Cardiovascular anatomy Flashcards
What are the 2 loops of general circulation?
Pulmonary circulation & systemic circulation
What is pulmonary circulation
Takes blood from the heart to the lungs and back
Low pressure
What is systemic circlation
Blood distributed from the heart through the body and back
High pressure
Which way do arteries take the blood?
Away from the heart
Which way do veins take the blood?
Toward the heart
How does blood leave the heart
Either through pulmonary artery (right ventricle) or aorta (left ventricle) to smaller arteries, arterioles, capillaries, venules, to veins
How many times does blood flow through capillaries?
Once except the portal system (2 capillary beds)
What portal systems are there?
Hepatic portal system
Hypothalamic-hyophyseal portal system
What are portal systems for?
Drug Absorption
What is the Surgeon’s pericardal sac?
3 layers
Pericardial mediastinal pleura
Fibrous pericardium
Parietal serous pericardium
What is the endocardium?
Lines the lumen of the heart
Which ventricle has thicker myocardal muscle?
Left
What surrounds the outside of the heart?
Visceral serous pericardium
What is the epicardium?
Visceral serous pericardium
What is myocardium?
Myocardial muscle
Where is the heart located?
Angled caudally & to the left between the 3rd and 6th intercostal space
What is the conduction system
Sinoatrial node (starts signal) Atrioventricular node (slows signal)
Purkinje fibers (conduct impulses)
What is the trabecula septomarginalis
A septum that conducts purkinje fibers across the lumen of the right ventricle
Why is the AV node important?
It slows the signal to ensure that the atria contract before ventricles
Where is the base of the heart?
Apex?
Base of the heart is located cranially
Apex is located caudoventrally
What is the auricular portion of the wall? The atrial?
Auricular portion of the heart touches the left thoracic wall
Atrial portion of the heart touches the right thoracic wall
Where is the coronary groove?
Dorsal auricular groove between left atrium and left ventricle
What is the subsinuosal groove?
Dorsal groove between left and right ventricle
What is the paraconal interventricular groove
Ventral aspect on the right ventricle
What is the conous arteriosis?
Conical pouch located on the upper left angle of the right ventricle that leads to the pulmonary trunk
What are the divisions of the right atrium?
Main part: Sinus venarum
Blind part: right auricle
What in flow of blood is associated with the right atrium?
Cranial vena cava
Caudal vena cava
Coronary sinus - venous return to the heart
What out flow of blood is associated with the right atrium?
Right atrioventricular orifice (blood flow from atrium to ventricle)
What is the intervenous tubercle?
Located in the right atrium and diverts inflowing blood from caval veins in to right AV orifice
What are the pectinate muscles?
Located in right atrium
Interlacing muscles to strengthen atrial wall
What is the in flowing blood supply to the right ventricle?
Right AV orifice
Where is the right AV valve located?
In the AV orifice
What is the out flowing blood supply to the right ventricle?
Pulmonary trunk
Where is the pulmonary valve located?
In the pulmonary trunk
What are the papillary muscles?
Conical shaped muscular projections that give rise to the chordae tendinae
What are the chordae tendinae?
Parachute cords that prevent the eversion of the AV valves
What are trabeculae carnae?
myocardial ridges on the lining of ventricles
What is the in flow to the left atrium?
Pulmonary veins
What is the out flow of the left atrium?
Left AV orifice (location of left AV valve)
What other features does the left atrium consist of?
Left auricle
pectinate muscles
What is the in flow for the left ventricle?
Left AV orifice
What is the outflow for the left venticle?
Aortic orifice (location of Aortic valve)
What features does the left ventricle consist of?
Same as right but more robust
Papillary muscles, chordae tendinae, trabeculae carnae
What are the coronary arteries?
Arise from ascending aorta
Left coronary & right coronary
Which side of the circulatory pattern is more developed?
Left side
What are the branches of the left coronary artery?
Circumflex, subsinuosal interventricular, paraconal interventricular, septal
What are the branches of the cardiac veins?
Great cardiac vein
Middle cardiac vein
Coronary sinus
What is the coronary sinus?
A collection of veins that collect blood from the heart muscle and delivers deoxygenated blood to the right atrium
What is sytole
Cardiac contraction
What is diastole
Cardiac relaxation
What does the lub sound mean
Closure of AV valves (atrial contraction)
What does the dub sound mean
Closure of semi-lunar valves (ventricle contraction)
What is a murmur?
The sound from turbulent blood flow
What causes murmurs?
Leaky valves, Narrow valves (AV[systole], semilunar[diastole])
Where is the pulmonary point of maximal intensity felt?
Low in the left 3rd intercostal space
Where is the aortic PMI felt?
High in the left 4th intercostal space
Where is the left AV valve?
Low in the left 5th intercostal space
Where is the right AV valve?
Low in the right 4-5th intercostal space
What is aortic stenosis?
Systolic murmur
What are the two principal branches of the aortic arch?
Brachiocephalic trunk, aorta
What branch comes from the aorta?
Left subclavian
What branches come from the brachiocephalic trunk?
Right subclavian, left common carotid artery and right common carotid artery
Where does the vertebral artery run through?
Transverse foramen
Where does the thoracic artery associate?
Caudal surface of the rib
When does the axillary artery begin?
The subclavian artery becomes the axillary artery after the first rib
What veins form the cranial vena cava?
Right external jugular vein
Subclavian vein
Right brachiocephalic vein
Left brachiocephalic vein
How is lymph returned to the venous system?
Thoracic duct
Right lymphatic duct
Characteristics of the thoracic ducts
Empties near the left venous angle
Receives lymph from 3/4 of the body
Characteristics of the right lymphatic duct
Empties near the right venous angle
Receives lymph from the right half of the head, neck and right thoracic limb and shoulder
What are the unique features of fetal circulation?
Shrunken lungs are nonfunctional and resistant to blood flow
Oxygenation and nutrient waste exchange occurs in the placenta
What circulatory structures are necessary in the fetus?
Umbilical arteries Umbilical vein Ductus venosus Foramen ovale Ductus arteriosus
What are the umbilical arteries?
originates from the internal iliac arteries.
Umbilical arteries carry fetal blood through the umbilical cord to placenta for nutrient waste exchange
What is the umbilical vein?
Returns fetal blood from placenta to the fetus
What is the ductus venosus?
A channel in the fetal liver for the umbilical vein
What is the foramen ovale?
Passage through the interatrial septum that allows blood to bypass the lungs from the right to left atrium
What is the ductus arteriosus?
Vascular connection between the pumonary trunk and the aorta which allows most of the blood to pass from the right ventricle directly to the aorta
How does the foramen ovale work?
Pressure in the right fetal atrium is higher than the left. Blood moves to left atrium
What are the lung changes that occur at birth?
Lungs inflate decreasing pulmonary resistance
Increased pulmonary blood flow
Increased pressure from venous return to the left atrium closes foramen ovale
What are the circulatory changes that occur at birth?
Increased pO2 causes smooth muscle contraction and the closing of umbilical arteries, umbilical vein, ductus venosus and ductus arteriosus
What changes occur over time after birth?
umbilical arteries regress to form round ligaments of the urinary bladder
umbilical vein becomes round ligament of the liver
In the liver, ductus venosus becomes ligamentum venosum
Ductus arteriosus becomes ligamentum arteriosum
Foramen ovale fibroses to become fossa ovalis
If the foramen ovale does not close, are there patholigcal signs?
Not generally because the higher left atrium pressure keeps the valve of the foramen ovale closed
