Immunity And Lymphatic System Flashcards
Immunology
Study of the physiologic mechanisms by which the body recognizes foreign materials, and works to neutralize or eliminate them
Antigen
Any foreign substance in the body that does not have a characteristic cell surface markers of that individual it is also capable of eliciting an immune response
When encountering an antigen, the main system recognizes it as non-self, and there is an appropriate immune response against the antigen
Types of immunity
Innate which is nonspecific immunity
acquired, which is specific immunity
Innate immunity
Intact skin, mucosal barriers is the body’s first line of defense to prevent the entry of pathogens
inflammatory response
Fever
Inflammatory response
Innate immunity
protective tissue response to injury or invasion
Vascular changes, arterioles and capillaries dilate, hyperemia
Causes heat and redness
Increase blood flow equals increased leukocytes (neutrophils) to defend against invaders
Speed healing process by engulfing cell debris, by phagocytosis
Damaged tissue releases histamine, which increases cell permeability
Swelling increased pressure on nerve endings is pain
Histamine role
Damaged tissue releases histamine, which increases cell permeability
This allows white blood cells and plasma to escape capillaries and enter the damaged tissue
Suppurative inflammation
Pyogenic bacteria (pus)
Steps of inflammatory response
Dirty nail puncture skin
Bacteria enter and multiply
Injured cells, release, histamine
Blood vessels dilate, and become permeable, releasing inflammatory exudate
Blood flow to the damage site increases
Neutrophils move towards bacteria and destroy them
Wound healing
Regeneration, which is the replacement of destroyed tissue with the same type of cells
Fibrosis, where fibroblast produce collagen fibers from a meshwork which result in scar tissue, and can be raised and hard, also known as a keloid
Acquired immunity
Specific immunity
Lymphatic system
Acts as bodys second line of defense to recognize and destroy foreign substances, and to prevent the proliferation of mutant cells
Uses specificity and memory
The body produces a specific response to the invader, immune system has a memory so if the same organism is countered again there is a more rapid response.
Passive acquired immunity
Receipt of protective substances produced by another human or animal
Active acquired immunity
Immunity develops, following direct exposure to the pathogenic agent
Immunizations or vaccinations are special types of active acquired immunity
Lymphatic system
Spleen- major lymph filter, hemopoiesis
Lymph nodes- initial filter within lymphatic system
Lymphocytes -widely distributed throughout the body
B lymphocytes
Acquired immunity
Humoral immunity lymphocytes, originate in stem cells in bone marrow
Differentiate into plasma, cells are memory cells, dormant until activated by the same antigen
More potent and rapid response
Secrete antibodies into the blood stream – plasma proteins, called immunoglobins
Particularly used in fighting bacterial infections
T lymphocytes
Cell mediated immunity
Cytotoxic T cells
Helper, T cells
Suppressor T cells
Mature in thymus gland
Affected by HIV and AIDS
Cell mediated t lymphocytes
T cells interact directly with their targets attacking body cells, invaded by pathogens
Responsible for continual recognition and removal of bacteria, viruses fungi, parasites, tumors and foreign tissue
Is responsible for rejection of transplant, tissue hypersensitivity, and auto immune diseases
How do T lymphocytes contribute to the immune system?
Turn the system on and off
When turning it on the cytotoxic T cells and helper, T cells are natural killers of cells. They directly attack and kill invader cells, and sometimes normal cells as well
when they turn the system off the suppressor T cells stop all cytotoxic T cell functions, therefore, reducing the immune response this is important to have when the bodies immune system is attacking its own normal tissue
Leukocytes
White blood cells
Protect the body against foreign invasion
Infection stimulates white blood cell production
Types of leukocytes
Neutrophil
Eosinophil
Basophil
Monocyte
Lymphocyte
Neutrophil
Most numerous of the white blood cells
Kills organisms by phagocytosis
Neutrophils die, following phagocytosis
Accumulation of dead neutrophils contribute to the formation of pus
Monocytes
Macrophages, large eaters
Participate in phagocytosis
Identify antigens as foreign invaders can introduce the pathogen to lymphocytes stimulating specific immune response
Stimulation of macrophages can boost immune system
Lymphocytes
Help kill tumor cells and control immune responses
Eosinophils and basophils
Allergic reactions and parasitic infestations
Infectious disease in developed countries and developing countries
Accounts for one out of 10 deaths in developed countries
Accounts for six out of 10 deaths in developing countries
Contagious disease two types
Communicable, transmitted from he went to human like measles or influenza
Non-communicable, not transmit it directly from humans like rabies or cholera
Epidemiology
Study of the transmission, occurrence, distribution and control of disease
Incidence
Number of new cases of a disease in a population
Prevalence
Number of existing cases
Reservoir
The source of an infectious agent, such as humans, animals, insects, soil, and water
Horizontal transmission
Infectious disease is transmitted directly from an infected person to a susceptible person
Vertical transmission
Occurs from one generation to the next
Parenteral route of transmission
Occurs through a port of entry
Fomites
Inanimate objects that are contaminated by direct contact with the reservoir
Viruses
Cellular organisms made up of only in RNA or DNA nucleus covered with proteins
Completely dependent on host cells
Cannot replicate unless they invaded host cell and stimulate it to participate in the formation of additional virus particles
Not susceptible to antibiotics cannot be destroyed pharmacologically, antivirals might mitigate
Bacteria
Single celled micro organisms with well defined cell walls
Can grow independently without the need for other cells
Can mutate and develop insensitivity or resistance to antibiotics
Staphylococcus infections
Staphylococcus aureus is the most common bacterial pathogens normally residing on the skin
Inoculated into deeper tissues where it causes suppurative infections
Spread through direct contact with colonized surfaces or persons
It cannot invade through intact skin or mucous membranes, usually invades through traumatic event
It’s not easily removed by scrubbing
Group A streptococci
One of the most frequent bacterial pathogens of humans of any age
Causes diseases of many organ systems
Bacteria, invade, and cause tissue necrosis creating an acute inflammatory response
Examples include strep throat , necrotizing, fasciitis, cellulitis, and myositis
Group B streptococci
Leading cause of neonatal, pneumonia, meningitis and sepsis
Common cause of community acquired pneumonia
Pseudomonas
Major opportunistic, pathogen, and one of the most antibiotic resistant bacteria
Most frequent hospital, or nursing home acquired infection (nosocomial)
Thrives on moist environmental surfaces
This infections have a characteristic fruity odor
Fight infections include skin and soft tissue the central nervous system and bone and joints
Is a transient organism, unable to survive more than 24 hours on the skin
It is easily removed by washing with soap, water, and friction
Gangrene
The death of body tissue due to loss of vascular supply, followed by bacterial infection, and putrefaction.
It can be dry, moist gas, and all of which need to be quickly recognized and treated to prevent further loss of tissue digits or limb
Nosocomial infections
Also known as hospital acquired infections
About 1.7 million patients in the US contract a hospital base infection each year.
About 99,000 deaths in the US per year
The principle roots of transmission is direct contact transmission from healthcare staff to patient and indirect contact transmission through the hospitals by ventilation system
