Chapter 22 - Lymphatic System & Immunity

Pathogen

disease producing microbe

Immunity

ability to ward off damage or disease

Innate Immunity

protections present at birth

Adaptive Immunity

introduction of pathogens that creates specific recognition

Lymphatic System - Components

lymph

lymphatic vessels

red bone marrow

lymphatic tissue

lymph nodes

lymphatic organs

Interstitial Fluid

components filtered from blood plasma through capillary tissue

most is reabsorbed into capillaries

Lymph

interstitial fluid that enters lymphatic vessels

Lymphatic Tissue - Structure

reticular connective tissue that contains large amounts of lymphocytes

Lymphatic System - Function (3)

1) drains excess interstitial fluid

2) transports dietary lipids (vitamins)

3) carry out immune responses

Lymphatic Capillaries

ends as lymphatic vessels

closed on one end

between cells of tissues

Lymphatic Vessels

start as lymphatic capillaries

has thin walls and valves

Lymph Trunks

start as lymphatic vessels

named after the regions of body they drain

Lymphatic Ducts - Function

start as lymphatic trunks

two collecting cuts that drain lymph into subclavian veins

lymphatic Ducts - Types (2)

1) right lymphatic duct

2) thoracic duct

Right Lymphatic Duct

drains the following into the right subclavian vein

• right side of head

• neck

• thorax

• right upper limb

Thoracic Duct

drains the following into the left subclavian vein

• lower limbs

• abdominal region

• left upper limb

• left side of thorax

• left side of head

• left side of neck

Orange lymph drains into the…

right lymphatic duct → right subclavian vein

Green lymph drains into the…

thoracic duct → left subclavian vein

Lymph - Cycle

blood plasma → blood capillaries → lymph capillaries → lymph node → lymph vessels → lymph trunk → lymph duct → subclavian vein → blood plasma

Skeletal Muscle Pump

muscle contraction compress lymphatic vessels and force lymph towards subclavian veins

Primary Lymphatic Organs

sites where stem cells divide

red bone marrow

thymus

Secondary Lymphatic Organs

lymph nodes

spleen

lymphatic nodules

Thymus - Location

behind the sternum

Thymus - Structure

a soft organ that contains lobules of lymphocytes and macrophages

surrounded by connective tissue that extends inside

Thymus - Function

thymosin produces lymphocytes that will mature into T-cells to provide immunity

Lymph Nodes - Location

along lymphatic pathways

Lymph Nodes - Structure

encapsulated by connective tissue

lymphocytes and macrophages

Lymph Nodes - Function

filter and cleans lymph as it flows through the node

Breast Cancer

development of malignant tumor within the breast

Breast Drainage

75% of lymph fluid of the breasts drains into lymphatics in the lateral quadrants

drains into the 20-40 axillary lymph nodes

Spleen - Location

upper left quadrant of the abdomen

Spleen - Structure

largest lymphatic organ

wrapped in connective tissue and contains blood

Spleen - Function

filters blood by removing damaged blood cells and bacteria

Lymphatic Nodules - Structure

masses of lymphatic tissue surrounded by a capsule

Lymphatic Nodules - Location

mucous membranes lining GI, respiratory, urinary, and reproductive tracts

also appendix and tonsils

Mucosa-Associated Lymphatic Tissue (MALT)

locations in mucous membranes where lymph nodules are located

First Line of Defense

skin and mucous membranes

Second Line of Defense

antimicrobial substances, phagocytes, inflammation, fever

Phagocytosis - Phases (5)

1) chemotaxis

2) adherence

3) ingestion

4) digestion

5) killing

Chemotaxis (1)

chemicals that attract phagocytosis are released from microbes, WBC, damaged tissue, or complimentary proteins

Adherence (2)

phagocyte attaches to microbe

Ingestion (3)

plasma membrane of phagocyte send out pseudopods to engulf microbe, becomes phagosome

Digestion (4)

phagosome enters cytoplasm and merges with lysosomes and becomes a phagolysosome, digestive enzymes break down substances

Killing (5)

microbe is killed and materials that cannot be degraded become residual bodies

Phagocytosis - Cycle

phagocyte → phagosome → phagolysosome → residual bodies

Inflammation - Conditions

• pathogens

• abrasions

• chemical irritations

• distortion

• cell disturbance

• extreme temperatures

Inflammation - Symptoms (PRISH)

P - pain

R - redness

I - immobility

S - swelling

H - heat

Vasodilation

increase diameter of arterioles

promotes fluidity, brings more plasma and immune cells

Increased Capillary Permeability

substances normally retained in the blood are permitted to pass from blood vessels

promoted defensive proteins such as antibodies and clotting factors to injured area

Antigens

large molecules that the body does not recognize as itself

lymphatic system will identify specific antigens, remember them, and destroy them

apart of an adaptive immune response

Lymphocyte Origin

red bone marrow releases premature lymphocytes to later mature

Lymphocyte Development

• T-lymphocytes become T-cells in the Thymus

• B-lymphocytes become B-cells in the bone marrow

T-Cells - Function

interacts directly with non-self antigens to kill

provides a cellular immune response

B-Cells - Function

interacts indirectly by producing antibodies to kill antigens

provides a humoral immune response

Adaptive Immunity - Types (2)

1) cell-mediated immunity

2) antibody-mediated immunity

Cell-Mediated Immunity

cytotoxic T-cells directly attack invading antigens such as…

• intracellular pathogens

• cancer cells

• foreign tissue transplants

Antibody-Mediated Immunity

B cells transform into plasma cells and synthesize specific proteins called antibodies or immunoglobins

effective against extracellular pathogens

Antibodies - Definition

specialized plasma proteins created by B-cells that provide immune reactions

also called immunoglobins

Immunoglobins - Types (5)

1) IgG

2) IgA

3) IgM

4) IgD

5) IgE

IgG - Antibody

tissue fluid and plasma that defends against bacterial cells, viruses, and toxins

only antibody that can cross the placenta

IgA - Antibody

exocrine gland secretions that provides protection of mucous membranes

• tears

• saliva

• gastric juices

• etc

IgM - Antibody

in blood plasma and reacts with blood cells during transfusions

IgD - Antibody

found in the surface of B-lymphocytes and functions of B cell activation

IgE - Antibody

found in mast cells and basophils for allergic reaction

Primary Immune Response

when B-cells or T-cells become activated for the first time

Secondary Immune Response

B-cells and T-cells use their memory and reactivate against a specific antigen

Natural Acquired Active Immunity

after exposure to an antigen for the first time

Artificially Acquired Active Immunity

use of vaccines to artificially produce antibodies

Naturally Acquire Passive Immunity

antibodies passed from mother to fetus

Artificially Acquired Passive Immunity

injection of antibodies

Psychoneuroimmunology (PNI)

field that deals with common pathways that link nervous, endocrine and immune systems

1

tissue cell

2

interstitial fluid

3

blood capillary

4

lymph capillary

1

right lymphatic duct

2

lymphatic vessel

3

thoracic duct

cisterna chyli

5

lymphatic vessel

6

thoracic duct

4

submandibular node

5

cervical node

6

thymus

7

intestinal node

8

appendix

9

red bone marrow

10

axillary node

11

mammary node

12

thoracic node

13

spleen

14

peyer’s patches

15

iliac node

16

inguinal node

Afferent Lymph Vessel

lymph capillary → lymph node

towards lymph node

Efferent Lymph Vessel

lymph node → lymph trunk

away from lymph node