LYMPHATIC SYSTEM

Fluid balance
Fat absorption
Defense

Functions of Lymphatic System

Edema

tissue damage

Lacteals

lymphatic vessels of the small intestines

Chyle

a milky fluid consisting of lymph and emulsified fats; formed in the small intestine during digestion of ingested fats; color white

Lymph

fluid that enters lymphatic capillaries; composed of water and some solutes; fluid that passes lymph vessels

Lymphocytes

cells; fights cancer cells

B cells
T cells
Natural Killer cells

Three types of Lymphocytes

Lymphatic vessels

drainage system in our body

Lymph nodes

remove foreign substances

Tonsils

trap microorganisms/pathogen; tonsilitis

Spleen

filtering blood; site for lymphocyte proliferation

Lymph nodes
Spleen
Tonsils
Thymus gland

Four major organs of Lymphatic System

Lymphatic capillaries and vessels

carries fluid in one direction (valves) from tissues to circulatory system

lymphatic capillaries

tiny, closed-ended valves; fluid moves easily; in most tissues; join to form lymphatic vessels; made up of endothelial cells

lymphatic capillaries is permeable because they are composed of what?

simple squamous epithelium

lymphatic vessels

resemble small veins; where lymphatic capillaries join; one way valves to prevent backflow

right lymphatic duct

where lymphatic vessels from right upper limb and right head, neck, chest empty; empties into right subclavian vein

thoracic duct

rest of body empties from lymphatic vessels; empties into left subclavian vein

Tonsils

trap or remove pathogens

pharyngeal
palatine
lingual

three types of tonsils

palatine tonsil

each side of oral cavity

pharyngeal tonsil

near internal opening of nasal cavity; adenoid

lingual tonsil

posterior surface of tongue (least infected)

Lymph nodes

size of kidney; located near lymphatic vessels; lymph passes through before entering blood; lymph moves through and immune system is activated if foreign substances are detected; removal of microbes by macrophages

Spleen

graveyard of RBCs; size of clenched fist; located in abdomen: filters blood; detect and respond to foreign substances; destroy old red blood cells; blood reservoir for emergency

WBC

spleen produce what blood cell in adults?

white pulp

lymphatic tissue surrounding arteries

red pulp

contains macrophages and red blood cells that connect to veins

Thymus gland

bilobed gland: triangular in shape
located in mediastinum behind the sternum
stops growing at age 1
decrease in size at the age of 60
produces and matures lymphocytes

immunity

ability to resist damage from foreign substances

innate, adaptive

two types of immunity

innate immunity

present at birth
defense against any pathogens
accomplished by physical barriers, chemical mediators, cells, inflammatory response

Physical barriers

first line of defense

skin
mucous membrane
tears
saliva
urine

types of physical barriers

chemical mediators

chemicals that can kill microbes and prevent their entry into cells

Lysozyme
Mucous membrane
Histamine
Interferons

types of chemical mediators

lysozyme

an enzyme found in saliva and sweat and tears that destroys the cell walls of certain bacteria

mucous membrane

prevent entry of microbes; produces hydrochloric acid and protein digesting enzymes that might kill pathogens

Histamine

promote inflammation by causing vasodilation

Interferons

proteins that protect against viral infections by stimulating surrounding cells to produce antiviral proteins

White blood cells

produce in red bone marrow and lymphatic tissue that fight foreign substances

phagocytic cells

ingest and destroy foreign substances

neutrophils
macrophages

examples of phagocytic cells

Elie Metchnikoff

the one that discovered phagocytosis

Neutrophils

first to respond to infection but die quickly; least effective

macrophages

monocytes; leave blood and enter tissues; can ingest more than neutrophils (more effective); protect lymph in lymph nodes and blood in spleen and liver

Kupffer cells
histiocytes
microglial
alveolar macrophages

give the specific names of macrohages to the ff:
in liver
connective tissue
brain
lungs

basophils

count increased if you have allergies; made in red bone marrow; leave blood and enter infected tissues; can release histamine

histamine

basophils can release what?

Mast cells

found in skin, liver, gastrointestinal tract, and urogenital tract

leukotrienes

mast cells can release what?

