Respiratory anatomy; lungs and pleura Flashcards
What are the three main components of the thoracic cavity?
Right pleural cavity (contains the right lung)
Left pleural cavity (contains the left lung)
Mediastinal cavity (contains the heart and great vessels)
What four components make up the upper respiratory tract?
- Paranasal sinuses
- Nose
- Pharynx
- Larynx
These are bony projections within the nasal cavity, or sliding pieces of bones on the lateral walls of the nasal cavity
Nasal turbinates
What is the function of the nasal turbinates? (2)
Decreases turbulence of air coming in to the respiratory tract, and warms the incoming air to body temperature
Which parts of the nasal cavity have a particularly rich blood supply?
Vestibular area and inferior turbinate
What type of epithelium lines the sinuses and upper respiratory tract?
Pseudostratified ciliated columnar epithelium
The posterior nares leads to the opening of the _________
pharynx
What surface modifications are present in the vestibule (just inside the nasal cavity?)
Vibrissae (hairs) and glands
Name the four pairs of paranasal sinuses
Frontal, maxillary, ethmoid, ad sphenoid
What are the three functions of the paranasal sinuses?
- Air passageway
- Warms, moistens, and filters the air
- Provides resonance for the voice
Name the three subdivisions of the pharynx
- Naso pharynx
- Oropharynx
- Laryngopharynx
This is the common passageway for the respiratory and digestive tracts, lined with mucous membrane. Extends from the base of the skull to the esophagus.
Pharynx
This part of the upper respiratory tractl lies between the root of the tongue and the upper part of the trachea
Larynx
The larynx lies anterior to which three cervical bodies?
C3-C6
What are the three main functions of the larynx?
- Serves as an air passageway
- VOICE PRODUCTION
- Protects airway against entrance of solids or liquids
What part of the upper respiratory tract contains the true vocal cords?
The larynx
What is the lower respiratory tract comprised of? (4)
- Trachea
- Bronchial tree
- The lungs (lobes and segments)
- Alveoli
The trachea extends from the inferior aspect of the __________ to the __________.
larynx, carina (or principle bronchi)
What type of cartilage make up the C-shaped rings of the trachea?
Hyaline cartilage
How many tracheal rings do we have?
About 15-20
The posterior surface of the trachea is a layer of smooth muscle called the ________
trachealis
What type of epithelium lines the trachea?
Pseudostratified ciliated columnar epithelium
The trachea divides into the right and left principle bronchi at the level of the __________, which is also the same level as the ______ _________.
carina, sternal angle
What is the most common site of foreign body inhalation?
Right main/principle bronchus
Which principle bronchus is straighter and more in line with the trachea?
The right main/principle bronchus
What are the two functional subdivisions of the respiratory tract?
The conducting zone and the respiratory zone
This subdivision of the respiratory tract consists of the passageways for air. They run from the nasal cavity to the terminal bronchioles.
Conducting zone
This subdivision of the respiratory tract is the site of gaseous exchange. Involves respiratory bronchioles, alveolar ducts, alveolar sacs, and alveoli.
Respiratory zone
Name some of the components of the “respiratory zone” of the respiratory tract.
- Respiratory bronchioles
- Alveolar ducts
- Alveolar sacs
- Alveoli
What is the main site of gas exchange in the lungs?
The alveoli
What are the three factors facilitating change in the diameters of the thoracic cavity?
- Joints of the sternum
- Joints at the vertebrae
- Obliquity of the ribs
Which rib articulates with the manubriosternal joint/sternal angle?
The second rib
The slight movement of the sternal angle on inspiration causes which ribs to lift up and out?
Ribs 2-7
Which movement increases the transverse diameter of the ribcage? This type of movement is known as what?
Ribs 2-7 rotating on their axes around anterior and posterior attachments, increases the transverse diameter of the ribcage.
This type of movement is called “bucket handle movements”
What movement within the ribcage increases the anterioposterior diameter of the ribcage? What is the term for this type of movement?
The movement at the sternal angle carries ribs 2-6 up and down, gliding at constotransverse/ costovertebral joints, causing abduction of ribs and increases the anterioposterior diameter of the ribcage.
This type of movement is also known as the pump-handle movement.
Which movement increases the vertical diameter of the thoracic cavity?
The contraction of the diaphragm
What causes air to be sucked into the lungs?
The fall in intrathoracic pressure after the diaphragm contracts downwards, expanding the volume of the chest cavity
On inspiration, the diaphragm moves _______ and the abdominal muscles ________.
down, relax
On expiration, the diaphragm relaxes and moves _______, while the amdominal muscles ________.
up, contract
Where is diaphragmatic referred pain felt?
