Roof: Suprapleural membranes
Posterior: Vertebral bodies
Lateral: Ribs
Anterior: Sternum and costal cartilages
Floor: Diaphragm (not explicitly stated, but implied by structure)
Description: True ribs
Articulation: Each attached to the sternum via its own costal cartilage
Description: False ribs
Articulation: Attach to the sternum by "hitchhiking" with the costal cartilage of rib 7
Description: Floating ribs
Articulation: No anterior articulation
Head: Articulates with vertebrae
Tubercle: Articulates with transverse process of vertebrae
Body: Main section of the rib
Costal Groove: Along inferior surface for vessels/nerves
Neck: Section just before the head
Angle: Location where rib bends
Cup for Costal Cartilage: Area of attachment to cartilage
Rib 1:
Grooves for subclavian artery and vein
Tuberosity for serratus anterior
Scalene tubercle
Single facet on head (articulates directly with one vertebral body)
Ribs 11 & 12:
No neck or tubercle
No costal cartilage cup
Manubrium: Articulates with first rib
Sternomanubrial Joint: Also known as the "sternal angle"
Body of Sternum: Articulates with ribs 2-7
Xiphoid Process: Terminus of the sternum
Costal Cartilage: Various joints formed (costochondral and sternochondral) for ribs 1-7
Superior Articular Facets: Articulate with head of ribs
Costocorporeal Joint: For head of the rib articulations
Costotransverse Joint: For tubercle of rib articulation
Transverse Processes: Important for rib movement
Elevation and depression axes for rib movement during respiration
Costal Cartilage: Connects ribs to sternum and vertebrae
Demifacets & Intervertebral Discs (IVD): Important for rib articulation with vertebrae
Intra-Articular Ligament: Aids in stabilizing the rib heads for movement
ist the 4 different joints of rib articulation
Costocorporeal Joint: Articulation between the head of the rib and the vertebrae.
Costotransverse Joint: Articulation between the tubercle of the rib and the transverse process of the vertebrae.
Costochondral Joint: Joint that connects the rib to its costal cartilage.
Sternocostal Joint: Articulation between the costal cartilage of ribs 1-7 and the sternum.
Costocorporeal Joint:
Synovial joint formed between the head of the rib and the demifacets of adjacent vertebrae.
Costotransverse Joint:
Synovial joint formed between the tubercle of the rib and the transverse process of the corresponding vertebra.
Costochondral Joint:
Primary cartilaginous joint (synchondrosis) connecting the rib to its costal cartilage.
Sternocostal Joint:
Synovial joints (for ribs 2-7) formed between the costal cartilage of the ribs and the sternum. Rib 1 has a non-synovial joint (costal cartilage to manubrium).
Costocorporeal Joint:
Function: Facilitates rib movement during respiration, allowing elevation and depression of ribs that modify thoracic volume.
Costotransverse Joint:
Function: Aids rib rotation and movement, contributing to the mechanics of respiration.
Costochondral Joint:
Function: Provides stability and flexibility at the junction where ribs meet costal cartilage, aiding in respiratory movements.
Sternocostal Joint:
Function: Allows the ribs to attach securely to the sternum while permitting limited movement, essential for accommodating thoracic expansion during breathing.
Movements: Facilitates rib movement during respiration, allowing for elevation and depression of ribs that modify thoracic volume.
Movements: Aids rib rotation and lateral movement, contributing to the mechanics of respiration.
Movements: Provides stability and flexibility at the junction where ribs meet costal cartilage, aiding in respiratory movements.
Movements: Allows the ribs (1-7) to attach securely to the sternum while permitting limited movement, essential for accommodating thoracic expansion during breathing.
