Anatomy of the Resp. System Flashcards
(144 cards)
1
Q
Where does the trachea divide?
A
At the carina which is under the manubrium sterni junction and at the second right costal cartilage
2
Q
Which lung is inhaled material more likely to end up in?
A
The right lung because the right main bronchus is more vertical
3
Q
Bronchi (which are roughly the first 7 divisions after the trachea) have:
A
Walls consisting of cartilage and smooth muscle, epithelial lining containing cilia and goblet cells and endocrine cells
4
Q
What endocrine cells are found in the bronchi?
A
Kulchitsky and amine precursor and uptake decarboxylation (APUD) cells which contain 5-hydroxytryptamine (5HT, serotonin)
5
Q
Bronchioles (approx. divisions 8-25) have:
A
No cartilage and a muscular layer which progressively gets thinner, a single layer of ciliated cells, no goblet cells and contains granulated Clara cells which produce surfactant-like substances
6
Q
Small airways refers to:
A
Bronchioles < 2mm in diameter
7
Q
What is the main cell type lining the alveoli (covers largest area)?
A
Type 1 pneumocytes
8
Q
What are the properties of type I pneumocytes?
A
They have a very thin layer of cytoplasm, thin barrier to gas exchange. They are also joined by tight junctions which limit the movement of fluid in and out of the alveoli
9
Q
How to alveoli of adjoining lobules communicate?
A
Through pores of Kohn (holes joining them)
10
Q
Where are type II pneumocytes normally found?
A
They are found generally in the borders of the alveoli
11
Q
What are the properties of type II pneumocytes?
A
They contain lamellar vacuoles which are the source of surfactant, they are more numerous than type 1 but cover less epithelium.
12
Q
Where are type I pneumocytes derived from?
A
Type II pneumocytes
13
Q
What 3 cell types are present in the alveolus?
A
Type I pneumocytes
Type II pneumocytes
Large alveolar macrophages – to assist with defending the lung
14
Q
What is a lung fissure?
A
An invagination in the pleura which separates the lung into lobes
15
Q
What divides the bronchopulmonary segments?
A
Fibrous septa which extend inwards from the pleura – each segment is supplied by its own segmental bronchus
16
Q
What does a terminal bronchiole supply?
A
An acinus which is just an area of lung within this further divisions in the terminal bronchioles cause alveoli to arise
17
Q
What are the bronchopulmonary segments divided into?
A
Individual lobules which are 1 cm diameter pyramidal in shape with their apex at the bronchiole supplying them
18
Q
Which lobe of the lung is in the front?
A
The upper lobe is anterior to the lower lobe so the sounds heard from the front relate to the upper lobe (and middle lobe in the right)
19
Q
Where is the oblique fissure?
A
It begins just below the T4 vertebrae, moves laterally and inferiorly until it reaches the 6th rib and then follows its curvature anteriorly
20
Q
Where is the horizontal fissure?
A
Begins in at the right 4th intercostal space and extents posteriorly until it meets the oblique fissure as it crosses the 5th intercostal space
21
Q
What is the pleura?
A
A layer of connective tissue which is covered by a simple squamous epithelium
22
Q
Where is the visceral pleura?
A
The pleura which lines the lungs, it lines the interlobar fissures, is continuous at the hilum with the parietal pleura and continues on the bronchial tree until it joins the parietal pleura again
23
Q
Where is the parietal pleura?
A
Lines the body wall, and lines the inside of the hemithorax
24
Q
What way are the visceral and parietal pleura held in health?
A
They are in apposition except for a small amount of lubricating fluid which also hold them together in tension
25
What covers the diaphragm?
The parietal pleura above and the peritoneum below
26
What is the nature of the diaphragm’s muscle fibres?
They arise from the lower ribs and insert into the central tendon, half of the muscle fibres are slow-twitch and have a low glycolytic capacity so are relatively resistant to fatigue
27
What nerve supplies the diaphragm?
The phrenic nerve from C3 C4 and C5
28
How does the pulmonary artery reach the alveoli?
