1. 14
The Lymphatic and
Immune Systems: Your
Defense Systems

2. INTRODUCTION
 Immune and
lymphatic systems
work to protect body
from pathogens that
can produce disease
 Without these
systems, you would
not survive for long

3. THE DEFENSE ZONE
 If a group of
pathogens try to
enter body, they
must first get past
barriers, such as
intact skin and
secretions of
mucous
membranes

4. PHYSICAL BARRIERS
 Anything that
prevents invaders
from getting inside
your body prevents
infection
 Physical barriers
act as first line of
defense; located in
areas most likely to
be invaded
Skin and mucous membranes
of eyes, digestive,
respiratory, reproductive
systems

5. PHYSICAL BARRIERS
 Anything that
prevents invaders
from getting inside
your body prevents
infection
 Physical barriers
act as first line of
defense; located in
areas most likely to
be invaded
Skin and mucous membranes
of eyes, digestive,
respiratory, reproductive
systems

6. THE DEFENSE ZONE
 If pathogen does
get into body, it is
recognized as
not belonging
 Weapons in the
form of
specialized cells
are engaged by
immune and
lymphatic
systems to fend
off the pathogens

7. THE DEFENSE ZONE
 Weapons include
specialized cells and
powerful chemicals of
immune and lymphatic
systems
 Chemicals stimulate
inflammatory and clean
up responses
 Again, this is accomplished
by combined and integrated
efforts of immune and
lymphatic systems

8. THE LYMPHATIC SYSTEM
 Both the transport system
and barracks of immune
system
 Works closely with
cardiovascular system

9. THE LYMPHATIC SYSTEM
FOUR FUNCTIONS

10. STRUCTURES OF THE
LYMPHATIC SYSTEM
 Smallest pipes of lymphatic system called
lymph capillaries; run parallel to blood
capillaries

11. STRUCTURES OF THE
LYMPHATIC SYSTEM
 Lymph capillaries form network
between cells of connective tissues, but
unlike blood capillaries, are open ended

12. THE LYMPHATIC SYSTEM
 Proteins and fluids are lost from cardiovascular
capillaries and enter interstitial space.

13. THE LYMPHATIC SYSTEM
 Once this fluid enters
lymph capillaries, it is
known as lymphatic fluid
(lymph)
 Lymph: straw-colored,
clear fluid; primary
component is water

14. THE LYMPHATIC SYSTEM
 Lymph capillaries empty
into lymphatic vessels,
similar to veins including
valves; body movement
and contraction of
smooth muscles propels
lymph through system

15. FIGURE 14-1
THE LYMPHATIC SYSTEM AND THE RELATIONSHIP
BETWEEN BLOOD AND LYMPH CAPILLARIES

16. LYMPH NODES
 Large vessels empty into lymph nodes, ranging in size
from pinhead to an olive
 Lymph nodes: filters placed all along pathways or
vessels of lymphatic system

17. FIGURE 14-2
THE LYMPH NODE STRUCTURE
Small, encapsulated bodies
divided into sections
Consist of sections of
lymphatic tissue containing
WBCs known as
lymphocytes

18. LYMPH NODES
 Lymphatic tissue surrounded by lymphatic
sinuses filled with lymph fluid
 Filter and destroy pathogens using WBCs

19. LYMPH NODES IN THE BODY
 Concentrated in
cervical, axillary,
inguinal, pelvic,
abdominal,
thoracic, and
supra trochlear
areas
 Adenoids and
tonsils also part
of lymph system

20. LYMPHATIC TRUNKS
 Lymphatic
vessels exiting
lymph nodes
empty into one
of several
lymphatic
trunks

21. COLLECTING DUCTS
 Lumbar, intestinal,
and intercostal
trunks empty into
thoracic duct the
largest lymph
vessel; more than
two-thirds of
lymphatic system
drains into this duct
Lymphatic trunks empty into
one of two collecting ducts

22. COLLECTING DUCTS
 Bronchomediastinal,
subclavian, and
jugular trunks empty
into right lymphatic
duct; smaller duct
within right thorax
that empties into
right subclavian
vein

23. CIRCULATION OF
LYMPHATIC FLUID
 Lymphatic fluid flows in
only one direction: from
body tissues and organs
to heart
 Blood to tissue
 Tissue to lymphatic
capillaries
 Lymphatic capillaries to
lymphatic vessels

