9/15/2010
Thorax & Thoracic Wall. Muscles of Respiration. p Pleurae & Pleural Cavities. Respiratory Movements.
Structures of the Thorax that Produce Respiratory Movements Bones & Joints of the Thorax Muscles of Respiration Pleurae & Pleural cavities Respiratory Movements of the Chest
Inspiration
It requires expansion of the thorax and increase of the:
Anteroposterior diameter of the thoracic chest Transverse (lateral) diameter of the thoracic chest Vertical diameter of the thoracic chest
Expiration
It requires decrease of the above diameters and volume of thoracic cavity
9/15/2010
Bones of the Thoracic Cage
12 thoracic vertebrae
12 pairs of ribs articulate with them
12 pairs of ribs (24 costal bones)
Rib 17 true ribs 1 true
They have direct attachment to sternum
Rib 8-12 "false" ribs 8Rib 8-10 have attachment to sternum via the costal arch and cartilage 8of 7th rib
Costal arch is formed by cartilages of 7 to 10 ribs Rib 11-12 "fl ti " ribs 11- "floating" ib
They do not form costotransverse joints and have no attachment to the sternum or costal arch
One sternum. (It gives attachment to 2 clavicles.)
7 upper pairs of ribs articulate with it directly & ribs from 8 to 10 indirectly via the costal arch
Thoracic Cage
9/15/2010
Superior Thoracic Aperture
Inferior Thoracic Aperture
9/15/2010
Surface Markings of Ribs & Sternum
Male
Female
Typical Thoracic Vertebra (6)
(Presence of Costal Demifacets)
9/15/2010
Atypical Thoracic Vertebrae
Superior vertebral notch
T1
T10
T11 & 12
Inferior vertebral notch
The 1st & 2nd Ribs
Not Twisted Shaft
9/15/2010
A Typical Rib
Twisted Shaft
Sternum (Front view)
9/15/2010
Joints of Thoracic Cage
Costovertebral Joints
Sinovial
Joints of costal heads with vertebral bodies
They are reinforced by following ligaments: Radiate, Intraarticular
Costotransverse joints
They are reinforced by following ligaments Superior & Lateral Costotransverse ligaments
Sternocostal joints
Chondrosternal synovial joints (from 2nd to 7th ribs)
They are reinforces by Ligaments: Radiate sternocostal & Intraarticular
Interchondral synovial joints (from 6th to 9th cartilages
They are reinforces b Lateral & Medial Interchondral Ligaments by The
Synchondrosis of 1st costal cartilage with Manubrium Sterni
Costochondral Junctions between ribs and their cartilages Sternal Joints Symphyses
Manubriosternal Xiphisternal
Joints of Thoracic Cage
9/15/2010
Costovertebral Joints
Joint of costal head
Costovertebral Joints
9/15/2010
Chondrosternal & Interchondral Joints
Muscles of Inspiration
Quiet and Forceful Inspiration External intercostals Diaphragm F f lI i i Forceful Inspiration Scaleni (anterior, medius, posterior) Sternocleidomastoid Serratus anterior Serratus posterior superior Pectoralis major Pectoralis minor Levatores Costarum Quadratus Lumborum
9/15/2010
Muscles of Expiration
Quiet and Forceful Expiration Internal & innermost intercostals Subcostals Forceful Expiration Transversus thoracis Rectus abdominis Obliquus externus abdominis Obliquus internus abdominis Transversus abdominis Latissimus dorsi Serratus posterior inferior
10
9/15/2010
Intercostal Spaces & their Contents
Intercostal Spaces & their Contents
11
9/15/2010
Thoracentesis
12
9/15/2010
Right Dome
Left Dome
Central Tendon (Pericardial sac)
13
9/15/2010
Accessory Muscles of Respiration
Sternocleidomastoid
Pectoralis Major
Latissimus Dorsi
Serratus Anterior Pectoralis Minor External Intercostals
Anterolateral Abdominal Muscles
14
9/15/2010
Accessory Muscles of Respiration
Accessory Muscles of Respiration
15
9/15/2010
PLEURA
Pleura : is a serous membrane, investing the lungs and lining the walls of the pleural cavities.
Visceral Pleura: The inner membrane of the pleural cavity, or the membrane immediately surrounding the lung. It covers each lobe invaginating into the fissure(s) of the lung g g ( ) g (where there are extension(s) of the pleural cavity between lobes) and it is reflected over the root of the lung to the mediastinum, where it is continuous with the Parietal Pleura. Parietal Pleura: The outer membrane, lining the walls of the pleural cavity. It is subdivided into four parts:
The Costal Pleura: That portion of the parietal pleura bordering the Pleura: rib-cage. rib-cage The Mediastinal Pleura: That portion of the parietal pleura bordering the mediastinum. The Diaphragmatic Pleura: That portion of the parietal pleura bordering the diaphragm. The Cervical Pleura : That portion of the parietal pleura above the level of the superior thoracic aperture, projecting to the root of the neck.