It divides to accompany the bronchi then the arterioles follow the bronchioles, they have thin walls and contain little smooth muscle
29
How is the oxygenated blood drained?
The venules drain laterally to the lobules periphery, then pass centrally in the inter-lobular and intersegmental septa and eventually join to form the 4 main pulmonary veins
30
How is the lung tissue supplied?
Bronchial arteries arise from the descending aorta and supply tissues down to the level of the bronchioles, the bronchial circulation drains to the pulmonary veins
31
What are the tracheobronchial lymph nodes?
```
Pulmonary
Bronchopulmonary
Subcarinal
Superior Tracheobronchial
Paratracheal
```
32
What is the parasympathetic innervation of the respiratory system?
Comes from the vagus, stimulation of cholinergic postganglionic fibres causes the M3 receptors on the smooth muscle to cause muscle contraction and increased mucus secretion by goblet cells, when postganglionic noncholinergic fibres are stimulated the smooth muscle relaxes due to the mediation from nitric oxide (NO) and vasoactive intestinal peptide (VIP)
33
What is the sympathetic innervation of the respiratory system?
The sympathetic nervous division stimulates the B2 receptors which cause bronchial smooth muscle relaxation and decreased mucus secretion and increased mucociliary clearance. Sympathetic stimulation also causes contraction of the vascular smooth muscle, this is mediated by A1-ADR on the vascular smooth muscle
34
What comprises the upper respiratory tract?
nasal cavities
oral cavity
pharynx
larynx
35
What makes up the lower respiratory tract?
```
the respiratory tree -
trachea
right and left main bronchus
lobar bronchi
segmental bronchi
bronchioles
alveoli
```
36
what happens to the respiratory tract at the level of the C6 vertebrae?
the larynx becomes the trachea
| and the pharynx becomes the oesophagus
37
how many bronchopulmonary segments does each lung have?
10
38
what lines the inside of the bronchial tree up to but not including the distal bronchioles?
mucous glands which secrete mucous onto the epithelial surface
cilia - eyelashes which beat to sweep the mucous and anything stuck in the mucous superiorly to the pharynx to be swallowed - the mucociliary escalator
39
Name 2 things which interfere with the normal beating of cilia
cooling/ drying of the mucosa
| toxins in cigarette smoke
40
what is a wheeze?
the sound of air passing through constricted or narrowed airways
41
what is the hyaline cartilage and what is it's purpose?
it supports the walls of the trachea and the bronchi
helps to keep them patent
as you progress down the respiratory tree there is progressively less cartilage
no cartilage in most distal bronchioles and alveoli
42
where is there smooth muscle in the lungs?
there is progressively more smooth muscle as you go distally and is the most prominent in the bronchioles allowing them to constrict and dilate
there is no smooth muscle in the alveoli because it would inhibit diffusion
43
what is needed to ensure enough O2 and CO2 can diffuse between the alveolus and blood at the pulmonary capillary beds?
1. sufficient functioning lung tissue
2. sufficient O2 in the air we breathe in
3. no CO2 in the air we breathe in
4. minimal thickness of the walls of the alveoli (air sacs) to facilitate gaseous diffusion
5. minimal tissue fluid in the tissue spaces around the alveolar capillaries to facilitate gaseous diffusion
44
What are the 2 main ways air can be stopped from moving freely in and out of the lungs?
- the respiratory tract narrowing e.g. because bronchioles constrict, there is a swelling of mucosa - over production or a tumour externally pressing
- foreign bodies which have been inhaled
45
what makes up the nasal septum?
```
the bony (posterior) part which is the ethmoid bone superiorly and vomer inferiorly
the cartilagionous (anterior) part of the nasal septum
```
46
how many nasal cavities are there and what do the contain?
there are 2 nasal cavities each with
a relatively featureless medial wall
an interestingly featured lateral wall
a floor (formed from the palate)
a roof (formed by the midline part of the floor of the anterior cranial fossa)
47
What are the functions of the larynx?