24. CIRCULATION OF
LYMPHATIC FLUID
1.
Lymphatic capillaries
to lymph nodes
2.
Lymph nodes to
lymphatic vessels
3.
Lymphatic vessels to
lymphatic trunks
4.
Lymphatic trunks to
collecting ducts
5.
Collecting ducts to
subclavian veins and
then back to the blood

25. LYMPH ORGANS
 Spleen

Spongy saclike mass of
lymphatic tissue in upper left
quadrant of abdomen

Structurally similar to lymph
nodes but instead of lymphatic
sinuses has blood sinuses

Surrounding blood sinuses are
islands of white pulp containing
lymphocytes and islands of
red pulp containing both RBCs
and WBCs

26. LYMPH ORGANS
 Spleen

Functions to remove and
destroy old, damaged,
or fragile RBCs

Also filters pathogens
from bloodstream and
destroys them like lymph
node

Not vital organ; can be
surgically removed;
removal in children can
severely compromise
immunity, but has lesser
effect on adults

27. LYMPH ORGANS
 Thymus

Soft organ located
between aortic arch and
sternum

Very large in children
because it must fend off
new infections

Gets smaller; continues to
have some activity in
adults as immune system
fully matures in its ability
to fight infection

28. LYMPH ORGANS
 Thymus
 Site of mature
type of WBC
called a T
lymphocyte
(made in the
bone marrow)

29. FIGURE 14-3
SPLEEN, THYMUS, TONSILS, AND
LYMPHATIC VESSELS

30. LYMPHATIC AND IMMUNE
Stores and
Transports
Barriers
Nodes
Organs
Cells
Chemicals
Vessels

31. THE IMMUNE SYSTEM
 Comprised of cells,
chemicals, and barriers
that protect body from
invasion by pathogens
 Some processes active,
some passive, some
inborn, and others
change with experience

32. ANTIGENS-SELF OR
FOREIGN?
 Molecules on outer
surface of cell membrane
that identify them as friend
or foe
 Each living thing has
unique cell surface
antigens, allowing immune
system to distinguish
between cells that are
naturally yours and cells
that are not

33. ANTIGENS
 Ability called self-
recognition and non-selfrecognition; is heart of
how immune system
functions
 Well-functioning immune
system ignores self
antigens and attacks
non-self antigens

34. ANTIBODIES
 Proteins the body makes
that bind to antigens,
eventually destroying
them
 One of most potent
weapons of immune system
 Called into action when
foreign antigen invades
the body

35. INNATE VERSUS ADAPTIVE
IMMUNITY
 Innate (natural)
immunity
 First line of defense
against invasion
 Body's inborn ability to
fight infection
 Not affected by
environment
 Permanent

36. INNATE VERSUS ADAPTIVE
IMMUNITY
 Innate (natural)
immunity
 Prevents invasion,
or if pathogens do
get inside, takes
steps to stop
spread of
infection

37. INNATE IMMUNITY-RECOGNIZES A
FOREIGN INVADER
The body’s first line of
defense recognizes
that invader is present
but can’t identify it
specifically
Like setting off a metal
detector but not knowing
exactly what the item is
that did it

38. INNATE VERSUS ADAPTIVE
IMMUNITY
 Innate (natural)
immunity
 Cannot improve with
experience
 Because it does not
recognize specific
pathogens, it cannot
"remember" an
infection that body has
encountered before
“ I CAN’T REMEMBER”

39. INNATE VERSUS ADAPTIVE
IMMUNITY
 Crude mechanism
for defending body
 Indiscriminately
killing pathogens
and healthy tissue
alike
Take that, invader
I’m one
of you!!

40. INNATE VERSUS ADAPTIVE
IMMUNITY
 Adaptive (acquired) immunity

Backs up innate immunity, specifically targeting invaders and
sparing healthy tissue as much as possible

Remembers invaders from previous encounters and prepares
for future invasion, improving response with experience by learning
and changing

41. INNATE VERSUS ADAPTIVE
IMMUNITY

Innate and adaptive immunity work together

Innate immunity prepares way for adaptive immunity,
weakening pathogens and stimulating components of
adaptive immunity

42. INNATE VERSUS ADAPTIVE
IMMUNITY
 Adaptive immunity, in turn, stimulates innate immunity
attacking pathogen on two fronts

