Lymphatic System Quiz

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Questions and Answers

What is the primary function of the lymphatic system?

To filter waste from the blood

To assist in the removal of tissue fluid from interstitial spaces (correct)

To circulate blood throughout the body

To produce hormones that regulate metabolism

What is the term given to the tissue fluid once it has entered a lymphatic vessel?

Blood plasma

Lymph (correct)

Tissue fluid

Interstitial fluid

Which of the following tissues does not have lymphatics?

Muscle tissue

Nervous tissue

Epithelial tissue (correct)

Connective tissue

What is the characteristic of large lymphatics?

They have three layers like veins and contain valves Signup and view all the answers

What is a lymphatic nodule?

A rounded mass of cells Signup and view all the answers

What is the characteristic of lymphatic capillaries?

They have a thin layer of connective tissue and endothelial lining Signup and view all the answers

Where is the thymus situated?

In the superior mediastinum Signup and view all the answers

What is unique about the thymus in terms of T-cell specificity?

It is acquired only in the thymus Signup and view all the answers

What is the outer part of the cortex composed of?

Immature T-lymphoblasts Signup and view all the answers

What is the function of Hassall's corpuscles?

Their function is unknown Signup and view all the answers

What is the shape of the lymph node?

Ovoid or kidney-shaped Signup and view all the answers

What enters and leaves the lymph node through the hilum?

Efferent lymphatics and blood vessels Signup and view all the answers

Why is the peripheral zone of a lymphatic nodule dark in staining?

Because of the intense staining of the nuclei of closely packed small lymphocytes Signup and view all the answers

Which of the following cells are present in the germinal center of a lymphatic nodule?

Large lymphocytes, medium-sized lymphocytes, lymphoblasts, plasma cells, and macrophages Signup and view all the answers

Where are lymphatic nodules typically found?

In the lamina propria of the digestive and respiratory passages, in the white pulp of the spleen, and in the lymph nodes Signup and view all the answers

What is the function of lymphatic nodules?

To produce lymphocytes, have phagocytic activity, and produce antibodies Signup and view all the answers

What is the role of the thymus in the immune system?

It is a primary lymphoid organ that is responsible for the maturation of T-lymphocytes Signup and view all the answers

What happens to the thymus during puberty?

It undergoes involution Signup and view all the answers

Study Notes

Lymphatic System

The lymphatic system is a drainage system that removes tissue fluid from interstitial spaces and returns it to the blood.
It is formed of lymph vessels and lymphatic tissue.
Lymph is the name given to tissue fluid once it enters a lymphatic vessel.

Lymph Vessels

Lymphatic capillaries are small, thin-walled, irregular endothelial tubes surrounded by delicate connective tissue with lymphatic anchoring filaments.
Small and medium-sized lymphatics have an endothelial lining and a layer of connective tissue.
Large lymphatics are similar to veins, with three layers, and contain valves that prevent reverse flow.

Lymphatic Nodules

Lymphatic nodules are rounded, circumscribed masses of cells found in the lamina propria of digestive and respiratory passages, white pulp of the spleen, and lymph nodes.
Primary nodules contain packed small B-lymphocytes, while secondary nodules have a germinal center and a peripheral dark zone.
Functions of lymphatic nodules include producing lymphocytes, phagocytosis, and antibody production.

Lymphatic Organs

Primary Lymphoid Organs

Primary lymphoid organs are responsible for developing and maturing lymphocytes into immunocompetent cells.
They include bone marrow and the thymus.

Secondary Lymphoid Organs

Secondary lymphoid organs provide a site for immunocompetent cells to react with antigens and build an immunological response.
They include lymph nodes, spleen, tonsils, and mucosa-associated lymphoid tissues.

Thymus

The thymus is a primary lymphoid organ where T-lymphocytes mature.
It is situated in the superior mediastinum and undergoes involution during puberty.
T-cell specificity is acquired only in the thymus.
The thymus has two lobes, each divided into incomplete lobules with a cortex and medulla.
The cortex contains epithelial reticular cells, T-lymphocytes, immature T-lymphoblasts, mature T-lymphocytes, and macrophages.
The medulla contains the same cell population as the cortex, with Hassall's corpuscles of unknown function.

Lymph Node

Lymph nodes are ovoid or kidney-shaped bodies with a convex surface where afferent lymphatics enter, and a hilum where efferent lymphatics leave.
Blood vessels and nerves also enter or leave the node at the hilum.