Test Assessment on model 2

A 22-year-old woman is brought to the emergency department due to a tachyarrhythmia that is originating from a cardiac atrial cell. Attempts to slow the heart rate are undertaken by administering a medication that slows calcium influx into the AV node. Which of the following phases of the action potential of the AV node is being manipulated?

A. Phase 2

B. Phase 1

C. Phase 0

D. Phase 4

C. Phase 0

Prior to birth, most of the oxygenated blood from the placenta is shunted away from the pulmonary circulation through the foramen ovale and ductus arteriosus. The foramen ovale connect the right and left atria, whereas the ductus arteriosus connects which of the following two structures?

A. Right and left ventricles

B. Right and left coronary arteries

C. Right and left atrium

D. Aorta and pulmonary artery

D. Aorta and pulmonary artery

Which of the following occurs during ventricular diastole?

A. only the atrioventricular valves close

B. the semilunar valves close and the atrioventricular valves open

C. only the atrioventricular valves open

D. only the semilunar valves close

B. the semilunar valves close and the atrioventricular valves open

The artery that bifurcates into the right subclavian artery and the right common carotid artery is known as which of the following arteries?

A. Axillary

B. Common iliac

C. Brachiocephalic

D. Brachial

C. Brachiocephalic

Which of the following tend to decrease airway resistance?

A. treatment with acetylcholine agonist resulting in parasympathetic stimuli

B. exhalation to residual volume

C. stimulation by sympathetic fibers

D. decreased luminal diameter of bronchi

C. stimulation by sympathetic fibers

Chordae tendineae of the bicsupid valve, in a normal functioning heart, are found in which of the following structures?

A. Right ventricle

B. Left ventricle

C. Right atrium

D. Left atrium

B. Left ventricle

A condition known as pulmonary hypertension is characterized by high blood pressure in the pulmonary circuit. Which chamber of the heart would this condition most directly affect, and why?

A. left ventricle; high pressure in the pulmonary circuit requires the ventricle to have to pump harder, and can cause it to enlarge and fail as a result

 

B. eft ventricle; high pressure in the systemic circuit requires the ventricle to have to pump harder and can cause it to enlarge and fail as a result.

 

C. right ventricle; high pressure in the pulmonary circuit requires the ventricle to have to pump harder, and can cause it to enlarge and fail as a result.

 

D. right ventricle; high pressure in the aorta requires the right ventricle to pump harder, and can cause it to dilate and fail.

C. right ventricle; high pressure in the pulmonary circuit requires the ventricle to have to pump harder, and can cause it to enlarge and fail as a result.

The diaphragm is innervated by which of the following nerves?

A. left reccurent larygneal

B. phrenic

C. vagus

D. right recurrent laryngeal

B. phrenic

What anatomical structure prevents food and liquids from entering the trachea?

A. Epiglottis

B. Uvula

C. Tonsils

D. Larynx

A. Epiglottis

The ascending aorta arises from which of the following cardiac chambers?

A. Right atrium

B. Left atrium

C. Left ventricle

D. Right ventricle

C. Left ventricle

Which of the following occurs during expiration at a resting state?

A. diaphragm descends at least 5 cm

B. external intercostals relax, and the ribs become depressed

C. alveolar pressure becomes equal to atmospheric pressure

D. intra pleural pressure increases above intra alveolar pressure

B. external intercostals relax, and the ribs become depressed

A neonate was born at 28 weeks and is having difficulty breathing due to alveoli collapsing. Which of the following would most likely be the cause?

 A. Alveolar type I cells thickening

 B. Alveolar macrophage dysfunction resulting in bacterial infection

 C. Increased surface area of alveolar type I cells

 D. Alveolar type II cells not producing adequate pulmonary surfactant

D. Alveolar type II cells not producing adequate pulmonary surfactant

Which of the following best describes the function of the papillary muscle?

 A. Pull the semilunar valves closed.

 B. pull the chordeae tendinae taut during systole

 C. pull the atrioventricular valves closed

 D. Pull the semilunar valves open.

B. pull the chordae tendineae taut during systole

A patient presents with a condition called cystic fibrosis resulting in the mucous membranes in the respiratory track reabsorbing chloride ions causing mucus to become thick and sticky. Which of the following best describes how this will impact mechanics of breathing?

A. stimulation to muscarinic receptors will decrease resistance to air flow

B. increased ventilation to the alveoli

C. decreases ventilation due to increased resistance to air flow

D. increased perfusion at the alveoli

C. decreases ventilation due to increased resistance to air flow

A neonate born with a congenital defect where blood in the right atrium does not bypass pulmonary circulation resulting in mixing of oxygenated and deoxygenated blood would most likely be a defect in what anatomical structure?

A. apex of the heart

B. ligamentum arteriosum

C. foramen ovale

D. aortic arch

C. foramen ovale

Explanation: The foramen ovale is the fetal structure that allows blood to bypass the lungs by moving directly from the right atrium to the left atrium

A healthy 37 year old female was snowboarding in the mountains and she was getting short of breath easily (getting enough oxygen in her blood). Which of the following best describes why this would occur?

