Anatomy & Structure
The human heart has this many chambers.
What is 4?
Oxygen-rich blood leaving the left side of the heart travels through this main artery, the largest in the body.
What is the aorta?
A normal resting heart rate for teens and adults is typically between 60 and this many beats per minute.
What is 100 bpm?
Doing regular aerobic activity like running, swimming, or basketball strengthens this type of muscle found in the heart.
What is cardiac muscle?
About the size of a human fist, the human heart is located slightly to the left in this cavity.
What is the chest (or thoracic) cavity?
These upper two chambers of the heart receive incoming blood.
What are the atria (or atrium)?
Deoxygenated blood returns to the right side of the heart from the body through these two large veins.
What is the vena cava (superior and inferior)?
Known as the heart’s natural pacemaker, this group of cells initiates the electrical impulse for each beat.
What is the SA node (Sinoatrial node)?
High blood pressure is medically known by this eleven-letter term.
What is hypertension?
On average, the heart beats roughly this many times in a single day (Hint: around 100 thousand, 1 million, or 10 million?).
What is 100,000 times?
This muscular wall separates the left and right sides of the heart so oxygen-rich and oxygen-poor blood don't mix.
What is the septum?
The right side of the heart pumps blood to these organs to pick up oxygen.
What are the lungs?
The classic "lub-dub" sound of a heartbeat is actually created by the closing of these.
What are the heart valves?
A buildup of fatty plaque in the arteries can lead to a blockage, causing this medical emergency.
What is a heart attack (or myocardial infarction)?
This organ gets its own dedicated blood supply through the coronary arteries.
What is the heart itself?
These flap-like structures prevent blood from flowing backward inside the heart.
What are valves?
Blood returning from the lungs enters this specific chamber of the heart first.
What is the left atrium?
This diagnostic test records the electrical activity of the heart as squiggly lines on paper.
What is an ECG (or EKG / electrocardiogram)?
When reading blood pressure (e.g., 120/80), the top number represents this type of pressure.
What is systolic pressure?
Unlike other muscles in the body, cardiac muscle is involuntary, meaning it is controlled by this part of the nervous system.
What is the autonomic nervous system?
The heart is enclosed in a protective, fluid-filled sac called this.
What is the pericardium?
Microscopic blood vessels where oxygen and carbon dioxide are exchanged with body cells are called this.
What are capillaries?
The contraction phase of the cardiac cycle is called systole, while the relaxation phase is called this.
What is diastole?
This type of "good" cholesterol helps remove bad cholesterol from your bloodstream.
What is HDL (High-Density Lipoprotein)?
If you stretched out all the blood vessels in an average human adult, they would circle the Earth roughly this many times (1, 2.5, or 10?).
What is 2.5 times (approx. 60,000 miles)?