respiratory histology/embryology Flashcards Preview

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Flashcards in respiratory histology/embryology Deck (53)
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1
Q

What parts of the respiratory system make up the conducting zone

A
nasal cavity
pharnyx
larynx
trachea
bronchi
bronchioles
2
Q

what parts of the respiratory system make up the respiratory zone

A

respiratory bronchioles
alveolar ducts
alveolar sacs
alveoli

3
Q

what are the parts of the upper respiratory system

A

nasal cavity and pharynx

4
Q

what are the parts of the lower respiratory system

A

larynx
trachea
bronchioles
alveoli

5
Q

What are the functions of the nose

A

warm (via rich capillary network)

humidify and filter incoming air (via ciliated mucus membrane)

6
Q

What are the functions of the pharynx

A

passage way for food

passage way for air

7
Q

what are the parts of the pharynx, and what kind of epithelium do they have

A

nasopharynx (pseudostratified columnar ciliated epithelium)
oropharynx (stratified squamous epithelium)
laryngopharynx (stratified squamous epithelium)

8
Q

What are the three main cartilage of the larynx

A

epiglottis
thyroid cartilage
cricoid cartilage

9
Q

what are the functions of the larynx

A

direct air to the trachea and food to the esophagus
false vocal cords close the trachea while swallowing
true vocal cords produce sound

10
Q

What is the epithelium of the trachea like

A

ciliated pseudostratified columnar epithelium with goblet cells

11
Q

what do the cilia of the trachea do

A

move mucus and trapped debris up the trachea and down into the esophagus

12
Q

Right lung characteristics

A
shorter and wider than left
three lobes (superior, inferior and middle)
Two fissures (horizontal and oblique)
displaced by the liver
13
Q

left lung characteristics

A
longer and skinnier than right
2 lobes (superior and inferior)
1 fissure (oblique)
displaced by the heart
cardiac notch
14
Q

what are the functions of the bronchial tree

A

distribute air through the lungs

filter incoming air

15
Q

what is the path of air through the bronchial tree to the alveoli during inhalation

A
primary bronchi
secondary bronchi
tertiary bronchi
bronchioles
terminal bronchioles
respiratory bronchioles
alveolar ducts
alveolar sacs
alveoli
16
Q

what is the alveoli

A

microscopic air sacs, the site of gas exchange

17
Q

What are the four layers through which gases pass in the lungs into the blood

A

type 1 alveolar epithelial cell
basement membrane of alveolar cell
basement membrane of capillary cell
endothelial cell of capillary

18
Q

what lines the alveoli, and what is its function

A

surfactant, it reduces surface tension and prevents closure

19
Q

What is the basic transition of epithelial cells from the trachea to the alveoli

A

trachea and bronchi - ciliated pseudostratified columnar epithelium with goblet cells
bronchioles - simple cuboidal epithelium with clara cells
alveoli - simple squamous epithelium with surfactant

Gradual changes

20
Q

What are the characteristics of the alveolar type 1 cells

A

line the majority of the alveoli
site of gas exchange
flat and thin
no mitosis

21
Q

what are the characteristics of alveolar type 2 cells

A

do mitosis, create both type 1 and type 2 cells

produce surfactant

22
Q

what are the properties of surfactant

A

90 percent lipids 10 percent protein

23
Q

What is external respiratoin

A

gas exchange between capillaries and the environment

24
Q

what is internal respiration

A

gas exchange between the blood and the cells

25
Q

what are the three steps of external respiration

A

pulmonary ventilation (breathing)
gas diffusion across membranes and capillaries
transport of CO2 and O2 between alveoli and capillaries

26
Q

what are the parts of the pleural cavity (place in which the lungs sit)

A

parietal pleura attached to the chest wall
visceral pleura attached to the lung
pleural fluid between the layers
diaphragm as the floor of the cavity

27
Q

What are the cohesive forces of the lung and the chest cavity, and what do they ensure

