Exam 2 (Lecture 4) - Lymphatics and Nerves

Question 1

Which side of the animal are the heart valves best auscultated on?

Answer 1

1) Pulmonic, aortic, and mitral = left side

2) Tricuspid = right side

Question 2

In regard to the cranial thoracic vessels (the vessels that supply the head, neck, and thoracic limbs), what is the arterial branching pattern from the aorta in the canine?

Answer 2

The aorta gives off the brachiocephalic trunk and then the left subclavian artery.
- i.e. the left subclavian is a DIRECT branch from the aorta

The brachiocephalic trunk then give off the L and R common carotid arteries and then the right subclavian artery.

The left subclavian artery gives off the costocervical trunk.

Question 3

In regard to the cranial thoracic vessels, what is the arterial branching pattern from the aorta in the pig?

Answer 3

The aorta gives off the brachiocephalic trunk and then the left subclavian artery (just like in the dog).

The brachiocephalic trunk gives off the bicarotid trunk and the right subclavian artery.

The bicarotid trunk then gives off the L and R common carotid arteries.

The left subclavian artery gives off the costocervical trunk.

***The bicarotid trunk is a feature in the pig, ruminant, and horse.

Question 4

In regard to the cranial thoracic vessels, what is the arterial branching pattern from the aorta in the ruminant?

Answer 4

The aorta gives off the brachiocephalic trunk.

The brachiocephalic trunk gives off the left subclavian artery, the bicarotid trunk, and the right subclavian artery.

The left subclavian artery gives off the costovervical trunk.

The bicarotid trunk gives off the L and R common carotid arteries.

** In the ruminant, there are 4 branches from the costocervical trunk.

Question 5

What are the branches from the costocervical trunk in the ruminant?

Answer 5

1) Dorsal scapular artery
2) Supreme intercostal artery
3) Deep cervical artery
4) Vertebral artery

Question 6

In regard to the cranial thoracic vessels, what is the arterial branching pattern from the aorta in the horse?

Answer 6

The aorta gives off the brachiocephalic trunk.

The brachiocephalic trunk gives off the left subclavian artery, the bicarotid trunk, and at the right subclavian artery.

The bicarotid trunk gives off the L and R common carotid arteries.

The left subclavian artery gives off the costocervical trunk.

** In the horse, there are 2 branches from the costocervical trunk.

Question 7

What are the branches from the costocervical trunk in the horse?

Answer 7

1) Dorsal scapular
2) Supreme intercostal

Question 8

What does the supreme intercostal artery supply?

Answer 8

The first 2-4 dorsal intercostal arteries; caudal to that, the arteries are being derived from the thoracic aorta.

Question 9

What does the dorsal scapular artery supply?

Answer 9

This artery lies medial to the scapula, so it supplies the muscles medial to the scapula (serratus ventralis and epaxial muscles in that location).

Question 10

What does the deep cervical artery supply?

Answer 10

The epaxial neck muscles.

Question 11

What does the vertebral artery supply?

Answer 11

The vertebrae, spinal cord, and the muscles immediately around the vertebral column.

Question 12

What does the superficial cervical artery supply?

Answer 12

The cranial part of the shoulder.

Question 13

What is the last branch of the left subclavian artery? What does it become after that?

Answer 13

The last branch is the internal thoracic artery.

After that, it becomes the axillary artery.

Question 14

If you have to insert a needle into the thoracic cavity, where would you place it in relation to the rib and why?

Answer 14

The needle HAS to be placed along the cranial margin of the rib. This is because running along the caudal margin of the rib are arteries, veins, and nerves.

Question 15

Describe the azygous vein differences between the ruminant, horse and carnivore, and the pig.

Answer 15

1) The ruminant has a R and L azygous vein
2) The horse and carnivore have a right azygous vein only
3) The pig has a left azygous vein only

Question 16

In the ruminant, where does the LEFT azygous vein drain?

Answer 16

It drains into the coronary sinus on the RIGHT side of the heart.

Question 17

Discuss the arrangement of veins, nerves on the right side of the ruminant.

Answer 17

The azygous vein can terminate in either the right atrium or the cranial vena cava (individual/species variation)

Right azygous vein is immediately cranial to the tracheal bronchus.

Right recurring laryngeal nerve = courses around the right subclavian artery (on the left side, the left recurrent laryngeal courses around the ligamentum arteriosum).

Question 18

Describe the venous drainage of the caudal mammary glands.

Answer 18

Majority of the venous return is draining into the CRANIAL vena cava.
- superficial epigastric vein = milk vein of the dairy cow (HUGE vein dorsal to udder)

Cranial and caudal superficial epigastric veins anastomose together.
- They drain into the internal thoracic vein
- The internal thoracic vein drains into the subclavian vein
- The subclavian vein drains into the cranial vena cava

Question 19

Where does the cardiac plexus receive its innervation from?

Answer 19

1) Sympathetic innervation from the sympathetic chain and the cervicothoracic ganglion

2) Parasympathetic innervation from the vagus nerve

Question 20

What does the major splanchnic nerve provide the innervation to?

Answer 20

Sympathetic innervation to a lot of the abdominal viscera.

Question 21

What is the celiacocranialmesenteric ganglion?

Answer 21

Ganglion around the cranial mesenteric and celiac arteries.

Made up of branches from the major splanchnic nerve and the dorsal vagal trunk.
- Branches FROM the ganglion supply innervation to the cranial mesenteric artery.