Branching of Aorta 1

Question 1

how in general does the aorta develop

Answer 1

from 6 aortic arches surrounding primitive pharynx in the fetus

Question 2

where does the aorta develop from

Answer 2

the left 4th aortic arch

Question 3

where does the pulmonary trunk develop from

Answer 3

ventral parts of R & L 6th aortic arch

Question 4

where does the ductus arteriosus develop from

Answer 4

dorsal part of left 6th aortic arch

Question 5

what occurs to the right 4th aortic arch

Answer 5

usually obliterated

if persists –> together with ligamentum arteriosum can rise to vascular ring obstruction of esophagus

Question 6

where do the left and right coronary arteries arise from and what are their functions

Answer 6

aortic bulb –> ~15% of cardiac output

taking blood from the ventricles as it passes by and supplies the heart with oxygen rich blood

Question 7

what view of the heart is this and identify the coronary arteries

Answer 7

left lateral view

1. pulmonary trunk
2. left coronary artery

2’. paraconal interventricular branch

2’’. circumflex branch

3. great cardiac vein (continued by coronary sinus on the right side of the heart)

3’. paraconal interventricular tributary of 3

Question 8

where does the right coronary artery run

Answer 8

right coronary artery: first superficial appearace towards cranial margin of heart, goes around the cranial margin onto the right side

Question 9

where does the left coronary artery run

Answer 9

left coronary artery: makes external appearance and becomes superficial sending off branch that is going to caudal marigin and a branch travelling down to apex in the left ventricular groove supplies large area of the heart

Question 10

where does the circumflex branch of the left coronary artery run

Answer 10

travels on coronary groove and onto the right hand side

Question 11

what is the view of the heart and identify the coronary arteries

Answer 11

1. circumflex branch of left coronary artery

1’. right (subsinuosal) interventricular branch

2. right coronary artery

2’. right (subsinuosal) interventricular branch

3. coronary sinus
4. great cardiac vein
5. middle cardiac vein

Question 12

what are the species differences in L & R coronary arteries on right lateral view in ruminants, canines, equine and pig

Answer 12

ruminant & canine: left circumflex branch comes right around onto right side of heart and continues down to the interventricular groove and gives rise to subsinuosal branch on right side, the right coronary artery comes around on right side and peters out quickly –> larger area supplied by left coronary artery

equine & pigs: left coronary artery comes onto right side, the right coronary artery travels down to interventricular groove and gives rise to subsinuosal branch –> both right and left suppy equal amounts

Question 13

how does the aorta branch in the dog, cat, rabbit

Answer 13

after aorta leaves the base of the heart –> quickly gives rise to branches

1. brachycephalic trunk (subdivides into the right subclavian. left common carotid a.)
2. left subclavian artery

Question 14

how does the aorta branch in horse and cow

Answer 14

no independent left subclavian

large brachycephalic trunk giving rise to two common carotides and two subclavian vessels

Question 15

how does the aorta branch in the pig

Answer 15

common brachycephalic trunk and separate subclavian

differences in how brachycephalic gives rise to the branches compared to carnivore

Question 16

identify the branches of the aorta in the ventral aspect of the dog

Answer 16

Question 17

what do the L & R common carotid arteries supply

Answer 17

head and mid brain

Question 18

where do the L & R common carotid arteries run

Answer 18

ventro-lateral surface of trachea (or esophagus left)

Question 19

what are the L & R common carotid arteries a component of

Answer 19

ascend via the carotid sheath (vagosympathetic trunk and internal jugular vein)

the reccurent larygneal nerves travel alongside the carotid sheath but not inside it

Question 20

how does the brachiocephalic trunk divide in the canine

Answer 20

immediately into 3 branches and mirrors how left subclavian is branching

1. right subclavian artery
2. left common carotid artery
3. right common carotid artery

Question 21

where does the descending aorta run

Answer 21

left of midline

Question 22

how does the left subclavian artery arise

Answer 22

independent from brachiocephalic trunk

Question 23

identify the branches of the external carotid artery

Answer 23

Question 24

describe how the common carotid artery branches in the dog

Answer 24

common carotid artery splits into two branches

1. internal carotid artery: supplies the brain mostly
2. external carotid artery: supplies the other structures of head

