamine, heparin
• Release enhances
inflammation
Monocytes
• 2-8% of WBCs
• Remains in blood for 24hr
before becoming a
macrophage in tissue
• Macrophage=aggressive
phagocytes
• While active, secrete
chemicals that attract/stimulate
other WBCs
• Also secrete chemicals that
attract fibroblasts into region
Lymphocytes
• 20-30% of WBCs
• Note the round nucleus,
little cytoplasm
• Most lymphocytes reside
in connective tissue or
lymphatic organs
• In circulating blood: B
cells, T cells, and NK
cells
WBC Production
Platelets
• Anuclear cell fragments, contain cytoplasm and
proteins (4 m diameter)
• “Pinched off” from megakaryocytes in bone marrow
• Major participant in clotting response
Hemostasis
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Highly regulated process of halting blood loss
3 phases
1. Vascular phase
2. Platelet phase
3. Coagulation phase
Hemostasis: Vascular phase
Release of ADP and endothelins
Cutting triggers smooth muscle contraction of vessel wall
• Basal lamina exposed to bloodstream
• Endothelial cells release chemical factors, local hormones
--ADP, endothelins
• Endothelial cell membranes become ‘sticky’
--Platelets stick!
Hemostasis: Platelet phase
Hemostasis: Platelet phase
http://www.gcarlson.com/plavix.htm
http://www.platelet-research.org/
Hemostasis: Coagulation phase
Fibrin is
insoluble!