Biology Chapter: Immune Defense Mechanisms

Questions and Answers

What is the function of T helper cells in the immune response?

They kill pathogen-infected cells directly.

They release substances that activate B cells. (correct)

They produce antibodies to fight off pathogens.

They form antigen-antibody complexes.

What occurs when a B cell's antibody binds to a complementary antigen?

The pathogen is destroyed immediately.

The B cell loses its ability to recognize antigens.

The B cell is activated and divides. (correct)

The B cell undergoes apoptosis.

How do T killer cells respond to infected cells?

They bind and activate B cells.

They form memory cells to remember the antigen.

They release antibodies to neutralize the pathogen.

They attach to antigens on the infected cell and kill it. (correct)

What defines the specific immune response?

It is antigen-specific and targets specific pathogens. Signup and view all the answers

What do B memory cells do after the immune response?

They remain inactive until the same antigen is encountered again. Signup and view all the answers

What is the primary role of stomach acid in relation to pathogens?

It kills most pathogens that enter the stomach. Signup and view all the answers

What happens when the skin is damaged?

Pathogens can enter the bloodstream before blood clots form. Signup and view all the answers

What is the function of lysozyme found in mucosal secretions?

It damages bacterial cell walls, leading to their destruction. Signup and view all the answers

What characterizes the non-specific immune response?

It attacks all microorganisms regardless of their antigens. Signup and view all the answers

What occurs first in the process of phagocytosis?

The pathogen is recognized by the surface receptors. Signup and view all the answers

What role do T cells play in the immune response?

They bind to antigens presented by different immune cells. Signup and view all the answers

Which process involves the engulfing of pathogens by phagocytes?

Phagocytosis Signup and view all the answers

What triggers the inflammation response during a non-specific immune response?

Recognition of foreign antigens by immune cells. Signup and view all the answers

Study Notes

Stomach Acid and Pathogen Defense

Stomach acid primarily kills many pathogens ingested with food and drink, providing an initial defense.
Some pathogens can survive stomach acid and reach the intestines, where they may invade gut cells and cause disease.

Skin as a Barrier

Skin serves as a physical barrier protecting against pathogens.
Damaged skin allows pathogens entry into the bloodstream, increasing infection risk.
Blood clots form at injury sites to block pathogens, but some may infiltrate before clot formation.

Lysozyme Function

Mucosal surfaces in the eyes, mouth, and nose produce secretions like tears, saliva, and mucus containing lysozyme.
Lysozyme is an enzyme that kills bacteria by damaging their cell walls, leading to bacterial lysis (bursting).

Non-Specific Immune Response

This immune response targets all microorganisms non-specifically without regard for foreign antigens.
Initial action includes recognition of foreign antigens, triggering inflammation through released signaling molecules.
Vasodilation occurs to increase blood flow to the infection site, enhancing immune cell delivery.
Increased vessel permeability allows immune cells to exit blood vessels and infiltrate infected tissues.
Phagocytes play a crucial role by engulfing pathogens and presenting their antigens to activate further immune responses.

Phagocyte Mechanism

Phagocytes recognize pathogen antigens and engulf pathogens into a phagocytic vacuole.
Lysosomes fuse with vacuoles to break down pathogens using digestive enzymes.
Phagocytes function as antigen-presenting cells, displaying antigen fragments to activate T cells.

T Cells Overview

T cells, a type of white blood cell, are equipped with unique surface receptors that recognize specific antigens.
Binding of T cell receptors to antigens activates T cells, triggering cell division to produce clones.
Different T cell subtypes have specialized roles:
- T helper cells activate B cells and other immune cells.
- T killer cells kill pathogen-infected cells.
- Memory T cells remain for future antigen recognition.

Specific Immune Response Involving B Cells

B cells, another type of white blood cell, are covered in antibodies that bind to antigens.
Each B cell has distinct antibodies that recognize different antigens.
Upon binding to a complementary antigen, B cells become activated with help from T cells.
Activated B cells undergo mitosis to produce plasma cells, which secrete antibodies, and memory B cells for long-term immunity.
The specific immune response is tailored to target specific pathogens, highlighting the importance of T and B cells in immune defense.

Description

Explore the complex roles of stomach acid, skin barriers, lysozymes, and the non-specific immune response in protecting the body from pathogens. This quiz covers key concepts of how our body defends itself from infections and disease-causing microorganisms.