Thorax and Lungs Learning and Understanding Objectives
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Transcript of Thorax and Lungs Learning and Understanding Objectives
Thorax and Lungs
Learning and Understanding Objectives
• Understand:– Surface anatomy and the relationship of the
heart and lungs in the thoracic cavity– Functions of the pleural cavities– Projected placement of the lungs, visceral and
parietal pleura using anatomical landmarks– Functions & deformities of the thoracic cage and
vertebrae– Relationship of nerves, arteries, and veins– Hierarchy of respiratory system in the thorax– Clinical correlations
C7 Spinous Process(Veterbra Prominens)
Vertebral Border of Scapula
12th Rib
Inferior Angle of Scapula
Surface Anatomy of the Posterior Thoracic Wall
Thieme Atlas 4.1A
Thieme Atlas 9.1A
Surface Anatomy of the Anterior Thoracic Wall
Jugular Notch(T2 Vertebral Level)
Clavicle
Sternal Angle(T4 Vertebral Level)
Vertebral Levels of Thoracic Landmarks
(T2)
(T4)
(T9)
Visualize Internal Anatomy when
Looking at a Patient
Figure 21.13a, Marieb
R L
The Thoracic Cage
1.) Protects organs and structures of the thorax
2.) Provides stablesupport for the upper extremity and head
3.) Flexible and can change dimensionsduring ventilation
Thieme Atlas 5.1A
T2
T4
T9
Thieme Atlas 5.3
False Ribs (8-10)Attach to the 7th
costal cartilage
ThreeTypes of Ribs
True Ribs (1-7)Attach directly to
the sternum
Floating Ribs (11-12)No anteriorattachment
Anatomy of a Typical Rib
The Sternum
A blade-like bone with three parts:
ManubriumBody
Xiphoid process
It articulates with the clavicle and ribs 1 -7
Has several important landmarks
Thoracic Vertebrae
1.) Protects organs and structures of the thorax
2.) Protects and housesspinal cord
3.)Support structurefor the thorax and articulates with the ribs
4.) Flexible
Thieme Atlas 5.1C
Thoracic Vertebrae
[ We’ll study these in the lab]
Three Joints of Thoracic Cage
Joints of Thoracic Cage
Marieb, Fig 7.20 a & b
Movements of the Ribs
Thorax Cage Articulates with the Shoulder Girdle
Thieme, Fig 5.5A
Ratio of Anterior-Posterior Diameter : Transverse Diameter
Post.
Ant.
Children (< 6yrs old)
1:1
Adults (> 6yrs old)
Between
1:1.4 - 1:2
Physical Examination and Health Assessment, Table 18-3 Jarvis 2008
Normal
Kyphosis*
Scoliosis*
PectusCarinatum
PectusExcavatum
Barrel Chest*
Thieme 5.26
Anterior Thoracic Wall Muscles
Pectoralis Major
Look for this in Lab
From A.D.A.M. Interactive Anatomy
Pectoralis Minor
From A.D.A.M. Interactive Anatomy
Look for this in Lab
From A.D.A.M. Interactive Anatomy
Serratus Anterior
ExternalIntercostals(Inspiration)
InternalIntercostals
(Forced Expiration)
Muscles of Respiration
Depress ribs
(Contract thoracic cavity)
Elevate ribs
(Expand thoracic cavity)
Action of the Intercostal MusclesAction of the Intercostal Muscles
R LDiaphragm
Major Muscle of Inspiration
-Innervated by thePhrenic Nerve
C3, C4, C5
“C3, 4 & 5 keeps the diaphragm alive”
Muscles of Respiration
Diaphragm: Inferior view
Caval aperture
Psoas major
aorticaperture
esophageal aperture
right crus left crus
Quadratus lumborum
central tendon
Inspiration
Marieb 21.16d
Diaphragm flattensExternal intercostals contract to
raises the ribsVolume of thoracic cavity
increasesDecreases internal gas pressure
Deep inspiration also requires:
Scalenes, pectoralis minor, sternocleidomastoid, and serratus posterior superior all help to elevate the ribs
Erector spinae – extends the back
Expiration
Marieb 21.16d
Diaphragm and Ext. Intercostals relax
Volume of thoracic cavity decreases
Increase in internal gas pressure
Normally PassiveLittle or no muscle contraction
Little or no nerve stimulation of muscles
Forced Expiration Internal intercostals m. contract to
depress ribs
Respiration can be aided by the abdominal wall musclesRespiration can be aided by the abdominal wall muscles
Thieme 6.4B
Arteries of the Posterior Thoracic Wall
Intercostal arteriesIntercostal arteries
Thoracic aortaThoracic aorta
Thieme Fig 5.17 pg 56
Arteries of the Thoracic Wall
Intercostal a.Intercostal a.
