Thoracic wall and muscles of respiration Flashcards
Dorsal body cavities
Cranial(contains brain)
Vertebral(contains spinal cord)
Ventral body cavities
Thoracic
Abdominal
Pelvic
Is there something that physically divides the thoracic and abdominal cavities? If so what is it?
Yes, The diaphragm
Is there something that physically divides the pelvic and abdominal cavities? If so what is it?
No!
The thoracic cavity’s compartments
a pair of pulmonary cavities and a mediastinum
Thoracic cage(describe)
Bony structure of the thorax that includes 12 thoracic vertebrae, 12 pairs of ribs and costal cartilage, and the Sternum
Thoracic cage function
Protects the heart and lungs
Serves as attachment site for muscles(including muscles of respiration)
Flexible due to costal cartilage and joints
Levels of the vertebrae(including number of each one)
7 Cervical, 12 Thoracic, 5 Lumbar, 5 Sacral(fused), 4 Coccygeal(fused)
What are the intervertebral discs made out of ?
Annulus fibrosus- Fibrocartilage rings
Nucleus pulposa: inner gelatinous material
What type of joint is between the bony vertebra and the intervertebral disc?
Symphysis
lordosis
Concave posteriorly
kyphosis
Convex posteriorly
Which sections of the vertebral column have lordosis?
Cervical and Lumbar
Which sections of the vertebral column have kyphosis?
Thoracic and Sacral
Primary vs secondary curves of the spine
Primary develop during fetal development.
Secondary develop after birth
List secondary curves of the spine
Cervical and Lumbar
List primary curves of the spine
Sacral and Thoracic
What structure goes through the Intervertebral foramen?
Spinal nerve
What structure goes through the vertebral foramen?
Spinal cord
Differences between the Lumbar and Thoracic vertebra?
- Lumbar has a larger body( Body get bigger superior to inferior.
- Spinous process of the thoracic is longer and angled(to prevent excess movement of the thorax
- Location of the facets. Thoracic has costal facets on the body and transverse process but the Lumbar does not have costal facets.
How many ribs and costal cartilage are there ?
12 Pairs of ribs and costal cartilage
Which ribs are “typical ribs”?
Ribs 3-9
What are the parts of the ribs?
- Head
- Neck
- Tubercle
- Angle
- Costal groove
Function of the Rib head
It has 2 facets that articulate with the body of the corresponding vertebra and the vertebra superior to it.
i.e Rib 7 articulates with the body of T7 and T6
Function of the Tubercle
One articular facet for articulation with the transverse process of the corresponding vertebra
i.e Rib 7 articulates with transverse process of T7
Function of the costal groove
It houses the Intercostal vein, artery and nerve.
Which ribs are atypical
Ribs 1&2, 10-12
What are true ribs and which ribs are true?
They have costal cartilage attachments directly to the sternum.
Ribs 1-7
What are false ribs and which ribs are false?
Are indirectly connected to the sternum by attaching they’re own costal cartilage to others.
Ribs 8-10
What are floating ribs and which ribs are floating?
They do not attach to the sternum
Ribs 11 & 12
Costal margin
The cartilaginous border formed by costal cartilages
Costochondral joints
Ribs with costal cartilage
-synchondrosis
Sternocostal joints
Sternum with costal cartilage
- 1st rib: Synchondrosis
- 2nd-7th: synovial
Parts of the sternum
- Manubrium
- Body
- Xiphoid process
Manubrium(parts and location)
Jugular notch(suprasternal notch)(superior part) Sternal angle(manubriosternal joint)(inferior part) -Manubrium is the superior part of the sternum
Costal notches
Located on the body of he sternum for articulation with the costal cartilages
Pectoralis major (innervation and action)
- Medial and lateral pectoral nerve
- Main action upper extremities
- Accessory muscle of respiration (forced inspiration)
Pectoralis major (Attachment)
Proximal attachment:
-Clavicular head: Medial 1/2 of the clavical
-Sternocostal head: anterior surface of the sternum and costal cartilages 1-6
Distal attachment: Lateral lip of ther intertubercular groove of the humerus
Serratus anterior(innervation and action)
- Long thoracic nerve
- main action UE
- Accessory muscle of respiration(Forced inspiration)
Serratus anterior(attachment)
Proximal attachment: external surface of ribs 1-8
Distal attachment: anterior surface of the medial order of the scapula
Where are the nerves usually attached to on a certain muscle?
They usually attached inferiorly except on the serratus anterior which has the long thoracic nerve connected anterior to the muscle
Pectoralis minor(innervation and action)
- Medial pectoral nerve
- Accessory muscle of respiration (forced inspiration)
Pectoralis minor(attachement)
Proximal attachment: External surface of ribs 3-5
Distal attachment: Coracoid process of the scapula
Subclavius(Innervation and action)
- nerve to subclavius(yes, that’s the actual name)
- Accessory muscle of respiration(forced inspiration), moves the 1st rib
Subclavius(attachment)
Proximal:1st rib
Distal: clavicle(middle 1/3rd)
Intercostal muscles (list)
(Superficial to deep)
- External intercostal muscles
- Internal intercostal muscles
- Innermost intercostal muscles
Fiber direction of the intercostal muscles
(anteriorly)
- External is suprolateral to inferomedial (like putting your hands in your pocket)
- Internal is supromedial to inferolateral(perpendicular to the external)
- Innermost same way as the internal
Location of the intercostal muscles
- External: from turbercle of the rib to the costochondral junction(replaced anteriorly with external intercostal membrane)
- Internal: angles of ribs to sternum(replaces posteriorly with internal intercostal membrane)
- Innermost: only present laterally
Subcostal muscles
Cross between two intercostal spaces(internal aspect of the thoracic wall)
Transversus thoracis
4-5 muscle slips on the internal aspect of the anterior thoracic wall(aka internal aspect of the sternum)
what is in the costal groove and what is their order?
There is the intercostal vein, artery and nerve in between the internal and innermost intercostal muscles.
-Superior to inferior Vein, Artery, then Nerve(VAN)
Nerves in the costal groove and their levels
T1-T11 are called intercostal nerves
T12 is called subcostal
Origin of intercostal arteries
Posterior: Aorta
Anterior: arise from the internal thoracic artery (branch of the subclavian)
Where do the intercostal veins empty to?
Posterior: empty into the azygous venous system
Anterior: empty into the internal thoracic veins
Diaphragm(action/function, innervation)
- Major muscle of respiration
- Separates the thoracic and abdominal cavities
- Innervated by the phrenic nerve. C3,4,5 keeps you alive.
Diaphragm(attachment)
Xiphoid process, lower ribs and costocartilages, lumbar vertebra(L1-L3)
Opening of the diaphragm and location
- Caval (IVC) opening (T8)
- Esophageal hiatus(T10)
- Aortic hiatus(T12)
- *I(IVC) ate(T8) ten(T10) eggs(esophageal) at(aortic) twelve(T12)**
Movement of the thoracic cage during forced respiration.
Forced inspiration: Ribs move superiorly and laterally
Forced expiration: Ribs move inferiorly and medially
Muscles of inspiration and function
Primary: Diaphragm
Principal:
-External intercostal(maintain tone of intercostal spaces and elevate ribs increasing thoracic cavity dimensions)
-Internal intercostals(intercondral part)(function same as external)
Accessory: Pectoralis major and minor, and serratus anterior
Muscles of expiration
Quiet breathing: Expiration is from passive recoil of the lungs.
Forced expiration: Internal intercostals (interosseous part), subcostal muscles, Transversus thoracis, abdominals, rectus abdominus, External and internal abdominal obliques, and transversus abdominus
