Cardiovascular Anatomy

How many chambers are present in the heart?

4

What is the fibroserous covering of the heart?

Pericardium

What bony structure points towards the heart?

Olecranon

What are the layers of cardial tissue?

Fibrous pericardium-> serous pericardium-> epicardium-> myocardium-> endocardium

What portion of the diaphragm is the heart attached to?

The cupula

What structures does the pericardium enclose?

The heart and roots of great vessels

What is the fluid filling the pericardial space?

Pericardial fluid

What is the function of the pericardial fluid?

Facilitates movement of the heart against the pericardium

What are the functions of the pericardium?

1. Helps prevent overfilling of the heart 2. Protects the heart 3. Provides lubrication

What are common clinical considerations involving the heart?

1. Pericarditis 2. Pericardial effusion 3. Cardiac tamponade

What is the term for the base of the heart?

Basis cordis

What is the term for the apex of the heart?

Apex cordis

Which ventricle forms the apex cordis?

Left ventricle

Which border of the heart is formed by the right ventricle?

Cranial border

Which border of the heart is formed by the left ventricle?

Caudal border

What is the term for the right side of the heart?

Atrial face (facies artialis)

Which groove is present on the atrial face of the heart, marking the presence on an internal septum?

Right interventricular groove (Subsinousal interventricular groove)

What blood vessel passes through the right interventricular groove?

Interventricular artery

What chamber does the vena cava empty into?

The right atrium

What is the flow of blood through the heart?

Cranial and caudal vena cava-> right atrium-> right ventricle-> pulmonary trunk-> pulmonary artery-> lungs-> pulmonary veins-> left atrium-> left ventricle-> aorta-> body

What is the term for the left side of the heart?

Auricular surface (facies auricularis)

What structure is the outpouching of the atria?

Auricle (auricula cordis)

What groove is present on the auricular surface of the heart, marking the presence of an internal septum?

Left interventricular groove (Paraconal interventricular groove)

What blood vessel passes through the left interventricular groove?

Paraconal interventricular artery

What groove is present on the auricular face and most prominent in bovines?

Intermediate groove

What groove marks the separation of the atria from the ventricles?

Coronary groove (sulcus coronarius)

Which groove of the heart contains large amounts of fat?

Coronary groove

What is the first branch on the aorta?

Coronary artery

During pericardial effusion, which side on the body will the fluid accumulate towards?

The right side

Which side of the body should a pericardiocentesis be performed?

Right side

Why should a pericardiocentesis be performed on the right side of the body?

1. Fluid accumulation towards the right 2. Presence of cardiac notch 3. Avoid coronary vessels

What landmarks should be used to perform a pericardiocentesis?

5th-6th intercostal space; just above costachondrial junction

What great vessel empties the right ventricle?

Pulmonary trunk (pulmonary arteries)

What great vessel empties into the left atrium?

Pulmonary vein

What are the first 3 branches of the aorta?

1. Coronary arteries 2. Brachiocephalic trunk 3. Left subclavian artery

What are the portions of the aorta?

1. Ascending aorta 2. Aortic arch 3. Descending aorta (thoracic and abdominal)

What structure joins the aortic arch to the pulmonary trunk?

Ligamentum arteriosum (butallis ligament)

What is the butallis ligament a remnant of?

Fetal ductus arteriosus

How long does it normally take for the ductus arteriosus to be obliterated?

1 week postpartum

What clinical condition can be noticed in newborn animals while the ductus arteriosus closes?

Fetal heart murmur

What is the fetal opening between the atria?

Foramen ovale

What clinical condition can occur when the aortic arch develops incorrectly?

Persistent right aortic arch; occurs when the aorta develops from the right 4th aortic arch instead of the left

What vessel arises from the left 4th aortic arch?

Aortic arch

What vessel arises from the right 4th aortic arch?

Right subclavian artery

What vessels arise from the 6th aortic arch?

Pulmonary arteries and ductus arteriosus

What internal structure of the right atria demarcates the cranial and caudal vena cava?