A. lower atmospheric pressure lowers the PO2 and the diffusion gradient between the blood and the atmospheric is less

B. the external intercostals have difficulty elevating the ribs at high elevations.

C. physiological dead air space increases and atmospheric pressure decreases.

D. The higher altitude causes an increases in intrapleural pressure

A. lower atmospheric pressure lowers the PO2 and the diffusion gradient between the blood and the atmospheric is less

A 22-year-old woman is brought to the emergency department due to a tachyarrhythmia that is originating from a cardiac atrial cell. Attempts to slow the heart rate are undertaken by administering a medication that slows calcium influx into the AV node. Which of the following phases of the action potential of the AV node is being manipulated?

 A. Phase 4

 B. Phase 0

 C. Phase 1

 D. Phase 2

 B. Phase 0

Explanation: Phase 0 = depolarization caused by Ca²⁺ influx

To relieve (drain) fluid in condition known as cardiac tamponade, the heart can be approached with a large bore needle either from between the xiphoid and left costal margin, or through the left 5th intercostal space near the sternum. This technique is successful without damaging the heart due to the presence which of the following structures?

A. superior lobe of the left lung

B. aortic impression of the left lung

C. inferior lobe of the left lung

D. cardiac notch of the left lung

D. cardiac notch of the left lung

Which of the following best describes the recesses that the lungs do not completely fill and generally the depth of these recesses are approximately two intercostal spaces lower than the inferior border of the lungs?

 A. costodiaphragmatic

 B. costomediastinal

 C. costosternal

 D. costocervical

 A. costodiaphragmatic

A 27-year-old male presents with chest wall penetrating trauma to the left side from a car accident. He presents with shortness of breath and pain on the left side of his chest. Plain film Xray reveals increased black appearance on the left as compared to the right thoracic cavity. What is likely causing this presentation?

 A. decreased intrapleural pressure below atmospheric pressure

 B. increased intra alveolar pressure to match atmospheric pressure

 C. increased intrapleural pressure to match atmospheric pressure

 D. decreased intrapleural pressure below intra alveolar pressure

C. increased intrapleural pressure to match atmospheric pressure

Explanation: Pneumothorax = loss of negative intrapleural pressure → pressure equals atmosphere

What is the primary function of the external intercostal muscles during inspiration?

 A. increase the volume of the thoracic cavity

 B. promote elastic recoil of the chest wall

 C. increase the pressure within the thoracic cavity

 D. increase intra alveolar pressure

 A. increase the volume of the thoracic cavity

A patient was admitted to the emergency department with a myocardial infarction (heart attack). The patient undergoes an angiogram revealing the left anterior descending (interventricular) artery is significantly occluded. Which portion of cardiac tissue would most likely be affected by loss of blood flow in the above scenario?

 A. right atrial pectinate muscle

 B. pulmonary trunk

 C. right ventricular myocardium

 D. left ventricular myocardium

 D. left ventricular myocardium

Which of the following best describes the influence of chronic hypertension on the heart?

 A. increased right ventricular afterload

 B. inadequate coronary blood flow to the myocardium

 C. decreased force of contraction required by the left ventricle

 D. added demand required by the left ventricle to overcome pressure in the systemic arteries

D. added demand required by the left ventricle to overcome pressure in the systemic arteries

The internal wall surface of each ventricle displays large, smooth, irregular muscular ridges known as which of the following?

 A. pectinate muscle

 B. atrioventricular valves

 C. conus arteriosus

 D. trabeculae carneae

 D. trabeculae carneae

Which of the following best describes the apex of the heart?

 A. Projects slightly posterior and inferiorly toward the left side of the body

 B. Projects slightly anterior and inferiorly toward the left side of the body

 C. Projects slighty posteriori and inferiology toward the right side of the body

 D. Projects slightly anterior and inferiorly toward the right side of the body

B. Projects slightly anterior and inferiorly toward the left side of the body

Which of the following best describes the function of the papillary muscle?

 A. pull the atrioventricular valves closed

 B. Pull the semilunar valves open.

 C. pull the chordeae tendinae taut during systole

 D. Pull the semilunar valves closed

C. pull the chordeae tendinae taut during systole

A 67-year-old male presents with a pulmonary embolism (occlusion of blood flow to the alveoli). Why is this detrimental to the function of the lung?

 A. impairs ability of alveoli to fill with air

 B. results in hyper perfusion at the alveoli

 C. results in bursting of alveoli

 D. produces alveolar dead space due to impaired capillary blood flow

D. produces alveolar dead space due to impaired capillary blood flow

Explanation: Pulmonary embolism blocks blood flow, creating ventilated but unperfused alveoli → alveolar dead space

Which of the following best describes a result of parasympathetic stimulation on the cardiovascular system?

 A. increased contractility

 B. decreased afterload

 C. increased fluid retention

 D. decreased oncotic pressure

 C. increased fluid retention

Explanation: Parasympathetic stimulation slows the heart → lowers cardiac output → triggers compensatory renal fluid retention mechanisms.