In the absence of neural and hormonal influences the SA node generates action potentials at a frequency of approximately 100 times per minute. However, the resting heartrate is approximately 70 beats per minute, which suggests that:O the parasympathetic nervous system has more control over heart rate while at restO the sympathetic nervous system has more control over heart rate while at restthe heart is undergoing vagal escape while at restthe heart is not autorhythmic

The SA node's primary role is to serve as the heart's natural pacemaker. It starts an action…

Answered: In the absence of neural and hormonal…

Human Anatomy & Physiology (11th Edition)

11th Edition

ISBN:9780134580999

Author:Elaine N. Marieb, Katja N. Hoehn

Publisher:Elaine N. Marieb, Katja N. Hoehn

Chapter1: The Human Body: An Orientation

Section: Chapter Questions

Problem 1RQ: The correct sequence of levels forming the structural hierarchy is A. (a) organ, organ system,...

See similar textbooks

Similar questions

KEY Stimulus Medullary cardiovascular control center Sensory receptor Integrating center Efferent path Effector Change in blood pressure Parasympathetic Carotid and aortic baroreceptors neurons Sympathetic neurons SA node Ventricles Veins Arterioles Copyright 2009 Pearson Education, Inc. 1. In the diagram above, describe the role of the integrating center and two of the effectors. 2. What will atherosclerosis do to the peripheral resistance? 3. What will atherosclerosis do to the heart rate
In the lab, symphatetic stimulation of the heart will decrease heart rate increase heart rate O bring no change to heart rate because of the presence of sinoatrial node
1)In the regulation of heart rate, which of the following is the proper stimulus? Group of answer choices -Change in mean arterial pressure -mean arterial pressure -change in heart rate -heart rate 2) If a stimulus is a decrease in mean arterial pressure (MAP), what must be the response if using the baroreceptor reflex? Group of answer choices -Increase in heart rate -Decrease in heart rate -Increase in MAP -Decrease in MAP 3)The brainstem acts as the integrating center for the baroreceptor and chemoreceptor reflexes. Group of answer choices True False 4)A change in MAP causes a change in action potential firing along the afferent pathway of the baroreceptor reflex. Group of answer choices True False
Jake suffers from a mutation in voltage-gated calcium channels found in theirSA node. This mutation lowers the threshold at which the channels open.What effect do you think this mutation will have on his heart rate compared tosomeone with a normal threshold? Why does this effect occur?
Which is most involved in circadian rhythm The gracile fadciculus The medial lemniscus The para ventricular nucleus The sapracharismatic nucleus
Describe the movement in ions in action potentials of these cells - pacemaker cell - cardiac contractile cell
Activation of what adrenergic receptor directly causes stimulation of the heart? C-1 C-2 OB-1 O B-2
The next patient seen by the same doctor was suffering from hyperkalemia and was experiencing cardiac arrhythmias. Which of the following reason/s explain/s why this patient was experiencing cardiac arrhythmias? O hyperkalemia leads to an increase in action potential generation because potassium ions in the ECF makes the resting membrane potential more negative O hyperkalemia leads to a decrease in action potential generation because the potassium ion level in the ICF will cause hyperpolarization O hyperkalemia leads to an increase in action potential generation because the high level of potassium ions in the ICF will make achieving threshold easier O a and b
Mr Rupinder Patel is a 70 year old retired businessman. He has a past medical history of Congestive Cardiac Failure (CCF). This developed after he experienced a two myocardial infarctions 8 years ago. Both ventricles were affected. The death of his wife 2 years ago has led to Rupinder experiencing several episodes of depression which has been exacerbated by his sons both moving to Western Australia for work. The loneliness and sadness makes it difficult for him to be concordant with his CCF management and sustain the necessary lifestyle adjustments required to prevent exacerbations. This has resulted in several admissions to hospital for management and review of his CCF. For this current admission, Mr Patel was referred to hospital by his Nurse Practitioner, after recently rapidly gaining weight (currently 110kg), since his previous visit. The time now is 0800 and you have just come on for your morning shift. Mr Patel has been on the ward for only two hours after spending…
When we flung our arms around on the first day of class our heart rate increased to meet the demands of our exercising muscles. What was the mechanism by which this occurred? O Norepinephrine bound to receptors on the SA and AV nodes of the heart O The excess CO2 in the plasma generated by our skeletal muscles directly stimulated our cardiomyocytes to contract more frequently O Parasympathetic postganglionic neurons released acetylcholine onto the SA and AV nodes of the heart
During the refractory period a second action potential______. A cannot occur because voltage-gated Na+ channels are inactivated B cannot occur because the heart muscle cell has already returned to resting potential C can be initiated more easily because the threshold potential is reduced D can be initiated more easily because the calcium level in the sarcoplasm is increased
A likely effect of parasympathetic input to the heart would be to _____. Open additional potassium channels in pacemaker cells Promote calcium entry in pacemaker and contractile cells There is no parasympathetic input to the heart Decrease force of ventricular contraction

SEE MORE QUESTIONS

Recommended textbooks for you

Human Anatomy & Physiology (11th Edition)

Anatomy and Physiology

ISBN:

9780134580999

Author:

Elaine N. Marieb, Katja N. Hoehn

Publisher:

PEARSON

Anatomy & Physiology

Anatomy and Physiology

ISBN:

9781259398629

Author:

McKinley, Michael P., O'loughlin, Valerie Dean, Bidle, Theresa Stouter

Publisher:

Mcgraw Hill Education,

Human Anatomy

Anatomy and Physiology

ISBN:

9780135168059

Author:

Marieb, Elaine Nicpon, Brady, Patricia, Mallatt, Jon

Publisher:

Pearson Education, Inc.,

Human Anatomy & Physiology (11th Edition)

Anatomy and Physiology

ISBN:

9780134580999

Author:

Elaine N. Marieb, Katja N. Hoehn

Publisher:

PEARSON

Anatomy & Physiology

Anatomy and Physiology

ISBN:

9781259398629

Author:

McKinley, Michael P., O'loughlin, Valerie Dean, Bidle, Theresa Stouter

Publisher:

Mcgraw Hill Education,

Human Anatomy

Anatomy and Physiology

ISBN:

9780135168059

Author:

Marieb, Elaine Nicpon, Brady, Patricia, Mallatt, Jon

Publisher:

Pearson Education, Inc.,

Anatomy & Physiology: An Integrative Approach

Anatomy and Physiology

ISBN:

9780078024283

Author:

Michael McKinley Dr., Valerie O'Loughlin, Theresa Bidle

Publisher:

McGraw-Hill Education

Human Anatomy & Physiology (Marieb, Human Anatomy…

Anatomy and Physiology

ISBN:

9780321927040

Author:

Elaine N. Marieb, Katja Hoehn

Publisher:

PEARSON

SEE MORE TEXTBOOKS