Respiratory System Flashcards
What do the respiratory and cardiovascular systems cooperate to do?
What does the respiratory system do?
What does the cardiovascular system do?
supply O2 and eliminate CO2
respiratory system provides for gas exchange
cardiovascular system distributes respiratory gases
What does the respiratory system consist of? (7)
- nose
- paranasal sinuses
- pharynx (throat)
- larynx (voice box)
- trachea (windpipe)
- bronchi
- lungs
What are the 2 parts of the respiratory system from a structural POV?
upper respiratory system
lower respiratory system
What does the upper respiratory system consist of? (3)
- nose (external nose and nasal cavity)
- paranasal sinuses
- pharynx
What does the lower respiratory system consist of? (4)
- larynx
- trachea
- bronchi
- lungs
What are the 2 parts of the respiratory system from a functional POV?
conducting zone
respiratory zone
What is the conducting zone?
What is its function?
series of passageways whose function is to filter, regulate temperature, and moisten air and conduct it into lungs
What are the passageways of the conducting zone? (8)
- nose (external nose and nasal cavity)
- paranasal sinuses
- pharynx
- larynx
- trachea
- bronchi
- bronchioles
- terminal bronchioles
What is the respiratory zone?
What is its function?
passageways and tissues within lungs where gas exchange between air and blood occurs
What are the passageways of the respiratory zone? (4)
- respiratory bronchioles
- alveolar ducts
- alveolar sacs
- alveoli
Nose
What is the nose?
uppermost part of respiratory system that is subdivided into external nose and nasal cavities
Nose
What is the external nose?
anterior extension of nasal cavities formed by bones and cartilages covered by skeletal muscles and skin
Nose
What is the bony framework of the external nose?
formed by nasal, frontal, and maxillary bones
Nose
What is the cartilaginous framework of the external nose?
formed by septal and alar cartilages
Nose
What are nostrils (external nares)?
openings of external nose to exterior
Nose
How do the nostrils (external nares) diameter change?
by contraction of the covering muscles
Nose
What are nasal cavities?
What are they separated by?
two osseo-cartilagenous spaces separated by nasal septum
Nose - Nasal Cavities
Where do the nasal cavities start?
Where do they join to?
start at vestibule
joint to nasopharynx via choanae (internal nares)
Nose - Nasal Cavities
What is the vestibule?
area immediately above nostrils lined with skin
carries short coarse hairs
Nose - Nasal Cavities
What are the 4 boundaries of each nasal cavity?
roof
floor
lateral wall
medial wall
Nose - Nasal Cavities
What is the roof formed by?
What does the roof carry?
ethmoid bone
carries numerous openings for olfactory nerves
Nose - Nasal Cavities
What is the floor formed by?
maxillary and palatine bones that separates nasal cavity from oral cavity
Nose - Nasal Cavities
What is the lateral wall formed by?
maxillary, palatine, ethmoid, lacrimal bones, and inferior nasal concha
Nose - Nasal Cavities
What 3 curved bony shelves does the lateral wall caarry?
superior nasal conchae
middle nasal conchae
inferior nasal conchae
(all project inferiorly)
Nose - Nasal Cavities
What do the nasal conchae subdivide the lateral wall into?
3 groove-like passageways (superior, middle, and inferior meatuses) that receive paranasal sinuses and nasolacrimal duct
Nose - Nasal Cavities
What does the nasolacrimal duct do?
connects orbital cavity to nasal cavity, and carries tears
Nose - Nasal Cavities
What is the medial wall formed by?
(smooth)
nasal septum (main components include ethmoid and vomer bones) and septal cartilage
Paranasal Sinuses
What are paranasal sinuses?
several air-filled spaces contained within frontal, maxilla, ethmoid, and sphenoid bones
Paranasal Sinuses
What are the paranasal sinuses lined by?
respiratory mucus membrane
Paranasal Sinuses
Where are paranasal sinuses open?
on lateral wall of nasal cavities
Paranasal Sinuses
What are the functions of paranasal sinuses? (3)
- lighten the skull
- resonate the voice
- enhance efficiency of respiratory mucus membrane in filtration, humidification, and thermoregulation of inhaled air
What are the 2 nerves that supply nasal cavity and paranasal sinuses?