43. INNATE VERSUS ADAPTIVE
IMMUNITY-HUMORAL* & CELLULAR
*Humoral means found in body fluids

44. CELLS OF THE BODY
 White blood cells
(WBC or leukocytes)
are cells responsible
for defending body
against invaders
 Red blood cells
responsible for
carrying oxygen
throughout body
 Platelets
responsible for
blood's ability to clot

45. CELLS OF THE BODY
 Leukocytes

Form in bone
marrow; move to
other parts of body to
grow and mature

Not released into
bloodstream unless
infection present

Various types of
white blood cells
required to protect
body in varying
circumstances

46. LYMPHOCYTES
 T (for Thymus) and B
(for bone marrow)
cells
 Form in bone marrow;
some move to other
parts of body to grow
and mature
 T cells go to the
thymus to mature
 B cells stay, develop
and mature in the bone
marrow

47. LYMPHOCYTES-T AND B CELLS
 Specific T cells called T
helper cells stimulate
“killer T cells” which
directly bind to antigen
or pathogen and destroy
it
 T helper cells also
stimulate B cells to
make B plasma cells
which produce
antibodies and make B
memory cells

48. LYMPHOCYTES-T AND B CELLS
 Both formed in the
marrow both cells
stimulated by the
presence of a foreign
antigen
 B cells develop into
plasma cells which
forms antibodies to
specific antigen and
memory cells which
“remember” it later

49. TABLE 14-1 WHITE BLOOD CELLS
INVOLVED IN IMMUNE RESPONSE

50. CHEMICALS TO PROTECT BODY
FROM INVADERS
 Found in body; assist
in destroying and
neutralizing invaders
 Cytokines:

Involved in both innate
and adaptive immunity

51. CYTOKINES

Cytokines are proteins
produced by damaged
tissues and WBCs that
stimulate immune
response in variety of
ways:

Increasing
inflammation

Stimulating
lymphocytes

Enhancing
phagocytosis

52. INTERFERONS
 Cytokine produced
by cells that have
been infected by
virus
 Binds to neighboring,
uninfected cells and
stimulates them to
produce chemicals
that may protect
these cells from
viruses

53. INFLAMMATION
 Also called
inflammatory
response
 Typical symptoms:
pain, swelling,
heat, and redness

54. INFLAMMATION
 Deliberate action of body
in response to tissue
damage, whether
mechanical or pathological
injury
 Response helps to wall
off infected area to
prevent further spread and
allow battle to focus at site

55. INFLAMMATION
 When tissue is
damaged, cells
send out
chemicals such as
histamine, an
inflammation
modulator

56. INFLAMMATION
 These chemicals
attract WBCs to site,
increase
permeability of
capillaries, and
cause local
vasodilitation; extra
fluid causes
swelling
 More blood comes to
site, causing heat

57. INFLAMMATION
 WBCs destroy pathogens
and clean away dead cells
 Increase in fluid and cells
coming to area increases
pressure and creates pain
 Innate immune mechanism,
but plays important part in
adaptive immunity

58. FIGURE 14-5
CAUSES AND CONSEQUENCES OF THE
INFLAMMATORY RESPONSE.

59. FEVER
 During infection, immune
system releases cytokines
that promote
inflammation and immune
responses
 One of cytokine targets in
brain is HYPOTHALAMUS
responsible for setting and
maintaining body
temperature

60. FEVER
 Effect of cytokine is
elevated temperature
set point, or fever
 Rise in body temperature
is deliberate attempt by
immune system to
destroy pathogens

61. INNATE IMMUNITY-BARRIERS
 First, pathogens
must get past
physical and
chemical
barriers; most
pathogens kept
out by these
barriers
Tears, saliva, urine, mucous
secretions and sweat contain
chemical barriers

62. INNATE IMMUNITY

63. INNATE IMMUNITY
 Release of
cytokines and
stimulation of
inflammation
attract
macrophages to
infection site

64. INNATE IMMUNITY
 Macrophages
phagocytize
infected cells
 Release chemicals
to further stimulate
inflammation,
activate more
immune cells

65. INNATE IMMUNITY
Pathogens are under
attack from:
Phagocytosis
Noxious chemicals
Membrane rupture
Clumping
Alteration to molecular
structure

