Animal and Plant Defense Responses: Animal Defense Responses

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What does the first line of defense in the human body primarily consist of?

Inflammation and fever

Physical and chemical barriers (correct)

Immune system

Defensive cells and proteins

Which system is responsible for physical barriers in the defense mechanisms of the human body?

Integumentary system (correct)

Digestive system

Nervous system

Circulatory system

What type of immunity is associated with nonspecific defenses like inflammation and fever?

Hormonal immunity

Specific immunity

Innate immunity (correct)

Adaptive immunity

Which of the following is NOT part of the first line of defense in the human body?

Immune system Signup and view all the answers

What is the main purpose of the three lines of defense in the human body?

To prevent all foreign agents from entering Signup and view all the answers

What is the function of phagocytes in the immune system?

Engulf pathogens, damaged tissues, or dead cells. Signup and view all the answers

Which type of immunity is passed down genetically from parents and ancestors?

Inborn Immunity Signup and view all the answers

What do eosinophils do in the immune system?

Release destructive enzymes to destroy pathogens. Signup and view all the answers

What is the role of Natural Killer Cells in the immune system?

Seek out abnormal cells like cancer cells. Signup and view all the answers

When is Acquired Immunity considered to be active?

When obtained once a person comes in direct contact with a live pathogen. Signup and view all the answers

Which type of immunity is obtained during fetal development through the mother's placenta?

Passive immunity Signup and view all the answers

Which class of immunoglobulin is the only one that can cross the placenta to confer passive immunity on the fetus?

IgG Signup and view all the answers

What is the function of IgA in the body?

Provides localized defense of mucous membranes Signup and view all the answers

Which class of immunoglobulin promotes neutralization and crosslinking of antigens effectively in the complement system activation?

IgM Signup and view all the answers

What is the role of cells filled with keratin in the skin?

To make the skin impenetrable, waterproof, and resistant to invaders Signup and view all the answers

What is the primary function of IgE in the body?

Triggers allergic reactions Signup and view all the answers

What is the process of introducing an attenuated or weakened antigen in a susceptible host called?

Vaccination Signup and view all the answers

How do mucous membranes protect the body?

By producing sticky mucous that traps many microbes Signup and view all the answers

What is the function of the hair in the nose as mentioned in the text?

Acting as a coarse filter Signup and view all the answers

Which bodily fluid contains an enzyme called lysozyme that kills bacteria?

Saliva and tears Signup and view all the answers

What is the main function of cerumen (ear wax) as mentioned in the text?

Protecting the ear canal by trapping dirt and dust particles Signup and view all the answers

When do cells play a role in inhibiting or destroying a pathogen according to the text?

Before the pathogen penetrates the first line of defense Signup and view all the answers

Study Notes

Defenses of the Human Body

The human body has developed defense mechanisms to cope with constant attacks from microorganisms.
There are three lines of defense: physical barriers, defensive cells and proteins, and the immune system.

First Line of Defense

Physical barriers:
- Skin: cells filled with keratin make it impenetrable, waterproof, and resistant to toxins.
- Dead skin cells are shed and replaced, taking microbes with them.
Mucous membranes:
- Line internal surfaces of respiratory, digestive, urinary, and reproductive systems.
- Produce mucous that traps microbes.
- Hair in the nose acts as a coarse filter.
Chemical barriers:
- Sweat: washes away microbes and slows bacterial growth due to acidity.
- Mucous membranes: produce sticky mucous that traps microbes.
- Saliva and tears: contain lysozyme, an enzyme that kills bacteria by rupturing cell walls.
- Cerumen (ear wax): traps dirt and dust particles in the ear canal.

Second Line of Defense

Defensive cells and proteins:
- Phagocytes (e.g., neutrophils, macrophages) engulf pathogens, damaged tissues, or dead cells.
- Eosinophils discharge destructive enzymes to destroy pathogens too big for phagocytes.
- Natural killer cells seek out and destroy abnormal cells (e.g., cancer cells).
Inflammation and fever: nonspecific responses to infection.

Immunity

Types of immunity:
- Inborn immunity: genetic predisposition received from parents and ancestors.
- Acquired immunity: obtained through exposure to antigens, either naturally or artificially.

Acquired Immunity

Active acquired immunity: obtained once a person comes into direct contact with a disease, providing permanent immunity.
Passive acquired immunity:
- Naturally acquired: occurs when a person is exposed to a disease, providing temporary immunity.
- Artificially acquired: introduced through a vaccine, which stimulates antibody production.

Antibodies (Immunoglobulins)

Types of immunoglobulins:
- IgG: most abundant in blood, promotes opsonization, neutralization, and cross-linking of antigens.
- IgA: found in secretions (e.g., tears, saliva, mucus, breast milk), provides localized defense of mucous membranes.
- IgM: first antibody produced after initial exposure to an antigen, effective in complement system activation.
- IgE: triggers release of histamine and other chemicals that cause allergic reactions.
- IgD: acts as an antigen receptor in B cells, stimulating proliferation and differentiation.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Learn about animal defense responses in the context of Chapter 3 on Animal and Plant Defense Responses. Explore the defenses of the human body, types of immunity and antibodies, and the importance of body defense responses through investigation.