Exam 3 Flashcards

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1
Q

Muscle Cell/ Muscle Fiber

A

A cell that has differentiated for the specialized function of contraction

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2
Q

Functions of the muscular system

A

Heat, Movement, Posture, Structure

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3
Q

Myofibril

A

The long thin contracting protein subunits of a muscle cell that are composed of actin and myosin filaments.

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4
Q

Thick Filament

A

Myosin, essentially a molecule with 2 round heads and chain-like tail.

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5
Q

Thin Filament

A

A polymer of actin with tightly bound regulatory proteins troponin and tropomyosin

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6
Q

function and location of myosin heads

A

Function: Bind and hydrolyze ATP,
Location: attached to elongated tail region

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7
Q

Function and location of myosin head binding sites

A

Function: Facilates binding so cross-bridges can form
Location: on the actin filaments

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8
Q

Function and location of actin

A

Function: Shortens the sarcomere
Location: attached at their plus ends to the Z disc

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9
Q

Function and location of troponin

A

function: sarcomeric Ca2+ regulator
location: attached to the protein tropomyosin and lies within the groove between actin filaments

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10
Q

Function and location of tropomyosin

A

Function: Stabilizes actin filaments but also regulates muscle contraction
Location: in each of the two long-pitch helical grooves of actin

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11
Q

Function and location of Ca2+

A

Function: induces skeletal muscle contraction
Location: the cytosol

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12
Q

Sliding filament model of contraction

A

Within the sarcomere, myosin slides along actin to contract the muscle fiber in a process that requires ATP.

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13
Q

Excitation-contraction coupling

A

The rapid communication between electrical events occurring in the plasma membrane of skeletal muscle fibres and Ca2+ release from the SR, which leads to contraction

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14
Q

Steps in the process of excitation-contraction coupling

A

Step 1
Action potential spread along the sarcolemma to the T-tubules (transverse tubules)

Step 2
Calcium is released into the sarcoplasmic reticulum (S.R.)

Step 3
Calcium binds to actin and the blocking action of the tropomyosin is removed

Step 4
Myosin heads attach to begin contraction

Step 5
Calcium is removed and the binding sites on actin become blocked again by tropomyosin

Step 6
Muscle relaxes

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15
Q

Steps in cross bridge cycling, and the involvement of ATP, cross bridges, and the myosin head ATPase

A

Step 1
cross bridge formation: phosphorylated myosin head attaches to an actin myofilament

Step 2
the power stroke:
1) ADP and Pi are released from the myosin head
2) Myosin head changes to bend, low-energy state
3) Shape change pulls the actin towards the M line

Step 3
cross bridge detachment: ATP attaches to myosin, breaking the cross bridge

Step 4
cocking of the myosin head: attached ADP is hydrolyzed by myosin ATPase into ADP + Pi, bringing it back to a high-energy state

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16
Q

How a muscle cell obtains the ATP it needs

A

Using creatine phosphate

Using glycogen (no oxygen)

Using aerobic respiration

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17
Q

isotonic Contractions

A

Tension remains the same in the contraction

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18
Q

concentric contractions

A

total length of the muscle shortens as tension is produced

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19
Q

eccentric contractions

A

total length of the muscle lengthens as tension is produced

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20
Q

isometric contractions

A

Length remains the same, but tension changes

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21
Q

main steps in hemostasis

A

(1) vascular spasm, or vasoconstriction, a brief and intense contraction of blood vessels; (2) formation of a platelet plug; and (3) blood clotting or coagulation

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22
Q

Thrombus

A

A blood clot that forms inside one of your veins or arteries

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23
Q

Embolus

A

An unattached mass that travels through the bloodstream and is capable of creating blockages

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24
Q

Universal donor

A

Universal donors are those with an O negative blood type.

