Thorax prosection questions Flashcards
How many ribs are there in the dog?
Which tissues are these composed of?
13 ribs
Bone dorsally and cartilage ventrally
What are the limits of the thorax?
Cranial - thoracic inlet Caudal - Diaphragm Ventral - Sternum Dorsal - thoracic vertebrae Lateral - ribs and intercostal muscles
How many sternebrae are there in the dog and what are the names of the first and last of them?
8
1st = manubrium
8th = Xiphoid process
The heart sits between ribs … and …?
3 and 6
In the live animal, which rib spaces would you expect to be associated with each of the following valves: pulmonary, aortic, mitral and tricuspid?
Left side: P = 3rd A = 4th M = 5th Right side T = 4th or 5th
Which ribs contribute to the costal arch?
10-13
Which dorsal structures limit the area of the lungs that can be ausculated?
Epaxial muscles
Which lymph nodes would you normally palpate in the neck and thorax area in a normal dog?
Mandibular
Superficial cervical
Axillary
Accessory axillary
Where would you occlude the jugular vein in order to raise it for blood sampling?
Base of the neck
What is the term used for the joint between the atlas and the skull?
When would a vet want to access the space between these two bones?
Atlanto-occipital joint.
To sample CSF from the subarachnoid space
Can you name the cartilages of the larynx from cranial to caudal?
Epiglottis, thyroid, arytenoid, cricoid
What is the joint between the mandible and the skull called?
Temporomandibular joint
What actions will contraction of the sternocephalicus muscle and brachiocephalicus muscle cause?
- Sternocephalicus: Movement of the head from side to side
- Brachiocephalicus: Advances the forelimb, extends shoulder, lateral movement of the head.
Cranially each sternothyrohyoideus muscle divides into a ventromedial … and dorsolateral … component.
sternohyoideus
sternothyroideus
Are the tracheal cartilage rings open on the ventral aspect or the dorsal aspect?
Dorsal
From which major vessel does the common carotid arise?
Brachiocephalic trunk
Which 2 muscles insert on the caudal ribcage?
- Rectus abdominis
- External abdominal oblique
Which nerve arises from C5 with contributions from C6?
Phrenic nerve
From which major vessel does the axillary artery arise?
Subclavian artery
Which major vessel will the axillary vein drain into?
Subclavian vein
Which major forelimb nerves arise from the brachial plexus?
Subscapular, suprascapular, musculocutaneous, axillary, radial, median and ulnar nerves
Which organ does the phrenic nerve supply?
Diaphragm
What is achieved when the phrenic nerve fires?
The diaphragm contracts, flattening caudally and therefore increasing the size of the thorax.
This reduced the pressure in the alveoli, resulting in inspiration
In which direction do the internal and external intercostal muscle fibres run?
Internal run cranioventrally
External run caudoventrally
What are the functions of the internal and external intercostal muscles?
External = respiration Internal = active expiration
The thoracic cavity is under negative pressure. What would happen if the pleura is ruptured?
- air into thorax
- collapse of lungs
- ribcage moves outwards as pressure equalises
- pressure inside pleural sac is lower than atmospheric pressure
What differs in the thymus between young and adult animals?
In adults the thymic tissue is replaced by adipose tissue
In the caudal extent of the pleural cavity you would find a recess, what is this called?
Costodiaphragmatic recess - where the pleura reflects from the ribs onto the diaphragm
In the dog, what are the first two systemic branches arising from the aorta?
Brachiocephalic trunk
Left subclavian artery
Name one difference between the aortic arch of the dog vs the cow.
L and R subclavian arteries both arise from the brachiocephalic trunk in the cow
What does the thoracic duct contain, in life, and where does it originate and terminate?
- Contains lymph, called chyle when it has high conc of chylomicrons
- Runs from the cisternal chyli
- Drains into the major veins in the thoracic inlet
Where do sympathetic fibres exit the central nervous system?
Thoracolumbar segments
What are the left and right lung lobes in the dog?
Left = Cranial and caudal Right = Cranial, middle, caudal, accessory
In which chamber of the heart do the cranial and caudal vena cavae empty?
Right atria
Name one species in which there is both a left and right azygous vein
Ruminants and pigs
What is the name of the fold of mediastinum in which the caudal vena cava travels to the diaphragm?
Plica vena cava
