Module 5 Cardiovascular anatomy and physiology Flashcards
What is the Pericardium
Double walled sac surrounding the heart
List the layers of the pericardium 3
- Fibrous Pericardium - tough, loose fitting inextensible sac. surrounding heart
- Serous Pericardium - 2 layers
- Parietal layer (inside fibrous pericardium)
- visceral layer (epicardium) - integral part of heart wall.
- A pericardial Space with pericardial fluid separates the two layers, -this provides protection from friction
How much does the heart weigh?
250-300 grams
List and describe the three distinct layers of the heart
- Epicardium - Outer layer of heart wall
- Myocardium - Thickest, contractile middle layer, compresses heart cavities
- Endocardium - delicate inner layer of endothelial tissue
Note what is between the visceral and parietal layers of the heart?
Fluid
Describe the Atria, function and structure
- Two superior chanbers - receiving chambers because they receive blood from the veins
- They alternately contract and relax to receive blood, then push it into the ventricles
- Myocardial wall of atrium not that thick, they don’t need to exert much pressure, not moving blood very far.
- Auricle - earlike flap protruding from each atrium
Describe the Ventricles, form and function 3
- Two lower chambers, pumping chambers
- Ventricular myocardium thicker than Atrial
- Myocardium on L is thicker than on R
Look at the figure of the chamber and valves of the heart
Patton
List the heart valves and describe what they do.
- Atrioventricular (AV) valves: prevent blood from flowing back into atria
- Tricuspid valve - (Right AV valve): guards the R atrioventricular orifice; free edges of three flaps of endocardium are attached to papillary muscles by chordae tendineae
- Bicuspid or Mitral valve (left AV valve): similar to structure of tricuspid valve except has only two flaps
- Semilunar valves: half moon shaped flaps growing out from the lining of the pulmonary artery and aorta;
- Prevent blood from flowing back into the ventricles from the aorta and pulmonary artery
- Pulmonary valve: valve at enterance of the pulmonary artery
- Aortic Valve: valve at enterance of the aorta
What is the direction of blood flow through the heart?
Where does the heart receive its blood from?
- right and left coronary arteries, the first branches to come from the aorta
- Ventricles receive blood from both the right and left coronary arteries
- Most abundant blood supply goes to the myorcardium of the L ventricle
- Few anastomoses exist between the larger branches of the coronary arteries ( making it really bad if one is blocked)
Names of Coronary arteries (both names) And where they are located, as well as what parts of the heart they feed
- Anterior interventricular artery (Left anterior descending artery)
- Posterior interventricular artery ( posterior descending artery? or Right Posterior decsending artery?)
- Right marginal artery
- Right coronary artery
- Left coronary artery
- Circumflex artery
what routes do the Coronary Veins follow, where does the blood go after it flows through the coronary veins
- follow a course that parallels that of the coronary arteries
- after going through cardiac veins, blood enters the coronary sinus to drain into the right atrium.
What are the cardiac plexuses?
- They are part of the conduction system of the heart, and are locatedthe** near the arch of the aorta**
- They are composed of sympathetic and parasympathetic fibers
- Fibers from the cardiac plexus accompany the right and left coronary arteries to enter the heart
- Most of these fibers end in the SA node, but some end in the AV node, and in the atrial myocardium; the nodes are the hearts pacemakers
- Sympathetic nerves: Accelerator nerves
- Vagus fibers: inhibitory, or depressor, nerves
SA node (pacemaker) What does it do, what is it composed of?
- initiates each heartbeat and sets its pace
- Specialized pacemaker cells in the node possess an intrinsic rhythm (automaticity)
What is the difference between ordinary cardiac muscle tissue and the conduction system structures within the muscle?
- The conduction system fibers are more highly specialized and permit only rapid conduction of an Action Potential through the heart.
See diagram of the conduction system of the heart on paper.
in my notes.
Where do the coronary arteries branch off from?
They branch off from the aorta directly above the semilunar valve.
Angina Pectoris
characteristic pain felt beneath the sternum and in the left arm and neck when the coronary artery is occluded ( blocked )
In anatomical terms, where is the heart located?
- Mediastinum, or middle region of the Thorax, just behind the body of the sternum between the points of attachment of the second through sixth ribs.
- Posteriorly it rests against the bodies of the 5th to 8th vertebrae
- Lower border, or apex, rests on the diaphragm
- upper border - base, lies just below the second rib.
When does the heart reach its adult size and weight?
Between puberty and 25 years old
List the direction of blood flow through the heart. 14
- Right atrium ⇒2. Right atrioventricular (tricuspid) valve⇒3. Right ventriicle⇒pulmonary semilunar valve⇒4. pulmonary trunk, first portion of pulmonary artery⇒5. left and right pulmonary arteries⇒6. gas exchange tissue of the lungs⇒7. pulmonary veins⇒8. left atrium⇒9. left atrioventricular (mitral) valve⇒10. left ventricle⇒11. aortic semilunar valve⇒12. Aorta⇒branches of the aorta supply all the tissues of the body except the gas-exchange tissues of the lungs. ⇒13. Blood from the head, neck and upper extremities empties into the superior Vena Cava, blood from the lower body empties into the inferior vena cava. ⇒14. both these large vessels empty blood into the right atrium, and the cycle starts over again.
How do atrioventricular valves differ from semilunar valves?
- AV valves prevent blood flow from flowing back up into the atria from the ventricles,
- semilunar valves prevent it from flowing back down into the ventricles from the aorta and pulmonary trunk.
List the way blood flows through the heart
Look at figure 21-11 in patton