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25
Q

Universal recipient

A

a person of blood group AB, who can in theory receive donated blood of any ABO blood group

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26
Q

functions of the cardiovascular system

A

Transport blood and O2

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27
Q

main parts of the cardiovascular system

A

heart, Arteries, veins, capillaries, and blood

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28
Q

the flow of blood through the parts of the cardiovascular system

A

Blood—-> right atrium—–> tricuspid v. —-> right ventricle——> pulmonary arteries —–> Pulmonary veins—–> heart——->left atrium—-> mitral valve——> left ventricle——> Aortic v. ——> Aorta—–> body tissues

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29
Q

the attachment of the pulmonary and systemic circulation to the heart

A

Pulmonary circulation moves blood between the heart and the lungs. It transports deoxygenated blood to the lungs to absorb oxygen and release carbon dioxide. The oxygenated blood then flows back to the heart. Systemic circulation moves blood between the heart and the rest of the body.

30
Q

unique features of cardiac muscle tissue that allow it to perform its functions.

A

Intercalated discs, gap junctions

31
Q

how electrical impulses travel through the heart

A

Atrial depolarisation
Ventricular depolarisation
Atrial and ventricular repolarisation.

The electrical impulse travels from the sinus node to the atrioventricular node (also called AV node). There, impulses are slowed down for a very short period, then continue down the conduction pathway via the bundle of His into the ventricles

32
Q

The steps in the cardiac cycle

A

Atrial Diastole: In this stage, chambers of the heart are calmed. That is when the aortic valve and pulmonary artery closes and atrioventricular valves open, thus causing chambers of the heart to relax.

Atrial Systole: At this phase, blood cells flow from atrium to ventricle and at this period, atrium contracts.

Isovolumic Contraction: At this stage, ventricles begin to contract. The atrioventricular valves, valve, and pulmonary artery valves close, but there won’t be any transformation in volume.

Ventricular Ejection: Here ventricles contract and emptying. Pulmonary artery and aortic valve close.

Isovolumic Relaxation: In this phase, no blood enters the ventricles and consequently, pressure decreases, ventricles stop contracting and begin to relax. Now due to the pressure in the aorta – pulmonary artery and aortic valve close.

Ventricular Filling Stage: In this stage, blood flows from atria into the ventricles. It is altogether known as one stage (first and second stage). After that, they are three phases that involve the flow of blood to the pulmonary artery from ventricles.

33
Q

systole and how long it typically lasts

A

Contraction of the heart
Lasts: 0.3 to 0.4 second

34
Q

diastole and how long it typically lasts

A

Relaxation of the heart

Lasts: 0.5 sec

35
Q

the typical heart sounds, what produces them, and when they occur with respect to systole, diastole, and the cardiac cycle

A

s1- “lub”, created by the closing of the atrioventricular valves during ventricular contraction (systole)
s2-“Dub”,sound of the closing of the semilunar valves during ventricular diastole
s3- A galloping sound, sound of blood striking the left ventricle during early diastole
s4- A galloping sound heard in late diastole

36
Q

Cardiac output

A

Tthe volume of blood being pumped by a single ventricle of the heart, per unit time

37
Q

Cardiac rate

A

The number of times your heart beats per minute.

38
Q

Stroke Volume

A

The volume of blood pumped out of the left ventricle of the heart during each systolic cardiac contraction

39
Q

Typical values for Cardiac output

A

5-6 L/min in an at-rest to more than 35 L/min in elite athletes during exercise

40
Q

Typical values for Cardiac rate

A

60 to 100 beats per minute.

41
Q

Typical values for stroke volume

A

50 to 100 ml

42
Q

End Diastolic volume

A

the amount of blood that is in the ventricles before the heart contracts

43
Q

End Systolic Volume

A

the volume of blood in a ventricle at the end of contraction, or systole, and the beginning of filling, or diastole

44
Q

Typical values for EDV

A

70-155 mL

45
Q

Typical values for ESV

A

50 and 100 mL

46
Q

factors influencing blood pressure

A

Cardiac output.
Peripheral vascular resistance.
Volume of circulating blood.
Viscosity of blood.
Elasticity of vessels walls.

