Exam 3 Human Physiology Lecture

These are the textbook and Pointsolution questions

Muscle that has a striped appearance is described as being ________.

Elastic

Nonstriated

Excitable

Straitated

Muscle fiber and t tubericle fill in the blanks

know how to fill out

Depolarization of the sarcolemma means ________.

the inside of the membrane has become less negative as sodium ions accumulate

Which of the following statements about muscle contraction is true?

The Powerstroke occurs when ADP and phosphate dissociate from the myosin head

Muscle fatigue is caused by ________.

exhaustion of energy reserves and buildup of Lactic Acid levels

The muscles of a professional sprinter are most likely to have ________.

80 percent of fast twitch muscle fibers and 20 percent slow twitch muscle fibers

The correct order for the smallest to the largest unit of organization in muscle tissue is ________.

Filament, myofibril, muscle fiber, fascicle

During which phase of a twitch in a muscle fiber is tension the greatest?

contraction phase

From which embryonic cell type does muscle tissue develop?

myoblast cells

If cardiac muscle cells were prevented from undergoing aerobic metabolism, they ultimately would ________.

stop contracting

Which of the following statements is true?

Fast fibers have large glycogen reserves

Why do baroreceptors communicate to the CNS? What specific location in the CNS is the center for this communication?

regulate control over blood pressure; medulla obliganta

What is total peripheral resistance?

combined resistance to flow of all systemic blood vessels

What is cardiac output? CO

Blood volume circulated each minute

What type of diagram is this figure?

Electrocardiogram

The ________ layer secretes chemicals that help to regulate ionic environments and strength of contraction and serve as powerful vasoconstrictors.

Endocardium

Which of the following is unique to cardiac muscle cells?

Only cardiac muscle is capable of autorhythmicity

The first heart sound represents which portion of the cardiac cycle?

closing of the atrioventricular valves

A molecule of hemoglobin ________.

consists of four globin proteins, each bound to a molecule of heme

Interleukins are associated primarily with which of the following?

All of the above (had production of various lymphocytes, immune responses, and inflammation)

Two factors help maintain the pressure gradient between the veins and the heart. Those factors are:

respiratory and skeletal muscle pump

Which portion of the ECG corresponds to repolarization of the atria?

none of the above: atrial repolarization is masked by ventricular depolarization

At the end of atrial systole and just prior to ventricular contraction, the ventricles contain approximately 130 mL blood in a resting adult in a standing position. This volume is known as the ______________.

end diastolic volume (EDV)

A healthy elastic artery ________.

is compliant

The influx of which ion accounts for the plateau phase?

calcium

What is the role of tropomyosin in skeletal muscle contraction?

1. Option A

It blocks the binding sites on actin when calcium levels are low

1. Option B

   It triggers the release of calcium ions

2. Option C

   It provides structural support to myofibrils

3. Option D

   It enhances the binding of myosin to actin

1. Option A

   Correct:

   It blocks the binding sites on actin when calcium levels are low

   Correct answer

Which protein is involved in the thick filament of skeletal muscle and is crucial for muscle contraction?

1. Option A

   Troponin

2. Option B

   Actin

3. Option C

   Myosin

   Option D

   Tropomyosin

1. Correct:

   Myosin

   Correct answer

Which structure within the skeletal muscle cell stores calcium ions and releases them during muscle contraction?

1. Option A

   T-tubules

2. Option B

   Mitochondria

3. Option C

   Myofibrils

4. Option D

   Sarcoplasmic reticulum

1. Option D

   Sarcoplasmic reticulum

What is the primary physiological role of ATP in skeletal muscle contraction?

1. Option A

   ATP serves as a secondary messenger in muscle contraction

2. Option B

   ATP phosphorylates actin to initiate contraction

3. Option C

   ATP is produced during the contraction process

4. Option D

   ATP binds to myosin, allowing cross-bridge detachment

1. Option D

   ATP binds to myosin, allowing cross-bridge detachment

What distinguishes cardiac muscle from skeletal muscle?

1. Option A

   Cardiac muscle is smooth and voluntary, while skeletal muscle is smooth and involuntary.

2. Option B

   Cardiac muscle has no nuclei, while skeletal muscle is multinucleated.

3. Option C

   Cardiac muscle is unstriated and involuntary, while skeletal muscle is striated and voluntary.

4. Option D

   Cardiac muscle is striated and involuntary, while skeletal muscle is striated and voluntary.

1. Option D

   Cardiac muscle is striated and involuntary, while skeletal muscle is striated and voluntary.

Match the following muscle proteins with their functions or characteristics:

Prompts

Answers

1. 1

   Actin

   
   

2. 2

   Troponin

   
   

3. 3

   Sarcoplasmic reticulum

   
   

4. 4

   Myosin

Correct:

Organelle that stores and releases calcium ions.