CN I (olfactory nerve) CN V2 (trigeminal nerve, maxillary division)
What artery supplies the nasal cavity and paranasal sinuses?
branches of maxillary branch of external carotid artery
What does CN I (olfactory nerve) do?
starts from olfactory receptor neurons at roof of nasal cavity, and transmits special sense of smell
What does CN V2 (trigeminal nerve, maxillary branch) do?
conveys general sensation of mucus membrane of nasal cavity and paranasal sinuses
What is the pharynx?
12-15 cm muscular tube that acts as conduit for air (between nasal cavities and larynx) and food (between oral cavity and esophagus)
What systems is the pharynx part of?
respiratory
digestive
Where does the pharynx start and end?
start: base of skull
end: esophagus at level of vertebra CVI
What is the pharynx related to posteriorly?
cervical vertebrae
What does the pharynx receive anteriorly? (3)
nasal cavities
oral cavity
larynx
What is the pharynx subdivided into? (3)
nasopharynx
oropharynx
laryngopharynx
Pharynx - Nasopharynx
Where is the nasopharynx?
behind nasal cavities and above soft palate
Pharynx - Nasopharynx
What is the pharyngeal tonsil?
aggregation of lymphoid tissue on roof of nasopharynx
Pharynx - Nasopharynx
Where is the auditory (Eustachian) tube?
What does it do?
open on lateral wall of pharyngeal tonsil
connect it to middle ears to equalize air pressure between middle ears and pharynx
Pharynx - Nasopharynx
What is the mucosal membrane of the nasopharynx innervated by?
CN V2
Pharynx - Oropharynx
Where is the oropharynx?
behind oral cavity and extends from soft palate to superior border of epiglottis
Pharynx - Oropharynx
Where are the palatine tonsils?
on lateral walls between palatoglossal and palatopharyngeal folds
Pharynx - Oropharynx
What is the mucosal membrane of the oropharynx innervated by?
CN IX
Pharynx - Laryngopharynx
Where is the laryngopharynx?
behind larynx, and extends from epiglottis to beginning of oesophagus
Pharynx - Laryngopharynx
What is the mucosal membrane of the laryngopharynx innervated by?
CN X
What are the intrinsic muscles of the pharynx innervated by?
CN X
What is the pharynx supplied by?
branches of external carotid arteries
Where is the larynx?
in front of vertebrae CIV-CVI
What is the larynx open to?
laryngopharynx superiorly
trachea inferiorly
What is the larynx?
organ of phonation
Larynx - Cartilaginous Skeleton
How many cartilages are there?
What are they connected by?
9 cartilages
connected by intrinsic laryngeal muscles, membranes, and ligaments
Larynx - Cartilaginous Skeleton
How are the cartilages grouped?
unpaired (thyroid, cricoid, and epiglottis)
paired (arytenoid, corniculate, and cuneiform)
Larynx - Unpaired Cartilages
What is thyroid cartilage?
What is it formed by?
largest laryngeal cartilage
formed by 2 laminae that are fused anteriorly to form laryngeal eminence (Adam’s apple) in front of neck, but widely open posteriorly
Larynx - Unpaired Cartilages, Thyroid
What forms the superior horn and inferior horn?
superior horn: posterior border of each lamina projects superiorly
inferior horn: posterior border of each lamina projects inferiorly
Larynx - Unpaired Cartilages, Thyroid
What do superior horns and inferior horns each join to?
superior horns join to hyoid bone by ligament
inferior horns articulate with cricoid cartilage
Larynx - Unpaired Cartilages, Thyroid
What does the thyrohyoid membrane connect?
connects superior border of thyroid cartilage to hyoid bone
Larynx - Unpaired Cartilages, Thyroid
What does the cricothyroid membrane join?
joins its inferior border to cricoid cartilage
Larynx - Unpaired Cartilages
What is cricoid cartilage?
most inferior cartilage of the larynx that resembles a signet ring with its lamina (wide plate) facing posteriorly
Larynx - Unpaired Cartilages, Cricoid
What do lamina of cricoid cartilage articulate with?
arytenoid cartilages superiorly
Larynx - Unpaired Cartilages
What does the inferior border of cricoid cartilage connect to?
first cartilage ring of trachea by cricotracheal ligament (fibrous membrane)
Larynx - Unpaired Cartilages
What is the epiglottis?
leaflet-shaped cartilage
- handle is attached to interior side of laryngeal eminence
- wide part is located behind tongue
Larynx - Unpaired Cartilages
What is the function of the epiglottis?
acts as lid to close entrance of larynx during swallowing
Larynx - Paired Cartilages
What is the arytenoid cartilage?
