Unit 6 Immune System

immune system

it is involved with a whole bunch of different tissue groups, organ systems, and specialized defense cells. It protects the body from abnormal cells changes and harmful pathogens

Two main forms of immunity:

innate and adaptive immunity

innate immunity:

present at the surface of the body responds immediately to anything suspicious (has internal and external examples)

Internal innate immunity examples:

phagocytes

External innate immunity examples:

skin and mucous membrane

adaptive immunity:

takes time to fire up, recognizes previous pathogens to be better equipped to handle them it again

phagocytes defenses:

fever, releasing chemical signals and, causing inflammation

neutrophils:

Most abundant white blood cell. Ingest pathogens and then self destruct.

macrophages:

Uses cytoplasmic extensions to ingest pathogens, and can be reused over and over again.

Natural Killer cells:

(innate) Capable of killing infected or cancerous cells by injecting an enzyme that triggers apoptosis

inflammation is triggered by:

breach or injury to the skin

redness due to…

histamine molecules have been sent out, and causes heat at the site of the wound. It ratches up cells metabolic rates to better repair the cells. The histamine causes nearby capillaries to release protein rich fluids.

swelling due to…:

The release of protein rich fluids, which helps clot the blood

heat and pain to…

: When white blood cells are outnumbered to foreign entities they release pyrogenchemicals which allows cells to heal faster.

inflammatory response:

Skin is breached, histamine molecules are sent out and vasodilation occurs, nearby capillaries release protein rich fluids, neutrophils begin to die, so the skin cells call for leukocytosis to begin, neutrophils are attracted to the area, neutrophils flatten along the site and create walls. Monocytes arrive and become macrophages replacing the now dead neutrophils. The macrophages eat enemies and lingering carnage.

differences between innate and adaptive immunity:

Innate immediately tries to destroy foreign substances, while adaptive needs to be exposed to the specific pathogen and recognize it as a threat. The adaptive immune system can fight throughout the whole body at once through 1-2 cellular defenses

Humoral immunity:

a component of the adaptive immune system mediated by antibodies secreted by Bcells, which circulate in extracellular fluid to neutralize pathogens like bacteria and viruses

Lymphocytes:

B cells T cells Natural Killer cells

B cells:

produced and matured in the bone marrow, activate by interacting with antigen and becoming activefighters or effecter cells with lived memory cells ( Identify pathogens and produce specialized antibodies to neutralize them)

Active Humoral Immunity:

B cells bump into antigens and start cranking out antibodies. (only occursnaturally or via vaccination)

Passive Humoral Immunity:

receive of ready made antibodies from mothers placenta, breast milk. Can also be acquired via plasma. Antibodies are transferred into somebody before their active immunity could identify their particular antigen and create their own antibodies.

vaccines work by…:

introducing a pathogen into your body preparing the body to fight if that antigen comes around again. It does this by immediately engaging b cells

Cell mediated immunity:

antigen presenting cells t-cells helper t cells cytotoxic t cells regulatory t cells B cells

antigen presenting cells:

specialized white blood cells that engulf pathogens and display antigens on their surface for recognition by T Cells

T cells:

patrols the body to detect invaders, destroy infected or damaged cells, and orchestrate the immune response by activating other immune cells

Helper T cells:

they stimulate B cells to differentiate into plasma cells, which in turn produce antibodies and adaptive immune response (can activate kill cells)

cytotoxic t cells:

(adaptive) roam blood and lymph and are the cells that can destroy infected cells by triggering apoptosis

regulatory t cells:

release inhibiting cytokines that help prevent autoimmune disorders

B and T cell interaction:

B cells bind to intact pathogens through their surface receptors on MHC. A helper T cell with a matching receptor binds to the peptide-MHC complex on the B cell. The helper T cell sends signals through direct cell-to-cell contact and secretes cytokines to activate the B cell. These signals cause the B cell to divide rapidly and differentiate into antibody-producing plasma cells and memory cells