Correct:

Regulatory protein that binds calcium and affects tropomyosin.

Correct:

Thick filament protein responsible for muscle contraction.

Correct:

Thin filament protein that interacts with myosin to enable contraction.

1. 1

   Actin

   Correct:

   Thin filament protein that interacts with myosin to enable contraction.

2. 2

   Troponin

   Correct:

   Regulatory protein that binds calcium and affects tropomyosin.

3. 3

   Sarcoplasmic reticulum

   Correct:

   Organelle that stores and releases calcium ions.

4. 4

   Myosin

   Correct:

   Thick filament protein responsible for muscle contraction.

Increasing pressure in ventricles leads to aortic and pulmonary valves opening and blood ejection. This event occurs during:

1. Option A

   Systole

   
   

2. Option B

   Diastole

1. Option A

   Systole

Define stroke volume. How is it calculated?

1. Option A

   blood volume ejected by each ventricle with each beat, CO=SVxHR

2. Option B

   blood volume ejected by each ventricle with each beat, SV= EndDiastoleVolume – EndSystoleVolume

   
   

3. Option C

   blood volume ejected by each ventricle with each minute, SV= EndDiastoleVolume – EndSystoleVolume

4. Option D

   blood volume ejected by each ventricle with each minute, CO=SVxHR

1. Option B

   blood volume ejected by each ventricle with each beat, SV= EndDiastoleVolume – EndSystoleVolume

Referring to the cardiac cycle in terms of the ventricles (i.e. how we discussed in class). During _______ atrial contraction completes and ventricles fill. During ________ the ventricles contract and blood ejects.

Option A

systole; diastole

1. Option B

   systole; systole

   
   

2. Option C

   diastole; systole

   
   

3. Option D

   diastole; diastole

1. Option C

   diastole; systole

 At the beginning of isovolumetric ventricular relaxation 

1. Option A

   left ventricular pressure exceeds aortic pressure.

2. Option B

   the aortic semilunar valves are open.

3. Option C

   all valves are closed

   
   

4. Option D

   ventricular pressure is increasing.

1. Option C

   all valves are closed

A small amount of blood is located in the atria and the action potential is located at the AV Node. What is the next step in connecting the Cardiac Cycle and Electrical events?

Option A

contraction of the atria

Option B

action potentials spread down the Purkinje fibers

Option C

blood filling the atria

Option D

opening of the aortic and pulmonary valves

Option A

contraction of the atria

The myocardium cannot exhibit summation and tetanus. Why? Check all that apply.

1. Option A

   The muscle must relax and allow the heart to fill with blood again.

   
   

2. Option B

   The refractory period lasts almost as long as the duration of contraction, preventing a fiber from re-excitement.

   
   

3. Option C

   The SA node must await nervous stimulation from the sympathetic nerve.

1. Option A

   The muscle must relax and allow the heart to fill with blood again.

   
   

2. Option B

   The refractory period lasts almost as long as the duration of contraction, preventing a fiber from re-excitement.

1. Question 1

   What is the primary function of arteries in the circulatory system?

   • Option A

     To collect deoxygenated blood from the body

   • Option B

     To carry oxygenated blood away from the heart

   • Option C

     To store blood for later use

   • Option D

     To exchange gases with tissues

• Option B

  To carry oxygenated blood away from the heart

Question 2

What mechanism primarily drives blood flow in the veins?

• Option A

  Constriction of venous valves

• Option B

  Pulsing of capillaries

• Option C

  Skeletal muscle pump and respiratory pump

• Option D

  Pressure gradients from the left ventricle

• Option C

  Skeletal muscle pump and respiratory pump

1. Question 3

   Question 3

   1 Point

   Question 3

   Which type of blood vessel is primarily responsible for nutrient and gas exchange?

   • Option A

     Arteries

   • Option B

     Veins

   • Option C

     Capillaries

   • Option D

     Venules

1. Option C

   Capillaries

Question 5

What triggers the end of the systolic phase and the beginning of diastole in the cardiac cycle?

• Option A

  Contraction of the atria

• Option B

  Decrease in ventricular pressure leading to closure of the semilunar valves

• Option C

  Increase in atrial pressure

• Option D

  Relaxation of the ventricles

• Option B

  Decrease in ventricular pressure leading to closure of the semilunar valves

Question 6

Capillaries are the only blood vessels that allow for the exchange of oxygen and carbon dioxide between blood and tissues.

True

False

True

Question 4

What is the main role of the pulmonary circulation?

• Option A

  To filter blood through the kidneys

• Option B

  To deliver oxygenated blood to the body

• Option C

  To regulate blood flow through the arteries

• Option D

  To transport deoxygenated blood to the lungs for oxygenation

• Option D

  To transport deoxygenated blood to the lungs for oxygenation