2 pyramidal cartilages
Larynx - Paired Cartilages
What do the bases of arytenoid cartilages articulate with?
cricoid cartilage inferiorly
Larynx - Paired Cartilages
What are the 2 processes at the base of each arytenoid cartilage?
What is their function?
vocal process: serves as attachment site for vocal ligament
muscular process: point of attachment for some intrinsic muscles of the larynx
Larynx - Paired Cartilages
What are the corniculate and cuneiform cartilages?
2 small cartilages on each side contained within aryepiglottic fold that extends between arytenoid cartilage and epiglottis
Larynx - Interior
What are the 2 ligaments stretched between thyroid and arytenoid cartilages, on either side of the midline?
vestibular ligaments
vocal ligaments
Larynx - Interior
Where are the vestibular ligaments?
Where are the vocal ligaments?
vestibular: located superiorly
vocal: located inferiorly
Larynx - Interior
Do vestibular ligaments vibrate during phonation?
Do vocal ligaments vibrate during phonation?
vestibular: do not vibrate
vocal: vibrate
Larynx - Interior
What are vestibular ligaments covered by?
What are vocal ligaments covered by?
vestibular: mucus membrane of larynx to form vestibular (false vocal) folds
vocal: mucus membrane of larynx to form vocal (true vocal) folds
Larynx - Interior
What is the larynx subdivided into, and by what?
3 regions, by vestibular and vocal folds
- vestibule: area superior to vestibular folds
- infraglottic space: area inferior to vocal folds
- ventricle: middle region located between vestibular and vocal folds on each side
Larynx - Interior
What is the glottis?
vocal folds + rima glottidis (fissure between right and left vocal folds)
What is the trachea?
fibro-cartilaginous tube with 2.5 cm diameter, and 12 cm length
Where does the trachea start and end?
start:lower margin of cricoid cartilage at level of vertebra CVI
passes superior mediastinum
end: level of sternal angle and TIV-TV intervertebral disc, by dividing into left and right primary (main) bronchi
- at this point, carina (internal ridge) is formed by posterior and inferior projection of the last tracheal cartilage
Trachea
What is the carina?
internal ridge formed by posterior and inferior projection of the last tracheal cartilage
What is the trachea composed of?
~20 incomplete C-shaped cartilage rings
- open part of rings faces posteriorly towards esophagus, and is spanned by fibromuscular membrane
Trachea
Compare the right vs. left primary bronchus.
right primary bronchus is shorter, wider, and more vertically positioned compared to left primary bronchus
Trachea
What structures is the trachea related to?
esophagus posteriorly
thyroid gland and manubrium of sternum anteriorly
What supplies blood for the trachea?
subclavian arteries
What is the trachea innervated by? (2)
cervical sympathetic chains (trunks)
vagus nerves
Where are the lungs?
What are they separated by?
located on either side of mediastinum
separated by heart and its large vessels and posterior mediastinal structures
What is the lung?
half-cone shaped organ suspended within pleural cavity by its root attaching to mediastinum
What is the apex of the lung? Where is it?
round, extends above level of first rib into root of neck
What are the 3 surfaces of the lung?
- inferior (diaphragmatic) surface or base
- lateral (costal) surface
- medial (mediastinal) surface
What are the 3 borders of the lung?
- anterior border
- posterior border
- inferior border
Lung
What is the inferior (diaphragmatic) surface or base?
concave
sits on diaphragm
Lung
What is the lateral (costal) surface?
convex
related to ribs, intercostal muscles and sternum
Lung
What is the medial (mediastinal) surface?
concave
related to middle and posterior mediastinal structures
Lung
What does the medial (mediastinal) surface carry?
hilum
through which primary bronchi, pulmonary vessels, bronchial vessels, lymphatic vessels, and nerve enter or leave the lung to form root of lung
Lung
How many pulmonary arteries are there? What do they do?