1. Cartilages help to maintain the patency of the URT
2. Helps to prevent the entry of foreign bodies into the LRT (the vocal cords)
3. Produces sound (the vocal cords
48
what cartilages make up the skeleton of the larynx (voice box)?
the epiglottis
the thyroid cartilage
the cricoid cartilage
the 2 arytenoid cartilages (posteriorly)
49
what is the narrowest part of the larynx?
the rima glottidis
50
where in the URT do large foreign bodies tend block?
at the rima glottidis
51
how do the vocal cords protect the airway?
they can approximate in the midline to close the rima glottidis and prevent the foreign body being inhaled into the trachea directly inferior
a cough reflex can then be stimulated to expel the body
52
how do the vocal cords produce voice?
2 steps
Phonation - producing sound - air is expired over the vocal cords and they vibrate to produce sound
Articulation - producing speech - the sound is modified in the nose or mouth to make vowels and consonants
53
What are the aims of the heimlich manoeuvre?
for when there is a body lodged at the rima glottidis and an intake of breath for a cough is not possible
1. raise the abdominal pressure
2. which will force the diaphragm superiorly
3. which will raise the pressure in the chest
4. which will raise the pressure in the lungs
5. which will force air from the lungs into the trachea
6. which will force air through the rima glottidis to expel the foreign body out of the URT
54
What can inhibit the warming, moistening and cleaning of air in and out of the lungs?
1. cooling and drying out of the respiratory tract - damages the mucociliary escalator & predisposes to infection
2. breathing in infected foreign bodies or bacteria/viruses etc. - causes infection (commonly of the nose/throat/larynx/lungs)
55
How is the air warmed, humidified and cleaned when we breathe in?
1. the conchae greatly increase the surface area of the lateral walls of the nasal cavities and produce turbulent flow bringing the air into contact with the walls
2. the respiratory mucosa lining the walls of the nasal cavities has a very good arterial blood supply providing warmth
3. the respiratory mucosa produces mucous providing moisture
4. the “sticky” mucous traps potentially infected particles
5. the cilia of the mucosa waft the mucous to the pharynx to be swallowed (into gastric acid)
56
what are the parts of the pharynx?
nasopharynx - posterior to the nasal cavities
oropharynx - posterior to the oral cavity
laryngopharymx - posterior to the larynx
57
what is the normal route for air when breathing in?
```
nasal cavities
nasopharynx
oropharynx
laryngopharynx
larynx
trachea
```
58
Where are the tonsils?
they are located within the mucosa which line the pharynx and produce white blood cells to defend against infection
59
How many pairs of ribs are there?
12
60
what are the true ribs?
pairs 1-7 which attach through their costal cartilage to the sternum
61
what are the false ribs?
pairs 8-10 which attach via their costal cartilage above to the sternum
62
what are floating ribs?
pairs 11 and 12 which are not attached to the sternum
63
what are the parts of the sternum?
manubrium
body
xiphoid
sternal angle
64
What does the rib tubercle articulate with?
the transverse process of the vertebrae of the same number
65
What does the head of the rib articulate with?
the body of the vertebrae of the same number and the body of the vertebrae superiorly
66
what is the costal groove?
a groove on the inferior surface of the ribs for the intercostal NVB (travel between internal and innermost)
67
what type of joints are the sternocostal joints?
synovial`
68
What are the joints between the cartilage and ribs called?
costochondral joints
69
what are the 3 layers of skeletal muscles located between the ribs in the intercostal spaces?
external intercostal muscles
internal intercostal muscles
innermost intercostal muscles
70
where do the layers of intercostal muscles attach?
between the adjacent ribs
71
what is found between the parietal and visceral layers of the pleura?
the pleural cavity which is a space surrounding the lungs in all directions except where the the main bronchus enters the lung
72
what is the visceral pleura?
a skin attached to the lungs
73
what is the parietal pleura?
the internal lining of the4 chest wall
74
Where can the trachea be palpated?
at the jugular notch of the manubrium
75
where is the isthmus of the thyroid gland found in relation to the tracheal cartilages?
anterior to tracheal cartilages 2-4
76
what secretes pleural fluid?
the pleurae secrete pleural fluid into the pleural cavity as a lubricant and to provide surface tension
77
where does the lung develop from in an embryo?
the lung bud which pushes out from the mediastinum and is already covered in pleura
78
What is a lung lobe?
the area of lung which is supplied by each of the lobar bronchi
79
What is a bronchopulmonary segment?
the area of lung lobe which is supplied by a segmental bronchi - each lung has 10
80
how many intercostal spaces are there?