2nd Intercostal a. 2nd Intercostal a.
Subclavian a.Subclavian a.
Internal thoracic a.Internal thoracic a.
Internal thoracic a.Internal thoracic a.
Thieme 5.19A
Veins of the Thoracic Wall
Hemiazygos v..Hemiazygos v..
3rd Intercostal v. 3rd Intercostal v.Accessory
Hemiazygos v.Accessory
Hemiazygos v.
Intercostal v..Intercostal v..
Subclavian v.Subclavian v.
Internal thoracic vv.Internal thoracic vv.
Azygos v.Azygos v.
- supply intercostal muscles, abdominal muscles, and
skin of thorax & abdomen
- supply intercostal muscles, abdominal muscles, and
skin of thorax & abdomen
- major pathway for the sympathetic division of the autonomic nervous system
- supply visceral organs.
Nerves of the Posterior Thoracic Wall
Intercostal VAN (Vein, Artery, Nerve)
Thoracic Cavity
3 Compartments of the Thorax
(Heart)
(Great Vessels)
Superior Thoracic Aperture
(Thoracic Outlet )
The apex of the each lung extends above the first rib.
Superior Thoracic Aperture
(Thoracic Outlet )
The apex of the each lung extends above the first rib.
The diaphragm attaches at the inferior border of the ribs, sternum and
the body of vertebra T12..
The diaphragm attaches at the inferior border of the ribs, sternum and
the body of vertebra T12..
Inferior Thoracic Aperture
rib
Visceral Pleura[on the surface of
the lung itself]
Pleural MembranesSecrete serous fluid
– Allows for smooth breathing
Pleural cavity Potential space between the
visceral and parietal pleurae
Surface Tension between parietal and visceral pleura keeps the lungs ‘stuck’ to the thoracic wall during respiration– Necessary for proper
ventilationParietal Pleura
PARIETAL PLEURAPARIETAL PLEURAVISCERAL PLEURAVISCERAL PLEURA
PLEURAL CAVITY(SEROUS FLUID)PLEURAL CAVITY(SEROUS FLUID)
Pleural Membranes
Parietal Pleura:four parts cervical
mediastinal
diaphragmatic
costal
• A Vacuum Seal Makes Ventilation Work
Anterior PosteriorLateral
Midclavicular Midaxillary Paravertebral
Lung 6th rib 8th rib 10th rib
Pleura 8th rib 10th rib 12th ribThieme Atlas, pg 102
At the edges of the thoracic cavity the pleura extend lower
than the lungs to form the Pleural Gutter At the edges of the thoracic cavity the pleura extend lower
than the lungs to form the Pleural Gutter
Pneumothorax – Air in the pleural cavityDamage to visceral or parietal pleura can cause air to leak into the pleural cavity.
Causes: a penetrating wound, infection, cancer, asthma,
Treatment : treat wound, chest tube, thorascopic surgery
Pnemothorax can cause the affected lung to collapse leading to difficulty breathing, cyanosis, and possible shifting the
placement of the heart.