At the tip of the shoulder
What are the two main functions of the diaphragm muscle?
- Separates the thoracic cavity from the abdominal cavity
- Undergoes contraction and relaxation, altering the volume of the thoracic cavity and producing inspiration and expiration
Name the three sites of attachment of the diaphragm muscle
- Lumbar vertebrae & acruate ligaments
- Costal cartilages of ribs 7-10 (attaching directly to ribs 11-12)
- Xiphoid process of the sternum
What is the nerve supply to the diaphragm?
The phrenic nerve, stemming from C3, C4, and C5
What vessels supply blood to the diaphragm?
- Internal thoracic arteries (musculophrenic and pericardiophrenic)
- Superior phrenic artery (branch of the thoaracic aorta)
- Inferior phrenic artery (branch of abdominal aorta)
Lung activity is controlled by which branch of the nervous system?
Autonomic (contains both sympathetic and parasympathetic fibres)
Involuntary respiration is controlled by respiratory centres in the _________
brainstem
The parasympathetic nerve fibres supplying the lungs are derived from which cranial nerve?
The vagus nerve
The action of these nerve fibres are to stimulate secretion from the bronchial glands, contract teh bronchial smooth muscle, and vasodilate the pulmonary vessels
The parasympathetic nerve fibres
The sympathetic nerve fibres supplying the lung are derived from the
sympathetic trunks
The action of these nerve fibres stimulate relaxation of the bronchial smooth muscle and vasoconstriction of the pulmonary vessels
Sympathetic nerve fibres
Visceral afferent fibres conduct what type of impulses to the sensory ganglion of the vagus nerve?
Pain sensations
Name the three layers of intercostal muscles
External, internal, and innermost
In what order are the vessels arranged within the intercostal spaces?
From superior to inferior:
Veins
Arteries
Nerves
What muscle is used to assist breathing in quiet inspiration?
Only the diaphragm
What happens to the intercostal spaces in respiratory disease or laboured breathing?
Recession of the intercostal spaces
Which muscles can help with inspiration during laboured breathing?
Accessory muscles such as the SCM, scalenes, serratus anterior, Latissimus dorsi
What are the boundaries of the superior thoracic aperture?
Anteriorly: Superior border of manubrium and medial end of clavicle
Laterally: First ribs and their costal cartilages
Posteriorly: Body of T1 and costovertebral joints
What are some of the atypical features of the first rib?
- The first rib is the most curved and usually the shortest of all the ribs
- The shape is broad and flat, its surfaces looking upward and downward, hence its borders inward and outward.
- Has no costal groove
- The head is small, rounded, and possesses only a single articular facet, for articulation with the body of the first thoracic vertebra.
- Transverse tubercle: posterior and lateral to the neck; bears an articular facet for the transverse process of T1
Does the head of a true rib articulate with the vertebra or with the sternum?
The vertebra (specifically, the facets on the bodies of the thoracic vertebrae)
Where is the costal groove located on the ribs?
The lower border of the interior of the internal surface of each rib
Which ribs are atypical?
1,2 10, 11, 12
Which pair of ribs only have one facet each?
10th pair of ribs
State how the vertebrosternal ribs (2-7) articulate with the sternum
vertebrosternal ribs (2-7) articulate with the sternum through their costal cartilages
Which rib articulates with the sternum at the sternal angle?
2nd
What is the functional importance of identifying the sternal angle when performing a clinical examination of the chest?
Since sternal angle is a palpable landmark, One can use this landmark and hence the 2nd rib which articulates here to count the subsequent ribs and intercostal spaces
Name the three parts of the sternum
Manubrium, body, and xiphoid process
Name the articulations of a ‘typical’ rib with a ‘typical’ vertebra
- Vertebrocostal (facet/s on head of rib articulate with facet/s on sides of vertebral body)
- Costotransverse (facet/s on of tubercle of a rib articulate with facet/s on transverse process of vertebra)
Describe the direction the muscle fibres run in the external intercostal muscles
“Hands in pockets” originate at the lower
border of the rib above—insert into superior border of rib below.
Describe the direction the muscle fibres run in the internal intercostal muscles
“Hands to heart”; originate from
edge of the costal groove and inserts into the superior surface of the rib below.
In what order do the structures in the neurovascular bundle run (from superior to inferior?)
IC vein
IC artery
IC nerve
How does the “tripod” posture facilitate breathing?
Tripodding acts to increase the capacity of thoracic cavity and facilitate heavy/laboured breathing. In adopting this posture, this person is calling into
action the ‘accessory muscles of respiration’ into action (particularly for inspiration)
List some of the acessory muscles for inspiration
Pectoralis major, Neck muscles (sternomastoid, scalene muscles), Serratus anterior
What are the accessory muscles of expiration?
