The EAR by huanghengdong

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									        The EAR
External Ear
•Cartilaginous bony parts of
•external acoustic meatus
•Tympanic membrane

Middle Ear
(malleus, incus and staples
•Middle ear/tympanic cavity
eustachian tube
•Aditus to mastoid antrum
•Oval window
 (fenestra vestibule)
•Round window
 (fenestra cochleae)
Internal Ear
Semicircular canals
Internal acoustic meatus
              Nasal cavity and pharynx
•Superior, middle and
inferior conchae
•Superior, middle and
inferior meatuses


•Nasopharynx –
opening of
Eustachian tube
                        Note: Olfactory region of nasal cavity is the epithelium
                        lining superior conchae
       Trachea and bronchi
• The trachea bifurcates into R &
  L primary bronchi at the level of
  the sternal angle, the inside of
  the bifurcation is called the
• R is shorter, wider, and takes a
  more direct path to hilum of R
• Note its relationship to the
  oesophagus, aortic arch,
  thoracic aorta and Vena Cava
    Pleurae, cavities and mediastinum

•  Parietal pleura
     – Costal pleura
     – Diaphragmatic pleura
     – Cupula (cervical) pleura
     – Mediastinal pleura
• Visceral Pleura
• Costodiaphragmatic/
 costophrenic recesses
• Costomediastinal recesses

•   Mediastinum- potential space between 2 pleural cavities (that contain
    lungs), sternum and thoracic vertebra, that contains heart etc.

NOTE: no sensory innervation of visceral pleura. Phrenic and intercostal nerve
    innervate perietal pleura.
    : pleura, pericardium, peritoneum and tunica vaginalis of the testis are all
                                    Lungs the hilum
    The lungs are suspended freely, only attached at
•   Apex and Base
•   Margins- anterior and inferior
•   Surfaces-costal, medial, diaphragmatic
•   R lung- 3 lobes, 2 fissures
•   L lung- 2 lobes, 1 fissure, lingula and cardiac impression
           Systemic Blood Supply
•   two left bronchial arteries arise directly from the thoracic
•   a single right bronchial artery may also arise directly from
    the aorta but more commonly from the left superior bronchial
    artery or from one of the upper posterior intercostals arteries.
•   bronchial arteries branches supply the upper oesophagus,
    the main bronchi  respiratory bronchioles
•   anastomose with branches of the pulmonary arteries
•   The two bronchial veins drain only part of the blood supplied
    to the lungs by the bronchial arteries, primarily that near the
    more proximal part of the roots of the lungs
•   The right bronchial vein drains into the azygos vein, and the
    left bronchial vein drains into the accessory hemiazygos vein
    or the left superior intercostal vein. Bronchial veins also
    receive some blood from esophageal veins.

NOTE: parietal pleura supplied by arteries supply thoracic wall
            Pulmonary Blood Supply
• Each lung has 1 pulmonary artery and 2 pulmonary veins

• The pulmonary trunk  right and left pulmonary arteries
  (2)secondary lobar arteries (5)  tertiary segmental arteries
•   right and left superior lobar arteries arise, before entering the hilum
• The arteries and bronchi run parallel course

• Four pulmonary veins, a superior and an inferior pulmonary vein
  on each side, carries blood to the left atrium of the heart.
     –   The middle lobe vein joins
    with the right superior
    pulmonary vein.
• Segmental veins 
   lobar veins (5) 
  pulmonary veins (4)
• The pulmonary veins run
Roots of the

The lungs are attached
to the mediastinum by the
roots of the lungs
the bronchi, pulmonary
arteries, superior and
inferior pulmonary veins,
the pulmonary plexuses
of nerves (sympathetic,
parasympathetic, and
visceral afferent fibers),
and lymphatic
Lymphatic drainage-
 Superficial plexus: lung tissue and visceral pleura bronchopulmonary
    (hilar) lymph nodes
 Deep Plexus: root of lung pulmonary lymph nodes bronchopulmonary
    (hilar) lymph nodes
            Then together  bronchomediastinal lymph trunks  junction of
    subclavian and internal jugular veins
     Nerves of lungs and visceral pleura
•   The right and left pulmonary plexuses,
    anterior and posterior to the roots of the
    lungs, receive sympathetic contributions
    from the right and left sympathetic trunks
    and parasympathetic contributions from the
    right and left vagus nerves (CN X).

•   After contributing to the posterior
    pulmonary plexus, the vagus nerves
    continue inferiorly and become part of the
    esophageal plexus, often losing their
    identity and then reforming as anterior and
    posterior vagal trunks.

