Weeks 1, 2 and 3 Flashcards
Does the lymphatic system return leaked fluid to the blood, also helps in transporting absorbed lipids from the gut?
Yes
What are lacteals?
Specialised lymph capillaries present in intestinal mucosa.
Do lymphatic trunks, which are formed by union of largest collecting vessels, drain large areas of the body?
Yes
Are lymphatic vessels named for regions of the body they drain?
Yes.
Are some of the names for lymphatic vessels the following:
- Paired lumbar
- Paired bronchomediastinal
- Paired subclavian
- Paired jugular trunks
- Single intestinal trunks
Yes.
What is lymphangitis?
A condition in which lymphatic vessels appear as painful red lines under the skin.
Is lymphangitis caused by inflammation of larger lymphatic vessels that contain vaso
vasora?
Yes.
In lymphangitis, do the vaso vasora become congested with blood?
Yes.
Do larger lymphatics, like blood vessels, receive their nutrients from branching vasa vasorum?
Yes.
Is the lymph system a low-pressure system like venous system?
Yes.
Is lymph propelled by:
– Milking action of skeletal muscle
Pressure changes in thorax during breathing
– Valves to prevent backflow
– Pulsations of nearby arteries
– Contractions of smooth muscle in walls of lymphatics
Yes.
Physical activity increases flow of lymph;
Immobilization of area keeps needed inflammatory material in area
for faster healing
Yes.
Lymphedema: severe localized oedema
Yes.
Caused by anything that prevents normal return of lymph to blood
– Examples: tumours blocking lymphatics or removal of lymphatics during cancer
surgery
– Lymphedema may improve if some lymphatic pathways remain and enlarge
Yes.
• Immune system cells
– T cells: attack and destroy infected cells
– B cells: produce plasma cells, which secrete antibodies
Yes.
Other lymphoid immune cells
– Macrophages
– Dendritic cells
Yes.
Supporting lymphoid cell
– Reticular cells produce reticular fibers called stroma in lymphoid organs
Yes.
Lymphoid Tissue
Houses and provides proliferation sites for lymphocytes
– Offer surveillance
Yes.
Lymphoid Tissue
Largely composed of reticular connective tissue, a type of loose
connective tissue
Yes.
Are there two main types of lymphoid tissues?
Yes.
Diffuse lymphoid tissue: loose arrangement of lymphoid cells and
some reticular fibers
– Found in virtually every body organ
– Larger collections in lamina propria of mucous membranes
Yes.
Lymphoid follicles (nodules): solid, spherical bodies consisting of tightly
packed lymphoid cells and reticular fibers
– Contain germinal centers of proliferating B cells
– May form part of larger lymphoid organs (nodes)
– Isolated aggregations in Peyer’s patches and in appendix
Yes.
Are lymph nodes the principal secondary lymphoid organs of body?
Yes.
Are the two main functions of lymph nodes:
1. Cleansing the lymph: act as lymph “filters”
2. Immune system activation: offer a place for lymphocytes to become
activated and mount an attack against antigens
Yes.
Do lymph nodes vary in shape and size, but most are bean shaped?
Yes.
Are lymph nodes small, less than 2.5 cm (~1 inch)?
Yes.
Are lymph nodes surrounded by external fibrous capsule?
Yes.
Lymph nodes: Do capsule fibers extend inward as trabeculae that divide node into
compartments
Yes.
Two histologically distinct regions of lymph node:
– Cortex
– Medulla
Yes.
Spleen functions
– Site of lymphocyte proliferation
– Cleanses blood of aged cells removes debris
– Stores breakdown products of RBCs (e.g., iron) for later reuse
– Stores blood platelets and monocytes for release into blood when needed
– May be site of foetal erythrocyte production
Yes.
• Spleen is encased by fibrous capsule and also has trabeculae
Yes.
• Histologically, consists of two components
– White pulp
– Red pulp
Yes.
Clinical homeostatic imbalance:
The spleen has a thin capsule, so direct blow or severe infection may
cause it to rupture, spilling blood into peritoneal cavity
Yes.
Splenectomy: surgical removal of ruptured spleen
Yes.
If spleen must be removed, liver and bone marrow take over most of its
functions
Yes.
Splenectomy: in children younger than 12, spleen will regenerate if a small part is left
Yes
Mucosa-associated lymphoid tissue (MALT)
– Lymphoid tissues in mucous membranes throughout body
Yes.
MALT: Protects from pathogens trying to enter body
Yes.
Malt: found in mucosa of respiratory tract, genitourinary organs, and
digestive tract; largest collections of MALT found in
– Tonsils
– Peyer’s patches
– Appendix
Yes.
Tonsils: Simplest lymphoid organs
Yes.
Tonsils: Form ring of lymphatic tissue around pharynx; appear as swellings of
mucosa
Yes.
Tonsils:Named according to location
– Palatine tonsils, Lingual tonsil, Pharyngeal tonsil, Tubal tonsils
Yes.
• Tonsil function - gather and remove pathogens
Yes.
Appendix: An offshoot of first part of large intestine
Yes.
Appendix: Contains a large number of lymphoid follicles
Yes.
Appendix: Location aids in functions (like Peyer’s patches)
Yes.
Appendix:
- Destroy bacteria, preventing them from breaching intestinal wall
- Generate “memory” lymphocytes
Yes.
Thymus: A bilobed lymphoid organ found in inferior neck
Yes.
Thymus: Functions as lymphoid organ where T cells mature
Yes.
Thymus is broken into lobules that contain outer Cortex and inner
Medulla
Yes
Thymus differs from other lymphoid organs
– Has no follicles
– Does not directly fight antigens
– Stroma is made up of epithelial cells, not reticular fibers
Yes.
The lymphatic vessels form a one-way system in which lymph flows only
toward the heart
– Returning leaked fluid back to the circulation
– Transporting absorbed nutrients (lipids) from the gut
Yes.
• The lymphoid organs and tissues provide the structural basis of the
immune system
– Lymph nodes, spleen, thymus, MALT and tonsils
– Lymphoid cells are housed and mature here
– Some lymphoid organs perform additional functions
Yes.
Immune system: Innate (nonspecific) defense system • Always prepared • Responding within minutes • Two lines of defenses • Inflammation
Yes.
Immune system: Adaptive (specific) defense system • Takes longer to react than innate • Third line of defense
Yes
Innate defenses Surface barriers • Skin • Mucous membranes
Yes.
Innate defenses Internal defenses • Phagocytes • Natural killer cells • Inflammation • Antimicrobial proteins • Fever
Yes.
Adaptive
defenses
Humoral immunity
• B cells
Yes.
Adaptive
defenses
Cellular immunity
• T cells
Yes.
