nr222 unit 5 innate immune function (1/2)

A set of 50 flashcards covering innate immune function, lines of defense, blood cell types, phagocytosis, inflammation, and chemical defenses based on the lecture transcript.

What is the branch of the immune system that is present at birth and not specific to a particular pathogen?

Innate immunity (also known as nonspecific immunity)

What is the branch of the immune system that can marshal specific defenses against individual pathogens?

Acquired or adaptive immunity (also known as specific immunity)

What does the medical abbreviation CBC stand for when assessing immune system status?

Complete blood count

Which lineage of blood cells includes platelets, monocytes, macrophages, basophils, neutrophils, and eosinophils?

Myeloid lineage

Which specific lymphocytes are known as the "warriors" of the adaptive immune system?

T cells and B cells

Into which three categories can the first line of defense be broken down?

Physical, chemical, and microbiota barriers

How do mucous membranes provide physical protection?

They secrete mucus that prevents microorganisms from attaching to epithelial cells

What are three mechanical processes that physically remove microorganisms from the body?

Vomiting, defecation, and urination

What two specific properties of sweat provide a chemical barrier to infection?

Acidity and high salt concentrations

What is the antimicrobial secretion produced by sebaceous glands?

Sebum

Which enzyme found in tears and saliva can hydrolyze bacterial cell walls?

Lysozyme

What substance in the stomach destroys microorganisms present in food and drinks?

Hydrochloric acid (HCl)

In what three ways do resident microbiota act as a barrier to infection?

Preventing access to epithelial surfaces, competing for nutrients, and altering environmental pH

Which specialized cells located in the skin and mucosa phagocytize invaders and raise the alarm to the adaptive immune system?

Dendritic cells

What are the four types of cells capable of performing phagocytosis?

Neutrophils, eosinophils, macrophages, and dendritic cells

What is the first step of phagocytosis, involving the movement of cells toward bacteria?

Chemotaxis

What occurs during the adhesion step of phagocytosis?

Bacteria attach to receptors on the phagocytic cell surface

What is the name of the digestive vacuole that forms around bacteria in the cytoplasm during phagocytosis?

Phagosome

During phagocytosis, what is formed when a phagosome merges with a lysosome?

Phagolysosome

What two contents of a lysosome are responsible for killing and destroying bacteria?

Digestive enzymes and oxygen radicals

Where do all blood cells (leukocytes) originate?

From hematopoietic stem cells in the bone marrow

What characterizes granulocytes?

They contain granules in their cytoplasm that stain colors unique to each cell type

What percentage of leukocytes do neutrophils make up?

$$55-90\%$$

Which white blood cells are the first to arrive at a site of infection?

Neutrophils

What toxic forms of oxygen are released by neutrophils?

Superoxide anions and free hydroxyl radicals

What chemical that mediates inflammation is found in the dark blue granules of basophils?

Histamine

What color do the cytoplasmic granules of eosinophils stain?

Orange

Which specific pathogens do the peroxidase and lysozyme in eosinophil granules target?

Helminths

What do monocytes differentiate into when they migrate to tissues?

Macrophages

Which cells of the adaptive immune system produce antibodies and fight extracellular bacteria?

B cells

What are the specific targets of T cells?

Virally-infected cells and cancer cells

How are natural killer (NK) cells classified in terms of specificity?

They are nonspecific cells

What protein produced by virally-infected cells binds to nearby receptors to block viral replication?

Interferon

How many proteins are involved in the complement system?

Up to $50$ proteins

What are the three pathways by which the complement system can be activated?

Classical, lectin, and alternative pathways

What is the outcome called when complement proteins punch a hole into a pathogen's membrane?

Membrane attack complex (MAC)

What are the four characteristic signs of inflammation?

Redness, heat, swelling, and pain

What is the first event that occurs at the time of injury during inflammation?

Vasoconstriction of surrounding blood vessels and release of chemical mediators by mast cells

What process allows white blood cells to enter the tissue when blood vessels become more permeable?

Diapedesis

What is the name of the fluid plasma that seeps into tissue during inflammation?

Exudate

What is the medical term for the swollen and firm tissue caused by accumulation of exudate?

Edema

What substance found in swollen tissue is primarily composed of white blood cells?

Pus

Which cells are responsible for removing pus and damaged tissue during the resolution phase of inflammation?

Macrophages

Which part of the brain maintains the body's normal temperature?

The hypothalamus

How does fever assist the body's defense regarding iron availability?

It reduces the availability of iron, which many pathogens require for survival

What general term refers to substances that stimulate the brain to increase body temperature?

Pyrogens

What is a well-known exogenous pyrogen shed from gram-negative bacteria?

Endotoxin

What are two examples of endogenous pyrogens released by monocytes, neutrophils, and macrophages?

Interleukin-1 and tumor necrosis factor

What is the term for the cascading activation process seen in the complement system?

Cascading fashion (the first activated protein activates the next protein in series)

What specific type of cells do T cells and NK cells both target despite different specificity?

Virally-infected cells and cancer cells