•   Branches of the pulmonary plexuses
    accompany pulmonary arteries and
    especially bronchi to and within the lungs.
    Thoracic Wall
•   The intercostal muscles
      – External intercostal V
      – Internal intercostal /\
      – Innermost intercostal
•   serratus posterior
•    levatores costarum
•    subcostal (Crosses intercostal spaces)
•    transversus thoracis (radiate from

    posterior aspect of inferior sternum)
Respiratory Histological Features summary

             Bronchi Conducting Respiratory Alveoli
                     zone       zone
Epithelium   Ciliated     Columnar   Ciliated       Simple
             pseudo-                 columbnar or   squamous
             stratified              cuboidal
Hyaline      C-     Plates           Absent         Absent
cartilage    Shaped
Smooth       ++     ++++             +              -
Goblet       ++++         +++        ++             -
                         The Heart
•Ventricle wall thickness>atria, L ventricle> R
•Auricles- ear-like flaps of atrial walls
 R atrium- 4 openings IVC, SVC and coronary sinus, and
   atrioventricular orifice

  –Fossa ovalis,
  remanent of foramen
  ovale in fetus, oval
  depression in
  interarial septum
R ventricle-
2 openings R
   orifice and

    •R Atroventricular valve- guards AV orifice, is tricuspid, connects to chordae
    tendineae, with then attach to papillary muscles in ventricular wall
• L atrium- 5 openings- 4 pulmonary veins and L
  AV orifice
• L Atroventricular orifice is guarded by the mitral
  valve, which is bicuspid otherwise same R
• L ventricle- 2 openings- AV orifice and aortic

• Aortic and
  valves are
• Pulmonary
  veins do not
  have valves
         Coronary Arteries
• R and L coronary arteries arise from
  aorta, just after semilunar valve

• R coronary artery supplies R atrium and
  ventricle, SA and AV nodes and small
  part of IV septum and L ventricle (none of
  the L atrium)

• L coronary artery supplies L atrium and
  ventricle, most of IV septum including
  Bundle of His and Branches and small
  part of R ventricle (none of R atrium)
                             A cross-section of the
                             right and left ventricles
                             demonstrates the most
                             common pattern of
                             distribution of blood
                             from the RCA (red) and
                             LCA (pink) to the
                             ventricular walls and
• R Coronary  sinuatrial nodal branch
                R marginal Branch
Continues posteriorly AV nodal branch
                posterior IV branch

• L coronary artery

    circumflex branch L marginal artery
   Anterior IV branch  lateral IV branch

Note: Large vessels also need their own blood
   supply- vessels supplying large vessels are
   called vasa vasorum
                      Venous drainage
Venous drainage of the Heart is via the coronary sinus, which empties
  into the R atrium.
The great, middle, and small cardiac veins; the oblique vein of the left
  atrium; and the left posterior ventricular vein are the main vessels
   draining into the coronary sinus
    Conducting system
         of heart

•   generates and transmits the impulses that produce the coordinated contractions of
    the cardiac cycle
•   SA node- anterolaterally just deep to epicardium at junction of SVC and R atrium
            - initiates and regulates the impulses for the contractions of the heart
•   The AV - posterior inferior region of interatrial septum near opening of coronary sinus
            -distributes the signal to the ventricles
•Impulse travels down
Bundle of His, which divides
into Right, Left anterior and
Left posterior (often not
shown) bundles, before
dividing into Purkinje Fibres
which travel into the
myocardium and coordinate
        Cardiovascular Histology
•Common three layered structure for vessels of circulatory system
•TUNICA INTIMA- endothelium , basement membrane and collagenous
•TUNICA MEDIA- muscle layer, with elastic tissue
•TUNICA ADVENTITIA- outer supporting layer with collagen and sometimes
•In Heart- given special names ENDOCARDIUM, MYOCARDIUM &
• Subendothelial layer
  thickest in atria
                           Ventricular Wall
• Myocardium thickest
  in ventricles
• Epicardium is visceral
  layer of pericardium
Section of IV septum
•   3 Main Types of arteries- Elastic, Muscular, Arterioles
•   Elastic Arteries incl. Aorta, have a lot elastic fibres in media layer for
    normalisation of pressure
•   More distally there is less elastin and more smooth muscle to enable
    control of BP with lumen size- Muscular Arteries
•   Arterioles consist of only an intima, a fine internal elastic lamina and
    1-2 layer media.

                                           Aorta- note thick Media
            VEINS                    IVC

•   Layers less obvious
•   Lumen noticeably larger
•   Amount smooth muscle increases
    with size of lumen
•   Valves in large veins

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