66. INNATE IMMUNITY
 Chemicals have
specifically signaled
hypothalamus to
raise body
temperature and
you run a fever

67. INNATE IMMUNITY
 Remember: This is crude
warfare, with innate
immunity destroying
anything non-self
 Desperate attempt to
defeat invaders,
sometimes killing
uninfected cells…
All leading to activation
of adaptive immunity

68. INNATE IMMUNITY
 When phagocytic
cells ingest
pathogens, they
display foreign
antigen on cell
membrane,
essential for
activation of B and T
cells

69. ADAPTIVE IMMUNITY
 Fights specific
pathogens; has
memory, "learns"
from experience,
recognizes specific
pathogens

70. WHEN B CELLS ATTACK

71. ADAPTIVE IMMUNITY
Because of adaptive immunity,
immunizations are able to prevent
illness

72. ADAPTIVE IMMUNITY
Innate and adaptive immunity work hand in
hand; one cannot do its job without the other

73. ADAPTIVE IMMUNITY IS THEN
ACQUIRED
Exposure is either
Exposure is either
Acquired
Acquired
immunity
immunity
occurs as the
occurs as the
body
body
“adapts” to
“adapts” to
the
the
environment
environment
to which it is
to which it is
exposed
exposed
“passive”
“passive”
(nonspecific
(nonspecific
antigen exposure)
antigen exposure)
or “active”
or “active”
(specific targeted
(specific targeted
exposure)
exposure)
Exposure is
Exposure is
“natural” or
“natural” or
“artificial”
“artificial”
(created by
(created by
humans)
humans)

74. ACQUIRED ACTIVE IMMUNITY
Daily
Life
Acquired
during
vaccinations

75. ACQUIRED PASSIVE IMMUNITY

76. ACQUIRED ACTIVE IMMUNITY

77. FIGURE 14-10
TYPES OF IMMUNITIES

78. OUR IMMUNE SYSTEM
http://www.youtube.com/watch?v=MI-BLaj5nFk

79. THE BIG PICTURE
 Army of pathogens wants to
invade body; first must get past
body's barriers
 If invader gets inside body, series
of weapons stimulated by nonself-antigen
 Cells (neutrophils, macrophages,
and basophils) stimulated
 Chemicals (cytokines) released
that stimulate inflammation and
phagocytosis

80. THE BIG PICTURE
 Macrophages and other
cells which have
ingested some of
invaders move to
lymphatic system and
search lymph nodes,
looking for T and B cells
that will recognize
intruder

81. THE BIG PICTURE
 Helper T cells activate
and cause
proliferation of B
cells and cytotoxic
T cells, as well as
releasing chemicals to
further stimulate
phagocytosis and
inflammation
T cells (green) infected with HIV (red)

82. THE BIG PICTURE
 Cytotoxic T cells activated
and proliferate
 B cells produce
antibodies that destroy
invaders and further
stimulate immune response
 Cytotoxic T cells destroy
invaders directly and
release chemicals that
further stimulate immune
response

83. THE BIG PICTURE
 Immune response, both innate and adaptive, will
continue to be stimulated until feedback loop stopped,
at least in part by regulatory T cells
 Memory B cells and T cells stored in lymph nodes for
later use if another army of same types of pathogens
invade

84. THE BIG PICTURE
 Macrophages and other phagocytic cells will clean up
debris left by “warfare” waged by immune system and
body will return to normal

85. FIGURE 14-11
THE BATTLE PLAN OF THE BODY'S
DEFENSES

86. AUTO IMMUNE DISEASE
Read article “Auto Immune Diseases”
Read article “Auto Immune Diseases”
It is believed that
viruses can
incorporate genetic
material into human
cells that changes it’s
“ID CARD”, so that it
is then identified as
foreign, triggering an
antigen-antibody
reaction

87. AUTO IMMUNE DISEASES

88. CHAP 14 TAKE HOME EXAM
Complete Worksheet No. 1
Complete Worksheet No. 1
and the Labeling Activity 1 and 3
and the Labeling Activity 1 and 3
for credit (46 points) ..
for credit (46 points)
Questions #24 and #25 are
Questions #24 and #25 are
EXTRA CREDIT
EXTRA CREDIT
(worth 7 points)
(worth 7 points)
One ESSAY Question on the
One ESSAY Question on the
Lymphatic System will appear on
Lymphatic System will appear on
your FINAL EXAM
your FINAL EXAM