Question 1

Which of the following best describes the anatomical location and orientation of the heart in the human body?

Accepted Answer

The heart is located in the mediastinum, between the lungs, with its apex pointing down and to the left.

Question 2

Which chamber of the heart is labeled 'K' in the provided diagram, and what is its primary function?

Accepted Answer

Left ventricle; pumps oxygenated blood to the systemic circuit.

Question 3

Blood in the vessel labeled 'T' in the heart diagram is:

Accepted Answer

Oxygen-poor, returning from the body to the right atrium.

Question 4

Why is the muscle around chamber 'K' (left ventricle) thicker than around chamber 'N' (right ventricle)?

Accepted Answer

The left ventricle pumps blood to the entire body, requiring more force.

Question 5

Which of the following is a unique feature of cardiac muscle cells that supports their function?

Accepted Answer

They have intercalated discs that allow rapid electrical communication.

Question 6

What does it mean that heart muscle is 'autorhythmic'?

Accepted Answer

It can generate its own action potentials without external input.

Question 7

Which cells set the pace of the heart rate, and where are they located?

Accepted Answer

Sinoatrial (SA) node cells in the right atrium.

Question 8

Trace the spread of electrical activity through the heart's conducting system.

Accepted Answer

SA node → AV node → Bundle of His → Purkinje fibers

Question 9

What does an ECG (electrocardiogram) measure, and what is its clinical usefulness?

Accepted Answer

It measures the electrical activity of the heart and is used to detect arrhythmias.

Question 10

Given the ECG strip (second image), if each large box represents 0.2 seconds and there are 4 large boxes between R waves, what is the heart rate?

Accepted Answer

$$\frac{60}{0.8} = 75$$ bpm

Question 11

Which of the following best defines cardiac output?

Accepted Answer

The volume of blood pumped by the heart per minute.

Question 12

Calculate Alinah’s cardiac output at rest and during a 5K race, given her heart rate increases from 65 bpm to 150 bpm and her stroke volume rises from 70 mL/beat to 110 mL/beat.

Accepted Answer

Rest: $$65 	imes 70 = 4,550 mL/$$min; Race: $$150 	imes 110 = 16,500 mL/$$min

Question 13

A trauma patient loses 20% of total blood volume. Her heart rate increases to 120 bpm, but stroke volume decreases to 30 mL/beat. What is her cardiac output?

Accepted Answer

$$120 	imes 30 = 3,600 mL/$$min

Question 14

Why does heart rate increase but stroke volume decrease in a patient who has lost significant blood volume?

Accepted Answer

The heart compensates for lower blood volume by beating faster, but less blood returns to the heart, so each beat pumps less.

Question 15

Which of the following best describes the relationship between cardiac output (CO), stroke volume (SV), and heart rate (HR)?

Accepted Answer

$$CO = SV 	imes HR$$

Question 16

Which of the following is a correct statement about the autonomic effects on heart rate?

Accepted Answer

Sympathetic stimulation increases heart rate, while parasympathetic stimulation decreases it.

Question 17

Which valve is labeled 'I' in the heart diagram, and what is its function?

Accepted Answer

Mitral (bicuspid) valve; prevents backflow from left ventricle to left atrium.

Question 18

Which of the following best describes the blood in the vessel labeled 'G' in the heart diagram?

Accepted Answer

Oxygen-rich blood coming from the lungs to the left atrium.

Chapter 12: The Heart – Structure, Function, and Dynamics

Guida di studio - Domande di pratica

Study guide - Flashcard