Biology Chapter 5: Immune Defense Mechanisms

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Questions and Answers

Which of the following is a part of the second line of defence against microorganisms?

Cilia

Phagocytes (correct)

Gastric acid

Sebum

Which enzyme found in saliva and tears is responsible for destroying certain bacteria?

Salivase

Lysozymes (correct)

Sebum

Amylase

Which nonspecific defence cell is primarily responsible for attacking early cancer cells and virus-infected cells?

Mast cells

Natural killer cells (correct)

Neutrophils

Macrophages

What is primarily characterized by increased vascular permeability to serum proteins in the inflamed area?

Increased vascular permeability Signup and view all the answers

Examples of second lines of defence include:

Natural killer cells Signup and view all the answers

Which of the following processes is involved in the proliferative phase of wound healing?

Remodelling of collagen to increase tissue strength Signup and view all the answers

The aetiology (cause) of the acute inflammatory response could include:

Dust, bites and infection Signup and view all the answers

Which main phagocytic cells in the body include neutrophils?

Macrophages and neutrophils Signup and view all the answers

Which substance released by virus-infected cells helps protect uninfected cells?

Interferons Signup and view all the answers

What causes the swelling observed in an acute inflammatory response?

Leakage of fluid due to increased permeability of blood vessels Signup and view all the answers

Which type of microorganism is capable of producing endospores?

Bacteria Signup and view all the answers

Bacteria categorized as gram positive or gram negative are distinguished based on what characteristic?

Cell wall structure Signup and view all the answers

Which term is used to describe a mutated protein associated with diseases like Mad Cow and Creutzfeldt-Jakob?

Prion Signup and view all the answers

What characteristic distinguishes a virus from other microorganisms?

Dependence on a host cell for replication Signup and view all the answers

What defines an opportunistic infection?

It is caused by organisms that typically do not cause disease under normal conditions Signup and view all the answers

What is the significance of a superbug?

It is resistant to multiple antibiotics Signup and view all the answers

What is a healthcare-associated infection (HAI)?

An infection acquired by patients in hospital settings Signup and view all the answers

Which body part is most frequently associated with hospital-acquired infections?

Skin Signup and view all the answers

What does polypharmacy commonly refer to?

Concurrent use of multiple medications Signup and view all the answers

What is one of the main functions of natural killer cells?

To attack early cancer cells and virus-infected cells Signup and view all the answers

What type of microorganism requires a host cell for replication?

Virus Signup and view all the answers

What is the primary material involved in the infectious nature of a prion?

Protein Signup and view all the answers

Which of the following best describes a superbug?

A microorganism resistant to multiple types of antibiotics Signup and view all the answers

In the inflammatory response, which white blood cell is primarily responsible for phagocytosing pathogens and debris?

Neutrophils Signup and view all the answers

Which organisms are the most common cause of hospital-acquired infections?

Bacteria Signup and view all the answers

What is a true statement regarding the half-life of a drug?

It represents the time required for the drug's concentration to reduce by half Signup and view all the answers

Which of the following cells assists in the repair of tissues during wound healing?

Macrophages Signup and view all the answers

What characteristic distinguishes gram positive bacteria from gram negative bacteria?

Thickness of the cell wall Signup and view all the answers

What type of drug administration is represented by a patch applied to the skin?

Transdermal Signup and view all the answers

Which white blood cell is primarily responsible for engulfing pathogens and dead cells during an acute inflammatory response?

Neutrophils Signup and view all the answers

What is the significance of vasodilation in the inflammatory response?

It leads to heat and redness in the affected area. Signup and view all the answers

Which antimicrobial protein is found in both saliva and tears?

Lysozymes Signup and view all the answers

What type of immunity is provided by the secretion of antibodies by B lymphocytes?

Humoral immunity Signup and view all the answers

What is the role of CD 8 cells in the immune system?

Conduct a toxic attack on infected cells. Signup and view all the answers

Which clinical situation exemplifies active artificial immunity?

Vaccination against a disease. Signup and view all the answers

Which antimicrobial protein is specifically found in saliva and tears?

Lysozymes Signup and view all the answers

What is a characteristic event of the inflammatory phase of wound healing?

Fibroblasts invade the site and secrete collagen into the tissue. Signup and view all the answers

What does the innate defense system primarily protect the body from?

All foreign substances Signup and view all the answers

Which component serves as an important innate defense mechanism in the urinary tract?

Normal urine flow Signup and view all the answers

Isolating an infected person serves to break which part of the chain of infection?

Mode of transmission Signup and view all the answers

In the chain of infection, what does the mode of transmission refer to?

The way microorganisms are transferred from a source to a host. Signup and view all the answers

If an infection is transmitted through handling a contaminated object, what type of transmission is it?

Indirect contact transmission Signup and view all the answers

What term is used to describe antibiotics that inhibit bacterial replication to assist the host's immune response?

Bacteriostatic Signup and view all the answers

What is the significance of lysozymes in immune defense?

They break down cell walls of bacteria. Signup and view all the answers

Which antibiotic works by inhibiting cell wall synthesis?

Penicillin Signup and view all the answers

Study Notes

Immune System Defense Mechanisms

The second line of defense against microorganisms includes phagocytes, which engulf and digest pathogens.
The first line of defense encompasses physical and chemical barriers such as cilia, mucous, and lysozymes found in saliva and tears that destroy bacteria.
Inflammatory response involves increased vascular permeability, allowing serum proteins to enter inflamed areas, promoting healing.

