Canine Thorax, Autonomic Nervous System, and Heart -Final Exam Material Flashcards
What are the boundaries of the thoracic cavity?
dorsal: T1-T13
ventral: 8 sternebrae
lateral: 13 pairs of ribs and costal cartilages, costal arch
cranial: thoracic inlet
caudal: diaphragm
What are the openings of the diaphragm?
lumbocostal arches
aortic hiatus
esophageal hiatus
caval foramen
What is the clinical relevance of the openings of the diaphragm?
Hernias of abdominal viscera can occur through these openings.
How are serous cavities named?
According to location: parietal or visceral
According to the cavity they define: pleural, pericardial, and peritoneal
What is the endothoracic fascia?
The “glue” that holds the parietal pleura to the internal wall of the thoracic cavity
What does the mediastinum separate?
the right and left pleural cavities
What develops within the mediastinum?
the pericardial cavity
What are the recesses of the pleural cavities?
pleural capula (protrudes from thoracic inlet)
costomediastinal recess (space between costal wall and diaphragm)
costodiaphragmatic recess
mediastinal recess (contains accessory lobe of the right lung)
lumbodiaphragmatic recess
What are the subdivisions of the mediastinum?
cranial, middle, caudal
How does the azygos vein differ between species?
bilateral in the ox
only RIGHT azygos vein in the dog and the hose
only LEFT azygos in the pig
What are the boundaries of the cervical visceral space?
ventral: sternocephalicus, sternothyrohoideus
dorsal: longus capitis, longus coli
What makes up the conducting portion of the respiratory system?
trachea and bronchial tree
What is the name of the cartilage at the bifurcation of the trachea?
carina
What connects the cartilaginous rings of the trachea?
tracheal (annular) ligaments
What makes up the exchange portion of the respiratory system?
respiratory bronchioles, alveolar duct, alveolar sacs, alveoli
What is the main blood supply to the exchange portion of the respiratory system?
pulmonary arteries and veins
Theres a notch in a lobe of a lung. What is it called, what lobe of what lung is it on?
the caudal notch is on the middle lobe of the right lung
Which lung is bigger in the dog?
the right
What are lobes of the right and left lungs of the dog?
left: divided cranial lobe, caudal lobe
right: caudal lobe, middle lobe, cranial lobe, accessory lobe
How do equine lungs differ from carnivores?
The cranial lobe of the left lung is not divided in horses.
The right lung does not have a middle lobe.
How do bovine lungs differ from carnivores?
The cranial lobe is divided in both left and right bovine lungs. In carnivores, only the left cranial lobe is divided.
What are the branches of the aortic arch?
brachiocephalic trunk and left subclavian artery
What are the branches of the brachiocephalic trunk?
left and right common carotid and right subclavian
What are the branches of the R&L subclavian arteries and what do they supply? (hint: there are 4)
Costocervical trunk: supplies cranial intercostal spaces 1-3 and muscles of the neck
Vertebral artery: extends through the transverse vertebral formina, supplies brain and spinal chord
Superficial cervical artery: supplies superficial structures of the neck
Internal thoracic artery: supplies cranioventral quadrant of the abdomen
What are the branches of the internal thoracic artery and what does it continue as?
ventral intercostal aa.
musculophrenic a.
continues as the cranial epigastric a.
What are pulmonary ligaments?
Double layers of serous membrane that extend from the mediastinal (parietal) pleura to the visceral pleura
What is the plica vena cavae?
Fold of serous membrane (from the right mediastinal pleura) that envelops the caudal vena cava and right phrenic nerve
What makes up ganglia?
neuronal cell bodies
What are afferent neurons, interneurons, and efferent neurons?
afferent (unipolar) relay sensory input to the CNS
interneurons (bipolar) relay impulses inside the CNS
efferent (multipolar) neurons relay motor output from the CNS
What are the two types of motor output?
somatic: one neuron, skeletal / voluntary muscle
visceral / autonomic: two neurons (post and pre-synaptic), involuntary tissue
Where can you find pre-synaptic visceral efferent neurons? Where does the axon synapse?
The cell bodies are INSIDE the CNS.
Axon synapses into second automatic neuron in autonomic ganglion.
Where can you find post-synaptic visceral efferent neurons? Where does the axon synapse?
Cell body is inside the autonomic ganglion, part of the PNS.
Axon synapses with target tissues.
What are the types of nerves based on nerve impulse direction?