The abdominal muscles
What is the function of the paranasal sinuses?
Paranasal sinuses:
- Lighten the skull
- Provide resonance to the voice
- Increase surface area for conditioning of incoming air (as these have same respiratory lining as the nasal cavity, and are in communication with nasal cavity)
What type of lining does the upper respiratory tract have?
Pseudostratified ciliated columnar epithelium
Are paranasal sinuses present at birth?
At birth paranasal sinuses are only rudimentary. These develop further during 12-18 months of age
At what vertebral level does the trachea divide into the principle bronchi?
T3/T4
Name the anterior bony landmark for the “carina” of the trachea
The sternal angle
What are the tracheal rings made up of?
Hyaline cartilage
Which pleura lines the inner aspect of the ribcage?
Parietal pleura
Which pleura covers the outer surface of the lungs?
Visceral pleura
What is the purpose of pleural fluid?
This is the tiny amount of fluid in the pleural space that allows the layers of pleura to easily slide over one another during inspiration and expiration.
What are the four parts of the parietal pleura?
Cervical, costal, mediastinal, and diaphragmatic
What is the innervation of the parietal pleura?
Intercostal nerves and the phrenic nerve
Which of the two pleuras is sensitive to pain?
The parietal pleura
Which of the pleuras is sensitive to stretch (only)?
Visceral pleura
This is the area where the two sleeves of pleura form around the lung root; the area in which the two plural layers become adherant
The pulmonary ligament
These are the areas that the layers of pleura reflect to create recesses
Costodiaphragmatic recess and costomediastinal recess
This is the condition where fluid collects in the pleural space
Pleural effusion
This is the condition where pus collects in teh pleural space
Pyothorax
Name the three types of pleural effusions
- Hydrothorax (fluid)
- Hemothorax
- Pyothorax
List the three types of pneumothorax
- Closed
- Open
- Tension
In this type of pneumothorax, the parietal pleural membrane is punctured so air can move into the pleural space, but air cannot move as the damaged area is plugged. This causes compression of the lung, but the air is eventually absorbed through the lung and it returns to normal.
Closed pneumothorax
In this type of pneumothorax, the patient has sustained penetrating damage where air can move in and out of the pleural space. Air enters the pleural cavity during inspiration and exits during expiration.
Open pneumothorax
In this type of pneumothorax, a flap is created where air can come in, but cannot escape. Accumulation of air within the cavity results in increased pleural pressure. This compresses the lung and mediastinal structures, causing tracheal deviation and cario-pulmonary compromise.
Tension pneumothorax
This is the medical term for hyperventilation
Hyperopnea
The lobes of the lung are separated by
fissures
The right principle bronchus divides into how many branches, and what are they called?
Three secondary or lobar bronchi
Name the two lobes of the left lung
Upper and lower lobes
Name the three lobes of the right lung
Upper, middle, and lower
Secondary bronchioles subdivide into what type of bronchi?
Tertiary or segmental
Each tertiary bronchus supplies one _______________ segment.
bronchopulmonary
Name the contents of the lung hilum/roots
- Principle bronchus
- Pulmonary arteries
- Pulmonary vein
This structure is comprised of the alveolar epithelium and the capillary epithelium with their adherent basement membrane and epithelial cell cytoplasm. Pulmonary gas exchange occurs across this membrane.
The blood-air barrier
The blood-air barrier is comprised of what two structures?
The alveolar epithelium and the capillary endothelium
Pulmonary ________ bring deoxygenated blood to the lungs for gaseous exchange
arteries
Pulmonary _________ take oxygenated blood back to the left atrium of the heart to be distributed throughout the body
veins
The right bronchial artery branches off the third ______ _________ artery
posterior intercostal
The left bronchial artery branches off the ________ _________.
descending aorta
This is the network of nerves that supplies the lungs and contains both parasympathetic and sympathetic fibres
pulmonary plexus
The parasympathetic component of the pulmonary plexus has contributions from what nerve?
The vagus nerve
The sympathetic component of the pulmonary plexus has fibres from the ___________ ________
sympathetic chain
What is the effect of parasympathetic stimulation of lung tissue?
Bronchoconstriction due to smooth muscle contraction
What is the effect of sympathetic stimulation of lung tissue?
Bronchodilation due to relaxation of bronchial smooth muscle
The visceral pleura is innervated by __________ nerves via the pulmonary plexus and is sensitive to ______.
autonomic, stretch
Describe the innervation of the parietal pleura
The parietal pleura is innervated by the thoracic intercostal nerves and the phrenic nerve