Physiology Quiz: Action Potentials & Muscle Contraction

Which of the following ions is responsible for phase 1 of the action potential of working ventricular cardiomyocytes?

Which of the following ions is responsible for phase 1 of the action potential of conduction ventricular cardiomyocytes?

In relation to muscle contraction, the sarcomere consists of thin filaments of actin and thick filaments of myosin.

In relation to muscle contraction, the energy is used for the "rowing stroke" of the contraction.

In relation to muscle contraction, at rest, tropomyosin prevents actin-myosin binding.

In relation to muscle contraction, the actual length of actin and myosin filaments does not vary during contraction.

Which is the primary function of tropomyosin?

During muscle contraction, the energy obtained from the ATP hydrolysis is used to:

Which of the following circumstances leads to an INCREASE in cardiac output?

You receive a 5-year-old patient with bacterial meningitis in the Pediatric ICU. The patient suffers from septic shock, with a tendency to hypotension and tissue hypoperfusion. Which of the following measures seems LESS appropriate in this patient?

All of the following lead to a preload increase, EXCEPT for:

In relation to the cardiac cycle, which of the following statements is TRUE?

The phase of the cardiac cycle indicated by number 1 represents

The "auricular systole" is represented by number:

The closure of the mitral valve takes place before the closure of the tricuspid valve.

The closure of the pulmonary valve is delayed during inspiration.

The closure of the aortic valve is delayed during inspiration.

Branch blocks can lead to a reverse splitting of heart sounds.

Angiotensin I is converted to angiotensin II by renin.

Angiotensin II induces aldosterone release.

PAN inhibits the release of renin.

Juxtaglomerular cells can detect a decrease in circulating volume, activating renin release.

The increase in discharge rate of aortic and carotid baroreceptors leads to:

In conduction cardiomyocytes, unlike working cardiomyocytes, phase 0 of the action potential depends mostly on:

All of the following situations ones can lead to a DECREASE in blood pressure, EXCEPT for:

During a normal cardiac cycle, it is FALSE that the ventricular pressure is maximal during the ventricular ejection phase.

During a normal cardiac cycle, it is FALSE that the first cardiac sound corresponds to the closure of the atrioventricular valves.

During a normal cardiac cycle, it is FALSE that the rapid ventricular filling phase occurs at the beginning of diastole.

During a normal cardiac cycle, it is FALSE that during isovolumetric relaxation, the atrial pressure is greater than the ventricular pressure.

Which is the main responsible for airway resistance (or non - elastic resistance) during breathing?

In relation to the pulmonary elastic resistance, it is true that lungs with increased distensibility have trouble with air intake.

In relation to the pulmonary elastic resistance, it is true that lungs with decreased distensibility have trouble with expiration.

In relation to the pulmonary elastic resistance, it is true that total lung capacity is determined by lung distensibility.

In relation to the pulmonary elastic resistance, it is true that in a healthy adult, the residual volume after forced expiration is negligible.

A patient with increased lung distensibility probably presents

The concept of " vital capacity " in a conventional spirometry refers to:

The definition "volume of air remaining in the lungs after a normal expiration (not forced)" refers to:

The attached image represents a static spirometry. The volume of air indicated by number 1 represents:

After performing a forced spirometry, one of the most important data in daily clinical practice is the Tiffeneau index. A Tiffeneau index below 70% shows:

Which is the MOST important inspiratory stimulus in people without underlying disorders?

The measurement of the diffusing capacity for carbon monoxide (DLCO) enables the estimation of the functional status of the alveolar-capillary membrane. Which of the following agents leads to a decrease in DLCO, or in other words, to a decrease in the diffusion capacity of the alveolar-capillary membrane?

The pulmonary circulation presents a series of special characteristics that differentiate it from the systemic circulation. Which of the following is NOT a characteristic of the pulmonary circulation?

The oxygen-hemoglobin dissociation curve presents a sigmoidal shape. This enables that small variations in the partial pressure of oxygen in the middle part of the curve entail large changes in the oxygen saturation. On the other hand, there are also some factors that modify the oxygen affinity of hemoglobin, or in other words, that "shift the curve to the right" (lower affinity), or "shift the curve to the left" (higher affinity). Which of the following factors does not shift the dissociation curve to the right?

Which of the following properties is NOT typical of adaptive immunity?

Which of the following elements is NOT part of adaptive immunity?

What ion is responsible for phase 1 of the action potential in working ventricular cardiomyocytes?

What ion is responsible for phase 1 of the action potential in conduction ventricular cardiomyocytes?

What ion is responsible for phase 2 of the action potential in working ventricular cardiomyocytes?

What ion is responsible for phase 3 of the action potential in working ventricular cardiomyocytes?

What are the components of a sarcomere?

What is the primary function of tropomyosin?

What is the role of ATP hydrolysis in muscle contraction?

What circumstance leads to an increase in cardiac output?

What circumstance leads to a decrease in cardiac output?

What measure is less appropriate for a patient with septic shock?

What action does NOT lead to an increase in preload?

What is TRUE about atrial systole in the cardiac cycle?

What phase of the cardiac cycle is represented by number 1?

What phase of the cardiac cycle is represented by number 3?

What number represents auricular systole?

What statement about the cardiac cycle is FALSE?

What is the FALSE statement about the RAAS?

What is the effect of increased discharge of the baroreceptors?

What is the main factor in phase 0 of the action potential in conduction cardiomyocytes?

What does NOT lead to a decrease in blood pressure?

What is FALSE about a normal cardiac cycle?

What is the main factor in airway resistance?