4. Cardiovascular System Flashcards
What are the major parts of the heart? (5
Ventricle, Septum, Atrium, Valves, and Aorta
Ventricles
pump blood to other places
Septum
separates the left and right sides of the heart
Atriums
receiving chambers (where blood comes in)
Valves
make sure blood flows in the right direction
Aorta
largest artery in the body
Describe how your heart beats?
- the heart contracts when it pumps blood into the body (relaxes as chamber fills up)
- SA node creates electricity that makes your heart beat
- AV node accepts electricity from SA note and forms a bridge between atria and ventricles
What are the major signals in your heart?
S-A node (pacemaker) and A-V node (bridge)
S-A node
- pacemaker
- creates electricity that makes your heart beat
A-V node
- bridge between atria and ventricles
- the receptor of electricity from the S-A node
How do pacemaker and contractile cells differ?
- Pacemaker cells are AUTO RHYTHMIC (unstable resting membrane)
- Contractile cells are MYOCARDIAL (stable resting membrane)
- Pacemaker cells cause contractile cells to raise their action potential
What is the heart rate set by the SA node?
100 bpm
How does the autonomic nervous system affect heart rate?
- Parasympathetic (rest and digest) slows it down
- Sympathetic (fight or flight) speeds it up
Arteries
- left side
- carry oxygen to the body and are narrow
- narrow lumen (tunnel) to create high pressure
Arterioles
- smaller extensions of arteries
- provide oxygen to organ tissue
Veins
- right side
- carry deoxygenated blood back to the heart
Capillaries
- smaller extension of arterioles
- only thick enough to fit one blood cell at a time
- spread in between cells
allows for easy diffusion of nutrients because they have thin walls
Blood Vessels
- left side arteries
- right side veins
- refer to study guide for structure pg 5
What is Vasodilation?
- widening of blood vessels to deal with changes in pressure
- nitric oxide acts on the smooth muscle causing it to relax
- causes increase in vessel size
Where does the heart’s blood supply come from?
- the bone marrow
- cells in the bone marrow make blood cells
What is a heart murmur?
An abnormal sound from your heart made by narrowing or leaking of valves
