Lymphatic System Guided NotesName:______

Do Now

You drink a glass of water. What path does it take through the body?

Lymphatic System Function

The lymphatic system consists of two main parts, each with different functions:

  1. ______collect interstitial fluid and return it to the blood vessels
  2. ______house immune cells and help protect the body from disease

Lymphatic capillaries

Lymphatic capillaries collect interstitial fluid and dissolved particles, including proteins, cell debris, and pathogens

Surround blood capillaries in loose connective tissue

______ (have a true start)

______ensure fluid only goes in one direction – towards heart.

Other lymphatic vessels

Lymphatic capillaries join together to form lymphatic vessels.

Lymphatic vessels pass through multiple lymph nodes for

cleansing

Lymphatic vessels empty into the subclavian veins

What makes lymph flow?

______

______

Higher pressure of interstitial fluid than of lymph in

capillaries starts flow

Respiratory and skeletal muscle pumps help maintain flow in lymph vessels

Largest lymph vessels have smooth muscle walls that contract rhythmically to push lymph along

______

Minivalves in capillaries

‘true’ valves in large lymph vessels

Compare and contrast blood vessels and lymphatic vessels in terms of structure and function.

Lymph Nodes

______(phagocytes and lymphocytes)

Filter lymph, breaking down cell debris and destroying pathogens and cancer cells

There are thousands of lymph nodes scattered throughout the body.

Large clusters of lymph nodes occur in cervical (neck), axillary (arm pit), and inguinal (groin) area.

Other Lymphoid Organs

House immune cells, but do not filter lymph

______: trap and remove pathogens that enter throat

______: produces hormones and develops T-lymphocytes

______: filters blood, destroys old erythrocytes

______: destroy pathogens in intestines

Non-specific Body Defenses

Do Now

Name some structures or processes that protect us from disease.

The body has two systems that fight disease

  1. ______system

 Protects body from ______foreign substances

  1. ______system (aka ______system)

Protects body from ______ foreign substances

Surface Barriers

______and ______prevent pathogens from entering body

______

______in skin, vagina, and stomach ______

______in respiratory and digestive tracts ______

______contain an enzyme – lysozyme – that ______.

Cellular Defenses

The body has specialized cells that destroy foreign material

______(macrophages & neutrophils) – ______, such as bacteria and viruses

______(a type of lymphocyte) – ______that destroy cell membranes.

Inflammation

Inflammation occurs when an area that is damaged or infected becomes ______.

Occurs when damaged cells release chemicals that ______, ______, and ______.

How does it protect the body?

______to nearby tissue

 helps rid body of pathogens and dead cells

Helps speed healing

Fever

Fever is when the body’s temperature becomes elevated due to infection

Occurs when white blood cells release chemicals that reset the body’s thermostat

How does it protect the body?

______by causing the liver & spleen to take up nutrients

______to speed the healing process

Why do we get the chills when we have a fever?

Immune System Guided Notes

Do Now

What is the difference between the non-specific and specific defense system?

Which one is activated by vaccines?

The specific defense system

The specific defense system (aka immune system) recognizes and attacks specific pathogens.

The immune system has 3 important characteristics:

»Antigen-specific

»Systemic

»Has memory

What are antigens?

What does systemic mean?

Cells (and chemicals) of the immune system

»______

•______function in non-specific defense* to kill virus infected or cancerous body cells

•______mature in bone marrow. They become activated by binding to specific antigens then divide to form:

•______which release antibodies

•______which ‘remember’ specific antigens

•______mature in the thymus. They become activated by binding to specific antigens then divide to form:

•______kill virus infected or cancerous body cells

•______stimulate the production of immune cells and release chemicals which help destroy pathogens

•______stop activity of immune cells after infection is over

•______‘remember’ specific antigens

What do the B and T refer to?

Which cell has a similar function to NK cells? How are these two cells different?

Which cells directly attack pathogens?

»______

•Play a role in non-specific AND specific defense system

•______(non-specific system)

•Act as ______(specific system) by displaying fragments of these particles on their surface and activating T lymphocytes.

»Antibodies

•Proteins produced by plasma cells (B cells) that bind to specific antigens

•Binding of antibodies to pathogen causes their destruction / inactivation in one of a few ways

•______: Encourages other chemicals (complements) to punch holes in the surface of the pathogen, destroying it.

•______: Binding prevents viruses or toxins from entering healthy body cells

•______: clumping of antibody-bound particles, which makes them unable to enter healthy cells and more likely to be eaten by phagocytes

•______– the presence of antibodies ‘flags’ a pathogen, increasing the chance that it will be eaten by a phagocyte.

»Other important chemicals

•______– proteins that in blood that bind to pathogens; activity increased by presence of antibodies

•______– proteins that bind to virus-infected cells and reduce the ability of viruses to multiply; also work with T cells to increase recognition of virus infected or cancerous cells.

•______and ______– cause inflammatory response

•______and ______– released by T cells, increase immune response and directly destroy pathogens

Circle the chemicals you need to know!

Two branches of the Immune system

There are two branches of the immune system:

»The ______which involves the production of ______that fight ______(pathogens including viruses and bacteria that are among our cells, but not inside them).

»______which involves the activation of ______that destroy ______and ______.

The story of the lucky lymphocyte

The body naturally produces a HUGE array of B- and T- lymphocytes, with widely diverging receptors. Each receptor is capable of binding with only one type of antigen. These mature, but inactive, lymphocytes take up residence in lymphatic organs and wait to meet their antigen.

Most never will.

The lucky few lymphocytes that do bind to their antigen will undergo clonal selection so that they, and their multitude of offspring, can fulfill their destiny by participating in the humoral or cell-mediated immune response.

Humoral Immune Response

Primary vs. Secondary Humoral Immune Response

»The primary humoral immune response occurs the first time the immune system encounters a specific antigen.

Why?

»The secondary humoral immune response occurs any time after the immune system first defeats an antigen. This response is much faster and produces more antibodies.

Why?

How does this graph explain the function of vaccines?

Why are booster vaccinations necessary?

Types of acquired immunity

The least common method is artificial passive immunity. Used for exposures / disorders that are likely to be fatal before the body can mount its own immune defense.

Includes: antivenom, botulism, rabies, & tetanus

Cell-Mediated Immune Response

The humoral immune response involves the production of antibodies and memory B lymphocytes.

What does the cell-mediated immune response involve?

»T-cell activation

•Like B-cells, T-cells must bind to their one, specific antigen before they are activated.

•Unlike B-cells, T-cells cannot bind to free-floating antigens and must bind to an antigen-presenting cell, like a macrophage.

»Activated T cells will clone (multiply)

»T cells will do their specific jobs

Types of T cells

»Cytotoxic Ts ______

»Helper Ts have many jobs

•Encourage ______of activated B cells and cytotoxic Ts

•Encourage ______from plasma cells

•Release chemicals (lymphokines) which ______and enhance activity of phagocytes

»Suppressor Ts

•Release chemicals that ______, to slow immune response once antigen is destroyed

»Memory Ts

•Long-lived cells that remain for quick response upon subsequent infection

Why might helper Ts be thought of as the bridge between cell-mediated immunity and humoral immunity?