Thoracic Wall and Cavities Flashcards
How many pairs of costae are there?
12
What are the 3 types of ribs and which ribs are categorized in each type?
True ribs = 1-7
False ribs = 8-10
Floating ribs = 11-12
[rib types are classified based on their attachments to the sternum - aka their sternocostal joints]
Describe the sternocostal joints associated with true ribs
True ribs costal cartilages are attached directly to the sternum
Describe the sternocostal joints associated with false ribs
Costal cartilages of false ribs are attached indirectly to the sternum
Describe attachments of floating ribs
No direct attachment to the sternum
What type of joints are costovertebral joints?
Synovial plane joints
Describe costovertebral joints in terms of what 3 things the head of a typical rib articulates with
Head of a typical rib articulates with:
Superior costal facet of corresponding vertebra
Inferior costal facet of vertebra superior to it
Adjacent intervertebral disc uniting the two vertebrae
What type of joint is a costotransverse joint?
Synovial plane joint
What are the components of a costotransverse joint?
Tubercle of rib articulates with the transverse process of corresponding vertebrae
What type of movement occurs at a costotransverse joint?
Rotational movement of ribs 1-7 and gliding movement of ribs 8-10
Rotational movement of ribs 1-7 and gliding movement of ribs 8-10 occur via costotransverse joints. What overall movements of the rib cage are allowed by these joints during forced inspiration vs. forced expiration?
Elevation of ribs during forced inspiration
Depression of ribs during forced expiration
What are the 3 overall components of the sternum?
Manubrium
Body
Xiphoid process
What 4 things does the manubrium articulate with?
Clavicles (via SC joints)
1st pair of ribs
2nd pair of ribs at sternal angle
Body of sternum at sternal angle
The body of the sternum is composed of _____ fused _________
4; sternebrae
What 3 things does the body of the sternum articulate with?
Manubrium (via manubriosternal joint)
Costal cartilages 2-7
Xiphoid process
What movement occurs at the manubriosternal joint? What does this movement allow?
Hinge-like movement of body anteriorly and posteriorly - facilitates increased inspiration via thoracic cavity expansion
What joint connects the xiphoid process to the body of the sternum?
Xiphisternal joint
At what spinal level would you find the xiphisternal joint?
T8
What is the difference in sternum characteristics between males and females?
The angle between the manubrium and sternal body is larger in males - so they can have broader chest cavities and thus larger hearts and lungs
What are the 3 groups of intercostal muscles?
Exernal intercostals
Internal intercostals
Innermost intercostals
Of the intercostal muscles, which is the most superficial layers?
External intercostals
What is the orientation of the external intercostal muscle fibers, and what action does this lead to?
Fibers oriented inferomedially
Elevation of ribs
What are the attachments of the external intercostal muscles?
Extends from the tubercles of ribs to junction of costal cartilages with the bony ribs
External intercostal membrane passes from anterior margin to lateral sternal border
The internal intercostals are the middle layer of intercostal muscles. What are the attachments?
Extend from sternum to the mid-axillary line
Internal intercostal membrane passes from the lateral margin to the region of vertebral column to fuse with the superior costotransverse ligaments
What direction are the fibers of the internal intercostal muscles oriented? What action does this allow?
Fibers are oriented inferolaterally
Action: depression of ribs
The deepest layer of intercostal muscles are the innermost intercostals. What are their attachments?
Extend from angles of ribs to just anterior of mid-axillary line
Innermost intercostal membrane passes from anterior border to the lateral border of the transversus thoracis m.
What direction are the fibers of the innermost intercostals oriented? What action does this allow?
Fibers are oriented inferolaterally
Action: depression of ribs
What muscle associated with respiration is not associated with the intercostal muscles?
Transversus thoracis m.
What are the attachmens of the transversus thoracis m.?
Extends from posterior surface of lower half of body of sternum and xiphoid process to costochondral junction of ribs 3-6
What is the action of transversus thoracis m.?
Depression of ribs
What provides innervation to the intercostal muscles?
Intercostal nerves = ventral primary rami of T1-T11
What do the motor branches of the ventral primary rami of T1-T11 innervate?
Intercostal muscles and transversus thoracis m.
What do the cutaneous branches of the ventral primary rami of T1-T11 innervate?
Sensory innervation to lateral and anterior surfaces of thorax
Which intercostal nerves have branches that continue into the abdominal wall to provide motor and cutaneous innervation to the muscles and skin in that region?
Intercostal nerves T7-T11
T/F: parietal and visceral pleura have both sensory and motor innervation
False; they have sensory innervation only! No motor fibers associated with the pleura
What major arteries supply blood to the thorax?
Posterior intercostal aa. Superior thoracic aa. Supreme intercostal aa. Anterior intercostal aa. Musculophrenic a.
The posterior intercostal arteries are branches off of what?
Descending aorta
Where are the posterior intercostal arteries located?
Between 2 deepest layers of intercostal muscles in intercostal spaces 3-11
What do the posterior intercostal arteries supply?
Muscular branches supply intercostal, pectoral, and serratus anterior mm.
Also supplies breasts in females via intercostal spaces 3-5
The supreme thoracic arteries are branches off what artery? What do they supply?
Branches of axillary a.
Supplies intercostal spaces 1-2
What do the supreme intercostal arteries branch from? What do they supply?
Branches of costocervical trunk
Supply intercostal spaces 1-2
The anterior intercostal arteries are branches of what artery?
