Cardiovascular Physiology - Lecture 10 Flashcards
Vascular System(The Heart) and Respiratory System
Cardiorespiratory Systems
Hollow and Muscular. Left side behind Sternum, double pump system, and part of the autonomic N.S
The Heart
Why is the Heart a Dual-Pump
Pumps blood to lungs & body.
2 Atria
Receives blood coming back to the heart and sends it to ventricles
2 Ventricles
Lower chambers; pumps blood from heart to other organs.
Dividing Wall
Septum
Sling Shot Analogy
The Atria loads up the blood that it’s going to release into the Ventricles. Pulls back and fires
Superior and Inferior Vena Cava
Superior brings in deoxygenated blood from the brain and the inferior brings in deoxygenated blood from below the heart into the Atrium
Right Atria gets blood from Vena Cava and Left gets it from the lungs.
Role of Atria
Foramen Ovale
Small Gap between two Atria that some people have not harmful unless wide enough.
Why does the left side of the heart have more pressure?
It contains all the blood with the oxygen that’s needed to be sent throughout the entire body. So it’s going to need to push through the resistance which creates a lot of pressure.
Thin Walls
Atria
Primary Pump/delivery driver for all necessary organ systems
Role of Ventricles
Thick Walls; muscular and generate more contraction (squeeze blood out effectively)
Ventricles
It can deliver much more blood than the atria can.
Ventricles
3 muscle layers from inner to outer
Endocardium (Thin inner layer), Myocardium (Muscle Middle Layer), Epicardium (Outer protective layer)
What is the outer layer susceptible for?
Epicardium is susceptible to bacterial infection that can seep through it into Myocardium
Contracting cells are found here, and want contracting muscles to be thick and all muscular tissue. (Exercising can help build muscle thorough fibrous tissue)
Myocardium
Makes for a slippery surface for the blood to make contact with, which allows for the blood to be squeezed out.
Endocardium
Unique facts about cardiac muscle
Involuntary, contracts for your entire life, and it is not found anywhere else.
Own blood supply (coronary arteries), lots of oxygen, maximum blood flow within coronary vessels occurs when heart is relaxing
What cardiac muscles need
If the heart itself is pumping blood to other parts, it needs its own blood supply and nutrients (O2). It needs to get that from the oxygenated blood being pumped out.
Coronary Arteries
Why are some heart attacks not as bad as others
Depends on where the coronary artery gets clogged
(Left Ventricle = you’re fucked)
Which Artery carries deoxygenated blood?
Pulmonary Arteries
Which Veins carry oxygenated blood?
Pulmonary Veins
Tricuspid Valve
3 flaps, opens right atria to right ventricle
Pulmonary Valve
Opens the right ventricle to allow blood to go to lungs
Bicuspid Valve
2 flaps, allows oxygenated blood from lungs to open left atria and enter left ventricle.
Aortic Valve
Allows blood to leave left side of heart and not come back in
Chordae Tendinae
Holds the valves together; can snap.
You’re pulling the sling shot back which means you’re filling the heart with blood; it’s relaxing.
Diastole
Letting go of slingshot is the contraction; work/pressure
Systole
AV Valves open and blood flows into ventricles via suction. Low pressure and the slingshot is being pulled back.
Phase 1 of Cardiac Cycle, A.K.A. Diastole
All valves are closed, an increase in pressure and the ventricles are all full. Brief pause before release
Phase 2, A.K.A Isovolumetric Contraction Period
Contraction; letting go of slingshot. Pressure starts to go up possibly reaching 120 mmHg
Phase 3, A.K.A. Systole
After the release there’s a brief moment of relaxation where AV valves and ventricles are closed
Phase 4, A.K.A. Isovolumetric Relaxation Period
P wave
First phase of cardiac cycle where atria is filling
Q,R,S Wave
Where the ventricles are contracting/firing
T Wave
Where the ventricles are relaxing
What causes our heart rate to go up?
Sympathetic Nervous System
Parasympathetic
What causes your heart rate to go down and relax
What dictates Heart Rate?
Sympathetic and Parasympathetic
What other factors cause the heart rate to change?
Exercise, Toxins, Altitude, Heat/Cold.
Heart cells conduct electricity extremely well
Fun Fact
Primary Pacemaker that sets heart rate rhythm and generates nerve impulses to allow both atria to contract.
SA Node
What happens once the rhythm is set in the SA Node?
Heart cells will contract in atria and communicate an electrical signal to the second node
Pathway for signals to reach the ventricles; determines the contraction
AV Node