Chapter 16
Blood
About this Chapter
•
•
•
•
Plasma and the cellular elements of blood
Blood cell production
Red blood cells
Platelets and coagulation
Composition of Blood
Water
Amino acids
Albumins
Proteins
Globulins
Glucose
Fibrinogen
Ions
BLOOD
is
composed
of
Plasma
Organic
molecules
such as
Lipids
Trace elements
and vitamins
Nitrogenous
waste
CO2
Gases
such as
O2
Figure 16-1 (1 of 2)
Composition of Blood
Lymphocytes
Red blood
cells
Monocytes
BLOOD
is
composed
of
Cellular
elements
White
blood cells
include
Neutrophils
Platelets
Eosinophils
m
0
5
10
Basophils
15
Figure 16-1 (2 of 2)
Plasma Proteins
Table 16-1
Cellular Elements
• Three main cellular elements
• Red blood cells – also called erythrocytes
• Platelets – split off from megakaryocytes
• White blood cells – also called leukocytes
• Lymphocytes – are also called immunocytes
• Monocytes – develop into macrophages
• Neutrophils – neutrophils along with monocytes
and macrophages are known as phagocytes
• Eosinophils – eosinophils along with neutrophils
and basophils are also called granulocytes
• Basophils – tissue basophils are called mast cells
Hematopoiesis
Pluripotent hematopoietic stem cell
BONE MARROW
Uncommitted
stem cells
Committed
progenitor cells
Lymphocyte
stem cells
Erythroblast
Megakaryocyte
Figure 16-2 (1 of 2)
BONE MARROW
Hematopoiesis
Erythroblast
CIRCULATION
Megakaryocyte
Reticulocyte
Erythrocyte
Platelets
Neutrophil
Monocyte
Basophil
Eosinophil
Lymphocyte
Figure 16-2 (2 of 2)
Blood Cells
Table 16-2
Clinical Tests
• Hematocrit: ratio of red blood cells to plasma
MALES
FEMALES
40%–54%
37%–47%
14–17
12–16
4.5–6.5 x 106
3.9–5.6 x 106
4–11 x 103
4–11 x 103
Neutrophils
50%–70%
50%–70%
Eosinophils
1%–4%
1%–4%
<1%
<1%
20%–40%
20%–40%
2%–8%
2%–8%
150–450 x 103
150–450 x 103
Hematocrit
Hemoglobin (g Hb/dL* blood)
Red cell count (cells/µL)
•58%
plasma
volume
Total white cell count (cells/µL)
Differential white cell count
Basophils
100%
Lymphocytes
<1%
white
cells
Monocytes
Platelets (per µL)
*1 deciliter (dL) = 100 mL
42%
packed
red cell
volume
Figure 16-3
Focus on … Bone Marrow
Bone
marrow
(a)
Figure 16-4a
Focus on … Bone Marrow
Bone
cortex
Central sinus
Stroma of
marrow
Venous
sinuses
Radial
artery
Nutrient
artery
(b)
Figure 16-4b
Focus on … Bone Marrow
Mature blood cells squeeze
through the endothelium to
reach the circulation.
Stem cell
Platelets
Mature
neutrophil
Reticulocyte
expelling
nucleus
Fragments of megakaryocyte
break off to become platelets.
Reticular
fiber
Reticular cell
Stem cell
Venous sinus
Macrophage
Monocyte
The stroma is composed of
fibroblast-like reticular cells,
collagenous fibers, and
extracellular matrix.
Lymphocyte
(c)
Figure 16-4c
Red Blood Cells
Cytoskeleton
filament
Attachment
protein
(a) SEM shows biconcave disk shape
of RBCs.
(b) Cross section of RBC
Actin
(c) The cytoskeleton creates the
unique shape of RBCs.
Figure 16-5
Osmotic Changes to Red Blood Cells
• The disk-like structure of red blood cells
allows them to modify their shape in
response to osmotic changes
Figure 16-6
Iron Homeostasis and Metabolism
Iron (Fe)
in diet
1 Iron comes from the diet.
1
Intestine
Plasma
Fe
3
Fe･transferrin
2
Bone Marrow
Fe
5
Heme
Hb
RBC
synthesis
2 Fe absorbed by active
transport.