Sensory (afferent)
Motor (efferent)
Mixed (sensory + motor; somatic + autonomic)
What are the types of nerves based on origin?
spinal and cranial nerves
All cranial nerves are mixed nerves. True or false?
False mother fucker. All SPINAL nerves are mixed nerves.
How many spinal nerves are there?
8 cervical, 13 thoracic, 7 lumbar, 3 sacral
Not all cranial nerves are mixed nerves. True or false?
True!
Where do cranial nerves originate and what do they innervate?
originate from brain nuclei
innervate head and neck (vagus nerve is an exception)
How many cranial nerves are there?
12 pairs
What cranial nerves are purely sensory?
CN1 Olfactory
CN2 Optic
CN8 acustivovestibular
What cranial nerves are purely motor?
CN 4 trochlear
CN6 abducent
CN13 hypoglossal
What cranial nerves contain autonomic components?
CN3 oculomotor
CN7 facial
CN 9 glossopharyngeal
CN10 vagus
All spinal nerves are mixed nerves. True or false?
True AF!
What is in the dorsal root? (talking NS here)
Afferent neurons
What is in the ventral root? (talking NS here)
Efferent neurons
Dorsal vs ventral rami, go.
Dorsal rami: shorter, supply expaxial mm. and dorsal skin
Ventral rami = longer, give off both parietal and visceral supply, limb innervation, etc
Where do the 8 cervical spinal nerves emerge from?
CSN1: lateral vertebral formina of altas
CSNs 2-7: cranial to corresponding cervical vertebrae
CSN 8: emerges caudally to C7
Where do thoracic and lumbar spinal nerves emerge from>
Thoracic spinal nerves (TSN 1-13) and lumbar spinal nerves (LSN 1-7) emerge caudally to their correspondent vertebrae
Where do the sacral spinal nerves emerge from?
1st and 2nd sacral SN emergy through the sacral formina (dorsal and pelvic sacral foramina)
3rd sacral SN emerges through the intervertebral foramen between the sacrum and the first caudal verterbra.
What is the name of CN XI and what does it innervate?
The accessory nerve innervates the trapezius m.
What nerves penetrate the omotransversarius m?
CSN 3-5
What type of innervation do the phrenic nerves carry and to where?
Supply the diaphragm, somatic innervation
What are the origins of the sympathetic and parasympathetic NS?
sympathertic: thoracolumbar division
para: craniosacral division
All pre-synaptic axons (pre-SNS) enter ganglia adjacent to the vertebral bodies, via communicating rami. True or false?
True
Pre-SNS entering a ganglion is not the same thing as pre-SNS fibers synapsing on a post-SNS ell body in that ganglion!
Where do axons of pre-SNS neurons synapse?
On post-SNS cell bodies in:
- Ganglia of the paravertebral chain
- Ganglia located in the cervical region
- Pre-vertebral ganglia (in the abdominal cavity
What does the paravertebral ganglia contain, where is it located, and what does it form?
- Contains post-synaptic sympathetic (post-SNS) cell bodies
- Located on either side of the vertebral column
- Form the sympathetic trunk / chain (paravertebral chain) (10)
What are the ganglia of the cervical region?
Cervicothoracic ganglion
Middle cervical ganglion
Cranial cervical ganglion
What are the splanchnic nerves? Where do they originate? What axons are they made up of?
- Major and minor splanchnic n., lumbar splanchnic nn.
- Originate from paravertebral chain: communicate with pre-vertebral ganglia
- Made of pre-SYMPATHETIC axons that DO NOT synapse with the paravertebral chain
Where are pre-vertebral ganglia located? Name them.
Caudal to the diaphragm, located adjacent to major arterial branches of the abdominal aorta
Celiacomesenteric ganglion and plexus near celiac a. and cr. mesenteric a., made up of the celiac and cranial mesenteric ganglia
Caudal mesenteric ganglion near the caudal mesenteric artery
Where do the hypogastric nerves originate and what are they made up of?
Originate from caudal mesenteric ganglion
Made of post-SNS axons that innervate viscera of the pelvic cavity
Where are the pre-synaptic cell bodies of PSNS neurons located?
within brain nuclei and the sacral regions of the spinal cord
Where are the post-synaptic cell bodies of the PSNS neurons located?
within non-visible ganglia, in the walls of
the viscera they serve
What is the major parasympathetic motor supply to the internal viscera?