Hemothorax - Blood in the pleural cavity
• difficult ventilation• painful breathing, cyanosis,
tachycardia
• causes – trauma resulting in rupture of pleura
• treatment — remove source of bleeding, drain blood,
thrombolytic agents
• painful breathing, cough, fever, chills
• causes: infection, heart surgery, autoimmune, cancer
• treatment: drain fluid, anti-inflammatory, antibiotics, cancer
treatment
Pleurisy (Pleuritis) – Inflammation of the pleura
Thieme Cl. 5.200A
ThoracentesisThoracentesis
Procedure to remove excess fluid from the pleural space
Procedure to remove excess fluid from the pleural space
Most easily done from the back where the pleural gutter is
deepest and the neurovascular bundle is closer to the inferior
edge of the rib.
Most easily done from the back where the pleural gutter is
deepest and the neurovascular bundle is closer to the inferior
edge of the rib.
Thieme Cl. 5.200A
Chest Tube PlacementChest Tube Placement
To remove air or large amounts of fluid from the pleural space.
Common emergency procedure
Most commonly done along the mid-axillary line between the 4th
and 5th ribs
To remove air or large amounts of fluid from the pleural space.
Common emergency procedure
Most commonly done along the mid-axillary line between the 4th
and 5th ribs
SUP
MIDDLE
INF
SUP
INF
R L
3 Lobes
2 Lobes
Figure 21.8 Marieb
LungsLungs
Lobes Divided into 10 Bronchopulmonary Segments on each Side
Don’t need to name them individually
Lungs
Projections on chest
Inferior is posterior
Superior lobe is mostly anterior
Middle is lateral
Lungs
Projections on chest
Inferior is posterior
Superior lobe is mostly anterior
Middle is lateral
Thieme Atlas fig 8.4
R L
Lungs in situ ( Heart removed)Lungs in situ ( Heart removed)
Hilum—where air and blood enter and leaveHilum—where air and blood enter and leave
Arteries are up high. Bronchi are posterior and near the top. Veins tend to be more anterior and inferior.
Superficial lungs: lateral view
apex
lingula
superior lobe
horizontalfissure
inferior lobe
obliquefissure
middle lobe
right lung
leftlung
Medial Views of the Lungs
groovefor azygos vein
right pulmonary
arteries
bronchii
diaphragmaticrecess
right pulmonary
veins
cardiacimpression
groovefor
esophagus
groovefor aorta
left pulmonary
arteries
left pulmonary
veins
Oral CavityNasal CavityPharynxLarynxTrachea*Lungs*
Respiratory System
Respiratory System—Two Zones
• Conducting zone – Rigid conduits (pipes) for air to reach the sites
of gas exchange– Includes the nose, nasal cavity, pharynx,
trachea, and bronchi.
• Respiratory zone– Site of gas exchange – Consists of terminal bronchioles, alveolar
ducts, and alveoli
The Bronchial Tree One main trunk = Trachea
Two Primary bronchi = One left, one rightSecondary or lobar bronchi = 3 on right, 2 on left
Tertiary to bronchopulmonary segments = 10 each
Trachea
thyroidcartilage
right main bronchus
left main bronchus
trachealbifurcation
Anterior ViewAnterior View
Trachea
membranouswall with trachealglands
carinamucosa
cricoidcartilage
trachealcartilage
Trachea bifurcates into two primary bronchi
Carina at the bifurcation and is very sensitive to irritants – cough
reflex
Trachea bifurcates into two primary bronchi
Carina at the bifurcation and is very sensitive to irritants – cough
reflex
Posterior viewPosterior view
Hyaline Cartilage
Post.
Ant.
