Transcript The EAR - Ipswich-Year2-Med-PBL-Gp-2

The EAR
External Ear
•Helix
•Tragus
•Lobule
•Cartilaginous bony parts of
•external acoustic meatus
•Tympanic membrane
Middle Ear
•Ossicles
(malleus, incus and staples
•Middle ear/tympanic cavity
•Pharyngotympanic/
eustachian tube
•Aditus to mastoid antrum
•Oval window
(fenestra vestibule)
•Round window
(fenestra cochleae)
Internal Ear
Cochlea
Vestibule
Semicircular canals
Internal acoustic meatus
Nasal cavity and pharynx
Nose
•Superior, middle and
inferior conchae
•Superior, middle and
inferior meatuses
•Vestible
Pharynx
•Nasopharynx –
opening of
Eustachian tube
•Oropharynx
•Laryngopharyx
•Epiglottis
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
carina
• R is shorter, wider, and takes a
more direct path to hilum of R
lung
• Note its relationship to the
oesophagus, aortic arch,
thoracic aorta and Vena Cava
Pleurae, cavities and mediastinum
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Parietal pleura
– Costal pleura
– Diaphragmatic pleura
– Cupula (cervical) pleura
– Mediastinal pleura
• Visceral Pleura
• Costodiaphragmatic/
costophrenic recesses
• Costomediastinal recesses
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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
mesothelium
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Lungs
The lungs are suspended freely, only attached at the hilum
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
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two left bronchial arteries arise directly from the thoracic
aorta
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
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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.
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The middle lobe vein joins
with the right superior
pulmonary vein.
• Segmental veins 
lobar veins (5) 
pulmonary veins (4)
• The pulmonary veins run
independently
Roots of the
Lung
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 drainageSuperficial 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
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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).
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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.
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Branches of the pulmonary plexuses
accompany pulmonary arteries and
especially bronchi to and within the lungs.
Thoracic Wall
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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
pseudostratified
Hyaline
cartilage
Smooth
Muscle
Goblet
Cells
Columnar
Ciliated
columbnar or
cuboidal
Simple
squamous
CPlates
Shaped
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Absent
Absent
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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 ventricle2 openings R
atroventricular
orifice and
pulmonary
trunk
•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
Valves
• Aortic and
pulmonary
valves are
semilunar
• 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
IVS.
• 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
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generates and transmits the impulses that produce the coordinated contractions of
the cardiac cycle
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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
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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
contraction
Cardiac
Cycle
Cardiovascular Histology
•Common three layered structure for vessels of circulatory system
•TUNICA INTIMA- endothelium , basement membrane and collagenous
support
•TUNICA MEDIA- muscle layer, with elastic tissue
•TUNICA ADVENTITIA- outer supporting layer with collagen and sometimes
vessels
•In Heart- given special names ENDOCARDIUM, MYOCARDIUM &
EPICARDIUM
• Subendothelial layer
thickest in atria
• Myocardium thickest
in ventricles
• Epicardium is visceral
layer of pericardium
Ventricular Wall
Ventricular
Wall….
Section of IV septum
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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
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Layers less obvious
Lumen noticeably larger
Amount smooth muscle increases
with size of lumen
Valves in large veins
IVC