Questions and Answers
What is the unit rate of a car traveling 240 miles in 4 hours?
Which of the following is a characteristic of a proportional relationship?
If a shirt originally costs $20 and is now on sale for $18, what is the percentage decrease?
A bakery sells 480 muffins at $2 each. If they increase the price by 15%, how much will each muffin cost?
Signup and view all the answers
Which of the following represents a unit rate?
Signup and view all the answers
If x and y have a proportional relationship, which of the following is true?
Signup and view all the answers
What is the main function of the right ventricle?
Signup and view all the answers
Which layer of the heart is made up of cardiac muscle?
Signup and view all the answers
What is the path of blood circulation from the lungs to the rest of the body?
Signup and view all the answers
What is the purpose of the left atrium?
Signup and view all the answers
What is the purpose of the cardiovascular system?
Signup and view all the answers
What is the primary function of the left ventricle in the human body?
Signup and view all the answers
What is the normal range for systolic blood pressure in millimeters of mercury?
Signup and view all the answers
What factor affects blood pressure by increasing the amount of blood in the circulatory system?
Signup and view all the answers
What is the role of the SA node in the cardiac conduction system?
Signup and view all the answers
What type of blood vessel is responsible for carrying oxygenated blood away from the heart?
Signup and view all the answers
What is the function of the endothelium in blood vessels?
Signup and view all the answers
What is the term for high blood pressure, which can lead to cardiovascular disease and other health problems?
Signup and view all the answers
What is the function of the bundle of His in the cardiac conduction system?
Signup and view all the answers
Study Notes
Ratios and Rates of Change
Unit Rates
- A unit rate is a ratio that compares the number of units of one quantity to one unit of another quantity.
- Unit rates are used to describe a quantity per unit, such as miles per hour or dollars per pound.
- Unit rates are often used to make comparisons between different quantities or to describe a rate of change.
- Examples:
- 30 miles per hour (distance per time)
- $5 per pound (price per weight)
Proportional Relationships
- A proportional relationship exists between two quantities when the ratio of one quantity to the other is constant.
- If one quantity increases, the other quantity increases by the same factor.
- Proportional relationships can be represented by an equation of the form y = kx, where k is the constant of proportionality.
- Characteristics of proportional relationships:
- The graph is a straight line through the origin.
- The ratio of y to x is constant.
- If x increases, y increases by the same factor.
Percentage Increases
- A percentage increase is a way to describe a change in a quantity as a fraction of the original amount.
- Percentage increase = (new value - original value) / original value * 100
- Examples:
- A 25% increase from 100 to 125: (125 - 100) / 100 * 100 = 25%
- A 10% decrease from 100 to 90: (90 - 100) / 100 * 100 = -10%
- To find the new value after a percentage increase, multiply the original value by (1 + percentage increase as a decimal):
- 100 x (1 + 0.25) = 125
Ratios and Rates of Change
Unit Rates
- A unit rate is a ratio that compares the number of units of one quantity to one unit of another quantity.
- Unit rates are used to describe a quantity per unit, such as miles per hour or dollars per pound.
- Examples of unit rates include 30 miles per hour (distance per time) and $5 per pound (price per weight).
Proportional Relationships
- A proportional relationship exists between two quantities when the ratio of one quantity to the other is constant.
- The constant of proportionality (k) is the ratio of one quantity to the other in a proportional relationship.
- Characteristics of proportional relationships include:
- Graph is a straight line through the origin
- The ratio of y to x is constant
- If x increases, y increases by the same factor
- Proportional relationships can be represented by an equation of the form y = kx.
Percentage Increases
- A percentage increase is a way to describe a change in a quantity as a fraction of the original amount.
- Formula to calculate percentage increase: (new value - original value) / original value * 100
- Examples:
- 25% increase from 100 to 125: (125 - 100) / 100 * 100 = 25%
- 10% decrease from 100 to 90: (90 - 100) / 100 * 100 = -10%
- To find the new value after a percentage increase, multiply the original value by (1 + percentage increase as a decimal).
- 100 x (1 + 0.25) = 125
Heart Structure
- The heart is a muscular organ that pumps blood throughout the body, divided into four chambers: right atrium, right ventricle, left atrium, and left ventricle.
- The right atrium receives deoxygenated blood from the body, while the right ventricle pumps blood to the lungs.
- The left atrium receives oxygenated blood from the lungs, and the left ventricle pumps blood to the rest of the body.
- The heart is made up of three layers: epicardium (outer layer), myocardium (middle layer, made up of cardiac muscle), and endocardium (inner layer, lines the heart chambers).
Blood Circulation
- The cardiovascular system is a closed system, meaning blood is circulated throughout the body and returns to the heart.
- Deoxygenated blood from the body enters the right atrium, then flows to the right ventricle, and is pumped to the lungs.
- Oxygenated blood from the lungs enters the left atrium, then flows to the left ventricle, and is pumped to the rest of the body.
- Blood circulation is a vital function that supplies oxygen and nutrients to tissues and organs.
Arterial Blood Pressure
- Blood pressure is the force exerted by blood on the walls of arteries, measured in millimeters of mercury (mmHg).
- Normal blood pressure range is 90-120 mmHg (systolic) and 60-80 mmHg (diastolic).
- Factors that affect blood pressure include cardiac output, peripheral resistance, and blood volume.
- High blood pressure (hypertension) can lead to cardiovascular disease and other health problems.
Cardiac Conduction
- The cardiac conduction system generates and propagates electrical impulses that regulate the heartbeat.
- The SA node generates electrical impulses, which are relayed by the AV node to the ventricles through the Bundle of His and Purkinje fibers.
- The cardiac conduction system ensures a coordinated and efficient heartbeat.
Vascular Function
- Blood vessels are responsible for transporting blood throughout the body, and include arteries, veins, and capillaries.
- Arteries carry oxygenated blood away from the heart, while veins carry deoxygenated blood back to the heart.
- Capillaries allow for exchange of oxygen and nutrients with tissues, and are lined with endothelium, which helps to regulate blood flow and pressure.
- Vascular function is essential for maintaining healthy blood pressure and overall cardiovascular health.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Test your understanding of unit rates and proportional relationships, including their definitions, examples, and applications in making comparisons and describing rates of change.