11 pairs
81
what is found in the intercostal spaces?
a neuro-vascular bundle (vein, artery and nerve
| between internal and innermost intercostal muscle layers)
82
what is the nerve supply to the intercostal spaces?
Anterior ramus of spinal nerve (intercostal nerve)
83
what is the blood supply to the intercostal spaces?
Posterior: arterial supply – Thoracic aorta and venous drainage - Azygous vein
Anterior: arterial supply – Internal thoracic artery and venous drainage – internal thoracic vein
84
what is the diaphragm?
a skeletal muscle which forms the floor of the chest cavity and the roof of the abdominal cavity. It has an unusual central tendon and openings to permit structures to pass through.
85
what is the anatomical structure of the diaphragm?
it is arranged as right and left domes - the right dome usually more superior because of the liver
86
where does the muscular part of the diaphragm attach?
the sternum, the lower 6 ribs and costal cartilages and the L1-L3 vertebral bodies
87
what nerves supply the muscular part of the diaphragm?
the phrenic nerve, C3, 4 and 5 anterior rami.
88
what axons are supplied by the phrenic nerves?
the somatic sensory and sympathetic axons to the diaphragm and the fibrous pericardium
the somatic motor axons supplying the diaphragm
89
what is the route of the phrenic nerves?
they are the combined anterior rami of cervical spinal nerves C3, 4 & 5.
They pass through the neck on the anterior surface of the scalenus anterior muscle
They then descend over the lateral aspects of the heart in the thorax
90
What are the mechanics of inspiration?
the diaphragm contracts and descends which increases the vertical chest dimensions
the intercostal muscles contract and elevate the ribs incresaing the AP and lateral chest dimensions
the chest walls pull the lungs outwards due to the vacuum in the pleura causing -ve pressure and air to flow in
91
What are the mechanics of expiration?
the diaphragm relaxes and rises which decreases the vertical chest dimension
the intercostal muscles relax and lower the ribs decreasing the AP and lateral chest dimensions
the elastic tissue in the lugs recoils and air flows out of the lungs
92
what is involed in the complete examination of the breast?
```
all 4 quadrants
nipple
areola
axillary tail
regional lymphatics
```
93
where does the breast lymphatics drain to?
lateral quadrants - unilateral drainage to axillary nodes
| medial quadrants - bilateral drainage to the parasternal nodes
94
what blood vessels supply and drain the breast?
the subclavian and internal thoracic arteries and veins
95
where do you palpate the trachea?
at the jugular notch of the maubrium
96
What is at the level of the sternal angle?
the costal cartiage 2/ rib 2
97
where are the lungs connected to the mediastinum?
at the lung root
98
what is the costodiaphragmatic recess?
the space between the diaphragmatic parietal pleura and costal parietal pleura
the most inferior region is the costophrenic angle - there will be bluting of this if there is any abnormal fluid in the recess
99
what are the structures of the lung root?
```
1 main bronchus
1 pulmonary artery
2 pulmonary veins
lymphatics
visceral afferents
sympathetic nerves
parasympathetic nerves
```
100
where do you pt your stethoscope to listen to the lung apex?
the root of the neck - medial to mid-clavicular line
101
where do you pt your stethoscope to listen to the right middle lobe?
between right ribs 4 & 6 in the mid clavicular and midaxillary line
102
where is the horizontal fissure?
it follows right rib 4
103
where are the oblique fissures?
bilaterally at the level of ribs 6 anteriorly rising to T3 vertebral level posteriorly
104
where do you listen to the most inferior/ dependent part of the inferior lobe?
posteriorly in the scapular line at T11 vertebral level (the lung base)
105
what triggers a cough?
the stimulation of sensory receptors in the mucosa of the oropharynx, laryngopharynx, larynx and respiratory tree.
the receptors then communicate with the CNS
106
What does the CNS rapidly coordinate in order to produce a cough once it has been triggered?
