Transcript Lymphatic and Immune Systems - Holding

The Human Body:
Lymphatic and Immune Systems
Textbook Chapter 37
Review Topic 1-2
Lymphatic System

Your body has two transport networks that
circulate fluids:
– Circulatory system
– Lymphatic system

Consists of a complex network of organs, vessels,
and nodes throughout the body

Helps to:
– Distribute nutrients
– Absorb excess fluids
between cells
– Fight disease
– Remove waste products
from cells

Relies on muscle contractions
and valves to circulate the lymph

From the vessels, lymph collects
in small rounded lymph nodes
– Filter the lymph, trapping bacteria, viruses, fungi and cell
fragments
– Specialized immune cells ingest and destroy these wastes
– Vessels carry the lymph out of the nodes, returning it to
the circulatory system

Structures of the lymphatic system:
– Tonsils
 Lymph nodes on either
side of the throat
 Filter out bacteria and
viruses
 If a build up of pathogens occurs, it can result
in swelling and infection, causing them to need
to be removed
– Spleen
 Largest organ in the lymphatic system
 Filters and cleans the
lymph
 Contains white blood
cells to destroy harmful
bacteria and foreign organisms
– Thymus (part of endocrine system as well)
 Located in chest, above the heart
 Important in developing different types of white
blood cells (lymphocytes)
Immune System

There are different types of pathogens which
enter the body in different ways

Pathogens are disease causing agents
– Bacteria
– Viruses
– Fungi
– Protozoa
– Parasites

Many body systems protect you from pathogens
– Immune system fights off infection and pathogens
– Relies on physical barriers
to keep pathogens out
 Skin is the first line of defense
– Secretes oil and sweat, creating an acidic
environment which kills many pathogens on the
skins surface
 Eyes, nose, ears, mouth and excretory organs are
entrances to the body
– Protected by mucous membranes and cilia
 Once inside the body, the immune system relies
on the circulatory system
– Sends chemical signals to coordinate an attack
– Transports specialized cells to the infection
– Cells and proteins fight the body’s infections
 White blood cells
– Find and kill pathogens
– Types of white blood
cells:
 Phagocyte – cell that destroys pathogens
by surrounding and engulfing them
 Lymphocytes – white blood cells
that initiate the specific immune
responses
~ T cells destroy body cells that
are infected with pathogens
~ B cells produce proteins that
inactivate pathogens that have
not yet infected a body cell
 Proteins
– Antibodies
~ Made by B cells
~ Destroy pathogens
by making them
ineffective
~ Binds to the pathogen’s membrane proteins
~ Cause pathogens to clump together
- Makes it easier to be engulfed by
phagocytes
~ Antibodies activate proteins which weaken the
pathogen’s cell membrane

Immunity prevents a person from getting sick
from a pathogen
– Passive Immunity
 No immune response
 Transferred between generations through DNA
– From mother and child through
breastfeeding or through the umbilical
chord
– Active Immunity
 Produces a response to a specific pathogen
that has infected your body
 Occurs after your immune system reacts to
a pathogen invasion
 If exposed again, immunity is already
present and illness is prevents/lessened

Your body responds to the presence of
foreign particles and pathogens
– Specific defenses – cellular level, specific to type
of pathogen
– Nonspecific responses – occur the same way to
all pathogens
 Inflammation
 Fever

Cells of the immune system produce specific responses
– Antigens – proteins markers on the surface of cells
and viruses that help the immune system identify a
foreign cell or virus
– Memory cells – specialized T and B cells that provide
acquired immunity

The immune system rejects foreign tissues
– Tissue rejection occurs when the recipients immune
system makes antibodies against the protein
markers on the donor’s tissue

Many methods are used to control pathogens
– Antiseptics – chemicals that kill pathogens
 Ex. soap, vinegar, rubbing alcohol
– Antibiotics – target on type of bacteria or fungus
to prevent them from growing and reproducing
 Antibiotic resistance – occurs when bacteria
mutate so they are no longer affected by
antibiotics

Vaccines artificially produce
acquired immunity
– Vaccine – substance that
contains a antigen of a
pathogen (weakened or
dead forms) to cause your
immune system to make
memory cells (so it
prevents you from getting
sick in the future)

Allergies occur when the immune system
responds to harmless antigens
– Allergy – oversensitivity to a normally
harmless antigen
– Allergen – antigen that causes an
allergic reaction
 Ex. food, airborne, chemical

In autoimmune diseases, white blood cells
attack the body’s healthy cells
Autoimmune
Disease
Body Systems
Affected
The Immune System…
How Many
Affected
Rheumatoid
Arthritis
Integumentary
Breaks down tissues that
line joints, making
movement difficult
70 in 10,000
Type I Diabetes
Mellitus
Endocrine,
Digestive
Attacks the pancreas,
stopping the digestion
of sugars
60 in 10,000
Hashimoto’s
Thyroiditis
Endocrine
Attacks the thyroid gland,
causing it to make
fewer hormones
15 in 10,000
Multiple Sclerosis
(MS)
Nervous
Breaks down myelin
sheaths, disrupting
nerve communication
10 in 10,000
Graves’ Disease
Endocrine
Stimulates the thyroid
gland, causing it to
make more hormones
5 in 10,000

Leukemia is characterized by abnormal white blood
cells
– Cancer of the bone marrow
– Does not form tumors but
prevents bone marrow from
functioning properly
 Causes bone marrow to produce white blood cells
that do not develop properly and are immature
 Can be treated with bone marrow transplants,
radiation and chemotherapy

HIV targets the immune system
– Human immunodeficiency virus (HIV)
– A retrovirus that attacks and weakens
the immune system
 Retrovirus contains RNA instead of
DNA with 9 genes
– Can only live in human blood cells
 Cannot survive long outside of the body
 Cannot be transferred by touching of skin
or even through mosquitoes
– Transmitted when virus enters bloodstream
through the mixing of blood or other bodily fluids
 Sexual intercourse, umbilical chord between mother
and child, sharing of needles (drugs, tattoos, piercings)
– Reproduces in T cells, causing them to become
ineffective to stimulate an immune response
– HIV leads to AIDS (acquired immune deficiency
syndrome)
 Final stages of immune
system decline
– HIV is a virus
– AIDS is the condition
of having a worn-out immune system
 Results in death because a person’s immune
system cannot fight off infections
Immune System BrainPop