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Flashcards in Anatomy of the Respiratory Tract Deck (65)
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1
Q

What are the functions of the respiratory system?

A
  • Provide oxygen to all body tissues
  • providing a large surface area for gas exchange
    ventilation (providing air)
  • Remove carbon dioxide
  • Regulate blood pH
  • Defence against pathogens
  • protecting respiratory surfaces from dehydration and temperature changes
  • Produces sound
  • Olfaction (sensation of smell)
2
Q

How can the respiratory tract be organised?

A
  • upper or lower

- conductive or respiratory

3
Q

What makes up the upper respiratory tract?

A
  • Nose
  • Pharynx
  • Paranasal sinuses
  • Larynx
4
Q

What are the functions of the upper respiratory tract?

A
  • Warms and moistens and filters the air
  • Olfaction (smell)
  • Production and resonation of sound (produces in larynx, resonates as it gets moved up through the passageways)
  • (protects lower tract)
5
Q

What are the functional adaptations of the nose?

A
  • vibrissae
  • conchae
  • mucosa
  • rich capillary network under mucosa
  • seromucous glands
  • olfactory mucosa
  • paranasal sinuses
6
Q

What are the vibrissae?

A

hairs at entrance to nose which trap large dust particles

7
Q

What are the Conchae?

A

 Projections from lateral wall which produce turbulence
 Allow more time to warm and moisten the air
 Means airborne particles are more likely to come into contact with the mucous
 Creates circular air-currents that bring olfactory stimuli to the olfactory receptors

8
Q

What’s the mucosa and what does it do?

A

 Pseudostratified ciliated columnar epithelium with goblet cells
 Goblet cells produce mucous to trap particles
 Cilia waft the trapped particles to pharynx where they can be swallowed

9
Q

What does having a rich capillary network in the nose do?

A

the blood warms the air

10
Q

What do the seromucous glands do?

A

secretions moisten the air

11
Q

What are the Olfactory mucosa and what do they do?

A

 Located in upper aspect of nose, above the superior conchae
 Contains receptors for smell

12
Q

What are the paranasal sinuses and what do they do??

A

 Air filled spaces in bones around the nose
 Lighten the skull and resonate sound
 Secretions for the sinuses drain into nasal cavity

13
Q

What is the pharynx?

A

A fibromuscular tube that forms a communal passageway for respiratory and gastrointestinal systems

14
Q

What three regions is the pharynx divided into?

A

 Nasopharynx – posterior (behind) to nose
 Oropharynx – posterior to mouth
 Laryngopharynx – posterior to larynx

15
Q

What does the close proximity of gastrointestinal and respiratory systems lead to?

A

swallowing difficulties and aspiration of food and fluid

16
Q

What are the main functions of the Larynx?

A
 Maintains an open airway
 Prevents food and drink entering the lower respiratory tract 
 Sound production 
 Involved in coughing 
 Involved in defaecation
17
Q

What does the Larynx consist of?

A

 A cartilaginous skeleton (thyroid cartilage is Adam’s apple) (hyoid bone)
 A lining made of membranes – joins the cartilage inside
 Vocal cords – made of edges of membranes. Important in sounds projection and protecting the airway
 Muscles which move the vocal cords
 Glottis

18
Q

What is the glottis and what does it do?

A

 When air comes in it passes down through the glottis
 Slit like opening
 Space between the vocal cords
 Usually open to allow air flow
 Closed during swallowing to prevent aspiration
 Air vibrates over the vocal cords to produce sound
 The wider the cords are open the louder the sound

19
Q

What is the lower respiratory tract made up of?

A
  • Trachea
  • Primary bronchi
  • Secondary bronchi
  • Tertiary bronchi
  • Bronchioles
  • Terminal bronchioles
  • Respiratory bronchioles
  • Alveolar ducts
  • Alveolar sacs
  • Alveoli
20
Q

What is the trachea?

A
  • Tough, flexible tube, 4.5cm long, 2.5cm in diameter
  • Extends from the larynx to the carina
  • Lies anterior to the oesophagus (oesophagus is just behind)
  • Contains 15-20 horseshoe shaped cartilages which keep airway open
  • Posterior ends of cartilage are joined by trachealis muscle which constricts during coughing. Also is soft for when oesophagus expands
  • Lined by pseudostratified ciliated columnar epithelium with goblet cells
21
Q

What do pseudostratified ciliated columnar epithelium with goblet cells do?

A
  • Acts as a mucociliary escalator
  • Mucus layer which traps dust particle
  • Cilia aft particles up to the larynx where they get swallowed and ingested
22
Q

What is the bronchial tree made up of?

A
- Bronchi
 Primary 
 Secondary 
 Tertiary 
- Bronchioles
 Bronchioles
 Terminal Bronchioles
 Respiratory bronchioles
23
Q

What are the histological changes displayed as you go down the bronchial tree?

A

 Amount of cartilage decreases
 Amount of smooth muscle increases
 Height of epithelial cells decrease (columnar -> cuboidal -> flattened)

24
Q

What are the primary bronchi and what do they do?

A

 Supply each lung
 2-3cm long
 Right is wider and more vertical than left
 Left is more horizontal – means that foreign bodies are less likely to get through
 C-shaped cartilages (similar to trachea) – incomplete behind with muscle at the back

25
Q

What are the secondary bronchi (lobar) and what do they do?

A

 Supply lobes of the lung (3 on right, 2 on left)

 Plates of cartilage (in small pieces) still cover all of the secondary bronchi though

26
Q

What are the tertiary bronchi and what do they do?

A

 Supply segments of the lung (10 on right, 8 on left)

 Plates of cartilage (smaller than secondary bronchus). Between cartilage there is connective tissue and smooth muscle.

27
Q

What do the bronchi provide?