Internal thoracic a.
Where are anterior intercostal arteries found and what do they supply?
Found in intercostal spaces 1-6
Supply skin, intercostal mm., breasts, and thymus gland (anterior mediastinum)
What artery exists as the terminal branch of the internal thoracic a.?
Musculophrenic a.
What does the musculophrenic a. supply?
Supplies anterior intercostal arteries to intercostal spaces 7-9
What apertures are associated with the thoracic cavity?
Superior thoracic aperture
Inferior thoracic aperture
What are the boundaries of the superior thoracic aperture (posterior, lateral, and anterior)?
Posterior = body of 1st thoracic vertebrae
Lateral = 1st pair of costae
Anterior = manubrium
What are the boundaries of the inferior thoracic aperture (posterior, lateral, and anterior)?
Posterior = body of 12th thoracic vertebra
Lateral = 11th and 12th costae
Anterior = xiphoid process and costal cartilages 7-10
What separates the thorax from the abdomen, thus closing off the inferior thoracic aperture?
Respiratory diaphragm
The dome of the diaphragm rises to what levels on each side of the body? What purpose does it serve in terms of thoracic and abdominal viscera?
Right = rises to level of 5th intercostal space
Left = rises to level of 6th intercostal space
Provides protection to thoracic and some abdominal viscera
The right and left pleural cavities are separated by a 3D space called the _______
Mediastinum
Which division of pleura lines the pleural cavity?
Parietal pleura
What are the pleural surfaces associated with the parietal pleura?
Costal pleura
Mediastinal pleura
Diaphragmatic pleura
Cervical pleura
Which of the following is attached to ribs and intercostal spaces?
A. Cervical pleura
B. Mediastinal pleura
C. Costal pleura
D. Diaphragmatic pleura
C. Costal pleura
At which region of parietal pleura does it become continuous with the visceral pleura?
Mediastinal pleura (adheres to mediastinum)
Which pleural surface adheres to the superior surface of the respiratory diaphragm?
Diaphragmatic pleura
Which of the following lines the pleural cavity above the 1st ribs, in the root of the neck?
A. Cervical pleura
B. Mediastinal pleura
C. Costal pleura
D. Diaphragmatic pleura
A. Cervical pleura
Which is more sensitive in terms of pain, temperature, touch, and pressure - parietal or visceral pleura?
Parietal pleura
What are the 2 sources for sensory innervation to the parietal pleura?
Intercostal nerves T1-T11
Phrenic nerves
Sensory innervation of the parietal pleura is provided by intercostal nerves T1-T11 and the phrenic nerves.
What do the intercostal nerves T1-T11 supply fibers for specifically?
Pain and irritation to costal pleura in addition to supplying the periphery of the respiratory diaphragm
Sensory innervation of the parietal pleura is provided by intercostal nerves T1-T11 and the phrenic nerves.
What do the phrenic nerves supply fibers for specifically?
Pain and irritation to mediastinal pleura and diaphragmatic pleura
What concept refers to pleura extending to specific parts of the thoracic cavity (aka boundaries of the pleura)?
Lines of reflection
Which extends further, the parietal pleural layers or the visceral pleural layers?
Parietal pleural layers - so lines of reflection are not fully symmetrical
Where does the vertebral line of reflection occur?
Where costal and mediastinal pleura become continous posteriorly
Where does the sternal line of reflection occur?
Where costal and mediastinal pleura become continuous anteriorly
Where does the costal line of reflection occur?
Where the costal and diaphragmatic pleurae become continuous inferiorly
________ ________ occur where 2 layers of parietal pleura form an acute angle and are in direct contact with each other in the living person
Pleural recesses
What are the 3 major pleural recesses?
Right costodiaphragmatic recess
Left costodiaphragmatic recess
Left costomediastinal recess
During normal, quiet inspiration, the lungs do not fully occupy the thoracic cavity. This means that there is a space between visceral and parietal layers in the inferolateral corners of each side of the thoracic cavity. What is this space called?
Costodiaphragmatic recess (can be divided into right and left)
The right and left costodiaphragmatic recesses are located laterally along the _______ reflection
Costal
What pleural recess is located anteriorly along the sternal reflection and lies close to the cardiac notch?
Left costomediastinal recess
T/F: the lungs normally occupy the pleural recesses
False - they do not normally occupy these recesses
What may occur within the pleural recesses with certain respiratory infections?
Pus, fluid, or dead cells may collect in the recesses and be visible on a radiograph
_______ ______ covers the surfaces of the lungs and acts as a connecting layer; surrounding the roots of lungs like a sleeve, covering structures passing into the lungs like bronchi, pulmonary vessels, nerves, and lymphatics
Visceral pleura
_______ ______ = potential spaces between parietal and visceral pleura
Pleural cavities
What is contained in the pleural cavities and what purpose does this serve?
Pleural cavities contain pleural fluid produced by the pleural membranes - this fluid lubricates the surfaces of the pleural membranes and prevents adhesions
In which of the following would you find the lungs?
A. Pleural cavities
B. Pleural recesses
C. Pleural reflections
D. Pleural sacs
D. Pleural sacs
What is defined as the space contained within the visceral pleura?
Pleural sacs - THIS IS WHERE THE LUNGS ARE FOUND
A fracture at the head of the 6th rib would affect what costal facets of what vertebrae?
Superior costal facet of T6
Inferior costal facet of T5