Eosinophils

release chemicals to reduce inflammation; used during parasitic infection

Natural killer cells

recognize classes of cells such as tumor cells or virus infected cells

lysis cells

natural killer cells release chemicals to?

Inflammatory response

involves chemical and cells due to injury; signaled by presence of foreign substance; stimulates release of chemical mediators

physical barriers
chemical mediators
inflammatory response

types of innate immunity

adaptive immunity

defense that involves specific recognition to a specific antigen; acquired after birth; reacts when innate defenses don't work; slower than innate immunity; has memory; uses lymphocytes

B cells
T cells

what type of lymphocyte is used in adaptive immunity?

antigen-specific
systemic
has memory

3 things I should know about adaptive immunity

antigen

substance that stimulates immune response

self-antigen

molecule produce by person's body that stimulates immune system response; can be harmful (evolve autoimmune disease)

Antibody

proteins the body produces in response to antigen

stem cells

give rise to all blood cells (mother of all blood cells); give rise to some pre T cells and pre B cells

lymphocytes

type of WBC; involved in adaptive immunity; developed from stem cells

B cells

type of lymphocytes; involved in antibody-mediated immunity; originate from stem cells; matured in red bone marrow; move to lymphatic tissue after mature; lead to production of antibodies

T cells

type of lymphocytes; involved in cell-mediated immunity primarily and antibody-mediated immunity; mature in thymus gland; move to lymphatic tissue after mature

antigen receptors

lymphocytes have what in their surface?

B-cell receptors
T-cell receptors

receptors in B cell and T cell

specific antigen

each receptor only binds with a?

activated
begins

when antigen receptors combine with antigen, the lymphocyte is ___ abd adaptive immunity ____

major histocompatibility complex molecule (MHC)

contain binding sites for antigens; specific for certain antigens; hold and present a processed antigen on the surface of the cell membrane; bind to antigen receptor on B or T cells and stimulate response

cytokines

proteins secreted by a cell that regulates neighboring cells

antibody-mediated
cell-mediated

lymphocytes give rise to 2 types of immune responses:

antibody-mediated

effective against antigens in body fluids (blood and lymph); effective against bacteria, virus, toxins; uses B cells to produce antibodies

humoral response

antibody-mediated is also called?

Gerald Edelman
Rodney Porter

2 person who discovered the Y shape in antibody structure

variable region

V of Y; bind to epitopes of antigen using antigen-binding site

constant region

stem of Y; each class of immunoglobulin has same structure

antigen-binding site

site on the antibody where antigen binds

valence

number of antigen-binding sites on antibody

IgG, IgM, IgA, IgE, IgD

5 immunoglobulins used to destroy antigens

IgG

most common immunoglobulin

inactive antigen
bind antigens together
active complement cascades
initiate release of inflammatory chemicals
facilitate phagocytosis

effects of antibodies

Primary response

1st exposure of B cells to antigen
B cell undergoes division and forms plasma cells and memory cells

plasma cells

produce antibodies
person develop disease symptoms

3-14 days

days when plasma is effective against antigen

memory cells

occurs when immune system is exposed to antigen that has been seen before

antibodies

B memory cells quickly divided to form plasma cells which produce ______

cell-mediated immunity

effective against antigens in cells and tissues

Helper T cells

activates macrophages; help from B cells; promote production of Tc

Cytotoxic T cells (Tc)

precursor to cytotoxic T lymphocytes; inactive

Cytotoxic T lymphocytes (CTL)

destroys antigen on contact

Regulatory T cells

turn off immune system response when antigen is gone

naturally active acquired immunity

natural exposure to antigens causes production of antibodies; can be lifelong immunity

naturally passive acquired immunity

transfer of antibodies from mother to child

artificially active acquired immunity

injection of antigens using vaccines which cause the production of antibodies; vaccine or immunization

artificially passive acquired immunity

injection of antibodies from another person or animal

multiple sclerosis

destroys the white matter, myelin sheet of the brain, and the spinal cord

myasthenia gravis

it impairs the communication between nerves and skeletal muscles; affects the movement

grave's disease

protruding of eyeballs