Download transports lymph

Fig. 14.1-1
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Tonsils
Right lymphatic
duct
Cervical
lymph node
Thoracic duct
Thymus
Axillary
lymph node
Mammary
plexus
Subclavian
veins
Thoracic
duct
Spleen
Lymphatic vessel
(transports lymph)
Bone
marrow
(a)
Lacteals in
intestinal wall
Inguinal
lymph node
Fig. 14.2
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Arteriole
(from heart)
Blood
capillary
Venule
(to heart)
Valve closed
(backflow of lymph
is prevented)
Lymph
Fluid entering
lymphatic capillary
Valve open
(lymph flows
forward)
Direction of lymph
flow in capillary
Fluid entering
lymphatic
capillary
(a)
To venous system
Lymphatic
capillary
Tissue cells
(b)
Overlapping
epithelial
cells
Fig. 14.1
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Tonsils
Right lymphatic
duct
Cervical
lymph node
Thoracic duct
Thymus
Axillary
lymph node
Mammary
plexus
Area drained by
right lymphatic
duct
Subclavian
veins
Thoracic
duct
Spleen
Lymphatic vessel
(transports lymph)
Bone
marrow
(a)
Lacteals in
intestinal wall
Inguinal
lymph node
(b)
Area drained by
thoracic duct
Fig. 14.3
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Pharyngeal tonsil
Palatine tonsil
Lingual tonsil
Fig. 14.4
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Capsule
Trabecula
Lymphatic tissue
Cortex
Lymphatic sinuses
Lymphatic nodule
Germinal center
Afferent lymphatic vessel
carrying lymph to the
lymph node
Efferent lymphatic vessel
carrying lymph away from
the lymph node
Artery
Vein
Fig. 14.5
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Branch of
splenic
artery
Branch of
splenic
vein
White pulp
Splenic artery
Splenic vein
Red pulp
Trabecula
(a)
(b)
Capsule
Fig. 14.6-1
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Trachea
Lymph
nodes
Thymus
Adipose
tissue
Heart
(a)
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Fig. 14.7
Arterial circulation
Venous circulation
Heart
1
Lymphatic capillaries remove fluid from tissues. The
fluid becomes lymph (see figure 14.2a).
2 Lymph flows through lymphatic vessels, which have
valves that prevent the backflow of lymph (see figure
14.2b).
Lymphatic
capillary
Lymphatic
vessels
Valves
1
2
Lymph
5
Fluid
3 Lymph nodes filter lymph (see figure 14.4) and are
sites where lymphocytes respond to infections.
Lymph node
(filters lymph)
4 Lymph enters the thoracic duct or the right lymphatic
duct.
3
5
6
Lymph enters the blood.
Lacteals in the small intestine (see figure 16.14)
absorb fats, which enter the thoracic duct.
Thoracic duct or
right lymphatic duct
4
Chyle
7
Small intestine
Lacteals
(absorb fats)
6
Thoracic duct
7 Chyle, which is lymph containing fats, enters the
blood.
8
The spleen (see figure 14.5) filters blood and is a site
where lymphocytes respond to infections.
Spleen (filters blood)
8
9
Lymphocytes (pre-B and pre-T cells) originate from
stem cells in the red bone marrow (see figure 14.9).
The pre-B cells become mature B cells in the red bone
marrow and are released into the blood. The preT cells enter the blood and migrate to the thymus.
Red bone marrow
B cells
Pre-T cells
Bone
9
10 The thymus (see figure 14.6) is where pre-T cells
derived from red bone marrow increase in number and
become mature T cells that are released into the blood
(see figure 14.9).
Pre-T cells
T cells
Thymus
11 B cells and T cells from the blood enter and populate all
lymphatic tissues. These lymphocytes can remain in
tissues or pass through them and return to the blood.
B cells and T cells can also respond to infections by
dividing and increasing in number. Some of the newly
formed cells enter the blood and circulate to other
tissues.
10
B and T cells
All lymphatic tissues
11
Blood capillaries
B and T cells
Table 14.1a
Table 11.2-6
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display.
TABLE 11.2
Cell Type
Formed Elements of the Blood
Illustration
Description
Function
Red Blood Cell
Biconcave disk; no nucleus; contains hemoglobin,
which colors the cell red; 6.5–8.5 µm in diameter
Transports oxygen and carbon dioxide
White Blood Cells
Spherical cells with a nucleus
Five types of white blood cells, each with
specific functions
Nucleus with two to four lobes connected by thin
filaments; cytoplasmic granules stain a light
pink or reddish purple; 10–12 μm in diameter
Phagocytizes microorganisms and other
substances
Granulocytes
Neutrophil
Basophil
Eosinophil
Nucleus with two indistinct lobes; cytoplasmic
granules stain blue-purple; 10–12 μm in diameter
Nucleus often bilobed; cytoplasmic granules stain
orange-red or bright red; 11–14 μm in diameter
Releases histamine, which promotes
inflammation, and heparin, which
prevents clot formation
Participates in inflammatory response of
allergic reactions and asthma; attacks
certain worm parasites
Agranulocytes
Lymphocyte
Round nucleus; cytoplasm forms a thin ring
around the nucleus; 6–14 μm in diameter
Monocyte
Nucleus round, kidney-shaped, or horseshoe-shaped;
contains more cytoplasm than does lymphocyte;
12–20 μm in diameter
Produces antibodies and other chemicals
responsible for destroying microorganisms;
contributes to allergic reactions, graft
rejection, tumor control, and regulation
of immune system
Phagocytic cell in the blood; leaves the blood
and becomes a macrophage, which
phagocytizes bacteria, dead cells, cell
fragments, and other debris within tissues
Fig. 14.8
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Bacteria
enter tissue.
