Unit 3 Lecture

Question 1

What are the main lymphatic system functions?

Answer 1

1. Drain excess interstitial fluid
2. Transport dietary lipids
3. Carry out immune response

Question 2

What are the 2 primary and 3 secondary lymphatic organs and tissues?

Answer 2

Primary Lymphatic Organs:

1. Red bone marrow
2. Thymus

Secondary Lymphatic organs and tissues:

1. Lymph nodes
2. Spleen
3. Lymphatic nodules/follicles

Question 3

What do lymphatic vessels drain? Where do they originate?

Answer 3

• Lymphatic vessels drain excess ISF and return it to the blood stream
• Lymphatic vessels originate in “close-ended” lymph capillaries, which lie adjacent to blood capillaries in the tissue spaces

Question 4

What are two features of lymphatic capillaries that make them unique?

Answer 4

• Lymphatic capillaries are slightly larger than blood capillaries
• They have “one-way” valves

Question 5

Where are lymph nodes found?

Answer 5

• Lymph nodes are found at irregular intervals along the lymph vessels

Question 6

Memorize the track of the lymphatic system in the pulmonary circulation versus the systemic circulation

Answer 6

Question 7

Memorize the areas on the body where the lymphatic system attaches to the veins of the thoracic region of the body

Answer 7

Question 8

What areas of the body drain by the right lymphatic and thoracuc ducts

Answer 8

Question 9

What is non-specific resistance and what are the four different non-specific defenses?

Answer 9

• The body’s lines of defence against invasion by pathogens (e.g, bacteria, viruses, fungi, and environmental hazards)
• Non-specific defenses include:

1. Physical barriers (first line of defense)
2. Fever
3. Inflammation
4. Cells and chemicals that can kill and/or orchestrate the killing of pathogens (e.g, phagocytes, complement proteins, interferon proteins, and natural killer cells)

Question 10

What is the first line of defense?

Answer 10

Physical barriers

Question 11

What are the physical barries to pathogenic invasion?

Answer 11

• Skin: sebaceous glands, sudoriferous glands (sweat glands), and lysozymes
• Mucus membranes: mucus is secreted by specialized epithelial cells called goblet cells
• Hairs and cilia: mucus-coated hairs; cilia on specialized epithelial cells that line the trachea
• Acid: the pH of the stomach is about 2.0
• Tears: also contain lysozyme

Question 12

What is a fever?

Answer 12

Abnormally high body temperature in response to invading microorganisms

Question 13

How do fevers happen?

Answer 13

The body’s thermostat is reset upwards in response to pyrogens (chemicals secreted by leukocytes and macrophages exposed to bacteria and other foreign substances)

Question 14

Are fevers good? When do fevers become dangerous?

Answer 14

• At safe fever temperatures, the heart beats faster which is good because it can deliver white blood cells to the areas where they are needed. If it is too high, enzymes will become denatured where they will not be able to fold properly
• Too high of temperature: cells die
• Too low of temperature: organs stop working

Question 15

Why are moderate fevers beneficial?

Answer 15

• Moderate fever can be beneficial as it causes:
  
  • The liver and spleen to hold/hide iron and zinc (needed by microorganisms). The combination of raised fever and lowered iron inhibits bacterial growth
  • An increase in the metabolic rate, which speeds up the repair of tissues
  • Triggers production of interferons

Question 16

When is the inflammatory response triggered and why does it occur?

Answer 16

• The inflammatory response is triggered whenever body tissues are injured
  
  • Prevents the spread of damaging agents to nearby tissues
  • Disposes of cell debris and pathigens
  • Sets the stage for repair processes

Question 17

Does the inflammatory response work the same in the brain?

Answer 17

The brain works differently because you don’t want to lose memories and functions

Question 18

What are the 4 “cardinal” signs of acute inflammation

Answer 18

1. Redness
2. Heat
3. Swelling
4. Pain

Question 19

Memorize the 5 types of white blood cells and their abbundance of each

Answer 19

Question 20

Are all of the white blood cells always circulating through your blood?

Answer 20

No, over 90% of WBCs are in your spleen and tissues just chillin

Question 21

How do WBCs enhance the innate defenses when sick?

Answer 21

• Attacking microorganisms directly
• Hindering the ability of microorganisms to move, grow, reproduce, etc.

Question 22

Discuss neutrophil function, their %, and why their % would increase

Answer 22

• 60-70% blood WBCs
• % Increases if bacterial infection
• Fastest responders to bacteria
• Direct actions against bacteria
  
  • Release lysozymes to digest bacterial cell walls
  • Release defensin proteins that act like antibiotics and form pores in bacterial cell membranes, destroying them
  • Release strong oxidants (e.g, H2O2) that destroy bacteria
• Act like antibiotic by destroying bacterial structures
  
  • This mainly happens by neutrophils making a hole in the bacteria’s wall and then cell lysis occurs because the water rushes into the cell through the hole