Unit 3 Lecture Flashcards
What are the main lymphatic system functions?
- Drain excess interstitial fluid
- Transport dietary lipids
- Carry out immune response
What are the 2 primary and 3 secondary lymphatic organs and tissues?
Primary Lymphatic Organs:
- Red bone marrow
- Thymus
Secondary Lymphatic organs and tissues:
- Lymph nodes
- Spleen
- Lymphatic nodules/follicles
What do lymphatic vessels drain? Where do they originate?
- 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
What are two features of lymphatic capillaries that make them unique?
- Lymphatic capillaries are slightly larger than blood capillaries
- They have “one-way” valves
Where are lymph nodes found?
- Lymph nodes are found at irregular intervals along the lymph vessels
Memorize the track of the lymphatic system in the pulmonary circulation versus the systemic circulation
Memorize the areas on the body where the lymphatic system attaches to the veins of the thoracic region of the body
What areas of the body drain by the right lymphatic and thoracuc ducts
What is non-specific resistance and what are the four different non-specific defenses?
- The body’s lines of defence against invasion by pathogens (e.g, bacteria, viruses, fungi, and environmental hazards)
- Non-specific defenses include:
- Physical barriers (first line of defense)
- Fever
- Inflammation
- Cells and chemicals that can kill and/or orchestrate the killing of pathogens (e.g, phagocytes, complement proteins, interferon proteins, and natural killer cells)
What is the first line of defense?
Physical barriers
What are the physical barries to pathogenic invasion?
- 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
What is a fever?
Abnormally high body temperature in response to invading microorganisms
How do fevers happen?
The body’s thermostat is reset upwards in response to pyrogens (chemicals secreted by leukocytes and macrophages exposed to bacteria and other foreign substances)
Are fevers good? When do fevers become dangerous?
- 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
Why are moderate fevers beneficial?
- 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
When is the inflammatory response triggered and why does it occur?
- 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
Does the inflammatory response work the same in the brain?
The brain works differently because you don’t want to lose memories and functions
What are the 4 “cardinal” signs of acute inflammation
- Redness
- Heat
- Swelling
- Pain
Memorize the 5 types of white blood cells and their abbundance of each
Are all of the white blood cells always circulating through your blood?
No, over 90% of WBCs are in your spleen and tissues just chillin
How do WBCs enhance the innate defenses when sick?
- Attacking microorganisms directly
- Hindering the ability of microorganisms to move, grow, reproduce, etc.
Discuss neutrophil function, their %, and why their % would increase
- 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
