Control Of Heart Rate

Question 1

What are chemoreceptors?

Answer 1

Chemoreceptors are sensory receptors that respond to chemical changes in the blood, such as levels of oxygen, carbon dioxide, and pH.

Question 2

What role do baroreceptors play in heart rate control?

Answer 2

Baroreceptors detect changes in blood pressure and help regulate heart rate through the autonomic nervous system.

Question 3

True or False: Chemoreceptors are only sensitive to oxygen levels in the blood.

Answer 3

False. Chemoreceptors respond to oxygen, carbon dioxide, and pH levels.

Question 4

Where are baroreceptors primarily located?

Answer 4

Baroreceptors are primarily located in the carotid arteries and the aorta.

Question 5

What is the function of the autonomic nervous system in heart rate regulation?

Answer 5

The autonomic nervous system regulates heart rate through its sympathetic and parasympathetic branches.

Question 6

Fill in the blank: Increased carbon dioxide levels in the blood will ______ heart rate.

Answer 6

increase

Question 7

What is the response of the body to a decrease in blood pressure detected by baroreceptors?

Answer 7

The body increases heart rate and constricts blood vessels to raise blood pressure.

Question 8

Multiple Choice: Which of the following is NOT a function of chemoreceptors? A) Detect oxygen levels B) Detect blood pressure C) Detect carbon dioxide levels

Answer 8

B) Detect blood pressure

Question 9

How do chemoreceptors affect respiratory rate?

Answer 9

Chemoreceptors can increase respiratory rate in response to low oxygen or high carbon dioxide levels.

Question 10

True or False: The sympathetic nervous system decreases heart rate.

Answer 10

False. The sympathetic nervous system increases heart rate.

Question 11

What is the effect of the parasympathetic nervous system on heart rate?

Answer 11

The parasympathetic nervous system decreases heart rate.

Question 12

Fill in the blank: Baroreceptors send signals to the ______ to regulate heart rate.

Answer 12

medulla oblongata

Question 13

Which type of receptor would respond to high blood pressure?

Answer 13

Baroreceptors

Question 14

What happens to heart rate during exercise?

Answer 14

Heart rate increases to supply more oxygen to muscles.

Question 15

Multiple Choice: Which factor is least likely to affect heart rate? A) Blood temperature B) Blood pH C) Muscle activity

Answer 15

A) Blood temperature

Question 16

True or False: Chemoreceptors can influence heart rate indirectly through changes in respiratory rate.

Answer 16

True.

Question 17

What is the relationship between heart rate and cardiac output?

Answer 17

Heart rate is a component of cardiac output; increased heart rate generally increases cardiac output.

Question 18

Fill in the blank: The ______ nervous system is responsible for the fight or flight response that increases heart rate.

Answer 18

sympathetic

Question 19

What effect does high carbon dioxide have on blood pH?

Answer 19

High carbon dioxide levels lower blood pH, making it more acidic.

Question 20

Multiple Choice: Which hormone increases heart rate? A) Acetylcholine B) Adrenaline C) Insulin

Answer 20

B) Adrenaline

Question 21

What is the main function of the medulla oblongata in heart rate control?

Answer 21

The medulla oblongata processes signals from baroreceptors and chemoreceptors to adjust heart rate.

Question 22

True or False: Baroreceptors are more sensitive to rapid changes in blood pressure than to slow changes.

Answer 22

True.

Question 23

Fill in the blank: The ______ reflex is triggered by sudden drops in blood pressure.

Answer 23

baroreceptor

Question 24

What happens to baroreceptor sensitivity with chronic hypertension?

Answer 24

Baroreceptor sensitivity decreases with chronic hypertension.

Question 25

Multiple Choice: Which of the following would likely stimulate chemoreceptors? A) Increased oxygen levels B) Decreased carbon dioxide levels C) Increased carbon dioxide levels

Answer 25

C) Increased carbon dioxide levels

Question 26

What physiological changes occur when chemoreceptors detect low oxygen?

Answer 26

Increased heart rate and increased respiratory rate occur to enhance oxygen delivery.

Question 27

Fill in the blank: The ______ nervous system primarily regulates resting heart rate.

Answer 27

parasympathetic

Question 28

What is the significance of the heart rate variability?

Answer 28

Heart rate variability is a measure of autonomic nervous system function and can indicate cardiovascular health.

Question 29

True or False: Both chemoreceptors and baroreceptors contribute to homeostasis.

Answer 29

True.

Question 30

What is the primary chemical that chemoreceptors are sensitive to in the blood?

Answer 30

Carbon dioxide.

Question 31

Fill in the blank: The ______ is the area of the brain that integrates signals from both chemoreceptors and baroreceptors.

Answer 31

medulla oblongata

Question 32

What does the cardioacceleratory centre do to heart rate?

Answer 32

It sends fewer impulses along sympathetic motor neurones, resulting in less noradrenaline released at the SAN.

Question 33

How does the SAN affect heart rate?

Answer 33

The SAN reduces the frequency of impulses sent across the atria, leading to a decrease in heart rate.

Question 34

What happens to the rate of respiration after exercise?

Answer 34

The rate of respiration decreases, resulting in less CO2 produced.

Question 35

What is the effect of less CO2 on blood plasma?

Answer 35

Less CO2 dissolves in blood plasma, causing pH to increase.

Question 36

What is the result of less chemoreceptor stimulation?

Answer 36

Fewer impulses are transmitted to the cardiac centre in the medulla.

Question 37

How does exercise affect blood pressure?

Answer 37

Muscles contract strongly during exercise, putting pressure on veins and returning blood to the heart more quickly.

Question 40

What is released when we exercise?

Answer 40

Carbon dioxide ## Footnote Carbon dioxide is a byproduct of increased metabolism during exercise.

Question 41

What does exercise do to the pH of the blood?

Answer 41

Lowers it ## Footnote Increased carbon dioxide leads to the formation of carbonic acid, which decreases pH.

Question 42

What detects the change in pH of the blood during exercise?

Answer 42

Chemoreceptors in the medulla and the aortic & carotid bodies ## Footnote These receptors monitor blood composition and send signals to the cardiac centre.

Question 43

What is the role of the cardioaccelerator centre during exercise?

Answer 43

Sends increased frequency of impulses along sympathetic motor neurones ## Footnote This results in the release of noradrenaline at the SAN.

Question 44

What effect does noradrenaline have on the heart?

Answer 44

Emits more frequent impulses across the atria, increasing heart rate ## Footnote This is part of the body's response to increased physical activity.

Question 45

What happens to the rate of respiration during exercise?

Answer 45

Increases ## Footnote This leads to higher production of carbon dioxide.

Question 46

What happens to carbon dioxide in the blood?

Answer 46

Dissolves in blood plasma, forming carbonic acid ## Footnote This process contributes to the decrease in blood pH.

Question 47

What increases the concentration of H+ ions in the blood?

Answer 47

Formation of carbonic acid from dissolved CO2 ## Footnote More H+ ions lead to a lower pH.

Question 48

What sends impulses to the cardiac centre in the medulla?

Answer 48

Sensory neurones ## Footnote These neurones transmit information regarding blood chemistry changes.