Muscle 2-respiratory and everything in between Flashcards Preview

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Flashcards in Muscle 2-respiratory and everything in between Deck (99):
1

isometric contraction

no shortening, muscle tension increased but does not exceed load

2

isotonic contraction

muscle shortens because muscle tension exceeds load

3

Motor unit

Consists of the motor neuron and all muscle fibres (four to several hundred) it supplies

4

Muscle twitch

Simplest contraction resulting from a muscle fiver's response to a single action potential from motor neuron`

5

Latent period

events of excitation-contraction coupling

6

Period of contraction

cross bridge formation, tension increases

7

Period of relaxation

Ca2+ re entry into SR, tension declines to zero

8

Concentric contractions

muscle shortens and does work EX: bicep contracts to pick up a book

9

Eccentric contractions

muscle lengthens and generates force EX: when laying a book down causes biceps to lengthen while generating a force

10

Three mechanisms that ATP is regenerated by

- direct phosphorylation of ADP by creatine phosphate (CP)
- Anaerobic pathway: glycolysis and lactate formation
- Aerobic respiration

11

Creatine Phosphate

is a unique molecule located in muscle fibres that donates a phosphate to ADP to instantly form ATP

12

Slow oxidative characteristics

-Speed of contraction is low,
-Myosin ATPase activity is slow,
-Primary pathway for ATP is aerobic,
-Myoglobin content is high,
- Fiber diametre is small
- Many Mitochondria
- Many capillaries
- Color is red

13

Fast oxidative characteristics

-Speed of contraction is fast
-myosin ATPase activity is fast
-Primary pathway for ATP is aerobic
-Myoglobin content is high
-Glycogen stores is intermediate
-Fiber diametre is large
-Many mitochondria
-many capillaries
Color is red to pink

14

Fast glycolysis characteristics

-speed of contraction is fast
-Myosin ATPase activity is fast
-Primary pathway for ATP synthesis anaerobic glycolysis
-Myoglobin content is low
-Glycogen content is high
-fiber diametre is intermediate
-few mitochondria
-few capillaries
-color is white

15

Describe primary differences between skeletal and cardiac muscles

-Structure
-Gap junctions
-Contracts as unit
-T tubules
-Sarcoplasmic reticulum

16

Skeletal muscle characteristics

-structure is long striated, cylindrical, multinucleate
-no gap junctions
-no contraction as a unit
-T tubules are abundant
-sarcoplasmic reticulum is elaborate

17

Cardiac muscle

-structure is long striated, branched, one or two nuclei per cell
-there is a gap junction between cells
-There is a contraction as a unit
- T tubules are wider and there are less of them
-sarcoplasmic reticulum is less elaborate

18

Bohr effect

downright shift of the O2 dissociation curve. as a consequence of decreased Ph increased body temp and O2 this downright shift of association curve will increase oxygen to working muscles which can be described as an increase in arteriole venus oxidation difference

19

Hamburger effect

also called chloride shift, is a process which occurs in the cardiovascular system and refers to the exchange of bicarbonate (HCO3) and chloride (CI) across red blood cell membranes

20

Four factors that muscle contraction is affected by

1. Number of muscle fibers stimulated (recruitment)
2. Relative size of fibers
3. Frequency of stimulation
4. degree of muscle stretch

21

Force velocity relationship

linear but negative relation between force and velocity, there is an inverted U relationship between resistance and power, peak power output corresponds to force and velocity

22

VO2 max

the maximum rate that oxygen can be taken up from the ambient air and transported to and used by cells for cellular respiration during physical activity

23

Functions of the blood

-Transport
-Regulation
-Protection

24

Transport

Delivering O2

25

Regulation

maintaining body temperature

26

Protection

Preventing blood loss

27

Erythrocytes

RBC's, small diameter(7.5 um) cells that contribute to gas transport; have a biconcave disc shape; filled with hemoglobin for gas transport

28

Leukocytes

WBC's

29

Blood plasma

about 90% water,

30

Causes of hypoxia

-decreased RBC numbers due t hemorrhage or increased destruction
-Insufficient hemoglobin per RBC(ex: iron deficiency)
-Reduced availability of O2(ex: high altitudes or lung problems)

31

Spectrin

is a protein that will flexibility to RBC's

32

Right atrium

receives blood returning from systemic circuit

33

Left atrium

Receives blood returning from pulmonary circuit

34

Right ventricle

pumps blood through pulmonary circuit

35

Left ventricle

Pumps blood through systemic circuit

36

Atrioventricular valves

located between atria and ventricles

37

Semilunar valves

located between ventricles and major arteries

38

Tricuspid valve

(right AV valve): lies between right atria and ventricle

39

Mitral valve

(left AV valve, bicuspid valve): lies between left atria and ventricle

40

Pulmonary semilunar valve

located between
right ventricle and pulmonary trunk

41

Aortic semilunar valve

located between left ventricle and aorta

42

Coronary blood supply

functional blood supply to the heart muscle itself; shortest circulation in the body

