Ch. 21: The Lymphatic System V1 P3

Covers how lymph nodes filter lymph, how cancer can spread through them, how tonsils protect the throat, and how the spleen monitors blood and removes old red blood cells.

What is the most numerous lymphatic organ?

Lymph node

About how many lymph nodes does the lecture say a young adult has?

450

What are the two major functions of lymph nodes?

Filter lymph, activate B and T cells

What is the hilum of a lymph node?

Indentation where lymph exits

What surrounds a lymph node?

Fibrous capsule

What are trabeculae in a lymph node?

Capsule extensions dividing the node

What are the two main regions of a lymph node?

Outer cortex, inner medulla

What is an afferent lymphatic vessel?

Carries lymph into a node

What is an efferent lymphatic vessel?

Carries lymph out of a node

Why does a node have more afferent vessels than efferent vessels?

Slows lymph for filtering

Where are cervical, axillary, inguinal, and popliteal lymph nodes?

Neck, armpit, groin, behind knee

What is lymphadenitis?

Inflamed lymph node

What does metastasis mean?

Cancer spread to another site

How can cancer cells spread through the lymphatic system?

Lymph vessels to nearby node to downstream nodes

What characteristics of a lymph node does the lecture associate with cancer involvement?

Swollen, firm, painless

Why might axillary nodes be removed during breast cancer surgery?

Breast cancer may spread to nearby axillary nodes

Where are tonsils located?

Pharynx entrance

What do tonsils guard against?

Inhaled and ingested pathogens

What surface feature of tonsils houses lymphatic nodules?

Tonsillar crypts

What is tonsillitis?

Tonsil inflammation

What is tonsillectomy?

Surgical tonsil removal

What are the three tonsil groups named in the lecture?

Pharyngeal, lingual, palatine

Where is the pharyngeal tonsil?

Nasopharynx (adenoids)

Where is the lingual tonsil?

Base of the tongue

Which tonsils occur as a pair?

Palatine tonsils

What is the largest lymphatic organ?

Spleen

What are the spleen's two types of tissue?

Red pulp and white pulp

What is red pulp?

Blood-filled sinuses, removes old RBCs

What is white pulp?

Immune cells monitoring blood antigens

Why is the spleen called the erythrocyte graveyard?

Removes old red blood cells

What blood-forming role does the spleen have?

Makes fetal blood cells, can resume in severe anemia

What additional functions of the spleen does the lecture mention?

Monocyte reserve, blood volume regulation

What passes through the spleen hilum?

Splenic artery and vein