• Also called B lymphocytes
• oversee humoral immunity
• their descendants differentiate into antibody-producing plasma cells

B-Cells

• Lymphoid organ and endocrine gland active in immune response
• site of maturation of T lymphocytes

Thymus

• General term used to designate the lymphatic vessels that collect and transport lymph

Lymphatics

• Protective cells that phagocytize antigens, migrate to lymph nodes and present the antigen to T cells, causing them to activate and mount an immune response
• those in the skin are sometimes called Langerhans cells. in the skin

Dendritic cells

• any of the fibrous bands extending from the capsule into the interior of an organ
• strut or thin plate of bone in spongy bone.

Trabecula

• Pharyngeal tonsil

Adnoids

• protective cell type common in connective tissue, lymphoid tissue, and many body organs
• phagocytizes tissue cells, bacteria, and other foreign debris
• presents antigens to T cells in the immune system

Macrophage

• Large duct that receives lymph drained from the entire lower body, the left upper extremity, and the left side of the head and thorax

Thoracic Duct

• The indented region of an organ from which blood and/or lymphatic vessels and nerves enter and exit

Hilum

• Protein-containing fluid transported by lymphatic vessels

Lymph

• Members of B-cell clone
• specialized to produce and release antibodies

Plasma cells

• System consisting of lymphatic vessels, lymph nodes, and lymph
• drains excess tissue fluid from the extracellular space.
• nodes provide sites for immune surveillance.
• defense against foreign cells, cancer, and microbes
• maintains pressure and volume of the cardiovascular system
• Lipid absorption in small intestine

Lymphatic system

• A ring of lymphoid tissue around the entrance to the pharynx.

Tonsils

• Special lymphatic capillaries of the small intestine that take up lipids

Lacteal

• Agranular white blood cell that arises from bone marrow and becomes functionally mature in the lymphoid organs of the body

Lymphocyte

• provides for lymphocyte proliferation (rapid reproduction of a cell, part, or organism)
• immune surveillance and response
• blood-cleansing functions

- cleanses blood of aged cells, platlettes, microphages remove debris

-stores breakdown products of RBC

Spleen

• Small lymphoid organ that filters lymph
• contains macrophages and lymphocytes
• Immune system activation (lymphocytes activated and mount attack against antigens)

Lymph Node

An enlarged sac at the base of the thoracic duct; the origin of the thoracic duct

Cisterna Chyli

• Lymphoid tissues in mucous membranes throughout the body

1. tonsils
2. Peyer`s patches
3. Appendix
4. Mucous of respitory and genitourinary

Mucous- associated Lymphoid Tissue (MALT)

• This tissue dominates in all lymphoid organs except the thymus

Reticular connective tissue

Aggregates of lymphoid nodules located in the wall of the ileum of the small intestine are __________

Peyers patches

Collections of lymphoid tissue (MALT) that guard mucosal surfaces include all the following, EXCEPT __________.

the thymus

A major function of the lymphatic system is __________.

return of tissue fluid to the cardiovascular system

In addition to its lymphoid function, this organ holds a reservoir of platelets.

spleen

The lymphoid tissue's structural framework of is composed of

reticular connective tissue

his structure, attached to the cecum, is in an ideal location to destroy bacteria before they breach the intestinal wall.

appendix

What lymphatic structure absorbs excess tissue fluid?

lymphatic capillary

What lymphatic structure absorbs lipids in the intestine?

lacteal

Which of the following are located in the spleen's white pulp?

lymphocytes

Which sequence best describes the flow of lymph through the lymphatic system?

1. capillaries
2. vessels
3. trunks
4. ducts

Which statement below describes the lymphatic system's role in relation to the cardiovascular system?

It maintains blood volume and, hence, pressure.

Which statement is true of the thoracic duct?

It drains the lymph from the entire left side of the body and the right abdomen and leg.

Which statement is true about lymph nodes?

They have fewer efferent vessels than afferent vessels. This slows the flow of the lymph through the node.

Which of the following is the major lymphoid organ that "trains" T lymphocytes to become immunocompetent?

T cells develop in the thymus.

Which of the following are the principal lymphoid organs in the body?

The principal lymphoid organs in the body are the lymph nodes, which cluster along the lymphatic vessels of the body.

The lymphoid organ(s) located in the throat that defend(s) against invading bacteria coming in through the mouth and nose is (are) __________.

the tonsils

Which of the following statements about the spleen is FALSE?

It is best to perform a splenectomy if the spleen is damaged in a car accident

which of the following vessels transport fluid that leaks from the vascular system back into the blood?

Lymphatics transport fluid that leaks from the vascular system back into the blood.

Excess tissue fluid in the brain drains into the __________.

Excess tissue fluid in the brain drains into the CSF.

Lymphangitis presents itself as __________.

red lines under the skin that are sensitive to touch

Which of the following features is NOT common to both lymphatic collecting ducts and veins?

transport of chyle

When B lymphocytes are dividing rapidly, the __________ of the lymphoid tissue enlarge(s).

germinal centers

When B lymphocytes are dividing rapidly, the germinal centers of the lymphoid tissue enlarge

Where are plasma cells found in a lymph node?

Plasma cells are found in the medullary cords of the lymph node.

Large lymph capillaries in a lymph node spanned by crisscrossing reticular fibers are known as __________.

lymph sinuses

Which of the following cells would NOT be found in a germinal center in a lymph node?

monocytes

Which lymphatic structure may also be a site of erythrocyte production in the fetus?

The spleen is a site of erythrocyte production in the fetus.

Areas of lymphocytes suspended by reticular fibers in the spleen are known as __________.

white pulp

A sentinel node is the first lymph node __________.

that receives lymph drainage from a body area suspected of cancer

Blood plasma and lymph are identical except for their respective locations in the body. T or F?

False - Lymph is more like interstitial fluid than plasma, except for lymph from the digestive organs where it is a nutrient-rich fluid

How are lymphatic collecting vessels different from veins?

Lymphatic collecting vessels have endothelial flap valves, but veins do not.

All lymph is eventually returned to circulation via the?

subclavian veins

Which of the following is NOT a function of lymphatic vessels?

delivery of nutrients to tissues

-Lymphatic vessels have a role in carrying tissue fluid, leaked proteins, and absorbed fats to the blood. They do not deliver nutrients or gases to the tissues; that is the role of blood vessels.

Which of the following lists the correct order of lymph flow through the lymph node?

afferent vessel, subcapsular sinus, medullary sinuses, efferent vessel

1. afferent vessel
2. subcapsular sinus
3. medullary sinuses
4. efferent vessel

The lymphatic collecting vessels direct lymph to the lymph nodes. Afferent vessels deliver lymph to the node. The lymph then filters through the subcapsular sinus into a number of smaller sinuses that cut through the node's cortex and lead into the medullary sinuses. Lymph exits the node via the hilum, and is carried away from the node by efferent vessels.

Reticular connective tissue is found in all lymphoid organs and tissues T or F

False

The main role of the tonsils is to

gather and remove pathogens entering through the pharynx

Except for the __________ and the spleen, the lymphoid organs are poorly developed at birth.

tonsils

-Only the tonsils and the spleen are well developed by birth. Shortly after birth, the other lymphoid tissues and organs become populated by lymphocytes, and their development parallels the maturation of the immune system.