Three Layers:
Ectoderm: Surface
Mesoderm: Body wall
Endoderm: Forms gut tube
Somatic Lateral Plate Mesoderm: Forms body wall, innervated by:
Splanchnic Lateral Plate Mesoderm: Forms gut tube, innervated by:
Coelom: Potential space in ventral body cavity
pericardial, pleural, peritoneal spaces
Development of thorax and abdomen share common embryonic tissues that have homologous components
Pulmonary Cavities: Surround the lungs
Mediastinum: Contains heart and related structures
Abdominal Cavity: Contains digestive and other organs
Pelvic Cavity: Contains reproductive organs
Contain liquid and provide lubrication to organs in coelomic cavities (specific details not present)
A serous membrane is a thin layer of tissue that lines certain cavities in the body and covers the organs within those cavities. It secretes a lubricating fluid called serous fluid that reduces friction between the organs and the walls of the cavities. For example, serous membranes line the pleural cavities around the lungs, the pericardial cavity around the heart, and the peritoneal cavity in the abdomen.
Lungs: Real space (open respiratory pathway)
Contains: Lung tissue
Boundaries: Muscle and bone of body wall, mediastinal and suprapleural fascia
Internal Surfaces: Lined with pleura
Pleural Cavity:
Potential space, contains serous fluid (small volume)
Boundaries formed by:
Visceral Pleura: Attaches to lungs
Parietal Pleura: Attaches to thoracic cavity wall
Surface Tension: Provided by pleural fluid, negative pressure (2-8 mm Hg)
Puncture Effect: If punctured, air enters the pleural cavity causing lung deflation
Pleural Cavity: Between visceral and parietal pleura
Mediastinum: Space for heart and vessels
Pericardial Cavity: Between parietal pleura and pericardium (surrounding heart)
Phase 1: Inspiration (Breathing In)
Drawing air into the lungs
In response to increased thoracic volume
Dependent on muscle activity (diaphragm and accessory muscles of respiration)
Phase 2: Expiration (Breathing Out)
Air passing out of the lungs
In response to decreased thoracic volume
Quiet respiration: Passive process (elastic recoil of diaphragm and lungs)
Forced respiration: Active process (contraction of accessory muscles of respiration)
Superior View: Central tendon, pericardium, costodiaphragmatic recess where lungs expand
Inferior View:
Parts include Left Crus, Right Crus, costal origin, Central Tendon, median arcuate ligament, Aortic Hiatus, Oesophageal Hiatus, Caval Opening
Left and Right Crus: Support base of diaphragm
Openings: Aortic hiatus, esophageal hiatus, caval opening (T8, T10, and T12)
Cervical Roots: "C3, 4, 5: Keep the diaphragm alive."
Outer Edges: Innervated by lower intercostal nerves
Movement occurs in a specific plane
Elevation of ribs increases anterior-posterior dimensions of thorax
Inferior ribs move more than superior ribs
Movement in sagittal plane
Elevates ribs anterioly
Increases vertical A-P dimensions of thorax- Elevates ribs, increasing dimensions of thorax
Inferior ribs move more than superior ribs
Movement in corronal plane
Elevates ribs laterally
Increases transverse dimensions of thorax
Inferior ribs move ___more___ than superior ribs
Passive Inspiration/Expiration: Basic respiratory process
Forced Inspiration:
Diaphragm lowers as it contracts
Thorax expands
Forced Expiration:
Diaphragm rises as it relaxes
Thorax contracts
Origin (O): Inferior border of ribs
Insertion (I): Superior border of rib below
Innervation (N): Intercostal nerve
External Intercostals: Function like "hands in pockets"
Internal Intercostals: Perpendicular to externals, primarily during forced expiration
Innermost Intercostals: Less detail provided
External Intercostals
O: Inferior border of ribs
I: Superior border of the rib below
N: Intercostal nerve
Function: Hands-in-pockets movement
Internal Intercostals
Perpendicular to external intercostals
Mainly involved in forced expiration
Innermost Intercostals
Related anatomy of the intercostal neurovascular bundle includes:
Subcostal groove
Intercostal vein
Intercostal artery
Intercostal nerve
Components: Subcostal groove, intercostal vein, intercostal artery, intercostal nerve
Clinical Relevance: Location for needle insertion (explanation omitted)