Lymphatic System Study Guide

A set of vocabulary flashcards for studying the key concepts of the lymphatic system.

What are lymph nodes?

Tiny organs containing lymphocytes.

What is lymph?

Watery liquid formed from interstitial fluid.

What do lymphatic tissues consist of?

Lymphocytes and macrophages.

What is interstitial fluid?

Fluid around and between cells.

What happens to interstitial fluid that is not picked up by the blood capillaries?

It is collected in the lymphatic vessels.

What is the role of lymph nodes in the lymphatic system?

They provide immune protection.

What is the function of lymph nodes?

To filter the lymph of foreign organisms and dead cells.

Where is lymph returned to the circulatory system?

The subclavian veins.

How are lymph capillaries different from blood capillaries?

Lymph capillaries have one-way valves, blood capillaries do not.

What prevents the lymph from flowing backwards when skeletal muscles relax?

One-way valves.

What can occur if there is too much interstitial fluid?

Cell death due to slowed capillary blood supply and diffusion.

What are lacteals?

Specialized lymph capillaries in the lining of the small intestine.

What is chyle?

Fluid inside lymph capillaries once they absorb fat.

What is MALT?

Concentrations of lymphatic tissue without a connective tissue capsule.

Where is MALT located?

Deep to the mucous membranes of the respiratory, digestive, urinary, and reproductive systems.

What are the tonsils an accumulation of?

Lymphoid nodules located on each side of the throat.

What occurs in the germinal centers of lymph nodes?

Rapid mitosis of lymphocytes.

How do lymphocytes reach the blood to fight foreign invaders?

They are released into the lymph and eventually reach the blood.

What happens in lymph nodes when foreign invaders are detected?

The lymph nodes activate macrophages and lymphocytes to destroy the invader.

What does edema refer to?

A buildup of excess interstitial fluid in the tissues, leading to swelling.

What happens to blood after a fatty meal?

The blood looks cloudy due to fat from the lymphatic system.

What are groups of lymphocytes and macrophages collectively referred to as?

 Lymphatic tissue

What is the substance called that lymph vessels carry?

lymph

Approximately what percentage of interstitial fluid diffuses back into the capillaries?

90%

Once interstitial fluid enters a lymph vessel, what is it renamed?

Lymph

Where are lymph capillaries and vessels not found?

In the CNS

After being cleaned, where is lymph returned to?

The circulatory system

How can lymph move through the lymph vessels?

From contraction of smooth muscle in the larger lymph vessels and from pressure changes in the thoracic region during respiration

What would happen to the body without the lymphatic system?

 The body would not be able to maintain fluid balance.

What can occur if too much interstitial fluid creates too wide a space between the cells?

The capillary blood supply and diffusion of oxygen and nutrients is slowed, leading to cell death.

What is the function of the lymphatic system mentioned in the text?

 To maintain fluid balance by picking up excess interstitial fluid and returning it to the circulatory system

Where is the chyle eventually returned into the bloodstream?

 Left subclavian vein

Which subclavian vein receives more lymph: the right subclavian vein or the left subclavian vein?

The left subclavian vein

What is the least-organized form of MALT called?

 Diffuse lymphatic tissue

What are the main cellular components of diffuse lymphatic tissue?

Scattered lymphocytes, macrophages, and other cells

What is a characteristic of diffuse lymphatic tissue?

It has no boundaries and blends with surrounding tissue

What does the nasopharynx (adenoids) form around the throat?

A protective ring

Where are Peyer's patches located?

In the last 1/3 of the small intestine and in the appendix

Compared to lymph nodules, lymph nodes are:

More organized

What is the function of reticular fibers in lymph nodes?

They form a net of connective tissue throughout the lymph node

What do lymph nodes use to filter lymph as it travels through the lymph vessels?

Macrophages and lymphocytes

How many efferent lymph vessels are there for lymph to exit a lymph node?

one

What is one of the functions of lymph nodes?

They monitor the blood by receiving samples of the blood plasma.