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Transcript of Blood - dentistryju2017.weebly.com · Lymphopoiesis: the process which produces lymphocytes...
Blood - specialized form of connective tissue
- components:
- blood cells (several types)
- plasma (extracellular matrix)
Functions of Blood
• Transport nutrients and respiratory gases
• Transport waste products to organs and tissues where they can be recycled or released
• Transport hormones
• Transport immune cells throughout the body
• Helps regulate body temperature
Blood in the BODY
• 5-6 liters = 6 quarts
• pH of 7.35 -7.45
• Color is dependent on amount of Oxygen
– More oxygen = brighter the red
– Less oxygen = duller the red
Physical Characteristics
• Fluid
– Living 45%
• Cells (formed elements)
– RBC Erythrocytes (carry oxygen)
– WBC Leukocytes (immune)
– Platelets (clotting)
– Non living (Matrix) 55%
• Plasma (straw colored)
– 90% water
– 10 %
» Salt, nutrients, proteins (albumin), waste (CO2, ammonia,
urea), gases, hormones
HEMOCRIT: Ratio of
RBCs to Plasma
BUFFY COAT
Copyright © McGraw-Hill Companies
Figure 12-1
Serum = everything in plasma, minus the clotting factors
RBCs WBCs
Types 1 type 5 types
Not true cells True cells
Number Male: 4.5-5.5 million/mm3
female:4-5 million/mm3
4000-11000/mm3
Diameter 6-9um (7.5um) 6-20um
Life span 120 days Few days-years
Origin and
maturation
Bone marrow Bone marrow and lymphoid tissue
Shape Biconcave discs Spherical
Function Gas exchange Defense
Motility Non motile Motile
The Staining of Blood Cells
• Blood smears are usually stained with a mix of:
– Eosin, an acidic dye that stains pink to red
– Methylene blue, a basic dye that stains blue to purple
Erythrocytes (RBCs)
• Small, biconcave discs
• Transport oxygen and CO2, cytoplasm is full of hemoglobin molecules
• Have no nuclei or organelles
• Pick up O2 at lung capillaries and release it at body tissue capillaries
• Survive for ~100-120 days in the circulation. Worn out RBCs are removed by macrophages of the spleen and liver.
During their maturation process, the erythrocytes extrude
their nuclei, and the mature blood cells enter the
bloodstream, without their nuclei
Erythrocytes can be used as a size reference for other cell
types
5 millions/mm3
Biconcave shape provides a large surface to volume ratio,
facilitating gas exchange
Flexible
Eosinophilia/acidophilia due to their
High content of hemoglobin (basic protein)
Leukocytes
• Originate in the bone marrow and released continuously into the blood
• Travel in bloodstream but function mainly outside of the bloodstream (in loose CT)
• 5 types organized into 2 groups – Granulocytes
• Neutrophils
• Eosinophils
• Basophils
– Agranulocytes
• Lymphocytes
• Monocytes
Granulocytes Agranulocytes
Consequently, most leukocytes are concentrated in the
connective tissue of different organs
Leukocytes perform their major functions outside
the blood vessels
Leukocytes form a mobile army that helps protect the body from damage
By bacteria, viruses, parasites, toxins and tumor cells
Granulocytes
• Cytoplasmic granules (containing enzymes or
chemicals) makes cytoplasm look grainy
• Non-spherical nuclei with lobes
