Lecture 3: Cardiac and Vascular Function Flashcards
Look art the gross anatomy
Now
Describe the pericardium
Fibrous pericardium (anchor)
Parietal pericardium
Visceral pericardium / epicardium
Describe the layers of the heart
Epicardium
Myocardium
Endocardium
Describe the differences between the heart chambers
2 Ventricles (left wall thicker) IV septum
2 Atria - Thin walled
- Blood stored here (reservoirs)
Apex, Base
Describe the fibrous skeleton
Separates the Atria and Ventricles and which valves are mounted
- Prevents electrical conduction except via the bundle of his
Describe the aorta
Thick walled elastic artery
What do the aorta and PA do during systole and diastole?
Stretch during systole and release this energy back into the blood during diastole, pushing blood into the peripheral circulation
Describe the AV valves
Large openings (low pressure gradient) Thing leaflets Chordae tendon attached to papillary muscles
Tricuspid and mitral valves
Describe the semilunar valves
Three half moon cusps attached around valve rings (semilunar)
Describe the composition of the myocardium:
Cells : Myocytes and non-myocytes
ECM
Vascular tissue
How much of the myocardium is composed by myocytes?
30% of cells are myocytes and they make up 70% of myocardium by volume
What are the non-myocytes in myocardium?
Fibroblasts (90% of non-myocyte cells)
Endothelial cells
Vascular smooth muscle
Macrophages
Together form 67% of cells in myocardium
Whats in the ECM of myocardium?
Collagen Elastin Cells Vessels Nerves Gel metric molecules Growth Factors Cytokines Enzymes
How much myocardium is composed of vascular tissue?
60% of extracellular space is vascular tissue
Describe the relative sizes of a myocyte
80-100 micrometers in length
20 micrometers in diameter
What are the myofilaments in a myocyte?
Actin and myosin
What is a prominent anchor protein in myocytes?
Titan
Describe the structure of titan
Long fibrous protein that links myosin molecules to the z-disc
Whats the function of titan?
Dominates elasticity at short sarcomere lengths
Keeps myosin entered within the sarcomere
Generates the passive stiffness of myocytes