Intervenous tubercle

What internal structure divides the ventricles?

Interventricular septum

What are the portions of the interventricular septum?

1. Membranous portion (dorsal) 2. Muscular portion (ventral)

What artery supplies the muscular portion of the interventricular septum?

Left coronary artery

What artery supplies the membranous portion of the interventricular septum?

Right coronary artery

Where is a ventricular septal defect most likely to occur?

Membranous portion

What internal structure connects the interventricular septum to the ventricular wall?

Trabecular septum

What is the function of the trabecular septum?

Helps prevent overfilling of the heart

Which valve controls blood flow from the right atrium to the right ventricle?

Tricuspid valve (right atrioventricular valve)

How many cusps are present in the tricuspid valve?

3 cusps

What are the 3 cusps of the tricuspid valve?

1. Anterior (parietal) 2. Posterior (angular) 3. Septal

What structure connects the cusps to their corresponding papillary muscles?

Chordae tendineae

Which tricuspid cusp is directed towards the ventricular wall?

Parietal cusp

Which tricuspid cusp is directed towards the septum?

Septal cusp

Which tricuspid cusp is directed towards the apex cordis?

Angular cusp

What is the happening to the tricuspid valve during diastole?

Relaxation; allows filling

What is happening to the tricuspid valve during systole?

Contraction; prevents backflow

Which valve is present between the right ventricle and pulmonary truck?

Pulmonary valve (semilunar valve)

How many valves are present in the pulmonary valve?

3 valves

What are the three valves of the pulmonary valve?

1. Right 2. Intermediate 3. Left

Which pulmonary valve is directed towards the interventricular septum?

Left valve

What is stenosis?

A condition when the valves do not open properly to allow blood flow

What valve closure creates the first heart sound (lubb)?

AV valve closure

What valve closure creates the second heart sound (dupp)?

Pulmonary and aortic valve closure

Which ventricle of the heart is larger?

Left ventricle

What web-like structure connect the interventricular septum to the ventricular wall?

Trabeculae

What valve is present between the left ventricle and aorta?

Aortic valve

How many valves are present in the aortic valve?

3 valves

What are the 3 valves present in the aortic valve?

1. Right 2. Intermediate 3. Left

What is the location of the left coronary artery?

Lies between the pulmonary trunk and auricle of the left atrium

What is the valve present between the left atria and left ventricle?

Bicuspid valve (mitral valve)

How many cusps are present in the bicuspid valve?

2 cusps

What are the 2 cusps present in the bicuspid valve?

1. Anterior 2. Posterior

What is the fibrocartilaginous heart structure present in bovine and camelids?

Ossa cordis

Where is the ossa cordis located?

Between the left ventricle and aorta

What is the function of the ossa cordis?

Supports the aortic and tricuspid valves

What electrical node is present in the right atrium?

Sinoatrial node

What electrical node is present in the interatrial septum?

Atrioventricular node

Which part of the conducting system is present in the interventricular septum?

Bundle of His

Which part of the conducting system is present in the endocardium of the ventricles?

Purkinje fibers

What nerve supplies the SA node?

Right vagus nerve

What nerve supplies the AV node?

Left vagus nerve

Where is the cardiac plexus located?

Near the base of the heart; T1-T5

What is the shape of the dog heart?

Ovoid; more blunt apex cordis

Which species have a more pointed apex cordis?

Small ruminants and pigs

What is the shape of the ovine heart?

Conical

Which species have significant epicardial fat stores on the heart?

Ruminants

Which species does the left subclavian artery branch independently off the aorta?

Dogs and cats

What are the 3 main veins of the thoracic cavity?

1. Azygos vein 2. Internal thoracic vein 3. Intercostal veins

What vessel does the azgos vein empty into?

Cranial vena cava

What vessel does the internal thoracic vein empty into?

Brachiocephalic vein

What vessel do the intercostal veins empty into?

Azygos vein

What structures are drained by the azgos vein?

The abdominal and thoracic walls

Which species have only a right azygos vein?

Horses and carnivores

Which species have only a left azygos vein?

Swine