thorax and lungs

• Thorax


  The portion of the body extending from the base of the neck superiorly to the level of the diaphragm inferiorly

  
• Thoracic Cage


  • The outer structure of the thorax
  • Constructed of the sternum, 12 pairs of ribs, 12 thoracic vertebrae, muscles and cartilage
  • Function: Provide support and protection for many important organs including those of the lower respiratory system
• Sternum


  • Lies in the center of the chest anteriorly
  • Three Parts: Manubrium, Body, Xiphoid Process

  
• Suprasternal Notch


  • U-shaped indentation located on the superior border of the manubrium
• Sternal Angle (Angle of Louis)


  • A bony ridge palpated at the point where the manubrium articulates with the body of the sternum; location of the 2nd pair of ribs
• Ribs & Thoracic Vertebrae

  • 12 pairs of ribs
  • Each pair of ribs has corresponding intercostal spaces
  • Anteriorly the seven pairs articulate with the sternum by way costal cartilages
  • Ribs two through six are easy to count because of their articulation with the sternal body
  • Ribs seven through ten connect to cartilage of the pair lysing superior to them
  • This configuration forms an angle between he right and left costal margins meeting at the level of xiphoid process; commonly referred to as Costal angle
  • The 11th and 12th pairs of ribs are called "floating ribs" – attached posteriorly to the vertebrae
• Posterior Thoracic Landmarks


  • Vertebrae prominens – spinous process of the seventh cervical vertebra (C7)
  • The lower tip of each scapula is at the level of the seventh and eighth rib when client's arms are at hi side

  
• Vertical Reference Lines


  • Midsternal line
  • Midclavicular lines (right and left)
  • Vertebral line – midspinal
  • Scapular line – (right or left)
  • Mid–axillary line – runs from the apex of the axillae to the level of the 12th rib
  • Anterior Axillary line
  • Posterior Axillary line
• Thoracic Cavity


  • Consists of mediastinum and lungs
  • Mediastinum – central area in the thoracic cavity that contains the trachea, esophagus, heart and great vessels
  • Lungs – lies on each side of the mediastinum
• Lungs


  • Two cone-shaped, elastic structures suspended within the thoracic cavity
  • Apex - 3 -4 cm. above of the clavicles
  • Base – rests at the level of the diaphragm, 6th rib, MCL
  • Extends from Axilla apex to 7th –8th rib
  • Apex of lung is at C7
  • Base T10 (on deep inspiration to T12)
• Lobes of Lung


  • Right Lung: 3 lobes, upper, middle, lower
  • Left Lung: Left Upper Lung (LUL) and Lower Lung (LL) (2 lobes)
• Left Lung – no middle lobe
• Anterior chest contains upper & middle lobes with very little lower lobe
• Posterior chest has almost all lower lobe. Right middle lobe does not project into the posterior chest
• Pleural Membranes


  • Pleura – a thin, double-layered serous membrane
  • Parietal pleura – line the chest cavity
  • Visceral pleura – external surfaces of the lungs
  • In the healthy adult, lubricating serous fluid between the layers allows movement of the visceral layer over the parietal layer during ventilation without friction
  • In severe dehydration, it reduces the volume of pleural fluid, resulting in the increased transmission of lung sounds and a possible friction rub
• Trachea


  • Flexible structure that lies anterior to the esophagus
  • C-shape rings of hyaline cartilage compose the trachea
  • Helps to maintain its shape and prevent its collapse during respiration
• Trachea & Bronchi


  • Provide the passage for air to get into the lungs from the environment
  • Represent "Dead Space" in the respiratory system where air is transported but no air exchange takes place
  • Lined with mucous membranes containing cilia that help sweep dust, foreign bodies and bacteria that have been trapped by the mucus toward the mouth for removal
• Mechanics of Breathing


  1. Purpose of Respiration: To maintain adequate oxygen level in the blood to support cellular life

  2. External Respiration or ventilation: Accomplished by expansion of the chest, both vertically and horizontally

  3. Vertical expansion - contraction of diaphragm

  4. Horizontal expansion – intercostal muscles lift the sternum and elevate the ribs

  5. Inspiration: A slight negative pressure is created in the lungs in relation to the atmospheric pressure, resulting in an inflow of air into the lungs

  6. Expiration: Occurs with relaxation of the intercostal muscles and diaphragm

  7. Breathing patterns change according to cellular demand

  8. Involuntary control of respiration is the work of the medulla and pons

  9. The hypothalamus and the sympathetic nervous system play a role in involuntary control of respiration in response to emotional changes such as fear or excitement
• Hypercapnia


  An increase of carbon dioxide in the blood
• Hypoxemia


  Decrease oxygen
• Intestinal symptoms


  • Heartburn
  • Hiccups
  • Chronic cough
• Patients with asthma


  Often have GERD
• Crackles(Fine)- High-pitched, short , popping sounds
• Crackles (Coarse)- Low-pitched , bubbling , moist sounds
• pleural friction rub - Low-pitched dry , grating sound
• wheeze (sibilant)-High pitched, musical, sound
• wheeze (sonorous)- Low pitched, snoring or moaning sounds
• Kussmaul - Rapid, deep , labored
• cheyne- stroke respiration: regular pattern characterized by alternating periods of apnea
• Biot respiration: Irregular pattern characterized by varying depth and rate of respirations followed by periods of apnea
• Ataxic: Significance disorganization with irregular and varying depths of respiration
• Air trapping: Increasing difficulty in getting breath out
• Normal chest configuration


  • Elliptical in shape
  • AP diameter smaller than lateral diameter (1:2)
• Barrel chest


  • Thorax is round shaped
  • AP diameter to lateral diameter ratio is 1:1
  • Seen in aging adults, COPD, and chronic asthma
• Pectus excavatum (funnel chest)


  • Thorax has depression in lower sternum
  • Seen with congenital conditions that can cause murmurs or compress the heart and vessels
• Pectus carinatum (pigeon chest)


  • Sternum protrudes forward
  • Congenital
  • Increased AP diameter
• Scoliosis


  • Lateral S-shaped curve of the spine
• Kyphosis

  • Exaggerated increased rounding of the thoracic spine
  • Often seen with osteoporosis in older women