Inflammation and Healing

Acute inflammatory response (AIR) can be triggered by dust, bites, or infection, causing swelling due to fluid leakage from increased blood vessel permeability.
The proliferative phase of wound healing is characterized by the formation of new epithelial tissue.

Microorganisms Characteristics

Bacteria can be classified as gram-positive or gram-negative based on their cell wall structure.
Endospores are produced specifically by bacteria, allowing them to survive harsh conditions.
Prions, which are mutated proteins, are responsible for Mad Cow disease and Creutzfeldt-Jakob disease.

Cellular and Molecular Biology

Viruses require a host cell to reproduce, possessing genetic material surrounded by a capsid.
Fimbriae are appendages that allow bacteria to adhere to surfaces, aiding in infection establishment.
The process of protein synthesis begins with transcription, where mRNA is synthesized from DNA.

Antibiotics and Drug Mechanisms

Penicillin functions by inhibiting cell wall synthesis, making it effective against certain bacterial infections.
The therapeutic index measures a drug's safety, indicating its efficacy without harming the host.
Antibiotics that inhibit folic acid synthesis exploit the difference between human and bacterial metabolism for selective toxicity.

Infection Types and Control

Opportunistic infections can arise from normally harmless organisms when host defenses are compromised.
Healthcare-associated infections are acquired in medical settings, with common causes being bacterial agents.
Vector transmission refers to the spread of pathogens by insects, while fomites are inanimate objects that can carry infectious agents.

Drug Absorption and Administration

Transdermal administration, commonly via patches, bypasses gastrointestinal absorption, delivering medication through the skin.
The effectiveness of parenteral drug administration can be affected by local vascularization, impacting how the drug is absorbed.

Notable Scientists and Their Contributions

Robert Koch is credited with proposing the germ theory of disease, establishing the connection between specific pathogens and diseases.
Robert Hooke was the first to use the term "cell," advancing the field of cellular biology.

Miscellaneous Biological Concepts

Probiotics refer to beneficial bacteria that promote gut health.
The zone of inhibition in a disc diffusion test indicates the susceptibility of bacteria to antibiotics.

Additional Notes

Neutrophils are the primary white blood cells involved in the immediate response to infections, engaging in phagocytosis.
The innate defense system is non-specific and ready to combat all foreign substances entering the body.

Acute Inflammatory Response

Neutrophils are the primary white blood cells that enter injured sites to engulf pathogens and dead cells.

Signs of Inflammation

Vasodilation results in swelling and redness during the inflammatory process, contributing to visible inflammation.

Antimicrobial Proteins

Lysozymes are antimicrobial proteins found in saliva and tears, helping to protect against infections.

Innate Defense System

The innate defense system is always prepared to protect the body from all foreign substances, not limited to specific pathogens.

Second Line of Defense

Key players in the body's second line of defense include natural killer cells and phagocytes.

Urinary Tract Defense Mechanism

Normal urine flow is a critical innate defense mechanism in the urinary tract that helps eliminate pathogens.

Chain of Infection

Isolating an infected person prevents disease spread and breaks the chain of infection at the source.

Mode of Transmission

The mode of transmission involves how microorganisms are transferred from a source to a susceptible host.

Serology Reports

A serology report indicates the presence of specific antibodies in the blood, providing insights into immune response.

HIV Impact

HIV specifically destroys Helper T cells, which are crucial for a robust immune response.

Origin of Lymphocytes

B and T lymphocytes originate in the red bone marrow.

Plasma Cell Function

Plasma cells secrete antibodies, vital for immune defense.

Role of T Lymphocytes

T lymphocytes participate primarily in cell-mediated immunity.

Humoral Immunity

The secretion of antibodies by B lymphocytes is responsible for humoral immunity.

Function of CD8 Cells

CD8 cells perform a toxic attack on cells associated with antigens.

Specific Immune System

Natural killer cells do not belong to the specific immune system; these are part of the innate response.

Shingles and Previous Disease

An elderly individual developing shingles has previously been exposed to chicken pox.

Vaccination and Immunity

Vaccinating an individual exemplifies active artificial immunity.

Immune Response Categories

Both plasma cells and memory cells are components of the humoral immune response.

Types of Lymphocytes

The body's lymphocytes consist of two main categories: B cells and T cells.

Breastfeeding and Antibodies

Antibodies passed from a mother to her baby during breastfeeding represent passive natural immunity.

Active Natural Immunity

Active natural immunity occurs when someone becomes infected with whooping cough bacteria.

Cytotoxic T Cells Role

Cytotoxic T cells are part of the cell-mediated immune response, targeting infected or damaged cells.

B Lymphocyte Maturation

B lymphocytes mature in the red bone marrow.

Helper T Cells Function

Helper T cells release cytokines that activate various components of the immune system.

Adaptive Immunity

Adaptive immunity is also known as specific immunity, characterized by its targeted response to specific pathogens.

T Lymphocyte Maturation

T lymphocytes mature in the thymus gland.

Cell-Mediated Immune Response

T lymphocytes are primarily involved in the cell-mediated immune response.

Humoral Immune Response Product

Antibodies are produced as part of the humoral immune response.

Active Artificial Immunity Example

Vaccination against chicken pox illustrates active artificial immunity.

Cytokine Release

Activated Helper T cells release cytokines that facilitate immune responses.

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Description

Explore the second line of defense against microorganisms in this quiz, focusing on the roles of various bodily fluids and cells. Assess your understanding of the immune system's mechanisms, including the first line of defense and the inflammatory response.