AP Lymphatic System Review

What are infectious agents?

Organisms that cause damage, or possibly death, to the host organism that they invade. If damaging to the host then they are pathogenic

Where can the leukocytes of the immune system be found?

(Body tissues) lymphatic tissue, select organs, epithelial layers of the skin and mucosal membranes, and connective tissues of the body

Describe the protozoan infectious agent

- Eukaryotic cell that lacks a cell wall - Infections: trichomoniasis & malaria

Describe the fungal infectious agent

- Eukaryotic cells - Molds, yeasts & spores - Proteolytic enzymes from fungi are released to cause inflammation to cause redness & swelling - Fungal disease (mycoses) can cause athlete's foot, skin/nail infection, yeast infection

Name the five types of lymphatic trunks and the regions of the body from which they drain lymph.

- Jugular: from head and neck - Subclavian: from breasts, upper limbs and superficial thoracic wall - Bronchomediastinal: from deep thoracic structures - Intestinal: abdominal structures - Lumbar: lower limbs, abdominopelvic wall & pelvic organs

Describe the regions that are drained by the thoracic duct.

- Larger (from diaphragm to L. subclavian vein & jugular vein) - Drains lymph from L. head/neck/upper limb/thorax, abdomen, & lower limbs

Discuss the location and anatomic structure of lymphatic capillaries.

- Lymphatic capillaries are similar to blood capillaries (made of endothelium), but. they lack a basement membrane, are larger than blood capillaries and have overlapping endothelial cells - They're interspersed through areolar connective tissue among blood capillary networks except in red bone marrow, spleen, & CNS. Absent in epithelia & cartilage

Explain the mechanisms that move lymph through lymphatic vessels, trunks, and ducts.

- Lymphatic system lacks pump & is a low pressure system - Lymph capillary turns into lymph vessel, the vessel has valves to prevent backflow & pooling - It is moved through the skeletal muscle pump, respiratory pump in torso, pulsatile movement of blood in arteries & rhythmic contraction of smooth muscle in trunks & ducts

Describe the regions that are drained by the right lymphatic duct

- Near right clavicle - Receives lymph from right of head/neck, R. upper limb, & R. thorax (upper R. quadrant) - Returns lymph R. subclavian vein & R. internal jugular vein

Describe the viral infectious agent

- Not cells, made of viral DNA & RNA - Obligate intracellular parasites; must enter a cell to replicate - Viral DNA & RNA is replicated w/in cell and then kills off host - Cause a cold, HIV, chicken pox

Name the two categories of lymphatic tissue and organs

- Primary (maturation of lymphocytes) and - Secondary Structures (house of lymphocytes and immune cells) (site where immune response is initiated)

Identify components of the body that belong to each category of lymphatic tissue and organs

- Primary: red bone marrow & thymus - Secondary: lymph nodes, spleen. lymphatic nodules & mucosa associated lymphatic tissue (MALT)

Describe the bacterial infectious agent

- Prokaryotes - Some can/can't cause disease (most don't) - Can have increase virulence (cause serious illness) bc of sticky polysaccharide capsule - Pathogenic bacteria release enzymes or toxins that interfere with cell function - Can cause Clostridium tetani

Identify the two major types of lymphocytes.

- T-lymphocytes (immune cell that matures in THYMUS) - B-lymphocytes (cell involved in humoral immunity, matures into plasma cell). They mature in the BONE

Describe the location

- in trabeculae in certain portions of spongy bone in skeleton - Ex. in adults: flat bones skull, vertebrae, ribs, sternum, proximal epiphyses in femur & humerus

Describe the multicellular parasitic infectious agent

- live in host where they feed from - non microscopic organism - Ex: tapeworms infect intestinal tract of humans & mammals

Name the five major classes of infectious agents.

Bacteria, viruses, fungi, protozoans & multicellular parasites

Explain the function of lymph nodes

Filtering of lymph and disposing unwanted substances

Explain how fluid enters lymphatic capillaries.

Increased hydrostatic pressure in interstitial space pushes fluid into lymphatic capillary thru an opening (high pressure= high amount of fluid). Anchoring filaments prevent collapse. Pressure in lymph capillary = endothelial cells to close flap (lymph is trapped)

Describe lymph and its contents

Lymph is interstitial fluid not absorbed back in capillary exchange. When in lymph vessels, it is called lymph. It's made up of water, ions, proteins, cell debris and metastasized cells.

What are lymphatic capillaries

Lymphatic capillaries begin as blind-end vessels within connective tissue among most blood capillary networks and absorb excess fluid left during capillary exchange.

General function of red bone marrow.

Responsible for hemopoiesis (production of formed elements). Elements include erythrocytes, platelets, granulocytes, lymphocytes, etc.

Describe the structure of lymph nodes.

Small, oval/round encapsulated organs that are along the pathway of lymphatic vessels. They filter the lymph that is transported to them by lymphatic vessels.

Prions

small fragments of infectious proteins that cause disease in nervous tissue. It's not a cell/virus

Lymphedema

too much interstitial fluid accumulated due to a drainage issue in a body part