BIOL 2160 Final Exam Crousillac

Test Questions

Final Exam

What is the purpose of ryanodine receptors?

To release calcium from SR

Which event immediately precedes the power stroke in cross-bridge cycle?

Removal of inorganic phosphate (Pi)

What happens when SERCA pumps are destroyed?

Calcium can't be pumped back into the SR, so you won't be able to relax skeletal muscles

At the neuromuscular junction, the end plate potential occurs on what?

Skeletal muscle cell membrane

Crossbridges and ATPase activity are characteristics of what?

Thick filaments

What does the majority of calcium during skeletal muscle contraction come from?

SR

What is the purpose of DHP receptors in skeletal muscles?

To detect Action potentials along T tubules

When does myosin have the highest affinity for actin?

When it is bound to ADP plus inorganic phosphate

What is the immediate result of ATP hydrolysis during cross bridge cycle?

Cocking of the myosin head

What determines whether fiber is fast twitched or slow twitched?

How fast myosin can hydrolyze ATP to ADP and P

What will low intensity exercise most likely result in?

Increase in oxidative fibers

Which type of muscle is darker in color?

Oxidative fibers

In smooth muscle contraction, calcium binds directly to what?

Calmodulin

What shuts off smooth muscles contractions?

Phosphatases

Contraction is what?

Mechanical

What is the pathway of air?

Pharynx, larynx, trachea, bronchioles, alveoli

What does the conducting zone do?

Moves air from the larynx to the lungs

What zone is the air warmed and humidified in?

Conducting

What zone is the site of gas exchange?

Respiratory

What is the benefit of capillaries being physically attached to the alveoli?

It minimizes the distance the gases have to travel

What part of breathing is an active process?

Inhalation

During what part of breathing does the diaphragm contract?

Inhalation

How are volume and pressure related?

Decreasing volume increases pressure and vice versa (inversely)

If the alveolar pressure increases, what part of breathing is happening?

Exhalation

If the alveoli pressure of oxygen is 100 and the CO2 pressure is 40, what will the gases do?

Oxygen will move into the blood and CO2 will move into the alveoli

What usually happens when you work out?

Hyperpnea

Why is it important to have some CO2in your blood?

It regulates the pH of blood

Low intensity exercises will most likely result in:

Increase in oxidative fibers

Very high intensity exercises will result in the depletion of what?

ACh

Where does the majority of the calcium for smooth muscle contractions come from?

Outside the cell

What does calcium immediately bind to in the smooth muscle contraction?

Calmodulin

How is myosin inactivated in smooth muscle contraction?

Removing the phosphate group from the myosin head

What makes the hemoglobin in RBC so dark?

The 4 iron molecules

What separates the 2 sides of the heart?

Septum

Which side of the heart supplies the pulmonary circuit?

Right

Which side of the heart supplies the systemic circuit?

Left

Which valve separates the right atria and ventricle?

Tricuspid or Right AV

Which valve separates the left atria and ventricle?

Bicuspid/Mitral or Left AV

In AV valves, when atrial pressure is higher than ventricular pressure, what happens to ventricles?

They are relaxed

In AV valves, when ventricular pressure is higher than atrial pressure, what happens to ventricles?

They contract

In SL valves, when aortic pressure is higher than ventricular pressure, what happens to ventricles?

They are relaxed

In SL valves, when ventricular pressure is higher than aortic pressure, what happens to ventricles?

They contract

When the ventricles are relaxed what are the AV valves doing?

Open

When the ventricles are contracting what are the AV valves doing?

Closed

When the ventricles are contracting what are the semilunar valves doing?

Open

When the ventricles are relaxed what are the semilunar valves doing?

Closed

What happens if you have an issue with your mitral valve?

Your tissues won't get enough oxygen

Structure of muscle cell from smallest to largest:

Filaments, Myofibril, Muscle Fiber, Fascicle, Muscle body

What does the action potential in a Neuromuscular junction release?

ACh

What 2 binding sites does myosin have?

Actin and ATPase

When a muscle is a rest, what covers up the myosin binding site on actin?

Tropomyosin

What moves tropomyosin off the myosin binding site?

Calcium binding to Troponin

What do the ryanodine receptors release?

Calcium from the Sarcoplasmic Reticulum (SR)

What is the purpose of a DHP receptor?

To detect an action potential

What pulls open the ryanodine receptors?

DHP receptors

When does myosin have a low affinity for actin?

When ATP binds to it

What does ATP hydrolysis do to myosin?

It cocks the myosin head

What provides the energy for the power stroke?

The inorganic phosphate getting removed from ADP

What happens when ADP is removed from the myosin head?

Head is rigor

What twitch occurs if the load is less than or equal to the muscle tension?

Isotonic

What twitch occurs if the load is greater than the muscle tension?

Isometric

What can the brain use to speed up or slow down the heartbeat?

Hormones

What initiates the action potential in the heart?

SA Node

What muscle cells carry the charge in the heart?

Conduction fibers (Bundle of His)

What does the SA node control?

The contraction of the atria

What would happen if the AV Nodal Delay was shortened?

You wouldn't have as much blood leaving the heart as possible and it would have to work harder

What causes pacemaker cells to spontaneously depolarize?

Activity of the "funny" channels

What activates the funny channels?

Hyperpolarization

What is permeable to the funny channels?

Both Na+and K+

What is the purpose of the T-type Ca channels?

To get the membrane to threshold

What would happen if cardiac action potentials weren't so long?

Your muscles wouldn't stop contracting and you would get a severe muscle cramp (tetanus)

What does the current in cardiac muscle spread through to contractile cells?

Gap junctions

Diastole is:

Ventricular relaxation

Systole is:

Ventricular contraction

Are the semilunar valves open or closed during ventricular filling?

Closed

Isovolumetric contraction occurs between which two phases?

Atrial contraction/Ventricular relaxation and Ventricular ejection

Is isovolumetric contraction systole or diastole?

Systole

During isovolumetric relaxation, where is the pressure the highest?

Aorta

Where does internal respiration occur?

The mitochondria

Chapter 12

Cardiac Physiology

What is a fluid that carries materials to and from cells?

Blood

What is a series of tubes, including veins, arteries, capillaries, venues, and arterioles?

Blood Vessels

What is a pump?

Heart

How can you build pressure in a chamber?

Add more blood or contract that chamber

What is another name for red blood cells?

Erythrocytes

What carries oxygen bound to hemoglobin?

Erythrocytes (RBC)

What is another name for white blood cells?

Leukocytes

What are cells fragments that aid in blood clotting?

Platelets

What contains iron?

Hemoglobin

What mediates immune responses?

Leukocytes (WBC)

What is the liquid portion of blood that contains a lot of salts, water, and protein antibodies?

Plasma

What are the parts of blood?

Cellular portion (blood cells) and liquid portion (plasma)

What are vessels transporting blood away from the heart?

Arteries, arterioles, and capillaries

Which blood vessel transporting blood away from the heart is big?

Arteries

What is thick in diameter, has thick walls, and has very little internal resistance?

Arteries

What does a thick diameter mean?

Fast

What does having thick walls mean?

Difficult diffusion

Which blood vessel transporting blood away from the heart is small?

Arterioles

Which blood vessel transporting blood away from the heart is the smallest?

Capillaries