Pleurae
Parietal Pleura Visceral Pleura
16
9/15/2010
Arrangement of Pleura
Arrangement of Pleura
17
9/15/2010
Subdivisions of Parietal Pleura
PLEURAL CAVITY
Pleural Cavity is a slit-like cavity (containing a capillary film of slitserous fluid) between the visceral and parietal pleurae (with a negative sub atmospheric pressure). There are two (right and left) pleural cavities separated by the mediastinum in which the lungs are contained. All surfaces of the lung covered by the visceral pleura are surrounded by the lung, pleura, pleural cavity. The Pleural Recess is an extension of pleural cavity limited by two adjacent parts of the parietal pleura, which a lung can enter pleura, only during a deep inspiration. There are three main paired pleural recesses on each side of the thorax: Costodiaphragmatic Recess: reflection between the costal pleura. pleura and diaphragmatic pleura Costomediastinal Recess: reflection between the mediastinal pleura and costal pleura.
The left costomediastinal recess is larger than the right, due to the cardiac notch -- the impression left on the left lung from the heart.
Mediastinodiaphragmatic Recess: reflection between the mediastinal pleura and diaphragmatic pleura.
18
9/15/2010
Pleural Cavity
Pleural Cavities
19
9/15/2010
Right Pleural Cavity
Surface Markings of Pleurae
Parietal Pleura Visceral Pleura
20
9/15/2010
Respiratory Movements & Structures Producing Them
Inspiration
Elevation of sternal ends of ribs Pump handle (forward & upward) movement of sternum Increase of anteroposterior diameter of the chest Elevation of lateral shafts of ribs Bucket handle movement of ribs (upward & laterally) Increase of lateral (transverse) diameter of the chest Depression (lowering) of Diaphragm Increase of vertical size of the chest It results in expansion of the chest and drop of pressure in pleural cavities. It causes expansion of lungs and drop of pressure in alveoli. Atmospheric air will enter lungs through the airway and inflate & expand them.
Expiration
Pump handle (backward & downward) movement of sternum Depression of sternal ends of ribs Decrease of anteroposterior diameter of chest Bucket handle movement of ribs (downward & medially) Depression of lateral shafts of ribs Decrease of lateral diameter of chest Elevation of Diaphragm Decrease of vertical size of chest It results in reduction of chest volume and squeeze of lungs. Because of this and elastic recoil of lungs alveolar air will be pushed through airway into atmosphere
Events occurring during inhalation and exhalation:
Movements of ribs at costovertebral joints: Up and down gliding movements of costal head and tubercle, which permit rotation of costal neck around its long axis
Upward rotation brings about elevation of shaft and sternal end of a rib Down) during inspiration (tubercle glides Down) Downward rotation brings about depression of shaft and sternal end of Up) a rib during expiration (tubercle glides Up)
BucketBucket-handle inspiratory movement, when pail handle is raising, its convexity moves laterally, increasing transverse diameter of thorax. It occurs during elevation of shafts of ribs. Depression of shafts causes expiration. PumpPump-handle inspiratory movement, when sternal end is handle, elevating it also moves anteriorly like a pump handle increasing anteroposterior diameter of thorax. Depression of sternal end causes expiration.
Movements of Diaphragm: Depression of Diaphragm during its Contraction increases vertical diameter of thorax & causes Inspiration During relaxation Diaphragm is pushed up by abdominal organs thus decreasing vertical diameter of thorax and this causes Expiration
21
9/15/2010
Expansion of the Thorax in Inspiration
Expansion of Thorax in Inspiration (Bucket handle action)
22
9/15/2010
Expansion of Thorax in Inspiration (Pump handle action)
BacketBacket-Handle Movement of Ribs
23
9/15/2010
BacketBacket-Handle Movement of Ribs
PumpPump-Handle Movement of Ribs
24
9/15/2010
PumpPump-Handle Movement of Ribs
Forces During Quiet Breathing
25
9/15/2010
Arterial Supply of the Thoracic Cage
Venous Drainage of the Thoracic Cage
26
9/15/2010
Lymphatic Drainage of the Thoracic Cage
Segmental Innervation of the Thorax & Abdomen
27
