Physiology Exam 3

studied byStudied by 1 person
0.0(0)
get a hint
hint

Skeletal muscle functions

1 / 115

Tags and Description

116 Terms

1

Skeletal muscle functions

produce movement, maintain homeostasis, and generate heat

New cards
2

Muscle fiber

single muscle cell

New cards
3

Myofibril

contractile unit that runs the length of the muscle fiber

New cards
4

Myofilaments

thin and thick proteins within the myofibrils

New cards
5

Sarcomere

functional unit and smallest component of muscle fiber that can contract

New cards
6

A band

thick and thin filaments overlap

New cards
7

M line

proteins anchor thick filaments together

New cards
8

Z disc/line

line between 2 sarcomeres

New cards
9

Titin

allows for elastic recoil

New cards
10

Tropomyosin

covers actin cross bridge binding sites

New cards
11

Troponin

regulates tropomyosin position which regulates muscle contraction

New cards
12

Transverse tubule (T-tubule)

membrane that aids in spreading of signal

New cards
13

Sarcoplasmic reticulum

membranous network that contains stored Ca2+ ions that when released allows myosin-actin binding

New cards
14

What are the 3 mechanisms that require ATP?

  • Actin-myosin binding for power stroke

  • Unbinding of actin and myosin after power stroke

  • Transport of Ca2+ back to sarcoplasmic reticulum

New cards
15

Tendons

noncontractile tissues that attach to bone

New cards
16

Origin of a tendon

attachment that doesn’t move

New cards
17

Insertion of a tendon

attachment that does/can move

New cards
18

Isotonic

tension is constant while muscle length changes and tension on insertion is greater than opposing force

New cards
19

Concentric contraction

muscle shortens (bicep curl)

New cards
20

Eccentric contraction

muscle lengthens (lowering weight from biceps curl)

New cards
21

Isometric

tension develops at constant muscle length and tension on insertion is equal to the opposing force

New cards
22

Twitch

a single action potential in a muscle fiber which isn’t strong enough to produce movement on its own

New cards
23

What is muscle tension determined by?

  • Number of contracting muscle fibers

  • Resulting tension of each contracting fiber

  • Frequency of stimulation

  • Initial fiber at rest

New cards
24

Twitch summation

continued excitation of fibers

New cards
25

Tetanus

no muscle relaxation between stimuli (stronger contraction)

New cards
26

Smooth muscle

involuntary, lines hollow organs and tubes, stimulated by ca2+ concentration

New cards
27

What are the 2-types of smooth muscle?

multi-unit and single-unit

New cards
28

Multi-unit

contracts as smaller independent units stimulated by nerves

New cards
29

Single-unit

contract a single, coordinated unit (functional syncytium)

New cards
30

Cardiac muscle

line heart, branches interconnected cells (gap junctions)

New cards
31

What are the 3 parts of the circulatory system?

the heart, blood vessels, and blood

New cards
32

Transportation in systemic circuit

  • Respiratory system - oxygen

  • Digestive system - nutrients

  • Excretion - products not needed by the body

New cards
33

Regulation in the systemic circuit

  • Hormonal - from site of origin to target tissue

  • Temperature - vasodilation (release) and vasoconstriction (retention)

New cards
34

Protection of systemic circuit

  • clotting - protects against blood loss

  • immune - protects against pathogens

New cards
35

What is the blood flow through the heart?

Vena cava - right atrium - right ventricle - pulmonary artery - lungs - pulmonary veins - left atrium - left ventricle - aorta - system circuit

New cards
36

Pressure in pulmonary side of heart

low pressure, low resistance

New cards
37

Pressure in systemic side of the heart

high pressure, high resistance

New cards
38

Atrioventricular valves (AV)

between the atria and ventricles which close when ventricles empty (lub sound)

New cards
39

Semilunar valves

Between ventricles and arteries which closes when ventricles fill (dub sound)

New cards
40

What is the direction in which blood moves?

veins - atria - ventricles - arteries

New cards
41

What are the 2 specialized cardiac muscle cell types?

autorhythmic and contractile cells

New cards
42

Autorhythmic cells

initiate and conduct action potentials (don’t contract)

New cards
43

Contractile cells

are stimulated by autorhythmic activity and do the mechanical work for pumping

New cards
44

Sinoatrial node (SA node)

acts as the pacemaker of the heart

New cards
45

What are the 3 waveforms of an EKG?

p wave, qrs complex, and t wave

New cards
46

Systole

contraction and emptying, spread of excitation

New cards
47

Diastole

relaxation and filling, repolarization time

New cards
48

Cardiac output

blood pumped by each ventricle per minute and regulation depends on stroke volume and cardiac rate

New cards
49

Stroke volume

volume of blood pumped by each ventricle per beat

New cards
50

How does the parasympathetic division regulate the cardiac rate?

mostly innervates atria and modifies the pace

New cards
51

How does the sympathetic division regulate the cardiac rate?

innervates atria and ventricles which modifies the pace and contraction strength

New cards
52

Intrinsic control of stroke volume

cardiac muscle rests at less than optimal length for greater muscle fiber stretching and venous return

New cards
53

Frank-Starling law of the heart

in systole the heart will eject the volume of blood returned during diastole

New cards
54

Extrinsic control of stroke volume

causes vasodilation which results in a greater venous return

New cards
55

Arteries and arterioles

transport blood from heart to organs

New cards
56

Arteries

act as pressure reservoir (builds extra pressure)

New cards
57

Arterioles

branches from arteries to organs

New cards
58

capillaries

branched capillary beds which are sites of exchange between blood and surrounding organ tissue

