False
T or F: The cardiac Ryanodine receptor (RyR) is not dependent on free calcium to trigger the release of stored sarcoplasmic reticulum calcium.
Decrease
After muscle cell relaxation, the Na+/Ca2+ exchanger will ______________ the amount of intracellular calcium.
Slow Glycolytic
Which of the following is not one of the three types of skeletal muscle fibers?
Head: ATPase activity, which provides energy for movement
Tail: Binds cargo
Myosin: Myosin muscle
Which of the following is correctly matched regarding myosin?
Not Nucleation, Elongation, or microfilament growth
If the concentration of ATP was decreased in the cell, which of the following phases of microfilament formation would be most affected?
Attach directly to cargo
Which of the following description regarding Dynein is NOT correct?
Veins are composed of three tunics, with a thin tunica media and a thick tunica externa.
Veins are known as capacitance vessels that contain 65% of the blood supply
Veins have one way valves that prevent backflow of blood.
Veins have much lower blood pres
Which of the following statements regarding veins is true?
The cardiac glycosides inhibit the Na+/K+-ATPase pump, which causes an increase in intracellular Na+ => slowing of the Na+/Ca++-exchanger
Digitalis, a Na+/K+ ATPase pump blocker, is often prescribed to heart failure patients. Form your understanding of muscle contraction physiology and the Na+/Ca2+,
A and C
During ventricular diastole in the cardiac cycle, which of the following events are occurring?
a. The AV valves are open and the ventricles are passively filling
b. The AV valves are closed and the ventricles are filling
c. The pressure in the atria is ex
A and B
Using the Wiggers diagram, identify the cardiovascular events that correspond with the letter 'B'.
a. Mitral valve closing
b. Beginning of isovolumetric ventricular systole
c. Ventricular repolarization
d. A and B
e. A and C
F
Using the Wiggers diagram, which of the following corresponds to opening of the AV valve?
a. A
b. B
c. C
d. D
e. F
B and C
Autorhythmicity is due to which of the following physiological phenomenon?
a. L type calcium channels
b. The IF channels
c. Unstable resting membrane potential
d. A and B
e. B and C
D
Which letter indicates the pressure found in the capillaries?
a. A
b. B
c. C
d. D
e. E
C
Which letter indicated the pressure found in the right atrium?
a. A
b. D
c. G
d. E
e. F
Radius of vessel
According to Poiseuille's equation, a small change affects which of the following?
Peripheral Resistance and blood pressure
Rapid changes in vessel constriction and vessel dilation results in what to be altered?
Increase
Increasing the presence of stable-tubule only polypeptides (STOPs) will _______________ the length of microtubules
Decrease
Increasing the presence of katanin, MAPs will _________________ the length of microtubules
The microtubule motor protein kinesin will move its cargo towards the center of the cell.
Which of the following statements is incorrect?
>The microtubule motor protein kinesin will move its cargo towards the center of the cell.
>The microtubule motor protein dynein will move its cargo towards the center of the cell.
>The microtubule motor pro
Not effect
Increasing ATP will ___________ actin filament formation.
A, C, E, B, D, F
Put the following events of the sliding filament theory in order as they occur.
A. The myosin head is bound by crossbridges to the actin microfilament
B. The myosin neck extends and moves the head forward, attaches to adjacent actin
C. ATP binds to the my
The sarcomere shortens due to the M-lines moving inward.
When muscles contract, which of the following does NOT happen to the sarcomere?
>The sarcomere shortens due to the M-lines moving inward.
>The sarcomere shortens due to the Z-disc moving inward.
>The sarcomere shortens due to the myosin motor proteins pul
D. All of the above events occur during excitation-contraction coupling.
When excitation-contraction coupling of skeletal muscle takes place which of the following event(s) occurs?
A. Acetylcholine is released from the motor end plates into the synaptic cleft to bind to nicotinic receptors.
B. Bound acetycholine to nicotinic r
Decrease
Decreasing the number of F-channels on the sarcolemma of muscle cells will ___________ the myogenic property of the muscle.
True
T or F: GTP is the necessary energy cost to maintain the dynamic instability of the microtubule cytoskeletal network.
Conducting (Elastic) arteries
_______________ are the thick-walled arteries equipped with a large lumen that allows for low-resistance conduction of blood and can withstand and smooth out large fluctuations in blood pressure allowing blood to flow fairly continuously throughout the bo
False
T or F: Most (>80%)of your body's capillaries are open at one time.
E. All of the above are true
About the systemic blood pressure, which of the following is not true?
A. highest in the aorta
B. Declines throughout the length of the pathway of systemic circuit.
C. is 0mm Hg in the right atrium
D. The steepest change in blood pressure occurs in the ar
Parasympathetic tone is also increased.
