First line of defence

Question 1

What is the role of the skin in protecting the body against pathogens?

Answer 1

• Upper layer of the skin (epidermis) is composed of tightly packed cells that produce keratin
• It is held together by tight by tight junctions and is waterproof making it difficult for pathogen to penetrate
• strengthens the skin against breakages
• the skin is also waterproof- hindering the growth of pathogens
• produces sebum and sweat= acid
• produces antimicrobial substances

Question 2

Where are cilia located and what is their role in the respiratory system?

Answer 2

• Cilia are found in the respiratory tract, including the nasal passages and bronchus in the lungs
• Their role is to move in coordinated waves, sweeping mucus and trapped particles, including pathogens, out of the respiratory system.

Question 3

What is cilia

Answer 3

• Hairlike structures called cilia line that move in coordinated waves, removing the particles trapped in the mucus out of the nose
• The respiratory tract and the nose is lined with cilia that help move pathogens out of the body

Question 4

What is the role of mucous membranes in the body’s defense system?

Answer 4

• The mucous membrane lubricates and protects these organs and cavities from abrasive particles and bodily fluids, as well as invasive pathogens.
• Secrete mucus which prevents membranes from drying out and traps unwanted pathogens, dust and pollen
• lined with cilia which can remove mucus and trapped foreign particles and pathogens

Question 5

What are the locations of mucus membranes?

Answer 5

• Respiratory tract (nasal passages, , throat, bronchi,trachea
• Gastrointestinal Tract: the mouth, esophagus, stomach, small intestine, and large intestine.
• reproductive organs : urethra, bladder, vagina, cervix

Question 6

How does the body expel mucus and pathogens from the respiratory tract?

Answer 6

• cough
• the mucus and pathogens may be swallowed and directed into the gastrointestinal tract, where they can be neutralized by stomach acid (gastric acid) and destroyed by digestive enzymes.
• eliminates the mucus and pathogens from the body through feaces

Question 7

What role does stomach acid play in eliminating pathogens?

Answer 7

• Stomach acid is acidic with a low pH level
• Most pathogens are sensitive to acidic environments and cannot survive the high acidity of the stomach

Question 8

What is the typical pH range of urine?

Answer 8

• 4.5 to 8.0

Question 9

How does the acidic pH of urine create an unfavorable condition for pathogen growth?

Answer 9

• acidity of the stomach creates an unfavourable environment for the growth and survival of pathogens

Question 10

What pH levels do pathogens generally prefer

Answer 10

• neutral or alkaline pH levels

Question 11

How do antibodies in urine contribute to the body’s defense against pathogens?

Answer 11

Antibodies in urine help to fight against invading pathogens by recognising and binding to specific antigens on the pathogens, marking them for destruction by the immune system.

Question 12

Explain the role of urine as a natural defense mechanism against urinary tract infections.

Answer 12

• acidic pH level- prevents UTIs (bacteria)
• contains anti microbial substances such as antibodies and lysozyme- inhibit growth and reproduction of pathogens
• continous flow of urine physically flushes out the urinary tract removing any pathogens

Question 13

What is peristalsis?

Answer 13

Peristalsis is the muscular contraction of the ureters.
These contractions help propel urine from the kidneys to the bladder.

Question 13

How does peristalsis contribute to maintaining the health of the urinary system?

Answer 13

• ensures that urine flows in one direction and prevents any backflow of urine to the kidney- minimising risk of kidney infections
• expel any pathogens that may have entered the urinary system, reducing the risk of infection.

Question 14

What is sweat and sebum?

Answer 14

• Oily substance secreted by sebaceous glands

Question 15

What is the role of sebum and sweat in the first line of defence

Answer 15

• Contain antimicrobial substances that inhibit the growth and reproduction of pathogens such as bacteria and fungi on the skin
• Sweat is slightly acidic which creates an unfavourable environment for pathogens
• sebum hydrates the skin- preventing dryness and breakages- inhibt entry

Question 16

How does saliva protect the body against pathogens?

Answer 16

• Saliva contains antimicrobial substances, including antibodies which inhibit the growth of bacteria and other pathogens
• flushing action against microbes that washes away microbes
• Saliva helps maintain a slightly acidic pH in the mouth,

Question 17

How do tears serve as a natural defence barrier?

Answer 17

• contain antimicrobial proteins that help fight against bacterial and viral pathogens, protecting the eyes from infection
• Tears wash away dust, allergens, and foreign particles, maintaining clear vision and preventing damage or irritation.

Question 18

How does the vagina protect against sexually transmitted diseases

Answer 18

• The vagina maintains an acidic pH level due to the production of lactic acid produced by benefical bacteria
• the vagina is lined with mucus membranes that secrete mucus,
• natural self cleaning mechanism which helps remove dead cells, bacteria and other foreign microbes
• The presence of beneficial bacteria, particularly lactobacil helps prevent the overgrowth of yeast

Question 19

How do tears help in preventing infections in the eyes?

Answer 19

Tears help prevent infections in the eyes by washing away foreign particles, irritants, and potential pathogens.