New cards
59

Veins and venules

return blood from organs to heart

New cards
60

Venules

branch from organs

New cards
61

Large veins

act as blood reservoir

New cards
62

Artery and arteriole vessel anatomy

relatively thick smooth muscle, arteries have elastin fibers

New cards
63

Capillary vessel anatomy

only endothelial lining so it’s easier to exchange molecules

New cards
64

Vein and venule vessel anatomy

relatively thin smooth muscle and contain venous valves

New cards
65

Flow rate

volume of blood pumped at a given time and is the same throughout the system

New cards
66

What does adequate flow depend on?

pressure gradient and vascular resistance

New cards
67

Pressure gradient

pressure difference from the beginning to end of vessel

New cards
68

Resistance

opposition to flow through a vessel or the friction of moving liquid against stationary vessel walls

New cards
69

Viscosity

friction of fluid molecules against each other (not usually a huge factor)

New cards
70

Vessel length

overall surface area of vessel (greater length = greater SA = greater resistance)

New cards
71

Vessel diamter

more surface area for fluid to contact = greater resistance

New cards
72

Mean arterial pressure (MAP)

average pressure driving blood forward during cardiac cycle

New cards
73

Vasoconstriction

narrowing of vessel diameter which increases resistance and decreases flow

New cards
74

Vasodilation

widening of vessel diameter which decreases resistance and increases flow

New cards
75

Total peripheral resistance (TPR)

total resistance by all systemic vessels

New cards
76

Afterload

opposing pressure on ventricles during ejection (leftover blood in ventricles) which can reduce stroke volume

New cards
77

Blood pressure

force exerted on blood by vessel walls

New cards
78

What is the average systolic pressure?

120 mm Hg

New cards
79

What is the average diastolic pressure?

80 mm Hg

New cards
80

What are the factors affecting blood pressure?

cardiac output, total peripheral resistance, and blood volume

New cards
81

What is venous return influenced by?

arterial pressure, skeletal muscle pumps, sympathetic activity, respiratory activity, and blood volume

New cards
82

What happens if MAP raises above normal?

sympathetic activity decreases, promotes vasodilation, and lowers blood pressure

New cards
83

What happens if MAP falls below normal?

less blood volume delivered to arterioles and arterioles dilate which increase flow to capillaries

New cards
84

Blood/plasma volume

volume of blood in circulatory system

New cards
85

Hydrostatic pressure

pressure of any fluid enclosed in a space

New cards
86

Capillary hydrostatic pressure

exerted by blood on capillary wall

New cards
87

Interstitial fluid hydrostatic pressure

exerted by interstitial fluid on capillaries

New cards
88

Osmotic colloid (oncotic) pressure

from proteins that displace water

New cards
89

Plasma colloid osmotic pressure

plasma proteins create concentration difference

New cards
90

What happens during ultrafication?

  • higher capillary hydrostatic pressure

  • lower interstitial fluid hydrostatic pressure

  • lower plasma-colloid osmotic pressure

New cards
91

What happens during reabsorption?

  • lower capillary hydrostatic pressure

  • higher interstitial fluid hydrostatic pressure

  • higher plasma colloid osmotic pressure

New cards
92

Hypertension

high blood pressure (above 140/90mm Hg)

New cards
93

Hypotension

low blood pressure (below 100/60mm Hg)

New cards
94

Secondary hypertension

high blood pressure caused by other factors (like loss of elastin fibers in the heart)

New cards
95

Primary hypertension

unknown cause but is often underlying genetic tendency which is exacerbated by diabetes, smoking, etc

New cards
96

Orthostatic hypertension

the inability to respond to affect of gravity on venous return (happens in bedridden people)

New cards
97

What is the first step of external respiration?

ventilation or gas exchange between the atmosphere and air sacs (alveoli) in the lungs

New cards
98

What is the second step of external respiration?

exchange of O2 and CO2 between air in the alveoli and the blood in the pulmonary capillaries

New cards
99

What is the third step of external respiration?

transport of O2 and CO2 by the blood between the lungs and the tissues

New cards
100

What is the fourth step of external respiration?

exchange of O2 and CO2 between the blood in the systemic capillaries and the tissue cells

New cards

Explore top notes

note Note
studied byStudied by 27 people
Updated ... ago
5.0 Stars(1)
note Note
studied byStudied by 7 people
Updated ... ago
5.0 Stars(1)
note Note
studied byStudied by 9 people
Updated ... ago
5.0 Stars(1)
note Note
studied byStudied by 21 people
Updated ... ago
5.0 Stars(2)
note Note
studied byStudied by 9 people
Updated ... ago
5.0 Stars(1)
note Note
studied byStudied by 6 people
Updated ... ago
5.0 Stars(1)
note Note
studied byStudied by 5539 people
Updated ... ago
4.7 Stars(29)

Explore top flashcards

flashcards Flashcard793 terms
studied byStudied by 12 people
Updated ... ago
5.0 Stars(1)
flashcards Flashcard29 terms
studied byStudied by 15 people
Updated ... ago
5.0 Stars(1)
flashcards Flashcard70 terms
studied byStudied by 21 people
Updated ... ago
5.0 Stars(1)
flashcards Flashcard25 terms
studied byStudied by 11 people
Updated ... ago
5.0 Stars(1)
flashcards Flashcard20 terms
studied byStudied by 29 people
Updated ... ago
5.0 Stars(1)
flashcards Flashcard40 terms
studied byStudied by 12 people
Updated ... ago
4.7 Stars(3)
flashcards Flashcard97 terms
studied byStudied by 4 people
Updated ... ago
5.0 Stars(1)
flashcards Flashcard25 terms
studied byStudied by 98 people
Updated ... ago
5.0 Stars(1)