• All are phagocytic; they engulf and consume foreign
cells and material
• 3 main types
Large granules, Red Large granules, blue
Small granules, pale pink/
salmon pink
Granulocytes: Neutrophils
• Up to 5 lobes in nucleus connected by “threads” of nuclear material (polymorphs)
• light pink cytoplasm
• Called neutrophils because cytoplasm takes up red (acidic) and blue (basic) stains equally
• Specialized for responding to bacterial invasions- Acute infection- acute pyrogenic infections
• Specific granules
(secondary)
- Lysozyme
- Phagocytin
(bactericidal)
- Lactoferrin
(bacteriostatic)
- Collagenase
• Azurophilic granules
(primary)
- Myeloperoxidase
- Acid hydrolase
- Defensins
Polymorphs
Pus cells
Myelocytes
Microphage
Pus is pyrogenic
Few organelles
Neutrophilia
Neutropenia
Granulocytes: Basophils
• Rarest leukocyte – might not see these under the microscopes
• Usually have bi-lobed, S-shaped nuclei but their granules often makes it hard to see
• Has large granules that stain dark purple in basic dyes (basophil = basic loving)
• Granules contain histamine and other molecules that mediate inflammation in allergic reactions and parasitic infections
Granulocytes: Eosinophils
• Usually have bi-lobed nuclei
connected by a short “thread” of
nuclear material
• Large cytoplasmic granules,
which stain red with the acidic
eosin dye (eosinophil = eosin
loving)
• Help in ending allergic reactions
and in fighting parasitic
infections
Specific granules:
-Crystalloid
-Two parts:
Externum (pale): contains histaminase and sulfatase
Internum (dark): contains basic protein to kill parasites
Neutrophil Eosinophil Basophil
Percentage
(WBCs)
60-70 % 1-4% 0-1%
Size 10-12 um 10-14 um 10-12 um
Life span 3-4 days in
c.t
Few days Few days
Nucleus 2-5 lobes 2 lobes
(horseshoe)
Irregular
(s-shaped)
Phagocytic
activity
Most Least
Motility Most Least
General features
-Spherical in blood stream, irregular in c.t
-Highly motile with different shapes due to their amoeboid movement
-Leave blood stream by migrating between the endothelial cells by
a process called diapedesis
Agranulocytes
• Granules in cytoplasm are absent or too small to
see (nonspecific granules)
– Cytoplasm appears clear blue
• 2 types based on structure (not cell lineage):
– Lymphocytes
– Monocytes
Agranulocytes: Lymphocytes
• Round nucleus occupies most of cell volume
• Cytoplasm is light blue
• T cells
– Has different types, some directly kill foreign or infected cells; others activate phagocytes to destroy microbes
• B cells
– Differentiate into plasma cells
– Secrete antibodies that bind to specific antigens and mark them for destruction by phagocytic cells
Long term immunity
Cell mediated immunity
Humoral immunity
Lymphocyte
Natural killer cells
(NULL Lymphocyte)
T Lymphocyte B Lymphocyte
Cytotoxic
Helper
Memory cell Plasma cell
Suppressor
Large Small
Suppresses immune response to self Ag
Suppresses immune response of T and B lymphocytes
Kill virus-infected
and damaged cells
Help cytotoxic T
cells and B cells in
their immune
functions
Produces antibodies
Morphologically they can be classified into small (6-8 m) medium (10-14
m) and large (> 18 m).
