U2.2.1 Flashcards
Nonspecific Defense: First or Second line of defense?
- includes non-specific cellular and chemical responses to microbial invasion
The Second Line of Defense
What are the mechanisms under the Second Line of Defense?
- Phagocytosis
a. White Blood Cells
b. Macrophages - Inflammation
- Chemical responses
Second line of defense: What mechanism? Phagocytosis, Inflammation, or Chemical responses?
- refers to the ingestion of solid particles such as microorganisms or cellular debris by eukaryotic cells. It involves phagocytes, cells that engulf and digest foreign substances. The phagocytes include the white blood cells and macrophages.
- White blood cells, macrophages
Phagocytosis
Non-Specific Defense: Second line of defense: Phagocytosis: White blood cells or macrophages?
- also known as leukocytes
White blood cells
Non-Specific Defense: Second line of defense: Phagocytosis: White blood cells:
- __________ and _____________ are sometimes referred to as “professional phagocytes” since phagocytosis consists their primary function.
- ___________ also sometimes perform phagocytosis.
Neutrophils; monocytes; Eosinophils
Non-Specific Defense: Second line of defense: Phagocytosis: White blood cells:
- During early stages of inflammation, leukocytes accumulate and adhere to the epithelial cells of blood vessel walls at the site of injury, this process is known as ___________.
margination
Non-Specific Defense: Second line of defense: Phagocytosis: White blood cells:
- They move from the blood stream by passage through the endothelium and enter tissues. The outward passage of blood cells through intact vessel walls is called ________
diapedesis
Non-Specific Defense: Second line of defense: Phagocytosis: White blood cells:
- __________ move out first, followed by ____________ and ____________.
Neutrophils; monocytes; lymphocytes
Non-Specific Defense: Second line of defense: Phagocytosis: White blood cells or macrophages?
- tissue cell counterpart of monocytes.
- They constitute the Mononuclear Phagocyte System (MPS) and are distributed throughout the body either wandering or fixed
- named differently depending on their location
Macrophages
Non-Specific Defense: Second line of defense: Phagocytosis: What is its process?
- Chemotaxis
- Adherence
- Ingestion
- Digestion
- Elimination
Non-Specific Defense: Second line of defense: Phagocytosis: What process?
- the directional movement of cells in response to chemical stimulus
- initiated by chemotactic agents that attract phagocytes. These includemicrobial products, components of damaged cells, or chemicals released by leukocytes.
Chemotaxis
Non-Specific Defense: Second line of defense: Phagocytosis: Chemotaxis:
- Phagocytes use ___________ to move toward the chemical stimulus.
pseudopods
Non-Specific Defense: Second line of defense: Phagocytosis: What process?
- attachment of the phagocyte’s cell membrane to the surface of the material to be ingested. The attachment of phagocytes is a requirement for ingestion and may be unenhanced or enhanced.
- enhanced and unenhanced attachment
Adherence
Non-Specific Defense: Second line of defense: Phagocytosis: Adherence:
- also known as opsonin- independent or non-opsonic
- involves generalized recognition and attachment of phagocytes by way of its surface glycoproteins to certain components of microorganisms such as peptidoglycan, teichoic acids, lipopolysaccharide (LPS) and mannose which are not present in human cells
Unenhanced attachment
Non-Specific Defense: Second line of defense: Phagocytosis: Adherence:
- also called opsonin-dependent
or opsonic. - Attachment can be made easier through
the process of opsonization, in which the microorganisms are coated with serum proteins collectively called opsonins (antibodies such as IgG and IgM, and complement component C3b); therefore, increases the efficiency by which phagocytes ingest microorganisms.
Enhanced attachment
Non-Specific Defense: Second line of defense: Phagocytosis: What process?
- The phagocyte extends pseudopodia to surround the material and completely encloses the material within a membrane bound vesicle called phagosome.
Ingestion
Non-Specific Defense: Second line of defense: Phagocytosis: Ingestion:
- The phagocyte extends pseudopodia to surround the material and completely encloses the material within a membrane bound vesicle called __________.
phagosome
Non-Specific Defense: Second line of defense: Phagocytosis: What process?
- A digestive vacuole called phagolysosome is formed by fusion of the phagosome and lysosomes containing hydrolytic enzymes. After which, lysosomes release their contents, a process known as degranulation. For most bacteria, this is completed in 10-30 minutes.
Digestion
Non-Specific Defense: Second line of defense: Phagocytosis: Digestion:
- A digestive vacuole called ____________ is formed by fusion of the phagosome and lysosomes containing hydrolytic enzymes. After which, lysosomes release their contents, a process known as ____________. For most bacteria, digestion is completed in __________ minutes.
phagolysosome; degranulation; 10-30
Non-Specific Defense: Second line of defense: Phagocytosis: What process?
- The residual body — indigestible materials in the
phagolysosome are released from the phagocyte by
exocytosis in which the phagolysosome fuses with the cell membrane and expels its contents.
Elimination
Non-Specific Defense: Second line of defense: Phagocytosis: Elimination:
- The residual body — indigestible materials in the phagolysosome are released from the phagocyte by ________________ in which the phagolysosome fuses with the cell membrane and expels its contents.
Exocytosis
Non-Specific Defense: Second line of defense: Phagocytosis: What are its functions?
(a) Killing invading microbes.
(b) Disposal of damaged and dying cells from spleen.
(c) Removal of tissue debris from repairing wounds.
(d) Removal of debris as embryonic tissues replace one another.
(e) Removal of cancer cells.
(f) Suppression of the growth of spontaneously arising tumors.
