Lecture 2: Anatomy of the Heart Part 2 Flashcards
What is the function of the left and right pulmonary artery?
To transport deoxygenated blood from the right ventricle to the left and right lung for oxygenation
What is the function of the left and right pulmonary veins?
To take deoxygenated blood to the left atrium of the heart from the left and right lungs
What is the function of the right atrium?
To receive deoxygenated from the superior and inferior vena carvae and the coronary sinus and transport it through the tricuspid valve to the right ventricle.
What is the function of the Pulmonary semilunar valve?
To prevent blood returning to right ventricle during filling (diastole)
What is the function of the coronary sinus?
To carry deoxygenated blood from the heart back to the right atrium
What is the function of the tricuspid valve?
To prevent blood from returning to the right atria during ventricular contraction
What is the function of the chordae tendinae?
To stop the tricupsid from slamming shut and flicking through to the other side
What is the function of the right ventricle?
Pumping blood to the lungs for oxygenation via the pulmonary arteries
What is the function of the papillary muscles?
These muscles connect the chordae tendinae to the free edge of the atroventricular valves to stop them from slamming shut
What is the function of the left ventricle?
What is the function of the bicupsid valve?
To pump oxygenated blood through the aortic semilunar valve to the aorta to enter the systemic system
To prevent blood from returning to the left atria during ventricular contraction
What is the function of the aortic semilunar valve?
What is the function of the left pulmonary artery?
What is the function of the aorta?
To prevent blood returning to left ventricle during filling (diastole)
To transport deoxygenated blood from the right ventricle to the lungs to be oxygenated
To transport oxygenated blood from the left ventricle to the systemic system
What is the function of the left atrium?
Describe the atrioventricular valves, including the function and what they are called on the left and right side:
At what stage are the AV valves open?
At what stage are the AV valves closed?
To receive oxygenated blood from the pulmonary veins to transport through the bicupsid valve to the right ventricle.
Function: prevent blood returning to the atria during ventricular contraction
right side: tricuspid valve
left side: bicuspid valve
during diastole (filling phase)
during systole
Where are the AV valves located?
Describe the semilunar valves, including the function and what they are called on the left and right side:
How many cusps does the pulmonary (semilunar) valve have?
How many cusps does the aortic (semilunar) valve have?
Between an atrium and a ventricle
Function: prevent blood retuning to the ventricles during filling (diastole)
right side: pulmonary (semilunar) valve
left side: aortic (semilunar) valve
They are pushed open as blood flows out of the heart and closed as blood starts to backflow
3
3
At what stage are the semilunar valves open?
At what stage are the semilunar valves closed?
Where are the semilunar valves located?
Describe the flow of blood into the heart from the heart
during systole
during diastole
Between a ventricle and a exit tube (either the pulmonary artery or the aorta)
Immediately branching off the aorta are the right and left coronary arteries.
The RCA supplies the ventricular wall of the right ventricle.
The LCA branches to go over the inter ventricular septum and becomes the circumflex artery and the anterior inter ventricular artery which enters the left ventricle. The circumflex artery wraps between the left atrium and the left ventricle
Which side of the heart needs more blood supply and why?
Describe the flow of blood out of the heart
Describe cardiac muscles
The left side needs more blood supply because there is more muscle to pump the blood further around the systemic system
The deoxygenated blood from the left side of the heart drains into the great cardiac vein and the deoxygenated blood from the right side of the heart drains into the small cardiac vein.
Both of the cardiac veins drain into the coronary sinus to enter the left atrium
Similar to both smooth muscle and skeletal muscle:
one central nucleus like smooth muscle and striated like skeletal muscle
How thick are the capillary walls and why?
What is the function of myocardium?
What are capillaries made of?
There are only one red blood cell thick because to bring them closest to the interstitial space to allow for maximum gas exchange as the distance is short
beating of the heart
endothelium cells wrapped around to form a circle
Describe the cardiac muscle structure:
- are the striated?
- what do the cells look like?
- how many nuclei per cell?
- what do the nuclei look like?
- where are the cytoplasmic poles packed?
- how are they interconnected to neighbouring cells?
What is an intercalated disk (ICD)?
What percentage of the volume of the cell is made up of mitochondria?
Why is this significant?
- striated
- short branched cells
- usually one nuclei per cell
- central, oval shaped nucleus
- cytoplasmic poles packed at the poles of the nucleus
- interconnected with neighbouring cells via intercalated disks
a specialisation of cardiac muscle
20%
this mean that there is a very high ATP driven metabolism which is needed for the high energy requirements of cardiac muscle to beat
An intercalated disk is made up of what three intercellular junctions?
Describe the role of the adhesion belt
How does an adhesion belt work?
Do adhesion belts work in the vertical or horizontal portion?
- Adhesion belts
- desmosomes
- gap junction
Link the actin in one cell to the actin of another cell so that when the sarcomere in one cell contracts, it tugs on the actin of another cell to physically stimulate contraction.
by physical propagation of contraction
vertical
Describe the role of a desmosome in an ICD
What is the cytokeratin?
Describe the role of a gap junction
Do desmosomes work in the vertical or horizontal portion and why?
It links the cytokeratin of one cell to the cytokeratin of another cell with a lot of force (their skeletons are essentially buttoned together)
A cell’s flexible skeleton
For electrochemical communication from myocyte to myocyte to allow synchronisation between these short stubby cells to allow them to function as one long cell
vertical because it is perpendicular to the plane of contraction so you need them there to hold the neighbouring cells together
Do gap junctions work in the vertical or horizontal portion?
Briefly describe the conduction pathways of the heart
Conduction pathways of the heart are not ______ _______ but _______ ________ ________
horizontal
The first part of the conduction pathway is on the superior aspect of the right atrium. This is the sinoatrial node. It spreads through the atrial chamber by pathways called internodal pathways. When exiting the atrial chamber to enter the ventricular chamber, the pathways come together to form the atrioventricular node. This leads into the AV bundle which splits to the right and left bundle branches. The terminal parts of the network are Purkinje fibres.
nervous tissue
modified cardiac muscle
What is the sinoatrial (SA) node?
What is the purpose of the left and right bundle branches?
Describe Purkinje cells
a little cluster of cells that spontaneously conduct action potentials, the rate of which are increased by sympathetic nerves or decreased by parasympathetic nerves
They are specialised pathways making sure that after contraction of the atrium occurs, we shoot the contraction down towards the apex to get contraction from the apex back up, not just as a continuous wave from the atria into the ventricles
Differentiated myofibrils with
- central nucleus
- mitochondria
- glycogen
- lots of gap junctions
- some desmosomes
- a few adhesion belts
- make up 1% of cardiac muscle
