Anatomy Flashcards
what bones are there within the resp system?
sternum
12 pairs of ribs
12 thoracic vertebrae
what is the thorax inlet?
located at cross roads of sternum and clavicle and ribs.
important anatomical landmark
the space at the top of the rib cage to allow access
what is the costal facet?
site connection between rib and vertebrae
how are ribs 1 to 10 attached to sternum?
via costal cartilage
describe the 12 ribs
7 true pairs
3 false pairs
2 floating pairs
where is rib 1?
flat and under clavicle
describe thoracic vertebrae shape
- Heart shaped body
- Small circular, vertebral foraman
- Laminae are broad and overlap with those of the vertebrae
- Long downward pointing spinous process
what is the sternal angle?
important landmark
point at which costal cartilage of second rib articulates with sternum
where is the 2nd ICS?
below the 2nd Rib
what is the superficial IC?
external
how do the external IC muscles run?
fibres run downwards and forwards
what is the middle layer of IC?
internal IC
describe internal IC
fibres run downwards and backwards
why do the IC muscles run in different directions?
provide stability and strength
what is the deep IC layer?
innermost IC muscles
where do the posterior IC arteries arise from?
thoracic aorta
where do the anterior IC arteries arise from?
internal thoracic and musclephrenic
where do the posterior intercostal veins drain into ?
azygos system
what is the azygous system?
locates either side of vertebrae column and drains viscera within mediastinium as well as back of thoracic/ abdo walls.
where do the anterior IC veins drain into?
internal thoracic or musclophrenic
where do the intercostal nerves arise from?
ventral rami at T1-T11 to supply muscle, adjacent skin and pleura
describe the diaphragm
- Dome shaped skeletal muscle with a central tendon (anchors heart in place)
- Attached to xiphisternum, costal margin, 11th and 12th ribs and lumbar vertebrae
- Openings for IVC, oesophagus and aorta
- Fibrous pericardium fused to central tendon –
what innervates the diaphragm?
phrenic nerve
where do muscle fibres of the diaphragm arise from?
radially from margins of inferior thoracic aperture and converge at central tendon
what happens to the dome height, when the diaphragm contracts?
decreases so that thorax volume increases
what percentage of breathing is caused by diaphragm?
70-75%
what does the pectoralis major allow movement for?
adduction and medial rotation, flexion of humerus at shoulder joint
what is the role of the pectoralis minor?
depresses tip of shoulder and protracts scapula
where are the sternocleidomastoid and scalenes muscles?
deep - running from chest up to neck
describe the lungs shape
- Conical shaped with soft, spongy texture
- Apex of lung lies above the clavicle – rises 3-4cm above level of the first costal cartilage. The highest point of the apex is up to 2cm above medial third of clavicle/ just above neck of first rib.
where is the costal surface of the lungs?
adjacent to the ribs - smooth and convex as it is adapted to thoracic wall shape
what is the mediastinum surface of the lungs?
faces mediastinum deeply concave - as it is moulded to cardiac impression
which lung is wider and shorter?
right lung
how many lobes does the right lung have?
three - superior middle and inferior
how many fissures does the right lung have?
2 - oblique (downwards) and horizontal (across)
how many lobes does the left lung have?
2 - superior and inferior
how many fissures does the left lung have?
one - oblique
where is the hilum of the lung?
located on mediastiatinal surface, where pulomanary vessels, bronchi, lymphatic vessels enter/ leave the lung
what are the characteristics of the lungs?
- Compliance (distensibility) : ability of lungs to expand – connective tissue structure, level of surfactant, mobility of thoracic cage
- Elasticity – elastic tissue allows lung expansion during inspiration and recoil during expiration
what is the pleural cavity lined with?
mesothelial membrane called pleura
how many layers of serous membrane does pleura contain?
2
what are the two layers of serous membrane in pleura?
visceral - adheres to heart
parietal - adheres to thoracic wall
what innervates the pleura?
visceral - innervated by CNS - autonomic
parietal - innerved by somatic - helps expansion
what is the pleural cavity?
potential space between parietal and visceral layers containing thin serous fluid
accessory muscles are used during heavy breathy/ resp pathology, which muscles are these?
scalene, sternocleidomastoid, pectoralis major, trapezius, external intercostal
describe the pathway of external intercostal muscles?
from back and come toward the middle (down slope)
describe the structure of the internal intercostal muscles?
from front and slope downwards towards the back
describe the diaphragm movement during inhalation and exhalation
at rest - relaxed
inhalation - contracting
exhalation - relaxed
what is resp rate influenced by?
stress, blood gases, infection
what is the function of the conduction zone?
filters, warms and moistens
what is included within the conduction zone?
trachea, primary bronchi, secondary bronchi, tertiary bronchi
what is the trachea made up of?
hyaline cartilage in a horse shoe shape - prevents closure , back of the trachea is trachelis muscle - can constrict
what cells make up the trachea and following structures of the conduction zone and why?
modified pseudostratified columnar epithelial cells with goblet cells
- goblet produce mucus
- epithelial produce cilia
what are the non cilia cell types within the end of the conduction zone (tertiary bronchi)
non-ciliated columnar cells
what occurs within the respiratory zone?
gas exchange
what does the respiratory zone consist of?
bronchioles, terminal bronchioles, alveoli
what are the cell types within respiratory zones?
simple cupboidal ciliated epithelium
no cartilage
elastic fibres and smooth muscle
can bronchioles constrict?
yes
how many alveoli cells do we have?
enough to cover a tennis court
500 million
what is tidal volume?
breathing volume at rest - 500ml
what is total lung capacity?
total amount of air lungs can hold
can all air leave the lungs?
no - alveoli would collapse if all the air was removed
what is vital capacity?
purposeful large breath out and then breath in
what is normal O2 partial pressure?
10.3-13.5KPa
what is normal CO2 partial pressure?
4.5-6.0 kPa
what does VQ> 1 mean
well ventilated but poorly perfused
what does VQ< 1 mean?
poorly ventilated, well perfused
how can alveolar ventilation (V) and perfusion (Q) match?
altering bronchiole and pulmonary ateriole radius
- bronchiole dilate and due to hypercapnia (HIGH CO2)
- pulmonary arterioles constrict due to hypoxia - diverting blood to alveoli with more oxygen
how does CO2 travel in the body?
9% in plasma
10-13% in carbamino haemoglobin
78% in bicarbonate
what is a pneumothorax?
air/ fluid entering pleural cavity and will compress and collapse lung
what is a haemothorax?
blood in pleural cavity causing lungs to collapse
what is a tension pneumothorax?
air continues to enter pleural cavity and can not escape
pushes trachea towards contralateral side
what is the aortic knuckle on a chest X ray?
distal ascending aorta
what is the costophrenic angle - seen in CXR?
edge of diaphragm where meets other organs
what is costocardiac angle - seen on CXR?
angel between edge of heart and diaphragm
where does trachea sit in relation to other organs?
sits anterior to oesophagus
can be palpated above suprasternal notch
left main bronchus passes under arch of aorta and is longer and narrower than right
