Lymphatic system [Chapter 20]

A&PII Lymphatic System

What does the lymphatic system consist of?

lymph, lymphatic vessels, lymphatic tissues, and red bone marrow

What are lymphatic vessels

System of vessels that carry tissue fluid "lymph" to large veins

What are lymphatic capillaries?

blind-ended vessels that weave between tissue cells and blood capillaries, they pick up interstitial fluid near capillary beds

What is the lymphatic capillaries histology

Simple squamous epithelium

What are minivalves

Function as one way gates that allow interstitial fluid to enter lymph capillaries, do not allow lymph to escape from the capillaries.

What are lacteals

specialized lymph capillaries present in intestinal mucosa

What are collecting vessels

vessels that filter lymph through a series of lymph nodes

What do collecting vessels consist of

three very thin tunics and lots of valves

What are lymphatic trunks

formed by union of largest collecting vessels, drain large areas of body

What drains into the right lymphatic duct?

right upper arm and right side of head and thorax

What drains into the thoracic duct

Left hemicranium, left upper lung lobe, and EVERYTHING else besides the right upper arm.

Where does the Right lymphatic duct dump into

right subclavian vein

Where does the thoracic duct drain?

left subclavian vein

How does lymph transport

Smooth muscle in vessels, nearby arteries, skeletal muscular pump, respiratory pump, body move in gen

What are the functions of lymph vessels

Return fluids to blood, return nutrients like proteins to blood, carry pathogens to lymph nodes, carry lipids from intestines to blood

What are lymphoid cells

lymphocytes [T and B], macrophages, dendritic cells, reticular cells

What is the purpose of T and B lymphocytes

manage immune response and produce antibodies

What is the purpose of macrophages

To eat and destroy foreign substances in the body, Ie Mobile phagocytes

What are dendritic cells?

spiny-looking cells with functions similar to macrophages

What is the purpose of reticular cells

Produce the stroma of reticular fibers in lymphatic tissues

What is the histology of lymphoid tissue

Reticular connective tissue

What is diffuse lymphoid tissue

loose arrangement of lymphoid cells and some reticular fibers
in lots of organs, and spread out in organ layers

What are follicles?

Packed with cells and fibers
in nodes the peyer's patches
They have germinal centers for B cell proliferation

What are the primary lymphoid organs?

bone marrow and thymus; where Band T cells mature

What is the lymphatic function of red bone marrow

Where B and T cells are made, and where B cells mature

What is the lymphatic function of the thymus

Where T cells mature

What are the secondary lymphoid organs

lymph nodes, spleen, MALT
Where they are first exposed to antigens

What are the MALTs

mucosa-associated lymphoid tissue
Tonsils, Peryer's patches, appendix

What are lymph nodes

gland-like structures found inside the lymphatic vessels, Main secondary organ and are clustered all around the body

What is the purpose of lymph nodes

Cleanse lymph as it returns towards cardiovascular system, macrophages hang put in the stroma conducting phagocytosis
T cell activation site

What's housed in lymph node cortex

B & T cells, Follicles with germinal centers, dendritic cells as well as macrophages

What's housed in lymph node medulla

B & T cells as well as macrophages

What is the location and appearance of the spleen

Large, soft, flap-like, located on the left side of abdominal cavity near stomach

What is the purpose of the spleen

Lymphocyte proliferation and response, macrophages
Breaks down and recycles old erythrocytes, stores platelets

What is white pulp?

lymphocytes and macrophages

What is red pulp?

sinuses filled with erythrocytes

What is the cisterna chyli?

Enlarged terminus of the thoracic duct that receives lymph from the digestive viscera.

Pharyngeal tonsil (Picture)

B

Palatine tonsil (Picture)

C

Lingual tonsil (Picture)

A

Thymus (Picture)

Spleen (Picture)

vermiform appendix (Picture)

Where is MALT located?

Afferent vessels (Picture)

A

Capsle (Picture)

J

efferent vessels (Picture)

E

Lymph cortex (Picture)

A

Lymph medulla (Picture)

B

lymph trabeculae (Picture)

spleen red pulp (Picture)

spleen white pulp (Picture)

A

Peyer's patches (Picture)

lacteals (Picture)