1. deep inspiration using the diaphragm (phrenic nerves), intercostal muscles (intercostal nerves) & “accessory muscles of inspiration”
2. adduction of the vocal cords to close the rima glottidis (vagus nerves)
3. contraction of the anterolateral abdominal wall muscles (intercostal nerves) to build up intra-abdominal pressure which pushes the diaphragm superiorly and builds up pressure in the chest/respiratory tree inferior to the adducted vocal cords
4. the vocal cords suddenly abduct to open the rima glottidis (vagus nerves)
5. the soft palate tenses (CN V) and elevates (vagus nerves) to close off the entrance into the nasopharynx and direct the stream of air (at ~100mph!!) through the oral cavity as a cough rather than through the nasal cavity as a sneeze!
107
what CN sensory receptors are stimulated in sneezing?
CN V or IX
108
what CN sensory receptors are stimulated in coughing?
CN IX or X
109
what are the carotid sheaths?
they are protective tubes of cervical or neck deep fascia which attach superiorly to the bones of the skull and inferiorly blend with the fascia of the mediastinum
110
What in contained within the carotid sheaths?
the vagus nerve
the internal carotid artery
the common carotid artery
the internal jugular vein
111
How do the visceral afferents of the respiratory tree connect with the CNS to trigger a cough?
the visceral afferents travel from the visceral pleura to the respiratory plexus and then follow the vagus nerve to the medulla of the brainstem
112
how do the motor axons reach the mucous glands and bronchiolar smooth muscles?
they travel from the tracheal bifurcation along the branches of the respiratory tree
113
what are the mechanics of inspiration?
Diaphragm contracts and descends which increases vertical chest dimension intercostal muscles contract elevating ribs
Increases A-P and lateral chest dimensions
The chest walls pull the lungs outwards with them (pleura) Air flows into the lungs because of -ve pressure
114
how do the phrenic nerves cause greater flattening of the diaphragm in deep inspiration?
in a deep (forced) inspiration a greater outflow of action potentials of longer duration, via phrenic nerve occurs causing the diaphragm to flatten then descend maximally
115
what are the intercostal nerves?
the anterior rami of spinal nerves T1-T11
116
What are the names of the accessory muscles of deep (forced inspiration?
pectoralis major
pectoralis minor
sternocleidomastoid
scanlenus anterior, medial and posterior
117
where is the pectoralis major and what is its role in deep inspiration?
attaches between sternum/ribs & humerus
Adducts and medially rotates humerus
if the upper limb position is “fixed” (e.g. by holding onto the arm of the chair or the thigh) the muscle can pull the ribs upwards/outwards
118
what is the role of the pectoralis minor in deep inspiration?
can pull ribs 3-5 superiorly towards the coracoid process of the scapula
119
where does the sternocleidomastoid attach?
attaches between sternum/clavicle & mastoid process of temporal bone
120
where do the scanlenus anterior, medial and posterior attach to the ribcage?
between cervical vertebrae
| & ribs 1 & 2
121
what are the instrinsic muscles of the larynx and what are there properties?
they are all skeletal muscles and attach between the cartilages, they move the cartilages which in turn moves the vocal cords
these muscles aew all supllied by somatic motor branches of the vagus nerve CN X
they adduct the vocal cords in the cough reflex
122
what type of nerves are the vagus nerves (CNX)?
mixed cranial nerves
123
where do the vagus nerves connect with the CNS?
at the medulla (oblongata) of the brainstem
124
how do the vagus nerves descend through the neck?
within the carotid sheath
125
what is one function of the vagus nerves important to coughing?
to supply somatic sensory & somatic motor axons to the larynx:
sensory to the mucosa lining the larynx
motor to the intrinsic muscles of the larynx
126
how do the vagus nerves descend through the chest?
posterior to the lung root
127
what do the vagus nerves supply within the chest?
the parasympathetic axons to the chest organs including to the lungs via the pulmonary plexus
128
how do the vagus nerves pass though the diaphragm?
on the oesophagus
129
what happens to the vagus nerves when they reach the surface of the stomach?
they finally divide into many parasympathetic branches for the foregut and midgut organs
130
what happens in expiration to move air out of the lungs?