47
Q

Auscultatory (manual) blood pressure measurement method and how it works

A

Auscultatory (manual) blood pressure utilizes a sphygmomanometer, a device comprised of an inflatable cuff connected to a pressure gauge (generally a column of mercury). To measure an individual’s blood pressure, the deflated cuff is placed around the arm and inflated sufficiently to occlude arterial flow

48
Q

primary and secondary hypertension

A

High blood pressure that doesn’t have a known cause is called essential or primary hypertension. In contrast, secondary hypertension has a known cause.

49
Q

neuromuscular junction in excitation-contraction coupling

A

excitation-contraction coupling process begins with signaling from the nervous system at the neuromuscular junction

50
Q

motor end plate in excitation-contraction coupling

A

MEPs receive electrical signals from motor neurons, generate endplate potentials, and consequently induce muscle contractions

51
Q

end plate potential in excitation-contraction coupling

A

the voltages which cause depolarization of skeletal muscle fibers caused by neurotransmitters binding to the postsynaptic membrane in the neuromuscular junction

52
Q

muscle-surface voltage-gated Na+ channels in excitation-contraction coupling

A

The membrane depolarization at the synaptic cleft triggers nearby voltage-gated sodium channels to open.

53
Q

action potentials in excitation-contraction coupling

A

excitation-contraction coupling generates the AP to create cardiac muscle contractions

54
Q

T-tubules in excitation-contraction coupling

A

rapidly conduct electrical excitation and facilitate communication with the sarcoplasmic reticulum (SR

55
Q

voltage-sensitive receptors in excitation-contraction coupling

A

triggering intracellular calcium release for excitation-contraction coupling.

56
Q

terminal cisternae in excitation-contraction coupling

A

Helps form the triad

57
Q

Ca2+ channels in excitation-contraction coupling

A

opens the Ca2+ release channels in the TC-SR (surface facing the T-tubule).

58
Q

troponin in excitation-contraction coupling

A

Troponin binds to Ca2+

59
Q

tropomyosin in excitation-contraction coupling

A

covers the myosin binding sites and prevents cross-bridge formation when a muscle is relaxed

60
Q

actin filaments in excitation-contraction coupling

A

drawn toward the center of the sarcomere, overlapping the myosin filament

61
Q

myosin filaments in excitation-contraction coupling

A

Myosin heads attach to actin

62
Q

Ca2+ ATPase in excitation-contraction coupling

A

pumps the calcium back into the SR, lowering the calcium levels and producing muscle relaxation.

63
Q

the result of applying successive action potentials to a muscle.

A

Gradual increase in the force generated by that muscle

64
Q

summation

A

accumulating contractile force resulting from sequential activations applied to a muscle without sufficient interval to permit complete relaxation

65
Q

unfused tetanus

A

when the muscle fibers do not completely relax before the next stimulus because they are being stimulated at a fast rate

66
Q

complete tetanus

A

During complete tetanus, there’s no relaxation period between muscle contractions. Your muscle contractions completely fuse to create one continuous muscle contraction.

67
Q

fatigue

A

a decrease in maximal force or power production in response to contractile activity

68
Q

recruitment

A

process by which different motor units are activated to produce a given level and type of muscle contraction.

69
Q

factors that influence the force, velocity, and duration of skeletal muscle contraction

A

muscle fiber type, load and recruitment.

70
Q

characteristics of slow oxidative, fast oxidative, and fast glycolytic muscle fibers

A

Type 1: Slow oxidative (SO) fibers contract relatively slowly and use aerobic respiration (oxygen and glucose) to produce ATP. They produce low power contractions over long periods and are slow to fatigue.
Type 2 A: Fast oxidative (FO) fibers have fast contractions and primarily use aerobic respiration, but because they may switch to anaerobic respiration (glycolysis), can fatigue more quickly than SO fibers.
Type 2 B: Fast glycolytic (FG) fibers have fast contractions and primarily use anaerobic glycolysis. The FG fibers fatigue more quickly than the others[3].

71
Q

the formed elements that exist in blood and the purpose of each

A

red blood cells (erythrocytes)
purpose: carry oxygen from the lungs and deliver it throughout our body
white blood cells (leukocytes)
purpose: help the body fight infection and other diseases
platelets (thrombocytes)
Purpose:to prevent and stop bleeding