1. Human Biology Sylvia S. Mader Michael Windelspecht
Chapter 7
Lymphatic System and Immunity
Lecture Outline
Part 1
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2. The Lymphatic and Immune Systems
See separate FlexArt PowerPoint slides for all figures and tables pre-inserted into PowerPoint without notes 2

3. Points to ponder What is the connection between microbes and humans?
What are the parts of the lymphatic system and what are their functions?
What are the first and second lines of defense in nonspecific immunity?
What is cell-mediated and antibody-mediated immunity in the third line of defense?
What are the different types of B cells in these processes?
What is active and passive immunity? Be able to describe how they are different and examples of each.
Understand allergic reactions, tissue rejection, and immune system disorders as problems that the immune system faces.

4. How do microbes and humans interact?
7.1 Microbes, Pathogens, and You
How do microbes and humans interact?
Microbes are very abundant, both in the environment and as inhabitants of __________.
We use microbes to make many ______ and we even use them to make_______.
Microbes are important as ______________ to recycle nutrients.
Some microbes cause disease in humans; we call these pathogens.

5. 7.1 Microbes, Pathogens, and You
What are microbes?
Microbes are microscopic organisms and particles that include
bacteria,
viruses,
prions,
and other organisms such as fungi, multicellular parasites, and single-celled protistans.

6. How do the sizes of our cells, bacteria, and viruses compare?
7.1 Microbes, Pathogens, and You
How do the sizes of our cells, bacteria, and viruses compare?
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Virus
flagella
cell
Figure 7.3 Comparative sizes of viruses, bacteria, and eukaryotic cells.
Prokaryotic
cell
Eukaryotic cell

7. What are bacteria? Bacteria are ___________, prokaryotic organisms.
7.1 Microbes, Pathogens, and You
What are bacteria?
Bacteria are ___________, prokaryotic organisms.
They almost all have a ________.
Bacteria have DNA in a single chromosome.
They have ribosomes.
Some bacteria have accessory rings of DNA called plasmids.
Typically, they reproduce by binary fission, resulting in 2 cells that are identical to the original cell.

8. What are specific structures and shapes of bacteria?
7.1 Microbes, Pathogens, and You
What are specific structures and shapes of bacteria?
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Plasmid:
accessory ring of
DNA that often
carries resistant
genes to antibodies
Ribosome
Nucleoid
Sex pilus:
elongated, hollow
appendage used
for DNA transfer to
other bacterial cells
Plasma
membrane
Cell wall
Capsule:
gel-like coating
outside cell wall
Fimbriae:
hair like bristles that
allow adhesion to
surfaces
Flagellum a.
Figure 7.1 Typical shapes of bacteria. b.
SEM 16,000 c.
SEM 3,000 d.
SEM 25,000
b: © Dr. David M. Phillips/Visuals Unlimited; c: © Dr. Dennis Kunkel/Visuals Unlimited; d:© Dr. Gary D. Gaugler/Phototake

9. What are viruses? Viruses are small, _________ obligate parasites.
7.1 Microbes, Pathogens, and You
What are viruses?
Viruses are small, _________ obligate parasites.
They must reproduce inside of a ________.
They are _________ (not composed of cells).
All viruses have an outer protein coat called a capsid and nucleic acid (RNA or DNA) inside.
Some viruses have an envelope.
Viruses are specific to which cell type they will attach to and enter.

10. What are viruses? 7.1 Microbes, Pathogens, and You
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TEM 80,000×
Adenovirus: DNA virus with a polyhedral capsid and a fiber
at each corner.
fiber protein
fiber
proteinunit
capsid
DNA a.
Influenza virus: RNA virus with a spherical capsid surrounded
by an envelope with spikes.
20 µm
spikes
capsid
RNA
envelope b.
Figure 7.4 Typical virus structures.
a: © Dr. Hans Gelderblom/Visuals Unlimited; b: © K.G. Murti/Visuals Unlimited

11. What are prions? _______ are infectious protein particles.
7.1 Microbes, Pathogens, and You
What are prions?
_______ are infectious protein particles.
They cause degenerative disease of the nervous system.
Normal proteins change their shape.

12. Functions of the lymphatic system
Lymphatic ___________ absorb excess tissue fluid and return it to the bloodstream.
Lymphatic capillaries (lacteals) in the small intestine absorb fats associated with proteins.
The lymphatic system works in the production, maintenance, and distribution of lymphocytes in the body.
It helps in defense against ___________.

13. What are the components of the lymphatic system?
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Tonsil: patches of lymphatic tissue; help to prevent entrance of
pathogens by way of the nose and mouth
Right lymphatic duct:
empties lymph into the
right subclavian vein
Red bone marrow: site for the origin of all types of blood cells
Axillary lymph nodes:
located in the underarm region
Thymus: lymphatic tissue where T lymphocytes mature and
learn to tell “self” from “nonself”
Spleen: cleanses the blood of cellular debris and bacteria, while
resident lymphocytes respond to the presence of antigens
Thoracic duct: empties
lymph in to the left
subclavian vein
tissue
fluid
lymphatic
capillary
tissue cell
Inguinal lymph nodes:
located in the groin region;
cleanse lymph and alert
the immune system to
pathogens
blood
capillary
Figure 7.5 Functions of the lymphatic system components.

14. Lymphatic vessels One-way valve system that carries fluid called lymph
7.2 The Lymphatic System
Lymphatic vessels
One-way valve system that carries fluid called lymph
Made of capillaries, vessels, and ducts
Function to return tissue fluid (which includes water, solutes, and cell products) to the bloodstream
Larger vessels are similar in structure to _____ and even have valves