Respiratory defenses

Question 1

What are the primary portals of entry for pathogens

Answer 1

Respiratory tract

GI tract

Question 2

Name two secondary lymphoid tissues

Answer 2

Bronchial-associated lymphoid tissue (BALT)

Gut-associated lymphoid tissue (GALT)

Question 3

How are pathogens transferred across mucosa

Answer 3

By M cells

Question 4

What are mucus membranes

Answer 4

Layers of mucosal cells that line body cavities that open to the outside

Question 5

What antimicrobial substance does mucus contain

Answer 5

Lysozymes, lactoferrin

Question 6

Two characteristics of mucus

Answer 6

Contains antimicrobial substance

Mucosal cells are rapidly dividing

Question 7

Physical and chemical barriers in respiratory tract

Answer 7

Nasal hair
mucous secretions
irregular chambers
ciliated epithelium
cough reflexes
alveolar macrophages

Question 8

Barriers in the nasopharynx

Answer 8

Squamous epithelium
Nasal hairs
Turbinates including mucosal lymphoid tissue
Ciliated epithelium
Mucous layer
Innate factors
Secretory IgA and some IgG

Question 9

How do particles and bacteria come into contact with the mucosa lining the nasopharynx and larynx

Answer 9

An increase in air turbulence is caused due to the abrupt changes in direction of air flow that occur as the air moves through nasopharynx and larynx

Question 10

Barriers in larynx

Answer 10

Cords
Epiglottis
Cough reflex

Question 11

How are secretions above the sub-segmental level removed

Answer 11

By coughing

Question 12

How are the secretions below the sub-segmental level removed

Answer 12

Moved upward by the mucociliary mechanism

then removed by coughing

Question 13

Barriers in the trachea and bronchi

Answer 13

ciliated epithelium
Muscociliary escalator
cough reflex

Question 14

Barriers in small airways and alveoli

Answer 14

Epithelial cells 
Alveolar macrophages
Lymphocytes
Innate factors
IgG and IgA

Question 15

What are some secretions in the respiratory tract

Answer 15

Lactoferrin
Reactive oxygen species
Interfons
Inflammatory factors
Antibodies

Question 16

How many cilia is present in the ciliated cell in the trachea and bronchioles

Answer 16

200

Question 17

What happens to the ciliary beat rate as you move down the tracheo-bronchia tree

Answer 17

ciliary beat rate slower

Question 18

What impairs ciliary action

Answer 18

dehydration, smoking, inhalation of high oxygen concentrations, infections and ingestion of drugs

Question 19

What is broncho-constriction

Answer 19

Defence mechanism where bronchi constrict in an effort to prevent entry of the irritants like dust and aerosols

Question 20

where are lymphocytes found in the lung

Answer 20

In the submucosal collection BALT

Question 21

What three immunoglobulins are found in greater concentration in the lung than in serum

Answer 21

IgA, IgG3 and IgG4

Question 22

What two immunoglobulins contribute significanly to the defence against infection in lungs

Answer 22

IgG and IgA

Question 23

What immune cell is not present in healthy lungs

How does it arrive to the lungs

Answer 23

Neutrophils

Recruited to the lung by a variety of stimuli

Question 24

What immune cell is not present in healthy lungs

How does it arrive to the lungs

Answer 24

Neutrophils

Recruited to the lung by a variety of stimuli

Question 25

why is mucus not present in alveoli

Answer 25

Mucus is too thick and would slow movement of oxygen and carbon dioxide

Question 26

What defences are present in alveoli

Answer 26

Alveolar macrophages which ingest any deposited particle and digest them When lung is exposed to serious threat, neutrophils are recruited to help

Question 27

Where does proliferation occur in alveolar macrophages

Answer 27

Interstitium and alveolar space

Question 28

What happens to the debris of phagocytosis in alveoli

Answer 28

Moved up to the level of the bronchioles so that they can be removed by cilia or removed from the lungs by lymphatic system

Question 29

Where do particles between 5-10 microns deposite

Answer 29

In the trachea and main bronchi and can be removed by mucociliary transport

Question 30

WhaT IS CHEMOTAXIS

Answer 30

Process by which phagocytes are attracted to microorganisms

Question 31

What is the attachment stage of phagocytosis

Answer 31

the phagocyte adheres to the micorbial cell | Facilitated by opsonisation

Question 32

What is the ingestion phase of phagocytosis

Answer 32

Pseudopods of phagocytes engulf the microorganism and enclose it in a phagosome to complete ingestion

Question 33

What is the digestion phase of phagocytosis

Answer 33

Lysosomes fuse with the phagosome to form a digestive vacuole the microbe is killed and digested