PT 405 CH11 P1 Lymphatic and Immune System

What is the difference between nonspecific resistance and specific resistance?

nonspecific - general defense mechanisms; including external barriers, inflammation, and fever

specific - fights off a specific pathogen via cell-mediated or antibody-mediated immunity

What are the 3 functions of the immune system?

1. immunity
2. lipid absorption
3. fluid recovery and balance

What component of the lymphatic system contains endothelial cells that have a valve-like flap and is closed at one end?

lymphatic capillaries

What component of the lymphatic system carries lymph away from tissues?

lymphatic vessels

Describe the relationship between lymphatic capillaries, vessels, nodes, trunks. and ducts

capillaries - form vessels

vessels - contain valves and drains toward the trunks

nodes - distributed along the vessels to filter lymph

trunks - combines vessels and contains the jugular, subclavian, bronchomediastinal, intestinal, and lumbar trunks

ducts - drains tissues of body and move lymph into major veins

What is the difference between the right lymphatic duct and the thoracic duct?

right - drains the right side of the head, right upper limb, and right thorax

thoracic - drains remainder of the body

- The lymph flows at (high/low) pressure and speed, so it's moved by rhythmic contractions of lymphatic (capillaries/vessels).
- The flow is aided by _____ muscle pump and _____ pump aids flow from the abdominal and thoracic cavities.
- Lymph rapidly flows into the ____ veins
- ____ significantly increases lymphatic return

- low, vessels
- skeletal, thoracic
- subclavian
- exercise

Describe the 3 antigen-presenting cells (APCs)

macrophages - form from monocytes

dendritic cells - in epidermis, mucous membranes, and lymphatic organs

reticular cells - contribute to stroma of lymph organs

What are mucosa-associated lymphatic tissues (MALT)?

lymphatic tissue that is in passages that are opened to the exterior

What are lymphatic nodules?

masses of lymphocytes that congregate in response to pathogens

What are Peyer patches?

lymphatic nodule found at the junction of the small to large intestine

What occurs at the primary lymphatic organs and what are examples?

T and B cells become immunocompetent

red bone marrow and thymus

What occurs in the secondary lymphatic organs and what are examples?

immunocompetent cells populate

lymph nodes, tonsils, and spleen

What happens to lymph when is reaches a lymph node?

- enters through afferent vessels
- filtered to remove damaged cells and microorganisms
- exits through efferent vessels

What type of fibers trap foreign substances in the lymph nodes?

nodal reticular fibers

What 2 things proliferate in the lymph nodes?

- T cells
- plasma cells

What organ is covered by a capsule that has trabeculae that separate it into compartments?

lymph node

What are lymphatic nodules that form a ring around the border between the oral cavity and the pharynx?

tonsils

Describe the 3 types of tonsils

palatine - pair at the posterior margin of the oral cavity

pharyngeal (adenoids) - single tonsil on the wall of the pharynx

lingual - pair at the roof of the tongue

What two-lobed organ undergoes involution and is located in the mediastinum?

thymus

Describe the cortex and medulla of the thymus

cortex - contains lymphocytes and macrophages

medulla - reticular epithelial cells that produce thymic homrones and contains Hassall's corpsucles

What 4 types of cells are contained with the thymus?

- T cells
- dendritic cells
- epithelial cells
- macrophages

How do the T cells, dendritic cells, epithelial cells, and macrophages function together in the cortex of the thymus?

- immature T cells come from red bone marrow to proliferate and mature
- dendritic cells assist in maturation
- epithelial cells "educate" the T cells and produce hormones
- macrophages eat non-surviving T cells

How many T cells survive and enter the thymic medulla?

2%

What are Hassall's corpuscles in the thymic medulla?

layers of flat cells that degenerate and contain keratohyalin granules

What is the largest single mass of lymphatic tissue in the body?

spleen

What does the hilus of the spleen contain?

- blood vessels
- lymphatic vessels

What is the difference between the white and red pulp of the parenchyma in the spleen?

white - contains lymphatic tissue (lymphocytes and macrophages)

red - venous sinuses filled with blood and splenic cords (Billroth's)

What 5 cells are contained within the red pulp of the spleen?

- RBCs
- macrophages
- lymphycytes
- plasma cells
- granulocytes

What artery does blood enter the spleen?

splenic

What are the 2 functions of white pulp of the spleen?

- B and T cells carry out immune functions
- macrophages destroy pathogens

What are the 3 functions of the red pulp of the spleen?

- remove old RBCs and platelets
- store platelets
- produce RBCs in fetuses