Thorax Flashcards
What are the boundaries of the thoracic cavity
Cranial: thoracic inlet
Caudal: diaphragm
Lateral: ribs, muscles, skin
Dorsal: vertebrae, muscles, skin
Ventral: sternum, muscles, skin
Origin and insertion of serratus dorsalis cranialis
O: thoracic fascia and spines of first 6-8 thoracic vertebrae
I: cranial border and lateral surface of ribs 2-10
Action of serratus dorsalis cranialis
Lift ribs for inspiration
Origin and insertion of serratus dorsalis caudalis
O: thoracolumbar fascia
I: caudal border of last 3-8 ribs
Action of serratus dorsalis caudalis
Draw last few ribs caudally for expiration
External intercostal muscles run…
Craniodorsally to caudoventrally
Internal intercostal muscles run….
Caudodorsally to cranioventrally
External intercostal pulls ribs ____________ to assist in ________________
Cranially; inspiration
Internal intercostal pulls ribs ____________ to assist in ___________
Caudally; expiration
Where is transversus thoracis (parasternal) located
Inside ribcage from sternum to costochondral junction
Transversus thoracis pulls the costal cartilages __________ to assist with _______________
Inward; expiration
What muscles assist inspiration
Serratus dorsalis cranialis; external intercostal
What muscles assist expiration
Serratus dorsalis caudalis; internal intercostal; transversus thoracis (parasternal)
What are the epaxial muscles
Iliocostalis thoracis, longissimus, Spinalis thoracis
Where is rectus thoracis
From the 1st to 4th rib
What muscle acts to retract the ribs and keep the ribcage in place
retractor costae
What muscle acts to elevate the ribs and where is it located
levator costae; between the transverse processes of the vertebrae and upper aspect of the rib
What are four thoracic wall nerves
dorsal cutaneous, lateral cutaneous, lateral thoracic (innervates pectoralis), intercostobracial
where are VANs located
on the caudal border of the ribs
What is pleura
serous membrane that folds onto itself to form a two layered bag (visceral and parietal pleura)
T/F visceral pleura is only surrounding the lungs
T; costal, diaphragmatic, cupular and mediastinal pleura is parietal
what is the term for where the pleura extend beyond the first rib
the pleural cupulae
What are the four types of parietal pleura
costal, diaphragmatic, mediastinal and cupular
What is chylothorax
lymph in the thorax
what is the line of pleural reflection
where the costal pleura connects with the diaphragmatic pleura
what is the location of the cardiac notch in horses and what is its importance
3rd-6th intercostal spaces; if you put a needle in here it will not pierce the pleura
where is the location of the cardiac notch in cows
3rd-4th intercostal space
what separates the thoracic and abdominal cavities
the diaphragm; has tendinous and muscular regions
what are the parts of the diaphragm
tendinous: central tendon and L/R crura
muscular: sternal and L/R costal portions
what are the three main openings in the diaphram
aortic hiatus, esophageal hiatus, caval foramen (for caudal vena cava)
what is the purpose of the crura
attach to the ventral aspect of the 3rd/4th lumbar vertebrae centra
what animals are prone to chylothorax
cats