Exam 3, Dr. Carr, Immune System

differentiate between the roles of the b cells and t cells in adaptive immunity Long answer

Each individual B-cell has membrane-bound antibodies that can recognize only one randomly determined epitope (surface of antigen). Because there are vast numbers of B-cells in your body, there is a wide diversity of pathogens that can be potentially detected. B-cells constantly survey for foreign invaders, and will proliferate and secrete antibodies once a pathogen is detected. The antibodies will bind to the pathogen, allowing other immune cells such as macrophages can easily recognize and engulf it. Antibodies can also activate the complement system by recruiting certain complement proteins such as C1q, which ultimately leads to formation of the MAC and cell lysis. However, there is one problem with antibodies: they can only recognize pathogens that are extracellular, and are most effective in the blood.

humoral immunity protect against:

Extracellular microbes and their toxins toxin induced diseases infections (virulence related to polysaccharide capsule)

true or false. The innate immunity does not recognize all types of pathogens, including viruses, bacteria, fungal organisms, etc.

FALSE. They recognize all types of pathogens, including viruses, bacteria, fungal organisms, etc.

In what ways do fevers actually help us ?

Fever signals that the body is fighting infection. While fever may cause the patient to feel bad and ache, the body's elevated temperature actually helps white blood cells fight the infection. If you have a fever, avoid fever medications like acetaminophen or ibuprofen unless your fever is high and extremely uncomfortable. Try to control the fever by drinking plenty of fluids.

Innate Immune System is composed of two lines of defenses:

First line of defense consists of skin (mainly the epidermis), gastric acid in the stomach and mucus membranes. For instance, nasal mucus membrane serves as a filter to stop/obstruct the inward movement of large particles. The second line of defense consists of chemicals and cells that are released in the blood after being exposed to a pathogenic stimulus.

humoral immunity maturation:

Generated and matured in bone marrow

what are master cells of the immune system that initiate and coordinate the adaptive immune response

Helper T cells!

adaptive immunity components:

Humoral immunity, consisting of B cells and plasma cells Cell mediated immunity, consisting of T cells, which further matures into helper T cells, suppressor T cells and cytotoxic T cells

cell mediated protect against:

Intracellular microbes viruses parasites (leishmania) bacteria (mycobacteria, listeria) kill tumor cells

List the main components of the lymphatic system.

Lymph vessels, lymph nodes, tonsils, spleen, thymus

Chemical Barriers

Lysozyme, an enzyme produced in tears, perspiration, and saliva can break down cell walls and thus acts as an antibiotic (kills bacteria) Gastric juice in the stomach destroys bacteria and most toxins because the gastric juice is highly acidic (pH 2-3) Saliva dilutes the number of microorganisms and washes the teeth and mouth Acidity on skin inhibit bacterial growth Sebum (unsaturated fatty acids) provides a protective film on the skin and inhibits growth Hyaluronic acid is a gelatinous substance that slows the spread of noxious agents

Where are lymphocytes found in the lymphatic system?

Major parts of the lymphatic system include the lymphatic vessels, the lymph nodes, and cells called lymphocytes. The spleen, the tonsils, the appendix, bone marrow, and the thymus also belong to the lymphatic system.

humoral-

Of or relating to the body fluids or humors.

cell mediated maturation:

Originate in bone marrow and complete development in thymus

innate immunity components:

Physical barriers such as skin Chemical barriers Phagocytic cells, e.g., leukocytes Natural killer cells, e.g., NK cells Complementary proteins

Immune System Functions:

Scavenge dead, dying body cells Destroy abnormal (cancerous) Protect from pathogens & foreign molecules: parasites, bacteria, viruses

T cells are produced and mature in the

T cells Thymus (think T) gland.

Adaptive immunity cells are

The cells are highly specific.

Innate Defenses: Skin barriers

-Provide water tight surface, prevent free entry into body -Include lining of GI and respiratory tract 1) Skin 2) Mucosae

The Immune System has 3 Lines of Defense Against Foreign Pathogens:

1. Physical and Chemical Barriers (Innate Immunity) 2. Nonspecific Resistance (Innate Immunity) 3. Specific Resistance (Acquired Immunity)

B cells are ___________________ that play a large role in the ________________ immune response (as opposed to the cell-mediated immune response, which is governed by T cells).

1. lymphocytes 2.humoral

A __________________ immune response takes place the first time the body encounters an antigen. Further exposure to the same antigen activates plasma cells which induce a rapid and strong _______________ response.

