Lymphatics | 20.1 Part 3: Spleen, Lymphatic Nodules, and Tonsils

What is the biggest lymphatic organ?

Spleen

Where is the spleen located?

• lateral to left kidney

• Left quadrant of abdominal cavity

• Attached to the lateral border of the stomach via the gastrosplenic ligament

What is the entrance of blood vessels?

Hilum/Hilus

• Means indentation

Function of Spleen?

• Filters Blood

• Removes old, defective/worn-out RBCS; Recycles Iron

  • Blood graveyard

• Immune Function

• Stored Red blood cells & Platelets

• Site of fetal blood cell production

In an emergency, the spleen can help because it contains?

One cup of blood

• from storage

What type of capillaries does the spleen have?

Sinusoid Capillaries

What are the two main tissue regions of the spleen?

• White Pulp

• Red Pulp

What type of lymphoid organ is the spleen?

A major secondary lymphoid organ

Why is the spleen considered fragile?

It lacks a strong capsule.

What divides the spleen internally?

Trabeculae of connective tissue.

What is being described:

• Erythrocytes

• Platelets

• Macrophages

• B-Lymphocytes

Red Pulp

What is being described:

• T Lymphocytes

• B Lymphocytes

• Macrophages

White Pulp

What is the function of the white pulp area?

Immune Surveillance

What is the function of the red pulp area?

Blood Filtration

What cells are found in the germinal centers of white pulp?

Rapidly dividing B cells.

What cells surround the germinal centers in white pulp?

T cells, macrophages, and dendritic cells.

What happens to blood entering the spleen?

The splenic artery branches into arterioles, then sinusoids, and blood collects in venous sinuses before exiting via the splenic vein.

The spleen is attached to the?

Stomach

The marginal zone is the region between the?

Red pulp and white pulp

• Isolates particulate antigens from the circulation and presents these antigens to lymphocytes in the white pulp.

• A specialized layer of tissue that surrounds the white pulp and separates it from the red pulp

What is the difference between lymphatic nodes and nodules?

Lymphatic Nodules are not surrounded (or not completely surrounded) by a capsule

Where do you normally find Lymphatic Nodules?

Beneath the mucous membrane

• Mucosa Associated Lymphoid Tissue (MALT)

What body Systems contain Lymphatic Nodules?

• Digestive

• Respiratory

• Urinary

• Reproductive

  • Everything with openings

Seventy percent of our immune system is in our?

Gut associated Lymphatic Tissue (GALT)

What are specific examples of Mucosa Associated Lymphoid Tissue (MALT)?

• Bronchus Associated Lymphatic Tissue (BALT)

• Gut associated Lymphatic Tissue (GALT)

• Tonsils

Bronchus Associated Lymphatic Tissue (BALT) example?

Walls of bronchi

Gut associated Lymphatic Tissue (GALT) example?

• Peyer’s patches

  • Small Intestine, Ileum

• Appendix

Lymphatic Tissues have a lot of?

White Blood cells

Our normal microbiota is?

Also our protection

What tonsil is located on the roof of the posterior superior wall of the nasopharynx?

Pharyngeal Tonsil

• There is one

What tonsils lie on each side of the pharynx (specifically in the oropharynx)?

Palatine Tonsils

• There are two

What tonsils are at the base of the tongue?

Lingual Tonsils

• There are two

Adenoid Hypertrophy is when?

The pharyngeal tonsils become so swollen to the point it blocked the eustachian tube and air passage

What is adenoids?

When the pharyngeal tonsils become swollen

Tonsils become swollen due to?

Infection

How can cancer spread from one part of the body to another (Metasasis)?

Cells from primary site break away and spread to other parts of the body (through bloodstream or lymphatic system)

• They then grow and form secondary tumors/cancers

What is Metasasis?

Cancer spread from one part of the body to another

What is being described:

• are NOT fully surrounded by a capsule (unlike lymph nodes)

• sit directly in the mucosa of organs

• act as first‑line immune surveillance sites

• clusters of lymphocytes (mostly B cells, plus T cells and antigen‑presenting cells)

Lymph nodules

Lymph Nodule are commonly found in Lymphatic tissues that are?

Open and exposed to things from the outside world

What is the is the umbrella term for all lymphatic nodules located in mucosal linings?

Mucosa‑Associated Lymphoid Tissue (MALT)

What lymphoid tissues capture antigens from food and gut microbes, activate B cells, and produce IgA for mucosal immunity?

Gut‑Associated Lymphoid Tissue (GALT)

What lymphoid tissues start immune responses to inhaled or ingested pathogens?

• Crypts that trap pathogens from air and food

• Dense clusters of lymphatic nodules under the epithelium

Tonsils

What lymphoid tissues:

• Detect airborne pathogens

• Activate local immune responses in the lungs

Bronchus‑Associated Lymphoid Tissue (BALT)

Plasma is in?

Blood Vessels

Interstital Fluid is?

Between cells

Lymph is?

In lymph Vessels and returned into the blood stream