A

the lung tries to collapse
the chest tries to expand
these cohesive forces ensure transmural pressure

28
Q

what is pneumothorax

A

when air gets in the pleural space causing the chest and lung to become uncoupled and causes the lung to collapse

29
Q

what is compliance of the lungs

A

measure of the expandibility of the lungs

30
Q

what does low lung compliance cause

A

more work needed to expand the lung

31
Q

what is resistance of the lungs

A

degree of ease of airflow

32
Q

what affects resistance

A

number. length and diameter of the airways

33
Q

what determines the diameter of the airways, and thus lung resistance

A
sympathetic = bronchodilation
parasympathetic = bronchoconstriction
34
Q

what determines the compliance of the respiratory system

A

compliance of the lungs
- surface tension of liquid in the lungs
- elastic recoil of the lungs
stiffness of the chest wall

35
Q

what does emphysema cause in terms of respiratory compliance

A

emphysema causes an increase in compliance, meaning they easily inflate, but are hard to deflate

36
Q

what does fibrosis cause in terms of respiratory compliance

A

fibrosis causes a decrease in compliance, making the lungs stiff and difficult to inflate

37
Q

what causes us to inhale

A

diaphragm and external intercostals contract and cause the chest cavity to expand, increasing size of pleural cavity, lowering pressure of the pleural cavity, drawing air in

38
Q

what causes us to exhale

A

passive - relaxation of the diaphragm of the external intercostals
forced - contraction of internal intercostals and abdominal muscles
decreases pleural cavity size
increases pleural pressure
forces air out

39
Q

what is the main control center of respiration

A

medullary response center

40
Q

what are the parts of the medulllary response center, and what are their functions

A

dorsal respiratory group - sets normal rhythm

ventral respiratory group - controls inspiration and expiration when demand increases

41
Q

What do the pneumotaxic and apneustic centers or respiration control of the pons do

A

pneumotaxic - switch off inspiratory neurons

apneustic - prevents the pneumotaxic from switching off insiratory neurons

42
Q

what is alveolar ventilation

A

the volume of fresh air introduced into the gas exchanging regions of the lungs per minute
MAV = rate x tidal volume - dead space

43
Q

where does the majority of the air inspired go in the lungs

A

it goes to the smaller alveoli at the base of the lungs because of surfactant they are easier to expand. so the majority of the air goes into the base of the lungs

44
Q

what cause O2 to move from the alveoli, into the capillaries

A

the partial pressure of O2 in the capillaries is lower (40 mmhg) that the partial pressure of O2 in the alveoli (100mmhg) pushing it into the blood

45
Q

what causes CO2 to move from the capillaries into the alveoli

A

the partial pressure of CO2 in the capillaries is higher(45 mmhg) that the partial pressure of CO2 in the alveoli (40 mmhg) pushing it into the alveoli

46
Q

what causes O2 to move from the blood into the tissues

A

the partial pressure of O2 in the blood is higher(100 mmhg) that the partial pressure of O2 in the tissues (40 mmhg) pushing it into the tissues

47
Q

what causes the CO2 to move from the tissues into the blood

A

the partial pressure of CO2 in the blood is lower (40 mmhg) that the partial pressure of CO2 in the tissues (45 mmhg) pushing it into the blood

48
Q

what helps the blood carry oxygen and carb0n dioxide

A

RBCs and their hemoglobin

49
Q

what are the functions of RBCs

A

transport O2 and CO2 to and from the tissues

remove O2 and CO2 from the plasma, allowing gases to diffuse into the blood

50
Q

how many O2 molecules can one hemoglobin carry

A

4

51
Q

What are the two ways O2 travels in the blood

A

free in the plasma

bound to Hg on RBCs

52
Q

what are the three ways CO2 travels in the blood

A

free in the plasma 7%
bound to Hg on RBCs 23%
as bicarbonate 70%

53
Q

what allows the CO2 stored as bicarbonate to be transported out

A

Hg takes an H, and Cl- switches out for it