Chapter 24 Lymphatic

Pathogen

disease producing microbes

Immunity

ability to ward off pathogens

susceptibility

lack of resistance against pathogens

Innate non-specific immunity

immunity we are born with that does not adapt as we grow

Adaptive / specific immunity

immunity that changes as we grow and can recognize specific pathogens

What is the importance of the lymphatic system

Provide immunity and transport fluids

Functions of the Lymphatic system (4)

1. Transport fluids

2. Convert excess intersitial fluid to lymph

3. Immune response (lymphocyte production and maturation)

4. Transport dietary lipids from the digestive system (Lacteals)

What are lymphoid cells

cells that travel through the lymphatic system looking for pathogens

What are the four types of lymphoid cells

Macrophages, Nurse Cells (special epithelial cells), Dendric Cells, and lymphocytes

Macrophages

monocytes that left blood; phagocytisis and secondary antigen presenting cells

Special epithelial cells (Nurse Cells)

Cells in the thymus that secrete thymatic hormones

Dendric Cells

Internalize antigens and are the main APC

What are the three types of lymphocytes

T-Cells, B-Cells, Natural killer Cells

What are the 4 types of T-Cells

Helper T-Cells, Cytotoxic T-Cells, Regulatory T-Cells, Memory T-Cells

What are the 2 types of B-Cells

Plasma Cell and Memory-B cell

What do Natural killer cells do

What do Helper T-Cells do

initiate and lead immune response (activates cytotoxic cells)

What do Cytotoxic T-Cells do

destroy infected or cancerous cells

What do Memory T cells do

Remember pathogens to make future attacks more efficient (and searches for them)

What do Regulatory T-Cells do?

stop immune response

What do plasma cells do

produce antibodies to fight infections

What do Memory-B cells

remember what antibodies are needed for an immune response

What is the lymphatic system pathway

Heart → capillaries → ECF → Lymph plasma → Lymphatic vessels → Lymph nodes → Venous blood

What is the order of lymphatic vessels

Lymphatic: capillaries → vessels → nodes → trunks → ducts → venous blood flow

Right AND Left trunks

Jugular, subclavian, broncho mediastinal

Left ONLY trunks

Lumbar and intestinal

Where does the Jugular trunk drain from

head and neck region

Where does the subclavian trunk drain from

upper limbs, breast, superficial thoracic wall

Where does the broncho mediastinum trunk drain from

deep thoracic structures

Where does the intestinal trunk drain from

abdominal structures

Where does the Lumbar trunk drain from

lower limbs, pelvis, and abdominopelvic wall

What are the two lymphatic ducts

right lymphatic and thoracic

Where is the right lymphatic duct located

deep clavicle

Where is the thoracic duct located

below the diaphragm

Where does the right lymphatic duct return to

the right subclavian and internal jugular junction

Where does the thoracic duct return to

the left subclavian and internal jugular junction

Where does the right lymphatic duct drain from

the right upper quadrant of the body (head, neck, thoracic, upper limbs)

Where does the thoracic duct drain from

everywhere the right lymphatic doesn’t

What are lymphatic organs

organs containing lymphoid cells and ECM enclosed in connective tissue

What are the primary lymphatic organs

bone marrow and thymus

what are the secondary lymphatic organs

spleen and lymph nodes

Where the is thymus located

the superior mediastinum

What are the two structures of the thymus

Cortex and medulla

What is the function of the thymus cortex

Hold and mature T-Cells that migrate from red bone marrow: Release mature T-cells, Nurse cells, and macrophages into lymph

What is the function of the medulla thymus

Contains mature T-cells and epithelial cells

Where is the Spleen located

left upper quadrant, 9-11th ribs, inferior to diaphragm

What is its overall function

to filter blood, store lymphocytes, and support immune responses.

What are its structures (4)

Dense irregular tissue capsule, trabeculae (branches of splenic veins and arteries), Parenchyma = red pulp + white pulp

Function of white pulp

to generate immune responses and produce lymphocytes (T and B and macrophages)

Function of red pulp (contain splenic cords tubercule)

to filter blood, remove aged red blood cells, and store platelets.

Where are lymph nodes located

They are clusters of axillary, inguinal, and cervical regions

What are the functions of lymph nodes

to filter lymph, trap pathogens, and activate immune responses.