Lecture 15 Flashcards
Does the cardiac cycle every end
No, never ending loop
Define: atrial systole
Atrial systole: top chambers contract sending blood to the ventricles
Define Ventricular Systole
Ventricular Systole: bottom chambers contracting sending blood elsewhere
Is the blood in the aorta oxygenated or deoxygenated
Blood in aorta has always been oxygenated
Define diastole
Period of rest between contractions (diastole)
What is the importance of diastole
Gives heart time to relax, fill with blood, and get ready for next cycle
What is a healthy BP
Healthy blood pressure is 120/80
When is systolic blood pressure recorded
During the contraction of the heart
What can systole BP be explained as
Ex. think of the pressure on the wall of the hole when a hose is turned on
When is diastolic BP recorded
When the heart is passively filling with blood after a contraction
What is the diastolic BP AKA
AKA the afterloud
Are doctors more focused on the systolic or diastolic BP
Disatolic
Why are doctors more focused on diastolic BP
– Pressure needs to surpass diastolic blood pressure to allow blood to pass through heart
– Too high level means heart is overworking
When does your heart work most on least
Your heart works harder in exercise and less hard in rest
What do neural and endocrine signals control
Neural and endocrine signals control strength and rate of heart reactions
If the body does not need lots of oxygen, what will it do
If your body does not need lots of oxygen, acetylcholine will reduce HR
If the body needs lots of oxygen what will it do AND what are the results from this
If your body needs lots of oxygen, norepinephrine and epinephrine will increase HR and strength of contraction
- Increases stroke volume
- Increases cardiac output
- Higher cardiac output = more oxygen to blood = more energy
What can a max HR be
Heart rate can increase to nearly 200 bpm
How does cardiac output change from rest to excerise
Cardiac output can increase from 5L to 25L
– 40L/ minute in elite athletes
What do cardiac muscles called
Cardiomyocytes
How do caridomyocytes interact
Communicate through gap junctions to act as single organism
What is the role of the SA node
SA node is the pacemaker - sends electrical impulse leading to heart beat
How many beats does the SA node send per min
Sends 100 beats per minute
What acts on the SA node
Parasynthetic and synthetic nervous system act on node to control heart rate
