The Lymphatic System

Flashcards about the lymphatic system, covering its components, functions, and related concepts, based on lecture notes.

Lymph

Clear, colorless fluid lacking red blood cells but containing white blood cells.

Lymphatic Capillaries

Smallest vessels that transport lymph.

-large diameter

-Endothelial cells are overlapping (allows fluid to get in)

-no basement membrane

-valves

Trunks and Ducts

Largest vessels that transport lymph.

Lymphatic Tissue

Clusters of immune cells within the lymphatic system.

Lymphatic Organs

Collections of lymphatic tissues.

Fluid Recovery

Recovery of fluid in systemic circulation performed by the lymphatic system.

Lipid absorption

Connection to our digestive system.

the small intestines absorbs 95% of nutrients but a significant fraction of lipids is absorbed into lymphatic capillaries and transported to the top of your heart

Lacteals

Connects to the digestive system and used to absorb lipids and lymphatic fluids. loc. large intestines

Immunity

process of detecting foreign pathogens and mounting an immune response.

Lymphatic Fluid

Interstitial fluid that enters lymphatic capillaries.

Chyle

Lymph that is lipid-rich and transported through lacteals from the GI tract to the heart.

Cisterna Chyli

Sac that collects lymph from the lumbar and intestinal trunks; located posterior to the abdominal aorta; contains lipid-rich lymph.

Right Lymphatic Trunk

Collects lymph from the right side of the body above the diaphragm, right arm, neck, and head; drains into the right subclavian vein.

Left Lymphatic Trunk

Drains into the left subclavian vein.

collects from everywhere other than right side

Lymphatic Fluid Movement Control

Movement of lymphatic fluid controlled by valves, skeletal muscle pump, and respiratory pump (above the diaphragm)

Lymphatic Tissue- MALT

Mucosa-associated lymphatic tissue; diffused through the intestines.

-70% scattered through the intestines dissued through systems

lymphatic tissue- Lymphatic Nodules

Concentrated lymphatic tissue; functionally the same as diffused tissue; found on the surface of the digestive system.

Primary Lymphatic Organs

Organs producing and maturing immune cells (bone marrow, thymus)

Secondary Lymphatic Organs

Organs carrying out specific immune functions (lymph nodes)

Thymus:

Thymic Involution & Anamtomy

Thymic Involution- Shrinking of the thymus gland with age due to sex hormones (starts with puberty)

Outer Cortex- uneducated
immune cells —these cells die
and atrophy eventually
Inner Medulla- educated
immune cells recognize self
and non-self

-the educated survive

Spleen

Largest lymphatic organ; functions in recycling red blood cells

Spleen- Red Pulp

Phagocytosing old RBCs, contains sinusoids, recycles components.

spleen- White Pulp

WBCs, immune responses are carried out here.

spleen- Spleenomegaly

Enlarged spleen.

-can be removed

-not essential for life

associated with diabetes

Tonsils-

Pharyngeal Tonsil & more

found near the pharynx behind uvula

Also known as the adenoid, nose breathing is a better immunological filter.

-palantine tonsil, linguinal tonsil

-large tonsilar cyst- open to the exterior and catches large things

-Lymphatic nodules

cardiovascular vs. lymphatic system

direction of bloodflow:

cs- carries blood away from the heart versus

ls- carries lymph back to the heart.

Type of fluid:

cs- blood (plasma and cells)

ls- lymph

Pump:

cs-yes(heart)

ls-no

direction of lymph flow

lymphatic capillaries (millions)—→collecting vessels—→ lymphatic trunks—→collecting ducts (2)—→heart

blood capillaries

• small diameter

• tunica interna- endothelium + basement membrane

  endothelial cells arranged end to end

transport of lipids

Lymph Node Image

Structural Classification: Encapsulated vs. non-capsulated

encapsulated- bone marrow, lymph nodes, spleen, thymus

non-encapsulated- tonsils

lymph nodes overview

-600-700 lymph nodes

-act as filters

loc. GI
Lungs
Inguinal

Missing or sparse in
lower regions