Psudostratified columnar Epithelium (ciliated)
Figure 21.7, Marieb
•Has 16-20 C-shaped rings of Hyaline Cartilage•Functions to protect airway
•Prevent collapse of airway during breathing•Pseudostratified columnar epithelium•Ciliated to propel debris to the pharynx
•Has 16-20 C-shaped rings of Hyaline Cartilage•Functions to protect airway
•Prevent collapse of airway during breathing•Pseudostratified columnar epithelium•Ciliated to propel debris to the pharynx
Trachea
Respiratory Segment
Pulmonary Alveoli
Thieme Atlas fig 8.12
TerminalBronchioles
Where the gas exchange takes place between the outside world and the inside world -- blood
Figure 21.8a
Respiratory ZoneRespiratory Zone
300 million Alveoli – external to your body A potential site of invasion—bacteria, smoke,
particles, gases.
Respiratory Membrane
Figure 21.9.c, d
Respiratory Centers in the BrainstemPontine Respiratory Center
Medullary Respiratory Centers
Autonomic Innervationof the Respiratory System
• parasympathetic innervation is from the
vagus (CN X)
• sympathetic innervation is from sympathetic trunk
ganglia
Clinical Correlation - Lungs
Lung Compliance = Stretchability
• The ease with which the lungs can expand, (change in lung volume for a given change in pressure)
• Determined by two main factors– Distensibility of the lung tissue and surrounding thoracic
cage, disease can diminish compliance, but emphysema can
increase compliance. – Surface tension at the air-water interface in the alveoli.
Surfactant reduces the surface tension allowing the alveoli to expand more easily.
COPD (Chronic obstructive pulmonary disease)Hard to breath—Accessory muscles for forced inspiration and expiration. May involve emphysema—Need forced expiration
Figure 21.28
Muscles work more:
External Intercostals and diaphragm.
Accessory muscles:
Sternocleidomastoid,
Scalenes,
Serratus posterior superior
Patient may lean on table to elevate chest
(tripod posture).
Muscles work more:
External Intercostals and diaphragm.
Accessory muscles:
Sternocleidomastoid,
Scalenes,
Serratus posterior superior
Patient may lean on table to elevate chest
(tripod posture).
Pneumonia
• inflammation of aveoli causes build up of fluid in
the lungs
• causes – virus, fungi, bacteria
• treatment — antibiotics, antivirals
Tuberculosis• infectious disease caused
by the bacterium mycobacterium
tuberculosis
• symptoms include fever, night sweats, weight loss,
a racking cough, and splitting headache
• treatment — 12-month course of antibiotics
Emphysema• The walls of the alveoli begin to
breakdown.Alveoli lose their elasticity – increase in
lung compliance
• shortness of breath - difficult to remove air from the lungs – Continual forced
expiration
• causes – typically smoking
• treatment — irreversible, stop smoking, anticholinergics, lung volume reduction
surgery, lung transplant
Lung Cancer
• About 1/3 of all cancer deaths in the u.s.• 90% of all patients were smokers
• Three most common types are: * squamous cell carcinoma (20-40% of cases)
arises in bronchial epithelium * adenocarcinoma (25-35% of cases) originates
in peripheral lung area * small cell carcinoma (20-25% of cases)
lymphocyte-like cells that originate in the primary bronchi and subsequently metastasize
• Treatment — chemotherapy, radiotherapy
surgery (removal of sections of or whole lung• Treatment — chemotherapy, radiotherapy
surgery (removal of sections of or whole lung
Asthma • characterized by dyspnea (trouble breathing), wheezing, and chest
tightness• active inflammation of the airways
precedes bronchospasms (mast cells, allergies)
• airway inflammation is an immune response caused by release of products
that stimulate IgE and recruit inflammatory cells
• airways thickened with inflammatory exudates magnify the effect of
bronchospasms
• treatment – bronchodilators (inhalers, spacers), intubation, steroids, mechanical
ventilation in cases of extreme attack
Respiratory Centers in the BrainstemPontine Respiratory Center
Medullary Respiratory Centers
Autonomic Innervationof the Respiratory System
• parasympathetic innervation is from the
vagus (CN X)
• sympathetic innervation is from sympathetic trunk
ganglia