Circulatory System Flashcards
what is the muscle of the heart called?
myeocardium
The heart is the next most vital organ to what?
brain
What is angina pectoris?
chest pain caused by inadequate oxygen to the heart
what is the scientific name for a heart attack?
myocardial infarction
Chest pain caused by inadequate oxygen to the heart
angina pectoris
What is it called when veins from other parts of the body are used to bypass blockages in coronary arteries?
coronary bypass surgery
What is the average heart beats per minute?
72
What is each complete beat called
cardiac cycle
How long is each cardiac cycle?
0.8 seconds
What 2 parts is the cardiac cycle divided into?
Systole and diastole
Systole is which phase of the cardiac cycle?
contraction
diastole is which phase of the cardiac cycle?
relaxion
Define stroke volume
the volume of blood ejected from one ventricle with EACH BEAT
Define cardiac output
the amount of blood that one ventricle can pump EACH MINUTE
What is the average cardiac output?
5 Liters per minute at rest
What are intercalated disks?
electrical connectors that join all of the cardiac muscle fibers together
The SA node can also be known as what?
pacemaker
Where is the SA node?
the wall of the right atrium near the opening of the superior vena cava
Where is the AV node located?
the right atrium along the lower part of the interatrial septum
Where is the AV bundle located?
the septum of the ventricle
Where are the Purkinje fibers located?
the walls of the ventricles
What is the purpose of the purkinje fibers
depolarize causing the ventricles to contract
What is depolarization?
contracting
What is repolarization?
relaxation
What is another name for an electrocardiogram?
ECG
What are the three waves on an ECG?
P wave, QRS wave and T wave
Describe the P wave
associated with depolarization of the artia, small hill
Describe the QRS wave
associated with depolarization of the ventricles, spike
describe the T wave
associated with repolarization of the ventricles, small hill
Where do arteries carry blood?
away from the heart
Where do veins carry blood?
toward the heart
Where do capillaries carry blood?
from the arterioles to the venules
What is the name of the inner layer of endothelial cells in the arteries?
Tunica Intima
What is the layer of smooth muscle with some elastic tissue, thick in the arteries?
tunica media
What is the thin layer of fibrous elastic connective tissue in the arteries?
tunica externa
describe capillaries
microscopic vessels with only one layer called tunica intima
What is the inner layer in the veins that prevent retrograde movement of blood
tunica intima
What is the smooth muscle layer in veins that are thin in veins
tunica media
what is the heavy layer of fibrous connective tissue in the veins
tunica externa
What is the function of the arteries?
distribution of nutrients, gasses, etc., movement of blood under high pressure, assist in maintaining the arterial blood pressure
What is the function of capillaries?
serve as exchange vessels for nutrients, wastes and fluids
What is the function of veins
collect blood for return to the heart; low pressure vessels
Where does systemic circulation carry blood?
throughout the entire body
Where does pulmonary circulation carry blood?
to and from the lungs
The hepatic portal veins have how many capillary beds?
2
Hepatic portal circulation routes blood through what?
liver
What assists with homeostasis of blood glucose levels?
Hepatic portal veins
definition of blood pressure
push, or force, of blood in the blood vessels
Blood pressure is highest where and lowest where
highest in arteries and lowest in veins
Name the four factors that influence blood pressure
- Blood Volume
- Strength of ventricular contractions
- Blood viscosity
- resistance to blood pressure
what is the normal average blood pressure
120/80
in a blood pressure reading of 120/80… what is the 120
contraction
in a blood pressure reading of 120/80
relaxation
what is the venous blood pressure within the right atrium called
central venous pressure
5 things the venous return of blood to the heart depends on
- a strongly beating heart
- adequate arterial blood pressure
- valves in the veins
- pumping action of skeletal muscles as they contract
- changing pressures in the chest cavity caused by breathing