1
carries deoxygenated blood from right ventricle to lung
Lung
How many pulmonary veins are there? What do they do?
2
convey oxygenated blood from lung to left atrium
Lung
What does the anterior border carry?
(sharp border)
on left lung carries cardiac notch
Lung
What is the lingula of the anterior border?
part of left lung below cardiac notch
Lung
What does the anterior border separate?
medial surface from lateral surface on anterior side
Lung
What is the posterior border?
round
related to thoracic region of vertebral column
Lung
What does the posterior border separate?
medial surface from lateral surface on posterior side
Lung
What does the inferior border separate?
(sharp border)
medial and lateral surfaces from inferior surface
Lung
What does the inferior border cross?
- ribs 6 on anterior aspect of thorax
- ribs 8 on lateral aspect of thorax
- ribs 10 on posterior aspect of thorax
Lung
Compare the right and left lungs.
- right lung is slightly larger and heavier than left lung because middle mediastinum and its contents bulge more towards left side
- right lung is wider and shorter than left lung due to presence of liver under right dome of diaphragm
Lung
What is the right lung divided into?
3 lobes (superior, middle, and inferior) by oblique and horizontal fissure
Lung
What is the left lung divided into?
2 lobes (superior and inferior) by oblique fissure
Lung
What is the lingula of the left lung equivalent to in the right lung?
middle lobe
Lung
What is each lobe of the lung subdivided into?
bronchopulmonary segment – there are 10 segments in each lung
Lung
What happens to primary bronchi after passing through the hilum?
primary bronchi divide into secondary (lobar), then tertiary (segmental) bronchi
tertiary bronchi continue to divide and produce several generations of divisions including bronchioles, terminal bronchioles, and respiratory bronchioles
Lung
What are bronchioles?
smallest airways that do not carry any cartilage in their wall
Lung
What is the bronchial tree?
entire divisions of primary bronchi
Lung
What is lung tissue innervated by?
afferent and efferent branches of pulmonary plexus located at bifurcation of trachea
Lung
What is lung tissue formed by?
vagus nerves and sympathetic nerves arising from lateral horns of T1-T4 segments
Lung
What do vagus nerves do?
constrict bronchioles
Lung
What do sympathetic nerves do?
dilate bronchioles
Lung
What do bronchial arteries arise from?
Where do they pass?
What do they do?
thoracic aorta
pass through hilum
supply oxygen and nutrients to lung tissue
Pleura
What is each lung surrounded by?
pleural sac composed of 2 serous layers – inner visceral layer, and outer parietal layer
Pleura
What is the pleural cavity?
What does it contain?
space between visceral and parietal layers of pleura
contains few mL of serous fluid that lubricates surfaces of lungs to facilitate their movements
Pleura
Where is the visceral pleura?
intimately attaches to surfaces of lungs and extends into their fissures
Pleura
How does the visceral pleura continue as the parietal pleura?
reflects on itself at hilum to continue as parietal pleura to line inner surface of thoracic wall and extends over diaphragm and mediastinum
Pleura
What is the visceral pleura innervated by?
same sympathetic nerve fibers (T1-T4) that supply pulmonary tissue
Pleura
What does the parietal pleura consist of?
costal, diaphragmatic, and mediastinal parts
Pleura
What happens at the site of reflection between parts of the parietal pleura?
pleural recesses (gutter-like spaces) are formed that are not occupied by lungs during expiration
Pleura - Parietal Pleura
What is the costodiaphragmatic recess?
largest recess, surrounds convexity of diaphragm inside thoracic wall
lowest point of pleural cavity that crosses ribs 6 (anterior), 10 (lateral), and 12 (posterior)
Pleura
Where is the costodiaphragmatic recess formed?
between costal and diaphragmatic parts of parietal pleura
Pleura
What is the parietal pleura innervated by?
somatic nerves that supply walls of thoracic cavity (phrenic and upper intercostal nerves)