Different types express specific cell surface proteins
Agranulocytes: Monocytes
• Largest leukocytes
• Clear blueish cytoplasm (frosted glass appearance) & a large C-shaped purple nucleus
• Larger proportion of cytoplasm than lymphocytes
• Travel through bloodstream to reach connective tissues, where they transform into macrophages (large phagocytic cells)- Chronic infections
Never Let Monkeys Eat Bananas
Most common to least
Thrombocytes (Platelets) • Small non-nucleated
cytoplasmic fragments
• Broken off from larger cells called megakaryocytes
• Number: 200,000-400,000/mm3
• Diameter: 2-4 um
• Lifespan 5-10 days
• Aids in clotting by plugging tears in vessel walls
• Control the bleeding by plugging the defects in blood vessels and activating blood clotting cascades
Platelete has 2 zones
Outer pale basophilic
(clear) perpheriral zone:
hyalomere
Central dark granular
zone: granulomere
Granulomere: contains granules and
organelles
Alpha granules: clotting factors,
growth factors
Dense (delta) granules: serotinin, ATP,
ADP
Lambda granules: lysosomes
Hyalomere: contains cytoskeleton
Microtubule: maintain shape
Actin filaments: help contractions of
platelets and squeezing
Membrane channels
Open canalicular system
Dense tubular system
Have thick glycocalyx
Their main function is to continually monitor the vascular
system and detect any damage to the endothelial lining of
the vessels. If the endothelial lining breaks, the platelets
adhere to the damaged site and initiate a highly complex
chemical process that produces a blood clot
Thus preventing blood loss
MONOCYTE
Blood Cell Formation (Hematopoiesis)
• Begins during embryonic development
– yolk sac, liver, spleen, bone marrow
• Continues throughout life
– only in bone marrow after 28 weeks
• After birth, all blood cells originate in bone
marrow
The red bone marrow is a highly cellular structure and
consists of:
Hemopoietic stem cells
(the precursors of different blood cells) supported by a
reticular tissue.
As the individual ages and becomes an adult, the
red marrow is found primarily in the flat bones of the
skull, sternum and ribs, vertebrae, and pelvic
bones. The remaining bones, primarily the long bones
in the limbs of the body, gradually accumulate
fat, and their marrow becomes yellow. Consequently,
they lose the hemopoietic functions.
Myeloid: Erythroid
5:1
Granulocytes -Neutrophils
-Basophils
-Eosinophils
Erythrocytes
Megakaryocytes
Monocytes
T lymphocyte
B lymphocyte
Natural killer cells
Erythropoiesis: the process which produces erythrocytes
Granulopoiesis: the process which produces granulocytes
Thrombopoiesis: the process which produces thrombocytes
Lymphopoiesis: the process which produces lymphocytes
Monocytopoiesis: the process which produces monocytes
Blood Cell Formation (Hematopoiesis)
Are immature red blood cells (last stage)
The cell has extruded its nucleus, but is still
capable of producing hemoglobin
Supravital dye: precipitation of reticulum in the
cytoplasm
Normally, only about 1% of all red blood cells in
the bloodstream are reticulocytes
They circulate for about 1-2 days before
developing into mature red blood cells
An increase in reticulocytes ---- blood loss
(hemorrhage)
Reticulocytes
Are immature neutrophils
Band cell differentiates into mature granulocyte
(neutrophil)
Band cell is characterized by having a nucleus
which is curved (band shaped), but not lobar
An increase in band neutrophils: acute infection
Band cells
Band cell is almost a mature neutrophil, just
doesn’t have a segmented nucleus yet
Lymphopoiesis
Lymphoid stem cells
Hematopoietic stem cell
lymphoblast
Prolymphocyte
B Lymphocyte
T Lymphocyte Natural killer lymphocyte
Thymus
BM
Directly into blood
UNIVERSALITY
BLOOD
TYPE
SURFACE
PROTEIN
ANTIBODY RECEIVE
FROM
A A B A or O
B B A B or O
AB A B None A, B, AB, O
Universal
acceptor
O None A, B 0
Universal
Donor
1- Basophilia (deep blue): affinity for basic
dye methylene blue
(DNA, RNA (RIBOSOMES))
2- Eosinophilia (red): affinity for acidic dye
eosin
(hemoglobin within erythrocyte)
3- Neutrophilia (salmon pink/liliac):
characteristic of the specific
cytoplasmic granules of neutrophil
4- Azurophilia (purple): affinity for azure dyes,
typical of lysosomes
Useful links (optional)
http://highered.mheducation.com/sites/dl/free/0072507470/291136/t_cell_depe
ndent_antigens.swf
http://highered.mheducation.com/sites/dl/free/0072507470/291136/Cytoxic_T_c
ell_activity_against_target_cells.swf
http://highered.mheducation.com/sites/dl/free/0072507470/291136/immRespon
se.swf