When hemorrhage occurs, your body will make several adjustments in an attempt to increase blood pressure, which of the following does not occur?
False
T or F: Both atrial systole and ventricular systole occur at the same time so the maximum amount of force can be generated at the same time from the muscle of your heart
False
T or F: Force generated from the contraction of atrium is the main driving force to fill the ventricle with blood.
B. Lub- made by the AV valves closing
Which of the following heart sounds is CORRECTLY matched?
A. Lub- the second sound caused by the valves closing
B. Lub- made by the AV valves closing
C. Dup- made by the AV valves closing
D. Dup-the first sound caused by the valves closing
SERCA
Which of the following protein is in charge of pumping cytosolic Ca back into SR to allow relaxation to occur?
True
T or F: Muscle cell has a special feature, which is known as T-tubules, they help to ensure that the entire sarcolemma is depolarized uniformly in space and time.
B. Semilunar valves= the valves between ventricles and veins
Which of the following is not correctly matched?
A. CICR= Ca induced Ca release
B. Semilunar valves= the valves between ventricles and veins
C. AV valves= the valves between atrium and ventricle
D. all of above are correct
Cel division, Motility, and protein trafficking
What are the functions of microtubules?
Microtubules
What is composed of long strings of alpha and beta tubular isoforms?
1. Alpha and beta combine to form tubulin (dimer)
2. Polarity occurs on each dimer; alpha tubulin bound GTP and beta tubulin bound GDP bound
3. Added end to end; line of magnets where the negative alpha (GTP) end attracts the positive beta (GDP) end
4. Ch
What are the steps of Microtubule growth?
Systolic Pressure
Blood forced into the arteries during ventricular systole
Diastolic Pressure
The pressure in the arteries during ventricular diastole
Systole
Cardiac phase that consists of contraction
Diastole
Cardiac phase that consists of relaxation
Cardiac Cycle: Ventricular Diastole
Pressure in the atria exceeds ventricular pressure. The AV valves open and the ventricles fill passively
Cardiac Cycle: Atrial Systole
Atrial contraction forces additional blood into ventricles
Cardiac Cycle: Ventricular Systole (Isovolumetric contraction)
Ventricular contration pushes the AV valves closed and increases pressure inside the ventricle.
Cardiac Cycle: Ventricular Systole (Ventricular Ejection)
Increased ventricular pressure forces the semilunar valves open and blood is ejected
Cardiac Cycle: Ventricular Diastole (part 2)
As the ventricles relax, pressure in the arteries exceeds ventricular pressure closing the semilunar valves.
Atrial Contraction
Cardiac Cycle Phase 1
Isovolumetric Contraction
Cardiac Cycle Phase 2
Rapid Ejection
Cardiac Cycle Phase 3
Reduced Ejection
Cardiac Cycle Phase 4
Isovolumetric Relaxation
Cardiac Cycle Phase 5
Rapid filling
Cardiac Cycle Phase 6
Reduced filling
Cardiac Cycle Phase 7
Cardiomyocytes
What depolarize quickly but take much longer to repolarize
Sinoatrial Node
Found in right atrium; it initiates the heartbeat by sending excitatory impulses to cause atria to contract.
Atrioventricular Node
Found in right atrium near septum; stimulated by impulses from SA node and sends out impulses thru septum
Purkinje Fibers
What cause ventricles to contract.
P wave
Corresponds to depolarization of atria; leads to atria contraction
QRS complex
Corresponds to ventricular depolarization and precedes ventricular contraction or systole
T wave
Corresponds to ventricular repolarization followed by ventricular relaxation (diastole)
Electrocardiogram (EKG)
________________ is produced by electrical activity generated, detected and recorded by electrocardiograph
Right Ventricle
> Pulmonary Circuit
> Contracts less forcefully
> Less pressure/ resistance
> Shorter Distance
Left Ventricle
> Systemic Circuit
> Contracts more forcefully
> More pressure/ resistance
> Greater Distance
Lub
Atrioventricular valves close
Dub
Semilunar valves close
Sarcomeres
Z discs, A bands, and I bands; Arrangement of actin and myosin
Pericardium
Provides cushioning; friction free
Epicardium
Outer visceral layer lines the surface of the heart often infiltrated with fats
Myocardium
Major portion of the heart composed largely of cardiac muscle tissue.