Question 25

what does the occipital artery supply

Answer 25

middle and internal ear and meninges

Question 26

what does the cranial laryngeal artery supply

Answer 26

supplies larynx

Question 27

what does the ascending pharyngeal artery supply

Answer 27

pharynx

Question 28

what does the lingual artery supply

Answer 28

tongue and palatine tonsil

Question 29

what does the facial artery supply

Answer 29

lips lateral nose angle of mouth

Question 30

what does the caudal auricular artery supply

Answer 30

external ear and associated muscles

Question 31

what does the superficial temporal artery supply

Answer 31

masseter and upper and lower eyelids

Question 32

what does the maxillary artery supply

Answer 32

branches into 1. inferior alveolar 2. external opthalmic 3. ethmoidal 4. palatine 5. infraorbital

Question 33

what can the facial arteries be used for

Answer 33

pulse for larger species

Question 34

what can the superficial temporal arteries be used for

Answer 34

pulse transverse facial artery horses

Question 35

what are the branches of the internal carotid artery

Answer 35

enters cranial cavity (via guttural pouch in horses) contributes to arterial circle of brain (horses and carnivores) divides into divergent caudal and rostral branches

Question 36

what does the vertebral artery supply

Answer 36

contributes to blood supply of brain along with internal carotid artery gives rise to basalar artery which supplies brain

Question 37

gow does the left subclavian artery branch

Answer 37

divides into 4 branches before curving around 1st rib 1. vertebral artery 2. internal thoracic artery 3. superficial cervical artery 4. costocervical artery continues as axillary arteries which supply the forelimbs

Question 38

what do the right and left subclavian arteries supply

Answer 38

forelimbs and structures of neck and cervico-thoracic region give off 4 main branches before curving around 1st rib continues as the axillary arteries which supply the forelimbs

Question 39

what does the left subclavian artery branch

Answer 39

winds around the cranial border of the 1st rib to enter the limb through the axilla to become the axillary artery detaches 4 branches in ints intra-thoracic course 1. vertebral artery 2. costocervical artery 3. superficial cervical artery 4. internal thoracic artery continues as left axillary artery

Question 40

where does the left vertebral artery run

Answer 40

cranio-dorsally via transverse foramina to enter vertebral canal within the atlas

Question 41

what does the left vertebral artery form

Answer 41

basilar artery (brain) and the ventral spinal artery (spinal chord)

Question 42

what does the brachiocephalic trunk give rise to

Answer 42

L/R common carotid arteries right subclavian artery

Question 43

what does the left costocervical artery form

Answer 43

1st few dorsal intercostal arteries and deep cervical artery (dorsal cervical muscles of the neck)

Question 44

what does the left superficial cervical artery supply

Answer 44

supplies ventral neck muscles, cranial shoulder and upper forelimb

Question 45

where does the left internal thoracic artery pass

Answer 45

between sternum and transversus thoracis muscle

Question 46

what does the left internal thoracic artery form

Answer 46

ventral intercostal arteries/musculo-phrenic artery

Question 47

how does the left internal thoracic artery enter the abdomen

Answer 47

tunnels beneath diaphragm into abdomen

Question 48

what does the left internal thoracic artery form in the abdomen

Answer 48

cranial superficial/deep epigastric arteries

Question 49

what does left axillary artery supply

Answer 49

lateral chest wall and forelimb

Question 50

what does the left axillary artery branch into

Answer 50

external and lateral arteries branchial artery median artery

Question 51

how does the right subclavian artery

Answer 51

1. r. vertebral artery 2. r. costocervical artery 3. r. internal thoracic artery 4. r. superficial cervical artery 5. r. axillary artery 6. right brachial artery

Question 52

how does the thoracic aorta branch in the dog

Answer 52

1. 1st few intercostal arteries derived from costocervical artery 2. 4th and 5th inter-costal arteries arise from the descending thoracic aorta --\> supply vertebral column and intercostal structures 3. bronchesophageal arteries arise approx 5th intercostal arteries --\> supply bronchi and esophagus

Question 53

where does the position at which the aorta penetrates the diaphragm

Answer 53

1. aortic hiatis: contains aorta, thoracic duct, azygous vein left to midline