Lecture 10 - Cardiovascular 3 The Heart Flashcards
Where is heart located
In mediastinum
How does heart sit in chest
2/3rds to the left
What is approximately size of heart
Vary with body size
About 310g male and 225g female
About two fist clench together
What is a survivable birth defect re: location of heart
Right sided heart - 1 per 200 rats
Where is Apex of heart
Bottom left side
What are 2 types of pericardium
Fibrous and serous
What is structure is fibrous pericardium
Tough, loose fitting inextensible sac
What is structure of serous pericardium
- Parietal layer lies inside the fibrous pericardium
- visceral layer (epicardium) adheres to the outside of the heart
- pericardial space with pericardial fluid separates the two
What to heart covering protect against
Friction
What are the three layer distinct layers that make up wall of the heart
Epicardium
Myocardium
Endocardium
What is epicardium
Outer layer of heart
Visceral layer of serous pericardium
What is myocardium
Thick, contractile middle layer of heart wall
- compresses the heart cavities and the blood within them with great force
What is endocardium
Delicate inner layer of endothelial tissue
How is heart divided into right and left
By the septum ( ventricles separated by inter ventricular septum)
How many chambers are there
4
What are receiving chambers
Atria because they receive blood from veins
Where are atria
Top of heart superior to the ventricles
How to stir receive and push blood
Relax to receive and contract to push
Is myocardial wall of atria thick and why
No because they dont have to move blood far ; just sending into ventricles
What is article of heart
Earlike flap protruding from each atrium
What are the pumping chambers
Two lower chambers which are the ventricles that push blood into larger networks of vessels
Describe ventricle myocardium
It is thicker than atria’s because great force must be generated to pump blood a large distance;
- myocardium of left ventricle thicker than right as must pump blood much farther
What are the valves of the heart
Mechanical devices that permit the flow of blood in one direction only
What do atrioventricular (AV) valves do
- prevent blood from flowing back into the atrium from the ventricles when the ventricle contract