Week 2 Heart Flashcards
What are the different types of pipes?
Arteries, veins, and capillaries.
What is an artery?
Blood vessel that carry blood AWAY from the heart
What is a vein?
A blood vessel that carry blood TOWARDS the heart.
What are capillaries?
Connect arteries to veins.
Smallest blood vessel
Where does exchange take place?
Capillaries
Where blood is moved out to cells or from cells into the blood
Where does the heart sit?
In the mediastinum (space between the lungs)
Just behind the sternum
Just anterior to vertebral column
How much of the heart is to the left of midline?
2/3 of heart
Why is it useful for the heart to be between the sternum and vertebral column?
For CPR
You can squish it artificially due to something solid in front and behind it.
What happens to the proportion of body weight made up of the heart as they get older?
It decreases
At birth, the heart makes up ___ of body weight?
130
In an adult, the heart makes up ___ of body weight?
1/300th
The shape of the heart tends to mirror what?
The shape of the thoracic cavity
What does apex mean?
Bottom point of the heart
What does base mean?
Top part of the heart
Where are all the major blood vessels enter and exit from?
The base of the heart
What is the heart surrounded by?
Protective sac called pericardium
Does the pericardium stretch? Y/N
NO
What is the layer attached/touching the heart?
Visceral pericardium
What is the layer outside the visceral pericardium?
Parietal pericardium
What is the space between the visceral pericardium and parietal pericardium?
Pericardial space
What is found in the pericardial space?
Pericardial fluid
What is the visceral and parietal pericardia TOGETHER called?
Serous pericardium
What is the outermost layer of the heart called?
Fibrous pericardium
What is in between the fibrous and parietal pericardium?
Space with little fluid but NOT pericardium fluid
How much pericardial fluid in between the visceral and parietal pericardium?
10-15 ml of pericardial fluid
What happens if the serous pericardium overproduce pericardial fluid?
We can’t stretch fibrous pericardium.
Heart gets squashed if there’s too much fluid.
What are one of the physical properties of a fluid?
You can’t compress it.
What is it called if you have inflammation in the pericardial space?
Pericarditis
What is cardiac tamponade?
When someone has an injury to the heart and blood can get out and into the pericardial space.
Causes a decrease how effective heart can function.
What is the groove that runs around the base of heart where blood vessel attach?
Coronary sulcus
What is the coronary sulcus?
Coronary sulcus is a groove in between the atria and ventricles in the heart
What is a coronary sinus?
part of a blood vessel
Why are there some fat on the heart?
Provides cushion and protection for blood vessels as heart expands and contracts
What are the three layers of the heart wall?
Epicardium, myocardium, and endocardium
The epicardium and the ___ are the same thing
Visceral pericardium
What is the epicardium?
Thin covering that attaches to the muscle beneath it (myocardium) by a thin layer of areolar connecting tissue.
What is the myocardium?
Thickest layer, muscle of the wall of the heart, it does the work.
Built to have sheets running in diff directions so we can contract in all directions
What is the lining of the heart called?
Endocardium
What does endocardium line with?
Continuous with the lining of the blood vessels, endothelium
What are the flaps and valves of the heart covered with?
Endocardium
Is cardiac muscle striated?
Yes
It has sarcomeres
What is different about cardiac muscle tissue?
The cells are connected to each other with intercalated discs.
What do you find in an intercalated disc? This means what?
Gap junction
An action potential can travel from one cardiac muscle cell into the next one, sodium can move through gap junctions
What do you describe the myocardium as?
Functional syncytium
What is a functional syncytium?
They function like one really big cell
What is the reason for functional syncytium?
We want myocardium, in particular areas of the heart, to have all the cells to contract at the same time.
What is the difference between cardiac muscle and skeletal muscle?
Cardiac muscle is autorhythmic
Why is cardiac muscle autorhythmic?
Cardiac muscle cells have their own inherit rate of depolarization at threshold
They don’t need an action potential from a nerve to start depolarization, so they don’t need it for contraction.
Why DONT we need action potential from the nervous system?
to start depolarization and lead to a contraction?
Why do we need nervous system input?
to adjust the contraction and how much time between contractions or how forcefully we need the muscle to contract.
What is another difference between cardiac and skeletal muscle cells?
- Cardiac muscle cells are much SMALLER.
- have only ONE nucleus
- sometimes cells branch to help wrap myocardium around a space
What are desmosomes? And what is the purpose?
Connect 2 cells
They are there to strengthen connection. Help hold myocardium together. As well as on either side of sarcomeres, NOT inside.
What is behind the aorta?
A section of myocardium that separates the RA from the LA called interatrial septum.
Where does the blood from the myocardium go back into?
Comes back into the RA from a different vessel.
What is the RA and RV separated by?
A class of cardiac valve called atrialventricular valve or AV valve.
What is the valve between the right atrium and the right ventricle called
Tricuspid valve
- has three flaps on valve
Where do you ONLY see pectinate muscle?
Right atrium
What is the chordae tendineae?
It attaches at one end to the loose part of flap for tricuspid valve, the other end attached to the papillary muscle.
What is the papillary muscles part of?
Myocardium
When does the papillary muscle contract?
it contracts when rest of right ventricle contracts.
What does the chordae tendineae and papillary muscle do?
Keeps from opening backwards
- prevents back flow
How does blood move?
There is a pressure gradient.
Blood will always move where pressure is HIGHER to where pressure is LOWER.
Physiology of blood going back into right atrium from right ventricle.
As blood pressure in ventricle is higher, it will try to go back into the right atrium due to it being lower pressure.
Flaps in valve catch it and chordae tendineae and papillary muscle keep valve from opening the other way so blood can’t go back from ventricle to atrium.
How are the valves operated by?
The pressure gradient
If the pressure after the valve is HIGHER than before, what does the valve do?
It closes
What is the innermost part of the muscle myocardium?
Trabeculae cardinae
What is the job of trabeculae cardinae ?
The only muscle of myocardium that’s actually contracting to pull in rather than push in.
Gets myocardium moving
What does the moderator band do?
Part of conducting system (electrical system of heart) which helps carry signal to the free wall of right ventricle.
What is between the left ventricle and right ventricle?
Interventricular septum
What is the job of the right ventricle?
To pump blood to the lungs
What is not associated with the interventricular septum?
Free wall of the right ventricle
What is between the ventricles and blood vessels they pump blood into?
Semilunar valve
Do blood vessels pump blood?
No they carry blood
Difference between tricuspid valve and pulm valve?
No chordae tendineae in semilunar valves
Where does the left ventricle pump blood into?
aorta
What is another semilunar valve between LV and aorta called ?
Aortic valve
Parts of aorta
Ascending aorta, aortic arch, descending aorta
What is different from the right and left ventricle?
left ventricle has a thicker free wall
Why is the wall of the left ventricle thicker than right ventricle?
The right ventricle is pumping against a much lower blood pressure than left ventricle.
- pressure to pump blood into aorta is higher than to pump blood in lungs
Right ventricle is not pumping as far, only to lungs while left ventricle pumps to everywhere else
What is the normal arterial blood pressure in left ventricle pumping against
120/80
What is the normal arterial blood pressure in right ventricle pumping at peak?
25-30 mm of Mercury
What is the skeleton of the heart made up of?
Made of connective tissue, NOT bone.
What is the cardiac muscle attached to?
The four rings that make up the cardiac skeleton so it has something to pull against.