Tissue
damage occurs.
Chemical mediators
are released.
Chemotaxis,
increased vascular permeability,
increased blood flow
Increased numbers of
white blood cells and
chemical mediators at
site of tissue damage
Bacteria
are contained,
destroyed, and
phagocytized.
Bacteria gone
Tissue
repair
Bacteria remain
Additional chemical
mediators activated
Fig. 14.9
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Stem cell
Red bone marrow
Pre-B cell
Pre-T cell B cell
Circulation
Circulation
B cell
Pre-T cell
T cell
T cell
Circulation
Thymus
Lymph
node
Fig. 14.12
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Antigen-binding site
Variable regions
of light and
heavy chains
Heavy chain
Light chain
Complement-binding site
Site of binding to
macrophages, basophils,
and mast cells
Constant regions
of light and
heavy chains
Table 14.2
Fig. 14.13
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Antigen
(a) Inactivate the antigen. An antibody binds
to an antigen and inactivates it.
Antibody
(b) Bind antigens together. Antibodies bind
several antigens together.
(c) Activate the complement cascade. An
antigen binds to an antibody. As a result,
the antibody can activate complement
proteins, which can produce inflammation,
chemotaxis, and lysis.
(d) Initiate the release of inflammatory
chemicals. An antibody binds to a mast
cell or a basophil. When an antigen binds
to the antibody, it triggers the release of
chemicals that cause inflammation.
Complement
cascade
activated
Inflammation,
chemotaxis,
lysis
Chemicals
Inflammation
Mast cell or basophil
(e) Facilitate phagocytosis. An antibody
binds to an antigen and then to a
macrophage, which phagocytizes the
antibody and antigen.
Macrophage
Fig. 14.14
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More
memory
B cells
Memory
B cells
B cell
1
Fewer
plasma
cells
Memory
B cells
2
More
plasma
cells
More
antibodies
Magnitude
of response
Fewer
antibodies
Secondary
response
First
exposure
Primary
response
Second
exposure
Longer
response
time (3–14 days)
1 Primary response. The primary response occurs
when a B cell is first activated by an antigen. The
B cell proliferates to form plasma cells and
memory cells. The plasma cells produce
antibodies.
Shorter
response
time (hours to a few days)
2 Secondary response. The secondary response
occurs when another exposure to the same antigen
causes the memory cells to rapidly form plasma
cells and additional memory cells. The secondary
response is faster and produces more antibodies
than the primary response.
Fig. 14.16
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Cytotoxic
T cells
Activation of a
cytotoxic T cell
by antigen on the
surface of a cell
(see figure 14.15)
Release
cytokines
Produce inflammation,
initiate phagocytosis, and
activate T cells
Kill cells
on contact
Cytotoxic T cell
Target cell
T cell
Memory T cells
Target cell lyses.
Fig. 14.17
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Acquired adaptive
immunity
Active immunity
Passive immunity
Immunity is provided by the
individual’s own immune system.
Natural
Antigens are introduced
through natural
exposure.
Artificial
Antigens are
deliberately introduced
in a vaccine.
Immunity is transferred from another
person or an animal.
Natural
Antibodies from the mother
are transferred to her child
across the placenta or in milk.
Artificial
Antibodies produced by
another person or an
animal are injected.
Fig. 14.18
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Antigen
INNATE IMMUNITY
General response that
does not improve with
subsequent exposure
Physical
barriers
Neutrophils, macrophages,
basophils, and eosinophils
Chemical
mediators
Interferons prevent
viral infections.
Inflammation and phagocytosis
cause destruction of the antigen.
ADAPTIVE IMMUNITY
Specific response that
improves with
subsequent exposure;
begins with a
macrophage presenting
an antigen to a helper
T cell
Macrophage
Macrophage presents
processed antigen to
helper T cell
(see figure 14.10).
Helper T cell
Cytokines and antibodies
enhance inflammation
and phagocytosis.
Helper T cell proliferates and
secretes cytokines.
Helper T cell
Helper T cell
Helper T cell
can activate a
cytotoxic T cell
(see figure 14.15).
Helper T cell
can activate
a B cell
(see figure 14.11).
Cytotoxic T cell
B cell
B cell proliferates
and differentiates.
Plasma cell
Antibodies
Direct effects
against antigen
Cytotoxic T cell proliferates
and differentiates.
Memory B cell
Memory T cell
Responsible
for adaptive immunity
secondary response
Antibody-mediated immunity
Antibodies act against antigens in solution
or on the surfaces of extracellular
microorganisms.
Cytotoxic T cell
Lysis of cells
expressing antigen
Cytokines
Cell-mediated immunity
Cytotoxic T cells act against antigens bound to MHC
molecules on the surface of cells; they are effective
against intracellular microorganisms, tumors, and
transplanted cells.