Immune - 1st line defense

Question 1

What is the first line of defence against pathogens?

Answer 1

The skin and mucous membranes

Question 2

What type of barrier does the skin provide?

Answer 2

Physical barrier

Question 3

What is the outer layer of the skin called?

Answer 3

Epidermis

Question 4

What is the function of the dermis?

Answer 4

Contains accessory structures such as sebaceous glands and sweat glands

Question 5

What immune function do sebaceous glands and sweat glands serve?

Answer 5

Stop bacteria from undergoing mitoses

Question 6

What does sweat contain that contributes to its antimicrobial properties?

Answer 6

IgA

Question 7

What do fatty acids in sebum do?

Answer 7

Inhibit microbial growth

Question 8

Fill in the blank: The skin acts as a physical barrier with layers of tightly-packed _______.

Answer 8

epithelial cells

Question 9

What does sweat do besides removing microbes?

Answer 9

Contains IgA

Question 10

True or False: The subcutaneous layer is part of the epidermis.

Answer 10

False

Question 11

What are some examples of other bodily fluids that help in defense against pathogens?

Answer 11

• Tears
• Saliva
• Breastmilk

Question 12

What is the primary function of mucous secretions in the immune system?

Answer 12

To trap and expel pathogens

Question 13

Where is the mucous membrane found?

Answer 13

Digestive, respiratory, and urogenital tracts

Also includes the conjunctiva lining the eyes

Question 14

What is the role of mucous membranes in the immune system?

Answer 14

Attempt to prevent entry into the membrane

They serve as barriers along with non-specific defenses

Question 15

What substances do saliva, tears, and mucus secretions contain?

Answer 15

Anti-microbial substances

They help wash away microbes

Question 16

How does mucus contribute to the immune defense?

Answer 16

Traps microbes and foreign particles

Question 17

What is the function of cilia in the respiratory tract?

Answer 17

Propel foreign substances towards the pharynx

This process is known as the mucociliary escalator

Question 18

What are the components found in tears and saliva?

Answer 18

IgA and lysozymes

Question 19

What is the function of lysozymes?

Answer 19

Break down bacterial cell walls

Question 20

What happens to IgA levels when a person is stressed?

Answer 20

IgA is lowered

Question 21

What might a Comprehensive Stool Analysis show if IgA levels are low?

Answer 21

Opportunistic growths

May include parasites, candida, and bad bacteria

Question 22

Fill in the blank: Mucous membranes provide a ______ barrier.

Answer 22

physical

Question 23

True or False: Saliva contains only IgA.

Answer 23

False

Saliva also contains lysozymes

Question 24

What is the role of hairs in the nose?

Answer 24

Hairs filter air in the nose

Hairs help trap dust and microbes, contributing to respiratory health.

Question 25

Why is the vagina acidic in menstruating women?

Answer 25

The acidity makes it unfavourable for microbes to inhabit ## Footnote This natural acidity helps maintain a healthy vaginal flora.

Question 26

What is the pH range of gastric acid?

Answer 26

pH 2-3 ## Footnote This high acidity is effective in destroying many bacteria.

Question 27

How do microflora protect against pathogens?

Answer 27

They outcompete pathogens for attachment sites and essential nutrients ## Footnote This competitive exclusion is crucial for maintaining health.

Question 28

What processes help expel pathogens from the body?

Answer 28

Excretion of urine and faeces, vomiting, and diarrhoea (the last two mechanisms are rapid means of expulsion)

Question 29

What analogy is used to describe the attachment of bacteria in the intestines?

Answer 29

Carpark analogy ## Footnote Good bacteria occupy attachment points to prevent harmful bacteria from attaching.

Question 30

Where is 70% of the immune system found?

Answer 30

In the digestive system, specifically in GALT (gut-associated lymphoid tissue) ## Footnote This area is critical for immune responses and learning from microbial exposure.

Question 31

What is the function of 'good' microflora?

Answer 31

Provides attachment to prevent bad organisms from attaching ## Footnote This helps maintain a balanced gut environment.

Question 32

What do leukocytes learn from?

Answer 32

They learn from the microbes in the digestive system that they are constantly being exposed to ## Footnote The microflora is next to the intestinal lining - only divided by an epithelial layer of cells. This exposure is vital for developing an effective immune response.

Question 33

True or False: Gastric acid has a pH of 7.

Answer 33

False ## Footnote Gastric acid is much more acidic, with a pH of 2-3.