Horse Thorax Lecture Flashcards
How many pairs of ribs does a horse have?
-Describe orientation
18 pairs of ribs that form a caudally prolonged rib cage.
-Last rib is close to coxal tuber
How is scapula orientated w/ribs?
Caudal angle of scapula lies over upper end of the 7th rib
Where is the point of the elbow on the horse?
Lowest part of the 5th rib or 5th intercostal space
What can restrict clinical access to the cranial part of the thorax?
Triangle between scapula and humerus that is occupied by the triceps muscle.
Common sites for thoracocentesis on horse?
-What should you be careful of?
Lower=7th IC space
Upper=13th IC space
Careful to avoid spur v around 7th IC space
What is the vertex of the thorax?
6th IC space of rib
What does the line of pleural reflection show clinical access to?
Craniodorsal=pleural cavity
Caudoventral=peritoneal cavity
T/F Diaphragm of horse is less oblique thatn in other domestic species?
F
More obilque
Define line of pleural reflection
Where the pleura that covers the diaphragm reflects on itself to become the costal pleura that lines the ribs
Ribs associated w/line of pleural reflection
Starts at 8th and 9th costochondral jxn and continues caudodorsally to 17th rib.
Importance of line of pleural reflection
-When aspirating, where should needle be placed?
Landmark separating pleaural and peritoneal cavities. When aspirating pleural fluids for clinical evaluation, the needle should be placed cranial to line of pleural reflection
Define costodiaphragmatic recess
Craniodorsal to the line of pleural reflection, diaphragmatic and costal pleura are separated by this potential space
Basal border of the lung for L and R
Ribs
6,11,16
Cardiac Notch for L and R
L=Ribs 3-6
R= 3rd rib and 4th IC space
Parts of the left lung
Parts of right lung
L=Cranial and caudal lobe
R=Cranial, caudal, accessory
When lung is moderately expanded, the base of each lung reaches
To a line passing through the upper part of the 16th rib, middle of 11th rib, and costochondral jxn of 6th rib
Which lung allows for extensive contact w/chest wall and why?
L due to deep cardiac notch which allows pericardium extensive contact w/chest wall btw 3rd-6th ribs.
Where is pleural tap done most safely and when?
Lower part of 7th IC space, ventral to margin of lung
-Introduce needle during full expiration
Define cupula pleurae
Cranial outpouching of right pleural sac beyond first rib and is vulnerable to penetrating wounds
Landmarks for auscultation of the lungs
Triangle defined by caudal angle of scapula (7th rib), point of elbow (5th rib), and upper end of the 16th rib.
Cranial and dorsal sides of the triangle are more or less straight but the caudoventral side, hypotenuse, is slightly bowed
Describe mediastinum of thorax
Thin and delicate and fenestrated at caudal portion
What can sits in the cephalic groove and easily damaged if horse runs into fence
Cephalic v and deltoid branch of superficial cervical a
What goes through aortic hiatus
Aorta
R azygous v
Thoracic duct
What goes through esophageal hiatus
Vagosympathetic trunk
Esophagus
