/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 2 How does the human body use a ch... [FREE SOLUTION] | 91影视

91影视

Log out

Learning Materials

Features

Discover

Chapter 33: Problem 2

How does the human body use a chemical barrier as part of the innate immune response? a. Mucus secretions trap and rinse pathogens out of the body. b. Urination carries pathogens out of the urinary tract. c. Low pH conditions in the stomach kill some pathogens and prevent other pathogens from growing. d. Cilia in the nasal passages and respiratory tract push mucus containing trapped pathogens out of the body

Short Answer

Expert verified
Option (c) is correct: The low pH in the stomach acts as a chemical barrier.

Step by step solution

01

- Understanding Innate Immune Response

The innate immune response is the body's first line of defense against pathogens. It includes physical barriers like skin and mucous membranes, as well as chemical barriers that destroy invaders.
02

- Chemical Barriers

Chemical barriers involve substances that can inhibit or kill microorganisms. Examples include enzymes in saliva, acidic pH in the stomach, and antimicrobial molecules in bodily fluids.
03

- Analyzing Option (c)

Option (c) mentions 'Low pH conditions in the stomach kill some pathogens and prevent other pathogens from growing.' This is a classic example of a chemical barrier because the acidic environment of the stomach inhibits microbial growth.
04

- Evaluating Other Options

Each of the other options describes a mechanical or physical process: (a) Mucus trapping, (b) Urination, (d) Cilia movement. These are not chemical barriers.
05

- Conclusion

Option (c) is the correct choice because it describes a chemical barrier that uses low pH to eliminate pathogens in the stomach.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91影视!

Key Concepts

These are the key concepts you need to understand to accurately answer the question.

chemical barriers
Chemical barriers are substances produced by the body to protect against pathogens. These barriers play a crucial role in the innate immune response. They leverage the chemical properties of various bodily fluids and tissues to inhibit or destroy microorganisms. Examples of chemical barriers include:
  • Enzymes in saliva and tears that break down bacterial cell walls
  • Low pH levels in the stomach that create an acidic environment hostile to many pathogens
  • Antimicrobial peptides in the skin and other tissues that can kill bacteria and viruses
These substances form an essential part of the immune system and help prevent infections before they can establish themselves in the body.
pathogens
Pathogens are harmful microorganisms that can cause diseases. They include bacteria, viruses, fungi, and parasites. Pathogens can enter the body through various routes such as inhalation, ingestion, or through breaks in the skin. Once inside, they can multiply and cause infections. The body employs multiple strategies to combat pathogens, including:
  • Physical barriers like skin and mucous membranes
  • Chemical barriers that use substances to kill or inhibit them
  • Various cells of the immune system that can recognize and destroy them
Understanding the different types of pathogens and how they interact with the human body helps in developing effective treatments and preventive measures against diseases.
immune system
The immune system is the body's defense mechanism against infections and diseases. It is composed of a network of cells, tissues, and organs that work together to detect and combat pathogens. The immune system can be divided into two main parts:
  • Innate immune response: The body's first line of defense, including physical and chemical barriers, and various immune cells like macrophages and natural killer cells that respond quickly to invaders.
  • Adaptive immune response: A more specialized response that targets specific pathogens, involving lymphocytes such as B-cells and T-cells. These cells remember past infections and provide long-lasting immunity.
The innate immune response acts quickly to destroy incoming threats and sets the stage for the adaptive immune response to take over and eliminate infections more precisely.

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

What is the function of major histocompatibility class (MHC) I molecules? a. MHC I molecules assist with strengthening the cell membrane. b. MHC I molecules present antigens on the surface of a cell. c. MHC I molecules allow movement of materials across the cell membrane. d. MHC I molecules provide signals for processes involved in cell division

How does the humoral immune response operate? a. The humoral immune response primarily targets infected host cells to destroy them before the infecting pathogen can reproduce. b. The humoral immune response produces antibodies that are specifically targeted against each pathogen. c. The humoral immune response produces cytotoxic T cells that induce apoptosis in pathogen infected cells. d. The humoral immune response is the only system that involves memory cells that are able to respond later to a pathogen that has invaded the body at an earlier time.

Why might different MHC I molecules between donor and recipient cells lead to rejection of a transplanted organ or tissue? a. The natural killer cells in the recipient will identify the MHC I molecules on transplanted organ as non-self proteins, causing lysis of transplanted cells. Other host cells will join to phagocytize the foreign cells. b. The neutrophils in the recipient will identify the MHC I molecules on transplanted organ as nonself proteins, causing lysis of transplanted cells. Other host cells will join to phagocytize the foreign cells. c. B lymphocytes in the recipient will identify the MHC I molecules on transplanted organ as nonself proteins. The foreign cells will then be engulfed and destroyed by B lymphocytes. d. The macrophages in the recipient will identify the MHC I molecules on transplanted organ as non-self proteins, causing lysis of transplanted cells. Other host cells will join to phagocytize the foreign cells.

What is the difference between natural killer cells and macrophages? a. Natural killer cells are not always present in the body and must be induced, whereas macrophages are constantly present. b. Natural killer cells actually kill foreign cells, whereas macrophages serve only a signaling function. c. Only macrophages can invade host tissues to fight foreign cells that make their way into those tissues. d. Natural killer cells kill foreign cells through the processes of lysis and proteolysis, whereas macrophages kill foreign cells by phagocytosis.

How can you explain that the same antibodies found in an infant鈥檚 body are also present in the infant鈥檚 mother? a. Antibodies produced in the mother鈥檚 body are passed to the infant via passive immunity through breast milk. b. Antibodies produced in the mother鈥檚 body are passed to the infant via active immunity through breast milk. c. Antibodies produced in the mother鈥檚 body are passed to the infant via passive immunity through the placenta. d. Antibodies produced in the infant鈥檚 body are passed to the mother through the placenta.
See all solutions

Recommended explanations on Biology Textbooks

Ecological Levels

Read Explanation

Biological Molecules

Read Explanation

Energy Transfers

Read Explanation

Ecosystems

Read Explanation

Cellular Energetics

Read Explanation

Genetic Information

Read Explanation
View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.