Anatomy - Immune System

The function of the immune system is to __________, __________, and __________ foreign substances at a cellular level.

recognize, fight, and defend

The immune system relies heavily on ____, specifically _____________.

WBCs, specifically lymphocytes

The goal of the immune system is to achieve __________.

immunity

resistance to disease

immunity

a microorganism that can cause disease

pathogen

anything that causes an immune response; the part of a pathogen our body recognizes as foreign and learns how to respond to

antigen

Antigens act as ___________ molecules to induce an immune response in the body, such as the production of antibodies,

signaling

proteins used by the immune system to bind to antigens and neutralize pathogens

antibodies

non-specific system of defense that has a rapid response time

innate defense

pathogen-specific system of defense that is acquired, has a slower response time, and can remember pathogens

adaptive defense

What are some mechanisms used in innate defenses?

• mucus

• antimicrobial proteins

• fever

• inflammation

• phagocytes

Adaptive defense uses ____________ as its primary mechanism.

humoral immunity

__________ and ____________ are examples of humoral immunity.

B cells and antibodies

What structures make up the 1st line of defense?

1. skin

2. mucous membranes

3. secretions

4. cilia

The 1st line of defense is ________.

external

The ______ is a mechanical barrier.

skin

lining of all body cavities that open to the exterior

mucous membranes

Which systems have mucous membranes?

1. respiratory

2. digestive

3. urinary

4. reproductive

What are some secretions in the 1st line of defense?

• acid secretions

• enzymes

• defensins

The 2nd line of defense is ________.

internal

abnormally high body temperature

fever

___________ are released by immune cells which raise the body’s temperature.

pyrogens

Pyrogens inhibit pathogens from __________.

multiplying

Pyrogens increase the _______________ of tissue cells, which speeds up the repair process.

metabolic rate

proteins that attack microorganisms directly and/or make it hard for them to reproduce

antimicrobial proteins

small signaling proteins secreted by virus-infected cells that diffuse to nearby uninfected cells to block viral takeover; get the immune system mobilized

interferons

plasma proteins that cause an amplified inflammatory response when activated

complement proteins

defensive cells that engulf pathogens to get rid of them

phagocytes

a type of phagocyte that is the most abundant WBC

neutrophils

phagocyte cells that use cytoplasmic extensions to reel in and engulf foreign invaders

macrophage

defensive cells that can kill your own cells by triggering apoptosis if they are infected

natural killer (NK) cells

NK cells help with killing both __________ and ____________ cells.

cancerous and virus-infected cells

NKs use the protein __________ to create pores in the cell membrane of the infected cell and inject enzymes to stimulate apoptosis

perforin

What are the 2 types of adaptive defenses?

1. humoral immunity

2. cellular immunity

Adaptive defenses recognize and remember __________.

antigens

Adaptive defenses use _____________ to destroy antigens.

lymphocytes

Humoral immunity is also known as ________________.

antibody-mediated immunity

Cellular immunity is also known as _________________.

cell-mediated immunity

Humoral immunity uses ___________ in humors.

antibodies

Cellular immunity uses ____________.

lymphocytes

Humoral immunity targets ___________ things, like bacteria and toxins

extracellular

Cellular immunity targets ___________ things, like cancerous cells.

cellular

Some B cells can turn into __________ cells.

memory

substances used to stimulate your immune system to guard against attack

vaccines

when enough people are vaccinated so microbes cannot spread

herd immunity

Humoral immunity is directed by __ cells.

B

Cellular immunity is directed by __ cells.

T

T cells can’t respond to antigens like B cells, so they rely on ________________.

antigen-presenting cells (APCs)

cells that engulf antigens and present their fragments on their surfaces so T cells can respond to them

antigen-presenting cells

What are the 3 types of APCs?

1. dendritic cells

2. macrophages

3. B cells