Introduction Flashcards
List the 3 main functions of the lymphatic system. (3)
- Absorbing fat and fat-soluble vitamins from the small intestines
- Removing waste from the tissues
- Providing aid to the immune system
What colour is lymph usually and where + why is it different? (2)
- Most lymph in the body is clear
2. In the lacteals, it is a creamy white due to the high concentration of lipids
Which way does the lymph flow and what is this system called? (2)
- Lymph flows towards the heart
2. One-way system (lymphatics in this case specifically)
Define: lymph
Excess tissue fluid
What is the purpose of lymph capillaries?
Aid in digestion by absorbing lipids
What type of cells do lymph nodes contain?
Lymphocytes
What is the main purpose of lymphocytes?
Destroy pathogens; remove foreign material
Name and list the functions of the two major categories of lymphocytes. (2)
- Macrophages → engulfs and destroys bacteria, viruses, and foreign substances
- Lymphocytes → responds to foreign substances in the lymphatic system
List the 4 other lymphatic organs and briefly describe each. (4)
- Spleen → cleans and filters the blood and destroys worn-out RBCs
- Thymus → produces thymosin = the hormone which functions in programming certain lymphocytes
- Tonsils → traps and removes any bacteria or other foreign pathogens entering the throat
- Peyer’s Patches → tonsil-like organ found in the wall of the distal part of the small intestines
What are the two defense systems of the body and how do they respond to foreign substances? (2)
- Innate defense system → responds immediately to protect the body
- Adaptive defense system → mounts an attack against the particular foreign substances
What are the body’s first lines of defense against invasions of pathogens? (2)
- Skin
2. Mucous membrane
Define: lysosomes
Enzymatic organelle which destroys bacteria
Where are lysosomes found? (3)
- Tears
- Saliva
- Other secretions
What is an inflammatory response?
A non-specific response that is triggered whenever body tissues are injured
List 4 common indicators of active inflammation. (4)
- Redness
- Heat
- Swelling
- Pain
What do cells release when they are injured and what do those substances function as? (3)
- Histamines
- Kinins
- A chemical alarm/alert to the rest of the body
What is the purpose of the inflammatory response?
To prevent the spread of damaging agents to nearby tissue
Define: pus
Mixture of dead or dying neutrophils, broken-down tissue, and living + dead pathogens
State the purpose of antimicrobial proteins and name the two most important types. (3)
- Enhance the innate defenses either by attacking microorganisms directly or by hindering their ability to respond
- Complement proteins
- Interferon
Define: complement proteins
Group of >20 plasma proteins that circulate the blood in an inactive state
Define: interferon
Viruses → essentially nucleic acids surrounded by a protein coat
What do viruses lack?
The cellular machinery required to generate ATP (mitochondria)
What is the main symptom of a fever and what is a fever in regards to foreign substances? (2)
- High body temperature
2. Systemic response to invading microorganisms
What part of the body regulates temperature?
Hypothalamus