1.primary 2. secondary

cells involved in humoral:

Ab synthesis requires 3 cells: t lymphocytes b lymphocytes macrophage

describe the structure and function of antibodies

An antibody, also known as an immunoglobulin, is a large Y-shaped protein produced by B-cells and used by the immune system to identify and neutralize foreign objects such as bacteria and viruses. either secreted into circulation or remain expressed on the surface of the B cell.

what would you call a molecule that stimulates an immune system reaction by b cells and t cells?

Antigens or immunogens

Plasma cell:

B cell that secretes antibodies specific to an ongoing infection

differentiate between the roles of the b cells and t cells in adaptive immunity

B cells produce antibodies that recognize and bind to extracellular pathogens, cytotoxic "killler" T-Cells recognize and kill cells infected with intracellular pathogens, and "helper" T-Cells provide the necessary co-stimulation for the former two cell types to operate.

Humoral Immunity main cells are

B lymphocytes

Depending on the kind of foreign invasion, two different immune responses occur:

CELL MEDIATED AND HUMORAL IMMUNITY

Clonal selection pt. 2 cuz I'm confused:

Clonal selection is a theory stating that B cells express antigen-specific receptors before antigens are ever encountered in the body. After B cell activation, the B cells clone themselves through clonal expansion, but during each cellular division, random mutations occur that gradually increase the binding affinity for B cell-produced antibodies to antigens.

Describe the function of the lymphatic system.

Drain fluid & protein, transport fats, make lymphocytes (immunity) of which B lymphocytes transform into plasma cells that make antibodies that fight infection.

Understand the role of clonal selection in humoral immunity:

During clonal selection, random mutations during clonal expansion cause the production of B cells with increased antibody-binding affinity for their antigens. The clonal selection hypothesis may explain why secondary immune responses are so effective at preventing reinfection by the same pathogen.

Active immunity-

produced due to contact with pathogen or its antigen immunity is not immediate, a time lapse occurs for its development lasts a long time antibodies are produced by the body in response to pathogen or antigen

Cells of adaptive immunity are normally in

silent mode and become active only when the antigen is identified. The cells of adaptive immunity develops over time.

cell mediated Immunity main cells are

t lymphocytes

Lymph

the colorless fluid of the lymphatic system that forms when plasma seeps out of blood vessels and into the interstitial fluid

Basophils:

the least common white blood cells that release chemical signals that trigger inflammation and allergies

epidermis

the outermost layer of the skin; consists partly of dry, dead cells that keep invaders outside the body

What do resident microbes do?

they live on the skin, in the gut, and elsewhere help prevent pathogens from colonizing (so like how the ppl at the front desk of the dorms prevent us from having fun)

what do complement proteins do

they signal phagocytes They serve as a marker to indicate the presence of a pathogen to phagocytic cells, such as macrophages and B cells, to enhance engulfment. This process is called opsonization. Certain complement proteins can combine to form attack complexes that open pores in microbial cell membranes. These structures destroy pathogens by causing their contents to leak . When innate mechanisms are insufficient to clear an infection, the adaptive immune response is informed and mobilized.

Once activated against a specific type of antigen, the innate immunity remains

throughout the life.

The inflammatory response (inflammation) occurs when

tissues are injured by bacteria, trauma, toxins, heat, or any other cause. The damaged cells release chemicals including histamine, bradykinin, and prostaglandins. These chemicals cause blood vessels to leak fluid into the tissues, causing swelling.

whats the job of lymph capillaries/lymph vessels?

to transport lymph

true of false. The span of developed adaptive immunity can be lifelong or short.

truuu

true or false. There are many white blood cells in the lymph nodes to help fight infection.

truuu

Immunization is a medical stargety for building up the boys defense agasint infectious diseases. TRUE OR FALSE.

truuuu

The diversity among adaptive response produced is _______.

very high

The diversity among innate response produced is _______.

very low.

adaptive immuntity- Memory cells are present

which identifies specific cells on each exposure.

Cells of innate immunity are

active all the time and are ready to combat as soon as a foreign body enters the human system. These cells are active since birth.

which type of cell presents an antigen to a helper t cell

an APC

What is a phagocyte?

besides the phag grace lockett, a type of cell within the body capable of engulfing and absorbing bacteria and other small cells and particles.

what are the hallmark signs of inflammation

The four cardinal signs of inflammation—redness (Latin rubor), heat (calor), swelling (tumor), and pain (dolor)—Redness is caused by the dilation of small blood vessels in the area of injury *redness *heat *swelling *pain (me when i get bitten by an ant)

how does inflammatory response isolate and combat damage or infection

The inflammatory response (inflammation) occurs when tissues are injured by bacteria, trauma, toxins, heat, or any other cause. These chemicals cause blood vessels to leak fluid into the tissues, causing swelling. This helps isolate the foreign substance from further contact with body tissues.

what is the lymphatic system?