CN X, vagus nerve
Describe the vagus nerve segments.
The left and right vagus nerve divide. The left divides into the left ventral vagal branch and the left dorsal vagal branch. The right divides into the right ventral vagal branch and the right dorsal vagal branch.
The right dorsal vagal branch and left dorsal vagal branch come together to form the dorsal vagal trunk.
The left ventral vagal branch and right ventral vagal branch come together to form the ventral vagal trunk.
What do the left and right recurrent laryngeal nerves curve around?
left: curves around the ligamentum arteriosum and the aortic arch
right: curves around the right subclavian a.
Why care about the vagus?
Vagal indigestion syndrome in cattle
Why care about the recurrent laryngeal nn.?
Vocal chord paralysis after thyroidectomy (unilateral)
What is the continuation of the fibrous pericardium to the diaphragm called?
phrenicopericardial ligament
How does the azygous vein differ across species and in fetal life?
Bilateral in fetus
Equine / carnivores – right persists
Pigs – left persists
Ruminants – bilateral
Where do the base and apex of the heart point?
Base of the heart points dorsocranially and the apex points caudoventrally and to the left
What intercostal spaces does the heart span?
spans intercostal spaces 3-6
What groove encircles the base of the heart?
Coronary groove
How do you know you’re looking at the auricular surface of the heart?
Both auricles are in view
▪ Left side as positioned in the animal
The paraconal interventricular groove is where and contains what?
next to the conus arteriosus of the right ventricle; AURICULAR SURFACE
contains the great cardiac vein and the left coronary artery
How do you know you’re looking at the atrial surface of the heart?
both atria are in view
The subsinuosal interventricular groove is where and contains what?
Atrial surface
Contains the circumflex branch of the left coronary artery
What are the divisions of the right atrium?
Divided into a main part (sinus) and a blind pouch (the auricle)
What are the four openings of the right atrium?
Coronary sinus
Caudal vena cava
Cranial vena cava
Atroventricular orifice – from atrium into ventricle (where the valve is located)
What does the coronary sinus do?
drains the heart itself (cardiac veins drain here)
What structure diverts the blood from the cranial and caudal vena cava into the right ventricle?
the intervenous tubercle
What structure is directly caudal to the intervenous tubercle?
fossa ovalis
Where do you find pectinate mucles?
right auricle
What separates the main compartment of the right atrium from the auricle?
Crista terminalis
Where are papillary muscles located?
in the ventricle
What are the chords extending from the AV valve to the papillary muscles?
chordae tendinae
What are the myocardial ridges in the heart?
Trabeculae carneae
What is the funnel shaped part of the right ventricle bordered by the auricles called?
Conus arteriosus
What structure allows passage of cardiac conduction fibers extending across the ventricles?
Trabeculae septomarginalis
Which ventricle has thicker walls?
left
What is the septal wall of the heart?
inside the ventricle, adjacent to the septum
What is the parietal wall of the heart?
inside the ventricle, adjacent to the ventricular wall (outer wall)
What arteries supply blood to the heart?
coronary arteries
How does blood bypass the lungs in fetal life? What are these structures called in an adult?
foramen ovale allows passage from the right atrium to the left atrium; called fossa ovale in the adult
Ductus arteriosus shunts blood from the pulmonary artery to the aorta; called ligamentum arteriosum in the adult
What is Patent ductus arteriosus (PDA)?
Persistent communication between the aorta and pulmonary artery
Typically blood shunts from left to right
One of the most common congenital cardiac defects
What is Patent foramen ovale?
“common atrium”
atrial septal defect
What is Persistent right aortic arch (PRAA) and what condition is it associated with?
PDA/ ligamentum arteriosum will weap around the esophagus, constricting it and leading to regurgitation after switching to solid food
mega-esophagus
What is pericardial effusion?
Accumulation of fluid in the pericardial sac
What is Dilated cardiomyopathy?
Abnormality in the myocardium that leads to decreased contractility
What is Hypertrophic cardiomyopathy?
disease of the left ventricle; usually in cats
What is Mitral valve insufficiency?
degenerative and progresses over time, congenital
How is heartworm disease contracted? How long does it take to show up on a test?
from mosquitoes
up to 6 months
What parts of the heart do heartworms affect specifically?
Take up residence in the pulmonary artery before backing up into the heart – specifically the right ventricle (due to size of the worms and number)