43

Cardiac muscle

one central nucleus (at most 2); contains large mitochondria (25-35% of cell volume) that afford resistance to fatigue; in comparison, mitochondria represent 2% of skeletal muscle

44

Intercalated discs

are connecting junctions between cardiac cells that contain

45

Similarities between cardiac and skeletal muscle

contraction is preceded by depolarizing action potential; depolarization wave travels down T tubules; causes sarcoplasmic reticulum (SR) to contract

46

Systemic circuit

Goes throughout the body, long high pressure circulation, receives oxygenated blood from left ventricle, blood gets pumped to tissues, then pumps deoxygenated blood into the right atrium

47

Pulmonary circultion

short low pressure that only pumps to the lungs to get rid of CO2, receives deoxygenated blood from right ventricle, pumps oxygenated blood into left atrium

48

Receiving chambers of the heart

right atrium and left atrium

49

pumping chambers of the heart

right ventricle and left ventricle

50

Atria

three veins empty into right atrium: superior vena cava, inferior vena cava, coronary sinus

51

Sinoatrial node

SA node, pacemaker in right atrial wall, about 75x/minute (sinus rhythm)

52

Atrioventricular node

AV node, delays impulses approximately 0.1 second- because fibers are smaller in diameter, have fewer gap junctions; inherent rate of 50x/minute in absence of SA node input

53

AV bundle

only electrical connection between atria and ventricles-right and left bundle
Right and left bundle branches: carry impulses toward apex of heart

54

Systole

period of heart contraction

55

Diastole

heart relaxation

56

End diastolic volume

volume of blood in each ventricle at the end of ventricular diastole

57

End systolic volume

volume of blood remaining in each ventricle after systole

58

Cardiac cycle

blood flow through heart during one complete heartbeat

59

Why do we care about VO2 max?

Because it's a good indicator of your cardiovascular health, the higher the Vo2 max the higher the ATP and longevity

60

Cardiac output equation

Heart rate (HR) x stroke volume

61

Cardiac output

amount of blood pumped out of each ventricle in 1 minute

62

Three factors of heart rate

autonomic nervous system, chemicals, other factors

63

Branches of autonomic nervous system

parasympathetic and sympathetic

64

Parasympathetic

conserves energy as it slows the heart rate

65

Sympathetic

regulates the bodys unconscious actions

66

How can we improve Venus return

By doing physical activity

67

Stroke Volume influencers

preload, contractility, Afterload

68

Preload

degree to which cardiac muscle cells are stretched just before they contract, most important part of pre load is venous return

69

Venous return

amount of blood returning to the heart

70

Contractility

Contractile strength at given muscle length

71

After load

back pressure exerted by arterial blood

72

More factors of heart rate

age, gender, exercise, body temp

73

Blood vessels

delivery system of dynamic structures that begins and ends at heart

74

Arteries

carry blood away from heart;

75

Capillaries

direct contact with tissue cells; directly serve cellular needs

76

Veins

carry blood toward heart

77

Positive inotropic agents

increase contractility

78

Negative inotropic agents

acidosis (excess H+) increased extracellular K+, calcium channel blockers

79

The three layer walls of vessels

1. Tunica Intima
2. Tunica media
3. Tunica externa

80

Three groups of arteries

-elastic arteries
-muscular arteries
-arterioles

81

elastic arteries

Thick-walled with large low-resistance lumen

82

Arterioles

smallest of all arteries

83

Microscopic vessels

diameters so small only single RBS can pass through at a time

84

blood flow

volume of blood flowing through vessel, organ, or entire circulation in given period

85

blood pressure

force per unit area exerted on wall of blood vessel by blood

86

resistance

opposition to flow

87

Three important sources of resistance

Blood viscosity
Total blood vessel length
Blood vessel diameter

88

Arterial blood pressure is determined by two factors

elasticity of arteries close to heart
volume of blood forced into them

89

Systolic pressure

pressure exerted in aorta during ventricular contraction

90

Diastolic pressure

Lowest level of aortic pressure

91

Pulse pressure

Difference between systolic and diastolic pressure

92

Mean arterial pressure (MAP)

pressure that propels blood to tissues

93

Factors aiding venous return

muscular pump
respiratory pump
sympathetic venoconstricition

94

Inspiration

gasses flow into lungs

95

Expiration

gasses exit lungs

96

spirometer

original, cumbersome clinical tool used to measure patient's respiratory volumes

97

anatomical dead space

does not contribute to gas exchange

98

alveolar dead space

space occupied by non functional alveoli

99

total dead space

sum of anatomical and alveolar dead space