Heart 101
Transcript
The heart pumps blood throughout the body.
Carrying oxygen and nutrients to every cell.
It’s this circulation of blood that is vital to sustaining life.
The heart is an organ made up of several tough layers of muscle.
The pericardium is the thin layer that covers the exterior while the endocardium lines the inside walls.
The heart is divided into four chambers.
Two upper and two lower.
The upper chambers known as the atrium receive blood coming into the heart.
The lower chambers are the ventricles that pump blood out.
Between each chamber are valves that open and close and help keep the blood moving.
They are the tricuspid, mitral, pulmonary, and aortic valves.
A pumping cycle starts when oxygen-depleted blood returns to the heart after circulating throughout the body.
The blood enters through the right atrium before flowing to the right ventricle.
It’s then pumped to the lungs via the pulmonary arteries.
There blood is rejuvenated by air that’s breathed in.
The oxygen rich blood returns to the heart through the left atrium where it goes to the left ventricle.
Then by way of the aorta artery the fresh blood is pumped throughout the body before the process repeats itself.
That process happens with every heartbeat.
And it’s relentless.
The heart beats 100,000 times a day.
40 million times a year and up to three billion times over an average lifespan.
But there are conditions that can disrupt a heartbeat and that normality.
They can range from myocardial infarction or heart attack to heart disease and hypertension.
In contrast, exercise and emotional excitement can also have an impact on a person’s heartbeat.
The various blood vessels that comprise the circulatory system are a network of veins, arteries, and capillaries that span over 60,000 miles throughout the body.
And the heart is the pump at the center of it.
Vocabulary List
nutrient
(noun) a substance that provides nourishment essential for growth and maintenance of life
vital
(adjective) essential to life or existence
sustain
(verb) to keep alive or in existence
exterior
(adjective) situated on or outside the surface
line
(verb) to form a layer on the inside of something
chamber
(noun) a small room or compartment
valve
(noun) a device that controls the flow of a fluid
deplete
(verb) to reduce the supply of something
via
(adverb) by way of
rejuvenate
(verb) to make young or new again
relentless
(adjective) continuous and not stopping
lifespan
(noun) the average length of time that a person or something lives
disrupt
(verb) to interrupt something by causing a disturbance or problem
range
(verb) vary or extend between specified limits
span
(verb) to stretch over
Grammar Lesson
In this lesson, we will observe the use of prepositions in this video:
-
verb + preposition
-
noun + preposition
-
adjective + preposition
vital + to
It’s this circulation of blood that is vital to sustaining life.
vital = adjective
The -ing form sustaining is used because to in this sentence is a preposition (not an infinitive marker).
made up + of
The heart is an organ made up of several tough layers of muscle.
make up = verb
divide + into
The heart is divided into four chambers.
divide = verb
known + as
come + into
The upper chambers known as the atrium receive blood coming into the heart.
know = verb
come = verb
return + to
A pumping cycle starts when oxygen repleted blood returns to the heart after circulating throughout the body.
return = verb
enter + through
flow + to
The blood enters through the right atrium before flowing to the right ventricle.
enter = verb
flow = verb
pump + to
It’s then pumped to the lungs via the pulmonary arteries.
pump = verb
rejuvenated + by
There blood is rejuvenated by air that’s breathed in.
rejuvenate = verb
pumped + throughout
Then by way of the aorta artery the fresh blood is pumped throughout the body before the process repeats itself.
pump = verb
range + from
They can range from myocardial infarction or heart attack to heart disease and hypertension.
range = verb
The verb range is commonly used with these patterns:
-
range from A to B
-
range between A and B
-
range in something
impact + on
In contrast, exercise and emotional excitement can also have an impact on a person’s heartbeat.
impact = noun