Lymphatic Immune System - Chapter 21

Front 1

Main functions of lymphatic system

Back 1

1) capillaries absorb excess tissue fluid and to return it to blood vascular system
2) Lacteals (lymphatic capillaries) in the small intestine absorb fats associated with proteins (part of digestion)
3) works in the production, maintenance and distribution of lymphocytes in the body
4) helps in defense against pathogens

Front 2

Main components of the immune system (cells.... organs)

Back 2

lymphocytes, lymphoid tissue and lymphoid organs

Front 3

Lymph

Back 3

term for tissue fluid once it is in lymphatic vessels

Front 4

functions of lymphatic vessels

Back 4

1) collect excess tissue fluid and blood proteins
2) return them to bloodstream

Front 5

Order of lymphatic vessels

Back 5

1) Lymph capillaries - first to receive lymph
2) Afferent lymph vessels
3) Lymph node
4) Efferent lymph vessel
5) Lymph trunk
6) Lymph duct
7) Subclavian vein

Front 6

Lymphatic capillaries
- location
- function
- characteristics

Back 6

- located near blood capillaries
- receive tissue fluid from connective tissue
- minivalve flaps open and allow fluid to enter
- high permeability allows entrance of tissue fluid, protein molecules, & pathogens

Front 7

Lacteals

Back 7

specialized lymphatic capillaries
- located in the villi of the small intestines
- receive digested fats
- fatty lymph = chyle

Front 8

Structure of Lymphatic vessels

Back 8

same 3 tunics as blood vessels
- has more valves than veins since lymph flow is unaided by heartbeat.
- Lymph is propelled by: 1) skeletal muscles bulging 2) nearby arteries pulsing
3) Tunica media of the lymph vessels

Front 9

Lymph nodes
- function
- number
- location

Back 9

1) cleanse the lymph of pathogens
2) body has about 500
3) superficial lymph nodes: cervical, axillary, inguinal, femoral, popliteal
4) deep nodes: tracheobronchial, aortic, celiac, iliac

Front 10

Microscopic anatomy of a lymph node

Back 10

1) fibrous capsule - surrounds it
2) trabeculae - connective tissue strands around each section
3) Afferent vessels - come into the node
4) Efferent vessels - carry lymph away from the node
5) cortex 6) Medulla

Front 11

5 major lymph trunks

Back 11

1) Lumbar trunks - receives Lymph from lower limbs
2) Intestinal trunk - receives Chyle from digestive organs
3) Bronchomediastinal trunks - lymph from thoracic viscera
4) Subclavian trunks - upper limbs and thoracic wall
5) Jugular trunks - drain lymph from head and neck

Front 12

Lymph ducts

Back 12

1) Thoracic duct - ascends along vertebral bodies
- empties at junction of L internal jugular and subclavian veins - drains 1/3 of body
- most inferior part is the CISTERNA CHYLI - at union of the lumbar & intestinal trunks
2) Right lymphatic duct - jugular and subclavian trunks - drains 1/4th of body
- empties into R internal jugular and subclavian veins

Front 13

Functions of the immune system

Back 13

1) recognize specific foreign molecules
2) destroy pathogens effectively

Front 14

Key cells in the immune system

Back 14

lymphocytes

Front 15

Lymphoid organs

Back 15

1) lymph nodes
2) spleen
3) Thymus
4) tonsils
5) aggregated lymphoid nodules
6) appendix

Front 16

3 Divisions of the immune system

Back 16

1) Nonspecific - 1st line of defense - physical & chemical barriers.
2) Innate - cells and antimicrobial secretions - inflammation and fever
3) Adaptive immunity - most important; specific: specific pathogen recognition, immunologic memory, amplification of immune responses

Front 17

examples of 1st line of immune defense

Back 17

- Physical barriers - integumentary system (skin, mucous, mucous membranes)
- chemical barriers 1) lysozyme (saliva, tears, sweat)
2) Acidic pH (stomach, vagina)
3) secretions of oil glands

Front 18

details of innate immunity

Back 18

2nd line of defense - phagocytosis
- neutrophils & macrophages
- cells involved in inflammatory response
- protective proteins:
1) complement:blood plasma proteins - bind to mast cells to release histamine; attract phagocytes to pathogens; form a membrane attack complex that make holes in some bacteria & viruses.
2) interferons - proteins produced by virally infected cells sent to warm neighboring healthy cells

Front 19

summary of inflammatory response

Back 19

1) injured tissue and mast cells release histamine--capillaries dilate and increase blood flow
2) Macrophages phagocytize pathogens and release cytokines - stimulate inflammatory response
3) neutrophils and monocytes (become macrophages) squeeze through the capillary wall and phagocytize pathogens
4) Blood clotting walls off capillary and prevents blood loss

Front 20

details of Adaptive immunity

Back 20

- 3rd line - protection against specific pathogens when nonspecific defenses fail
- depends on 2 types of cells:
1) B cells - converts into plasma cells, which produce antibodies and TAG
2) T Cells - a) helper T cells - secrete cytokines - help immune cells function b) cytotoxic T cells - killers

Front 21

Details of how cytotoxic T Cells work

Back 21

1) vacuoles contain granzymes and perforins
2) perforins punch holes in trage cells
3) granzymes go through the holes and cause the cell to undergo apoptosis
4) destroy virus infected cells and some cancer cells.

