Which heart chamber has the thickest wall
Left ventricle
The layer of the heart that contracts is _____________
Myocardium
The tiny mass of cells that forms the pacemaker of the heart is called the ______________
Sinoatrial (SA) node
Blood that nourishes the heart wall is provided by the right and left ___________
Coronary arteries
What are all the factors that increase peripheral resistance? (3)
What are the blood vessels that transport oxygen rich blood?
Arteries, Aorta and pulmonary veins
What is the major function of the cardiovascular system?
What is the transport vehicle?
The force moving the blood is?
Transportation
Blood is the transportation vehicle
Beating heart and blood pressure
what is the pathway of impulses through this system (5)
Intrinsic conduction system:
-controls the heart rhythm: the heartbeat “lub-dub” pattern
Pathway:
1. SA Node (pacemaker) (contracts atrium)→
2. AV Node (slows impulse so ventricles can fill) →
3. Bundle of His (carries impulse to ventricles)→
4. Right and Left Bundle Branches (go to R and L ventricle ensuring they contract at same time) →
5. Purkinje Fibers (tiny fibers carrying impulse to all muscle cells causes the ventricles to contract)
-This all happens in 0.8 of a second
what determines it with the equation?
Cardiac output – amount of blood pumped by 1 ventricle per minute
CO = HR x SV
The vagus nerve - slows down heart rate. Decreases cardiac output. parasympatheic nervous system.
Exercise - increases heart rate and cardiac output. sympathetic nervous system.
Epinephrine - adrenaline hormone increases heart rate and cardiac output as part of the sympathetic nervous system. fight or flight response.
Various ions - low calcium and potassium ions slow the heart.
arteries - transport blood away from heart, thicker
veins - transport blood to heart, thin, has valves
capillaries - where arteries and veins change, site of exchange of nutrients and waste
arterioles - branches of arteries, control blood flow into capillaries by getting bigger or smaller
venules - branch of veins with blood leaving capillaries, going back to heart
What is hepatic portal circulation?
Brain arteries:
-internal carotid (2)
- vertebral arteries(2)
Hepatic portal circulation -veins that drain the digestive organs of nutrients and go to the liver through the hepatic portal vein
Define pulse
How many beat per minute do we have?
and name several pulse points (5)
pulse - pressure wave of an artery
-70-76 beats per minute
-radial pulse-wrist
-brachial artery - ditch of arm
-common carotid artery - neck
-facial artery - jaw
-superficiial temporal artery-temple
What is systolic and diastolic pressure?
What is a healthy blood pressure rate?
the pressure against the walls of the blood vessels
-systolic pressure - pressure in the arteries when ventricles contract
-diastolic pressure - pressure when ventricles are relaxing
-healthy blood pressure is 120/70
it enables the transfer of nutrients, oxygen, waste products, and other substances between the blood and tissues.
-no decline in resting cardiac output
-age related diseases might slow it down
-delivers oxygen and nutrients all over the body
-removes its wastes
the capillary walls are just _______ layer thick, called the __________
one
tunica intima
What is the location of the heart in the thorax?
mediastinum
Which heart chamber has the thickest walls? What is the functional significance of this structural difference?
the left ventricle has the thickest wall because it pumps to the entire body
Why are the heart valves important?
because they keep blood flowing in 1 direction