Anatomy of Breathing 2 Flashcards
describe the important anatomical landmarks of the respiratory tract
C6 vertebra - larynx becomes trachea, pharynx becomes oesophagus
trachea can be palpated at jugular notch of manubrium
isthmus of thyroid gland is anterior to tracheal cartilages 2-4
describe the contents of the chest cavity
vital organs - viscera
major vessels and nerves
mediastinum - cavity in the middle of pleural cavities
right and left pleural cavities
explain the anatomy of the pleural cavities - defining parietal, visceral pleura and pleural fluid
parietal pleura - in contact with body wall (outer membrane), separates cavity from mediastinum, innervated by phrenic and intercostal nerves, a vacuum containing pleural fluid
visceral pleura - in contact with developing lung
the pleurae secrete pleural fluid into the pleural cavity - providing a lubricant and surface tension
define the lung apex and base and horizontal fissure
apex superior
base inferior
horizontal fissure on right lobe (between middle and superior lobe) - level with 4th costal cartilage
describe the intercostal spaces including their nerve and blood supply
11 pairs
each space carries neuro-vascular bundle;
vein, artery and nerve
between internal and innermost intercostal muscle layers
inferior surface of rib
nerve supply - anterior ramus of spinal nerve (intercostal nerve)
blood supply;
posterior - arterial supply - thoracic aorta
venous drainage - azygous vein
anterior - arterial supply - internal thoracic artery
venous drainage - internal thoracic vein
vessels meet at the anastomoses
describe the diaphragm
internal part of body wall;
forms the floor of chest cavity
forms the roof of abdominal cavity
has openings to permit structures to pass between 2 cavities
skeletal muscle with unusual central tendon (somatic structure - voluntary control)
anatomically arranged as right and left domes - right dome is normally more superior (due to liver inferior)
muscular part attaches peripherally to the sternum, the lower 6 ribs and costal cartilages and the L1-L3 vertebral bodies
muscular part is supplied by phrenic nerve
describe the phrenic nerves
combined anterior rami of cervical spinal nerves C3, 4,5
found in the neck on anterior surface of scalenus anterior muscle
found in chest descending over the lateral aspects of the heart and anterior of root of lung (vagus nerve passes posterior)
supplies somatic sensory and sympathetic axons to the diaphragm and fibrous pericardium
supplies somatic motor axons to the diaphragm - keeping the diaphragm alive
describe mechanics of inspiration
process initiated by diaphragm
- diaphragm contracts and descends - increasing vertical chest dimension
- intercostal muscles contract elevating ribs - increasing A-P and lateral chest dimensions
- chest walls pull the lung outwards with them (pleura) - pleura creates a vacuum, pulling visceral pleura and lung out with them. This creates negative pressure in lungs and so air flows in
describe mechanics of expiration
- diaphragm relaxes and rises - decreasing vertical thoracic dimension
- intercostal muscles relax, lowering ribs - decreasing A-P and lateral chest dimensions
- elastic tissue of lungs recoils - air flows out of lungs
describe the anatomy of the female breast
upper outer quadrent - superolateral (includes axillary tail)
upper inner - superomedial
lower outer - inferolateral (includes areloa and nipple)
lower inner - inferomedial
blood supply - subclavian and internal thoracic artery and vein
lymph nodes - unilateral drainage from lateral quadrants to axillary nodes
bilateral drainage from medial quadrants to parasternal nodes (chains run parallel and deep to sternal edges)
describe anatomy of the chest wall - refer to PP for diagram
superficial fascia is composed of adipose tissue and provides insulation
deep fascia is a tough, fibrous membrane and provides protection
deltoid muscle (shoulder)
pectoralis major (across thorax)
nerves; sensory nerves - intercostal long thoracic nerve - supplies serratus anterior (lies superficial) brachial plexus (posterior to artery)
blood supply;
subclavian artery and vein
scalenus anterior (cerivical vertebrae to 1st rib)
cephalic vein (delto-pectoral groove) drains the upper limb
explain the anatomy of the parietal pleura
costodiaphyragmatic recess;
most dependent (deepest) part of the pleural cavity (most inferior part when upright)
located between the diaphragmatic parietal pleura and the costal parietal pleura
its most inferior region laterally is the costophrenic angle
abnormal fluid in the pleural cavity drains into the recess (e.g. pleural effusion or haemothorax)
this causes the blunting of the angles and a fluid level seen on chest x-ray
explain the anatomy of the lung root
structures of the root of lung; 1 main bronchus 1 pulmonary artery 2 pulmonary veins lymphatics visceral afferents sympathetic nerves parasympathetic nerves
describe hilum of lung
contains main bronchi (hyaline cartilage in walls), pulmonary arteries, pulmonary lymph nodes, pulmonary veins
refer to PP
diagram the left and right lung
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