3 Transferrin protein
transports Fe in plasma.
RBC
Hb
4 Liver stores excess Fe as
ferritin.
Spleen
Old RBCs
destroyed
Hb
5 Bone marrow uses Fe to
make hemoglobin (Hb).
6
Bilirubin
Liver
8
Bile
Bilirubin
metabolites
in feces
7
4
Ferritin
Bilirubin
metabolism
6 Spleen converts Hb to
bilirubin.
Kidney
Bilirubin +
metabolites
7 Liver metabolizes bilirubin
and excretes it in bile.
8
8 Bilirubin metabolites are
excreted in urine and feces.
Bilirubin
metabolites
in urine
Figure 16-7
Red Blood Cells
• Live for about 120 days
• Hemoglobin components are recycled
• Amino acids are incorporated into new proteins
• Some iron from heme groups reused in new
heme groups
• Remnants of heme groups are converted to
bilirubin, then excreted as bile
• Jaundice results from elevated levels of bilirubin
Red Blood Cells
Table 16-3
Sickled Red Blood Cells
• Morphology can provide clues to the
presence of disease
Figure 16-8
Platelets Form from Megakaryocytes
Megakaryocytes are giant cells with
multiple copies of DNA in the nucleus.
The edges of the megakaryocyte
break off to form cell fragments
called platelets
Platelets
Endoplasmic
reticulum
Red blood cell
(a)
Figure 16-9a
Overview of Hemostasis and Tissue Repair
Damage to
wall of
blood vessel
1
Vasoconstriction
Collagen
exposed
Tissue factor
exposed
Platelets
adhere and
release
platelet
factors
Coagulation
cascade
2
Thrombin
formation
Platelets aggregate
into loose platelet
plug
3
Temporary
hemostasis
Clot: reinforced
platelet plug
Converts
fibrinogen
to fibrin
Fibrin slowly
dissolved by
plasmin
Cell growth and
tissue repair
Clot dissolves
Intact blood
vessel wall
Figure 16-10
Platelet Plug Formation
1 Exposed collagen binds
and activates platelets.
Lumen of
blood vessel
3
Prevents
platelet
adhesion
Intact
endothelium
2 Release of platelet factors
3 Factors attract more platelets.
4
2
Releases
prostacyclin
and NO
4 Platelets aggregate into
platelet plug.
1
Smooth
muscle cells
Collagen
subendothelial
layer
Exposed collagen
in damaged blood
vessel wall
ECF
Figure 16-11
Clotting Process
Table 16-4
The Coagulation Cascade
INTRINSIC PATHWAY
XII
EXTRINSIC PATHWAY
Collagen or other
activators
Damage exposes
tissue factor (III)
Active XII
VII
XI
Ca2+
Active XI
Tissue factor
(III) and
active VII
IX
Ca2+
positive feedback
Active IX
VIII
Ca2+
X
phospholipids (PL)
Active X
COMMON PATHWAY
Prothrombin
Ca2+,
positive feedback
Thrombin
V, PL
Fibrinogen
XIII
Fibrin
Active XIII
Ca2+
Cross-linked fibrin
Figure 16-12
Coagulation and Fibrinolysis
Coagulation
Clot
Thrombin
Fibrinolysis
Plasminogen
tPA
Fibrinogen
Fibrin
polymer
Plasmin
Fibrin
fragments
Figure 16-13
Coagulation
Table 16-5
Coagulation
Table 16-6
Coagulation
Figure 16-14
Summary
• Plasma and cellular elements
• Plasma, red blood cells, white blood cells,
platelets, and megakaryocytes
• Plasma proteins and their functions
• Five types of white blood cells
• Blood cell production
• Hematopoiesis and cytokines
Summary
• Red blood cell
• Transferrin, ferritin, bilirubin, bile, and jaundice
• Platelets and coagulation
• Hemostasis, platelet plug, platelet adhesion,
platelet aggregation, and fibrin
• Coagulation cascade, fibrinogen, thrombin,
plasmin, prostacyclin, and anticoagulants