Diaphragm relaxes and rises Decreases vertical thoracic dimension
Intercostal muscles relax lowering ribs Decreases A-P and lateral chest dimensions
Elastic tissue of lungs recoils, Air flows out of lungs
131
what are the accessory muscles of forced expiration?
the right & left anterolateral abdominal wall muscles contract forcefully increasing intra-abdominal pressure
the relaxed diaphragm is forced superiorly by the compressed abdominal contents
intra-thoracic pressure increases… increasing the pressure within the respiratory tree inferior to the vocal cords
132
what is a aponeurosis?
a flattened tendon of the obliques
133
what do the tendinous intersections of the abdominal wall muscles do?
they divide the 2 long flat muscles into 3 or 4 smaller quadrate muscles (6 pack/ 8 pack) which improves the mechanical efficiency
134
what are the rectus abdominis?
the muscles in the middle of the abdomen which are surrounded by the aponeurosis of the oblique muscles and tranversus abdominis (the rectus sheath)
135
what do the tonic (continuous low level)contractions of the abdominal muscles do?
they maintain posture and support the vertebral column (mechanical back pain can sometimes be improved by abdominal muscle exercises)
136
what do contractions of the abdominal muscles cause?
movement of the vertebral column (spine) e.g. flexion, lateral flexion and rotations
137
What are the pulmonary consequences of a chronic cough?
- dynamic compression in asthma (when expiration is difficult) this can cause a build up of air trapped in the alveoli and lead to rupture of the lung and the visceral pleura which allows the alveolar air to leak into the pleural cavity leading to a pneumothorax
138
what is a small pneumothorax?
when a small amount of air enters the pleural cavity via:
a) penetrating injury to the parietal pleura OR b) rupture of the visceral pleura
the vacuum is lost, the elastic lung tissue recoils towards the lung root and a small pneumothorax results (< 2cm gap between lung & parietal pleura)
139
what is a large pneumothorax?
when a large amount of air enters the pleural cavity via:
a) penetrating injury to the parietal pleura OR b) rupture of the visceral pleura
the vacuum is lost, the lung tissue recoils towards the lung root and a large pneumothorax results (> 2cm gap between lung & parietal pleura)
140
how do you diagnose a pneumothorax?
history
examination - reduced ipsilateral chest expansion, reduced ipsilateral breath sounds and hyper-resonance percussion (you can have a bilateral pneumothorax)
CXR - absent lung markings peripherally or a visible lung edge
141
how is a tension pneumothorax formed?
the torn pleura can create a one-way valve that permits air to enter the pleural cavity on each inspiration but prevents air escaping again on expiration
with each inspiration more air enters the pleural cavity
the pneumothorax expands & the lung collapses towards its root
eventually the build up of air in the pleural cavity applies tension (pressure) to the mediastinal structures and can cause a mediastinal shift
142
what are the consequences of a mediastinal shift?
tracheal deviation away from the side of the unilateral pneumothorax palpable at the jugular notch
SVC compression reducing venous return to the heart leading to hypotension (low arterial BP)
a tension pneumothorax can be bilateral
143
how do you manage a large pneumothorax?
```
needle aspiration (thoracentesis)
the siting of a chest drain
both procedures pierce the skin, superficial/deep fascia and 3 layers of intercostal muscles and parietal pleura via the:
4th or 5th intercostal space in the midaxillary line (the safe triangle is within the anterior border of the latissimus dorsi and the posterior border pectoralis major and the axial line superior to the nipple)
```
144
what is the emergency management of a tension pneumothorax?
a large gauge cannula inserted into the pleural cavity via the 2nd or 3rd intercostal space in the midclavicular line on the side of the tension pneumothorax
the cannula needs to pass through the skin the superficial and deep fascia, 3 layers of intercostal muscles and the parietal pleura