The lymphatic system is a network of tissues and organs that help rid the body of toxins, waste and other unwanted materials. The primary function of the lymphatic system is to transport lymph, a fluid containing infection-fighting white blood cells, throughout the body.

The response of the adaptive immunity

The response appears after a week or two, also called as delayed response type immunity.

The response of the innate immunity

The response comes immediately, hence also referred to as immediate immunity.

Physical Barriers-

The skin has thick layer of dead cells in the epidermis which provides a physical barrier. Periodic shedding of the epidermis removes microbes. The mucous membranes produce mucus that trap microbes. Hair within the nose filters air containing microbes, dust, pollutants Cilia lines the upper respiratory tract traps and propels inhaled debris to throat Urine flushes microbes out of the urethra Defecation and vomiting -expel microorganism

What is clonal selection?

The theory that lymphocytes bear antigen receptors before activation and that random mutations during clonal expansion cause the development of lymphocytes with high binding affinities for their antigens.

Adaptive or Acquired Immune System:

This system activates after innate response is fully activated. Initially, the antigen entered in body is identified by the specific immune cells, and then a cascade of reactions is started in the form of antigen antibody reaction to attack the antigen. This immune system also includes generating memory of antigens, which will save their identities in the memory cells so that a specific response will be initiated soon after entry of the same pathogen in future.

What are the roles of white blood cells in the immune system?

White blood cells (WBCs), also called leukocytes or leucocytes, are the cells of the immune system that are involved in protecting the body against both infectious disease and foreign invaders. All white blood cells are produced and derived from multipotent cells in the bone marrow known as hematopoietic stem cells.

Adaptive system is mainly responsible for more

complex reactions.

Macrophages:

consume pathogens and promote fever; form one important class of phagocytes; some wander throughout body other stay in one tissue; important role in initiating body's defense

Innate immunity- A same response is produced

every time pathogen invades.

Allergy/ Allergic reaction:

exaggerated immune response to a harmless substance

The potency and effectiveness levels are _______ of the adaptive

extremely high because the combat cells are highly specialized and powerful.

Humoral antibodies are

formed

Innate type of immunity is generally inherited how?

from parents and passed to offspring.

Adaptive immunity is not passed from the parents to offspring,

hence it cannot be inherited.

what does histamine do

histamine is produced by basophils and by mast cells found in nearby connective tissues. Histamine increases the permeability of the capillaries to white blood cells and some proteins, to allow them to engage pathogens in the infected tissues.

VIDEO ABT CLONAL SELECTION IT HELPS

https://www.khanacademy.org/science/health-and-medicine/human-anatomy-and-physiology/introduction-to-immunology/v/clonal-selection

Clonal selection in dr carrs words

ie-when an army of plasma cells and memory cells are produced from properly stimulated B cells

Innate immune system or Natural Immune System is also referred to as

immediate response immune system. This system activates within minutes to hours after a foreign agent invades within the human body.

Two types of white blood cells, T and B cells (lymphocytes), are also produced _____________.

in the LYMPH nodes and spleen (lymphocytes produced in lymph nodes makes sense)

what are the 2 main subdivisions of the immune system?

innate and adaptive immunity

Although the response is immediate of the innate, but the effectiveness and potency

is limited.

Vaccination:

is the administration of antigenic material (a vaccine) to stimulate an individual's immune system to develop adaptive immunity to a pathogen. Vaccines can prevent or ameliorate morbidity from infection. When a sufficiently large percentage of a population has been vaccinated, this results in herd immunity.

dermis

layer that lies beneath the epidermis which houses nerve endings, sweat and oil glands, and the blood vessels that nourish both skin layers

How do vaccines work?

like a training course for the immune system. They prepare the body to fight disease without exposing it to disease symptoms. When foreign invaders such as bacteria or viruses enter the body, immune cells called lymphocytes respond by producing antibodies, which are protein molecules.

why do lymph nodes swell during an infection?

lymphadenitis occurs when the glands become enlarged by swelling (inflammation), often in response to bacteria, viruses, or fungi. The swollen glands are usually found near the site of an infection, tumor, or inflammation.

b and t cells are what type of wbc

lymphocytes or lymphatic cells

cells involved in cell mediated:

macrophage helper T cells natural killer T cells cytotoxic T cells

what are cytokines

messenger proteins, travel through bloodstream, cause a rise in the body's temperature called fever

Where are white blood cells produced?

most white blood cells are produced in the bone marrow, the soft fatty tissue inside bone cavities.

cell mediated antibodies are

not formed

White Blood cell roles:

phagocyte - most common (75%) lymphocytes - most of remaining basophils - least common

Passive Immunity-

produced due to antibodies obtained outside immunity develops immediately lasts for a few days