Front 22

General characteristics of lymphocytes

Back 22

1) effective fighters of infectious organisms
2) each lymphocyte recognizes a specific foreign molecule
3) respond to antigens

Front 23

antigen

Back 23

any molecule inducing a response from a lymphocyte

Front 24

formation of lymphocytes

Back 24

1) originate in bone marrow
2) those which mature in the thymus are T lymphocytes
3) those which mature in the bone marrow are B lymphocytes
4) immunocompetence - mature and can recognize a unique antigen

Front 25

2 cells that present an antigen to a lymphocyte

Back 25

1) macrophage (monocytes are the unactivated version)
2) dendritic cell

Front 26

Effector lymphocytes

Back 26

- B & T lymphocytes that respond immediately and then die

Front 27

Memory cells (lymphocytes)

Back 27

- basis of acquired immunity
- clones of T & B cells that wait until the body encounters the antigen again

Front 28

Location and functions of Lymphoid tissue

Back 28

- General locations: 1) lymphoid organs (except thymus) 2) Mucous embranes of digestive, urinary, respiratory and reproductive tracts - i.e. Mucosa-assoicated lymphoid tissue
- Functions: 1) Main battle ground in fighting infection 2) activation site for lymphocytes 3) generation of most effector and memory lymphocytes

Front 29

7 subdivisions of Mucosa-associated lymphoid tissue (MALT)

Back 29

1) GALT - gut-associated (Peyer's patches)
2) BALT - bronchus -associated lymphoid
3) NALT - nose- associated
4) LALT - larynx-associated
5) SALT - skin-associated
6) VALT - vascular associated
7) CALT - conjunctiva- associated

Front 30

Primary lymphoid organs

Back 30

- sites of origin and maturation
1) Bone marrow
2) Thymus

Front 31

secondary lymphoid organs + location

Back 31

1) lymph nodes (throughout body)
2) spleen (Left upper quadrant)
3) adenoids - nasopharynx
4) tonsils - pharyngeal regoin
5) peyer's patches - aggregated lymphoid nodules of small intestine
6) appendix - right lower quadrant

Front 32

composition of Thymus
- how is different from other lymphoid organs

Back 32

- composition: cortex and medulla. Medulla contains Hassall's corpuscles
- differences: a) functions strictly in lymphocyte maturation
b) arises from epithelial tissue

Front 33

Function of lymph Nodes

Back 33

1) Lymph percolates through lymph sinuses
2)most antigenic challenges occur in lymph nodes
3) lymphadenopathy - swollen lymph node

Front 34

Characteristics of adenoids

Back 34

1) unencapsulated structure located on the posterior wall of nasopharynx
2) ungergoes absolute and relative enlargement during childhood and regresses during puberty
3) inflammatory and physiologic enlargement is associated iwth a) otitis media b) sinusitis c) obstructive sleep apnea

Front 35

characteristics & functions of the spleen

Back 35

1) largest lymphoid organ
2) site of hematopoiesis in the fetus
3) storage of platelets
4) 2 blood-cleansing functions
a) removal of blood-borne antigens
b) removal & destruction of old/defective blood cells

Front 36

Structure of the spleen

Back 36

1) White pulp - real lymphoid tissue. Provides the immune function
2) Red pulp - surrounds white pulp. responsible for disposing of worn out erythrocytes. Composed of venous sinuses, splenic cords

Front 37

4 groups of tonsils

Back 37

1) Palatine - back of throat
2) Lingual - very back of tongue
3) pharyngeal - top of pharynx
4) tubal

Front 38

Composition of tonsils

Back 38

1) simplest lymphoid organs
2) arranged in a ring to gather and remove pathogens
3) underlying lamina propria consists of MALT

Front 39

Characteristics and function of aggregated lymphoid nodules and appendix

Back 39

1) MALT - abundant in walls of intestines
2) fight invading bacteria
3) generate wide variety of memory lymphocytes
4) Aggregated - Peyer's patches - distal part of the small intestine
5) Appendix - tubular offshoot of the cecum

Front 40

Hodgkin's disease

Back 40

malignancy of lymph nodes

Front 41

Non-Hodgkin's lymphoma

Back 41

uncontrolled multiplication & metastasis of undifferentiated lymphocytes

Front 42

Chylotorax

Back 42

leakage of fatty lymph into the thorax

Front 43

Lymphangitis

Back 43

inflammation of a lymph vessel

Front 44

mononucleosis

Back 44

viral disease caused by Epstein-Barr virus that attacks B lymphocytes

Front 45

autoimmune diseases

Back 45

cytotoxic T cells or antibodies attack the body's own cells as if they were foreign
- examples: MS, lupus, myasthenia gravis, rheumatoid arthritis

Front 46

immunodeficiency disease

Back 46

disease in which the immune system is compromised and thus unable to defend the body
- examples: AIDS & SCID

Front 47

Tissue rejection

Back 47

when cytotoxic T cells respond to tissue that is not recognized as "self" tissue

Front 48

fetal origin of lymphatic vessels & lymph nodes

Back 48

lymphatic sacs

Front 49

fetal origin of thymus

Back 49

outgrowh of the endoderm

Front 50

fetal origin of spleen, lymph nodes and MALT

Back 50

mesodermal mesenchyme