Cardiovascular system 2 Flashcards
What is the name of the valves between the atria and ventricle
Atrioventricular valves (AV)
What type of AV valve is on the right side of the heart
Tricuspid valve
What type of AV valve is on the left side of the heart
Bicuspid (mitral) valve
What is the purpose of valves in the heart
To stop blood from flowing back where it just came (prevent backflow)
How do the valves work
When the pressure of one area is great than the other the valves open or close in response (pushed open against walls or closed together)
Describe the diastole phase
Filling phase (relaxed/resting) -of ventricles with blood- of the cardiac cycle AV valves open
Describe the Systole phase
Emptying phase - Muscles contracting to pump blood - AV valves closed. When pressure in heart exceeds pressure in arteries semilunar valves
What do semilunar valves do
Prevent blood from returning to ventricles during diastole (filling)
What type of semilunar valve is on the left side of the heart
Aortic valve - 3 cusps (flaps)
What type of semilunar valve is on the right side of the heart
Pulmonary valve - 3 cusps (flaps)
How do the AV valves not prolapse
Chordae tendineae and papillary muscles help control the closing of the leaflets
How does the heart get blood to its tissue/muscles
Through coronary, circumflex and anterior interventricular arteries
Start at left side of heart and runs through coronary grove then over surface of heart to the right side
How does the heart get deoxygenated blood from its tissue/muscles
Through coronary sinus, great and small cardiac veins.
Left side mostly drained by great cardiac vein
Right ride mostly by small cardiac vein.
Gathers into coronary sinus and drained into right atrium through Venus sinus
What is a capillary
Epithelial cell that forms junctions with itself and neighbouring cell
Why are capillaries only wide enough for one red blood cell to travel through at a time
So the red blood cell is as close to the walls as possible to allow easier diffusion (of gases)
Describe Cardiac muscle cell structure
Cardiomyocyte Striated Short Branched One (occasionally 2), central nuclei Organelles packed at poles of nucleus Interconnected with neighbours via Intercalated disks (ICD)
What aspects of Cardiac muscle cells are similar to smooth and skeletal
Smooth - short, num. of nuclei, nuclei position
Skeletal - Striated appearance
What makes up 20% of cardiac muscle cells cytoplasm
Mitochondria
2% in skeletal
Why do cardiac muscle cells have large amounts of mitochondria
Very energy dependant. Shifts metabolism to oxygen dependant (rather than food) so it can become a more flexible process
What are the three types of junctions (ICD) between cardiac muscle cells
Adhesion belts
Desmosomes
Gap junctions
Describe the purpose of adhesion belt junctions
Links actin from one cells to the actin from neighbouring cell. When one muscle contracts its actin pulls on it’s neighbours and forces it to contract as well (Physical propagation)
Describe the purpose of desmosome junctions
Tight, anchoring junctions - spot welding. Stops the cells from pulling apart when they contact
Describe the purpose of Gap junctions
Electrochemical communication between cells by allowing small molecules through - mostly calcium
What does the conduction system of the heart do
Ensures the right part of the heart beats at the right time
Increases efficiency
Controls closing of AV valves
Modified cardiac cells (Purkinje)
What can alter the rate of conduction impulse
Autonomic nerves