Endocardium
Inner surface of the heart consisting of connective and endothelial tissue
Atrioventricular (AV) valves
> Between the atria and the ventricles
> Prevent backflow into the atria when ventricles contract
> Tricuspid (3 flaps) valve- right side and Bicuspid/Mitral valve- left side
Chordae tendineae
Anchor AV valves to papillary muscles
Semilunar valves
> Between the ventricles and arteries
> Prevent backflow of blood into the ventricle
> Pulmonary semilunar valve- right side and Aortic semilunar valve left side
Heart
Serves as pump that establishes the pressure gradient needed for blood to flow to tissues
Blood
Transport medium within which materials being transported are dissolved or suspended
Blood Vessels
Passageways through which blood is distributed from heart to all parts of body and back to heart
Arteries
Carry blood away from the heart
Veins
Carry blood toward the heart
Lumen
Central blood-containing space surrounded by tunics. Arteries and veins are composed of this.
1. Tunica interna (intima)
2. Tunica media
3. Tunica externa (adventitia)
Three types of Tunics
Tunica interna (tunica intima)
Endothelial layer that lines the lumen of all vessels
Tunica media
Smooth muscle and elastic fiber layer, regulated by sympathetic nervous system
Tunica externa (tunica adventitia)
Collagen fibers that protect and reinforce vessels
Conducting (Elastic) Arteries
> Thick-walled arteries near the heart; aorta and its major branches
> Large lumen allow low-resistance conduction of blood
> Contain elastin fibers in all three tunics
> Withstand and smooth out large blood pressure fluctuations allowing blood to flow fa
Muscular (Distributing) Arteries
> Distal to elastic arteries; deliver blood to body organs
> Have thick tunica media with more smooth muscle and less elastic tissue
> Active in vasoconstriction
Arterioles
> Smallest arteries; lead to capillary beds
> Control flow into capillary beds via vasodilation and constriction
Capillaries
> The smallest blood vessels
> Walls consisting of a thin tunica interna, one cell thick
> Allow only a single RBC to pass at a time
Cardiac Glycoside
> Used to treat heart failure(HF). Inhibit Na/K APTase
> Higher cellular Na is exchanged for Ca by NCX, increasing intracelluar Ca
> Increase contractility
Contractility
>Muscle contracts forcefully
>Cells shorten and generate pulling force as they contract
Excitability
> Nerve signals or other factors excite muscle cells
> Electrical impulses to travel along the cells plasma membrane.
> Electrical nerve impulse stimulates the muscle cell to contract
Extensibility
Can be stretched to its normal resting length and beyond to a limited degree by contraction of an opposing muscle
Elasticity
If muscles are stretched, they recoil passively to their original resting length.
Skeletal Muscle Tissue
> Cells: Long and cylindrical, in bundles; Multinucleate; Obvious Striations
> Voluntary
Cardiac Muscle Tissue
> Cells: Branching, chains of cells, rod shape; Single or binucleated
Striations; Connected by intercalated discs
> Involuntary
Smooth Muscle Tissue
> Cells: Single cells, uninucleated; No striation; Lines hollow organs, blood vessels
> Involuntary
Myofilaments
Contractile proteins; Actin and Myosin
Sarcolemma
Plasma membrane
Sarcoplasm
Cytoplasm
Endoplasmic reticulum
Specialized for the storage of calcium
Epimysium
Outside the muscle"
Dense regular connective tissue surrounding entire muscle; overcoat
Perimysium
Around the muscle"
Within a muscle, muscle fibers (cells) are separated and bound into groups (fascicles)
Endomysium
Within the muscle"
Within each fascicle, each muscle fiber is surrounded by a fine sheath of connective tissue wrapping each muscle cell
Myofibrils
> Are long rods within cytoplasm
> Make up 80% of the sarcoplasm
> Are specialized contractile organelles found in muscle tissue
Z disc
Boundaries of each sarcomere
Thin (actin) filaments
Extend from Z disc toward the center of the sarcomere
Thick (myosin) filaments
Located in the center of the sarcomere
Overlap inner ends of the thin filaments
contain ATPase enzymes that split ATP (energy storing molecules) release the energy required for muscle contraction.
A band
Full length of the thick filament; Includes inner end of thin filaments (dark region)
H zone
Center part of A band where no thin filaments occur
M line
In center of H zone; Contains tiny rods that hold thick filaments together
I bands
Two regions on either side of the A band - thin filament (light region)
Sliding Filament Model
> Myosin head bound to actin called crossbridge
> ATP binds causing myosin head to detach from actin
> Myosin hydrolyze ATP to ADP and Pi, releasing energy, myosin head energized
> Myosin neck extends, moving myosin head forward, attaches to adjacent acti
Depolarization
Muscle activity is initiated by excitation: a ________________ of sarcolemma
Troponin C (TnC)
Ca2+ sensor; has 4 Ca2+ binding sites
Troponin I (TnI)
Links troponin to actin; inhibits actin-myosin ATPase
Troponin (TnT)
Tropomyosin binding subunit, which blocks sites on actin where myosin binds