A

A passageway for the air to move through

28
Q

What are features of the bronchioles?

A

 No cartilage
 Simple columnar epithelium with cilia
 Few goblet cells
 Smooth muscle – allows bronchiole to constrict and dilate
 Each gives rise to 50-80 terminal bronchioles

29
Q

What are terminal bronchioles?

A

 Simple columnar epithelium with cilia
 No goblet cells or mucous glands
 Clara cells – produce surfactant which reduces surface tension
 Each gives rise to 2 or more respiratory bronchioles

30
Q

What are respiratory bronchioles?

A

 Simple cuboidal epithelia
 No cilia
 Clara cells – produce surfactant
 Alveoli extend from the lumen: gas exchange occurs here

31
Q

Why do goblet cells stop before the cilia in bronchioles?

A

because the cilia needs to waft all the mucous out

32
Q

What is the alveoli?

A

The sit of gas exchange?

33
Q

How are alveoli distributed?

A
  • respiratory bronchioles lead to alveolar ducts
  • alveolar ducts are elongated airways with walls made of alveoli
  • alveolar ducts lead to alveoli sacs
  • alveoli sacs are spaces surrounded by clusters of alveoli
34
Q

What are the features of alveoli?

A
  • 150-305 million alveoli per lung
  • Surrounded by a network of capillaries
  • Provides an extensive surface area for gas exchange
  • Rich blood supply
35
Q

How does the blood supply to the alveoli work?

A
  • Entering: Pulmonary artery -> pulmonary arteriole -> capillary network around alveolus
  • Leaving: capillary bed -> pulmonary venule -> pulmonary veins
36
Q

What is the structure of an alveolus?

A
  • Wall is made up of type 1 alveolar cell: simple squamous epithelium
  • Type II alveolar cell: secretes surfactant (reduces surface tension and allows expansion of the lungs)
  • Macrophage: phagocytoses small inhaled particles and bacteria
  • Air has to pass through respiratory membrane from the alveolus into the capillary
  • Respiratory membrane is very thin promoting diffusion of gases
37
Q

What is the respiratory membrane made up of?

A

 epithelium of type I cell
 basement membrane of type I cell
 Basement membrane of capillary
 Endothelium of capillary

38
Q

Why is the respiratory membrane so thin?

A

Because the two basement membranes are often fused together

39
Q

What happens with the respiratory membrane if you are ill?

A

fluid can collect between the basement membranes making diffusion harder (pulmonary hypertension)

40
Q

What is the conductive portion of the respiratory tract concerned with?

A

filtering, warming and moistening the air and conducting the air into the lungs

41
Q

What does the conductive portion of the respiratory tract include?

A

all parts of the tract where gas exchange takes place

42
Q

What does the conductive portion of the respiratory tract consist of?

A
 Nasal cavity and paranasal sinuses
 Pharynx
 Larynx
 Trachea
 Primary bronchi
 Secondary bronchi
 bronchioles
 terminal bronchioles
43
Q

What does the respiratory portion of the respiratory tract consist of?

A

 Respiratory bronchioles
 Alveolar ducts
 Alveolar sacs
 Alveoli

44
Q

What is a mucosa?

A

A mucous membrane

45
Q

What does the respiratory mucosa consist of?

A

an epithelium and an underlying layer of areolar tissue. The lamina propria is the underlying layer of tissue. In the upper respiratory system the lamina propria contains goblet cells. In the lower system it contains smooth muscle cells

46
Q

When does the rate of mucous production in the nasal cavity and paranasal sinuses speed up?

A

when exposed to unpleasant stimuli

47
Q

Where contains nose hairs?

A

epithelium of the nasal vestibule

48
Q

What divides the right and left sides of the nose?

A

the nasal septum

49
Q

what supports the dorsum and apex of your nose?

A

the hyaline cartilaginous plate

50
Q

How is the nasopharynx separated from the oral cavity?

A

It has a soft palate that separates it

51
Q

Where does the oropharynx extend between?

A

the soft palate and the base of the tongue at the level of the hyroid bone

52
Q

What are the three large unpaired cartilages that form the larynx?

A

the thyroid cartilage, the cricoid cartilage and the epiglottis

53
Q

what do the the thyroid cartilage and the cricoid cartilage do?

A

protect the glottis and the entrance to the trachea

54
Q

What does the epiglottis do?

A

forms a lid over the glottis. It folds back over the glottis during swallowing

55
Q

Why are vocal cords highly elastic?

A

because the vocal ligaments consist of elastic tissue

56
Q

What muscles is the larynx associated with?

A

muscles of the neck and pharynx which position and stabilize the larynx and smaller intrinsic muscles that control tension in the glottal vocal folds. When you swallow both sets of muscles work together to prevent food or drink from entering the glottis

57
Q

What is laryngitis?

A

An infection or inflammation of the larynx

58
Q

What does the normal diameter of the trachea change due to?

A
  • the sympathetic division

- it increases the diameter of the trachea

59
Q

What does the carina do?

A

separates the openings of the right and left main bronchi at their junction with the trachea

60
Q

What happens in bronchitis?

A

bronchi and bronchioles become inflamed and constricted, increasing resistance

61
Q

What does sympathetic and parasympathetic activation of the bronchi lead to?

A

Sympathetic activation leads to bronchodilation and parasympathetic activation leads to bronchoconstriction

62
Q

What does tension in smooth muscles commonly cause?

A

causes the bronchiole mucosa to form a series of folds that limit airflow. This can be particularly severe in asthma

63
Q

What takes place in the bronchi’s during an allergic reaction?

A

bronchoconstriction

64
Q

What are the squamous epithelial cells in alveoli called?

A

pneumocytes

65
Q

What does surfactant contain?

A

phospholipids and proteins