week 5 - respiration Flashcards
parts of the upper respiratory tract
nasal cavity, paranasal sinuses
the pharynx
the larynx
function of upper respiratory system
warm inspired air to body temp
humidify air
filter for particulates
parts of lower respiratory tract
the larynx below level of vocal folds
trachea
bronchi
bronchioles
lungs
function of lower respiratory
gas exchange
where is the respiratory centre
medulla oblongata
which neurones automatically maintain a rhythmic cycling pattern
inspiratory and expiratory neurones
an apex
extends superiorly into the root of the neck, above first rib
costal surface
close to ribs/costa cartilages and intercostal spaces
mediastinal surface
close to the mediastinum anteriorly and vertebral column posteriorly. surface contains the hilum
diaphragmatic (base)
sits on the diaphragm
inferior border
separates the base from the costal surface
anterior border
separates costal surface from mediastinal surface
posterior border
separates costal surface from mediastinal surface
lobes and fissures of right lung
3 lobes separated by 1 horizontal (between superior and inferior) and 1 oblique fissure (between inferior lobe and other two)
superior lobe - contact with anterior thoracic wall, projects into root of neck
middle lobe - contact with anterior and lateral thoracic wall
inferior lobe - contact with posterior and inferior thoracic wall
lobes and fissures of left lungs
2 lobes separated by 1 oblique fissure
superior lobe - contact with upper part of anterior and lateral thoracic wall, projects into root of the neck
inferior lobe - contact with posterior and inferior part of the thoracic wall
lingula - projection that extends over the anterior surface of heart
hilum of lung
area which structures (roots) enter and leave the lung
- pulmonary artery
- 2 pulmonary veins
- main bronchus
- bronchial vessels
- nerves
- lymphatics
lungs in relation to vertebra
most superior aspect is level with T1, most inferior is level with T12
oblique fissure
posteriorly - midline, near spine of T4
laterally - descends diagonally, crossing 4th and 5th intercostal spaces to reach rib 6
anteriorly - follows rib 6 and its costal cartilage
horizontal fissure
lies anteriorly, following the contour of rib 4
pleura
thin membrane that encloses lungs and lines walls of thoracic cavity
one continuous layer
serous membrane - produces serous fluid that lubricates cavity
parietal pleura
lines pulmonary cavities and is adherent to thoracic wall, mediastinum and diaphragm
costal pleura - covers internal surfaces of thoracic wall
mediastinal pleura - covers lateral aspects of mediastinum
diaphragmatic pleura - covers superior aspect of diaphragm each side of mediastinum
cervical pleura - extends through superior thoracic aperture forming domed pleura over the apex of the lung
visceral pleura
covers lungs and is adherent to all its surfaces, including horizontal and oblique fissures
pleural cavity
potential space between the layers of pleura
doesn’t exist in healthy individuals
could fill with air or blood if punctured
pleura function
allows smooth movement of lungs during respiration
fluid provides surface tension to keep lung surface in contact with thoracic wall
pleural recesses
pleural cavity extends further than lungs
superiorly - 3-4cm above first costal cartilage
anteriorly - L+R approach each other posterior to sternum
inferiorly - costal pleura extends to rib 8 in the midclavicular line and to rib 10 in the midaxillary line
bones of the thorax
sternum
12 pairs of ribs + costal cartilages
12 thoracic vertebra
function of bones of thorax
provide attachment points for muscles of respiration
move to facilitate breathing
provide protection for the vulnerable organs within the thorax
sternum
manubrium
sternal body
sternal angle
xiphoid process
ribs
1-7 are true ribs (articulate directly with sternum, own costal cartilage)
8-12 are false ribs (articulate indirectly with sternum, shared costal cartilages
11-12 are floating ribs (don’t articulate with sternum, shorted and pointier)
diaphragm
large flat central tendon
innervated by R+L phrenic nerves which originate at C3-C5
3 structures through diagram are the aorta, inferior vena cava, oesophagus
intercostal neurovascular bundle
intercostal artery, vein and nerve travel together in intercostal space, lie at lower border of each rib
external intercostal muscles
extend from lower border of rib above to upper border of rib below
run around wall of thorax from tubercles of each rib posteriorly to cartilages of ribs
end in thin membranes
pull ribs up and forward during inspiration
internal intercostal muscles
run between most inferior lateral edge of the costal grooves of the ribs above to the superior margins of the ribs below
fibres run diagonally backwards and down
pull ribs down and inwards during active respiration
innermost intercostal muscles
incomplete and variable
separated form internal by bundle of intercostal blood vessels and nerves
movements of breathing
forwards
- anteroposterior
- pump handle, ribs are handle
backwards
- laterally
- bucket handle - ribs are handle pivoting sternum and spine
vascular tree
arteries, vein and capillaries
take poor oxygenated blood to lungs then return highly oxygenated blood to heart
airway tree
air filled branching tubes originating from trachea
conduct new atmospheric air to gas exchange surfaces and return used air to atmosphere
trachea
smallest total cross-sectional area so responsible for most of airways resistance
hyaline cartilage rings prevent collapse of inspiration
bronchi
trachea bifurcates at T4 into 2 primary bronchi which enter lung
right main bronchus - wider and shorter, more vertical to reach hilum
left main bronchus - oriented more horizontally and runs inferior to arch of aorta and anterior to oesophagus
primary divide into secondary (one per lobe) then divide into tertiary
bronchioles
12th division of bronchi, bronchioles are found
collapsible passage ways with smooth muscle walls
further 11 divisions and respiratory bronchioles are formed , they terminate at alveolar ducts - respiratory zone of the lower respiratory system
lung lobules
cluster of alveoli surrounded by capillaries
alveoli
basement membranes fused to the endothelium of the capillaries surrounding them
apical surface is covered in a surfactant - gasses dissolve to aid diffusion
upper respiratory tract
cavities lined with pseudostratified columnar epithelium
columnar cells have numerous cilia on their surface
epithelium also contains mucous secreting goblet cells
lower respiratory tract
in the more peripheral branches the epithelium becomes thinner though cells are still ciliated columnar with goblet cells.
bronchioles are lined by simple ciliated columnar epithelium
most proximal components are the respiratory bronchioles which are lined with cuboidal ciliated epithelium
The alveolar ducts are lined with flattened epithelium.
type I pneumocytes
thin cells for gaseous diffusion, 40% of cells but 90% of SA
type II pneumocytes
secrete surfactant
rounded and contain mitochondria
