Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

MBBS - Year 1 > Physiology - Soft Tissue > Flashcards

Physiology - Soft Tissue Flashcards

1
Q

What does the PNS consists of

A

All axons and ganglia outside CNS
Autonomic and somatic system
Cranial nerves (except II)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Divisions of autonomic nervsous system

A

Parasympathetic

Sympathetic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Motor nerves in somatic nervous system

A

Efferent

Afferent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Effernet motor nerves

A

Run from CNS to periphery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Afferent. motor nerves

A

Run from periphery to CNS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Motor unit

A

Motor nerve axon

All the muscle fibres it innervates

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What determines the size of motor unit recruited

A

Type of task and force

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Te reusing potential of the cell membrane

A

BIG differences between the electrical potential inside the cell compared to the outside (-70 to -90 mv)
Big differences between intracellular and extracellular ionic conc. Na is low inside and high outside and K is high inside and low conc

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Sodium ATPase pump

A

Na-K ATPase pump moves 2K+ molecules into the cell in exchange for 3Na+ molecules moved out
Maintains conc gradient of Na and K
Small direct effect on membrane potential

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Initiation of AP

A

Sensory receptors transducer energy to change potential of axon
Threshold is reached and VgNa channels open, starting the ap

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Steps of the action potential

A

Depolarisation
Repolarisation
Hyperpolarisation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Depolarisation

A

The inside of the cell becomes less negative with respect to the outside. VgNa channels are open (Na+ moves in) and VgK channels are closed.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Repolarisation

A

The cell is trying to restore balance and bring the potential difference of the cell more -ve than the outside. VgNa channels are closed and VgK channels open (K+ moves down the electrochemical gradient)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Hyperpolarisation

A

The eflux of K+ causes the inside of the axon to become TOO negative so the resting potential is restored using the Na-K ATPase pump

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Refractory period

A

The duration before another AP can be generated, regardless of stimuli

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Propagation of AP

A

Slight excess of +ve charge inside the axon hillock and excess of -ve charge outside so a potential difference builds up between the diff regions of the axon. This causes local circuit currents, opening VgNa channels so the action potential can advance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Increasing nerve conduction velocity

A

Larger diameter

Insulation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is muscle

A

Bundle of fibres that can contract to produce movement; this can be voluntary or involuntary

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Types of muscle

A

Striated (skeletal) muscle – locomotion and posture
Smooth muscle – peristalsis
Cardiac muscle – heart contraction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Contraction

A

Shortening

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Elasticity

A

Returning to resting state

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Hypertrophy

A

Increase in size

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Hyperplasia

A

Increase in number (usually muscle cells)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Structure of skeletal muscle

A

Tendon attaches to bone
Epimysium – muscle
Perimysium – fascicle
Endomysium – fibre

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What are muscle fibres filled with

A

Myofibrils

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Sarcolemma

A

Plasma membrane of muscle fibre

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Sarcoplasm

A

Cytoplasm inside muscle fibre

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Sarcolasmic reticulum

A

Smooth endoplasmic reticulum acts as a storage organelle for Ca2+

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Transverse tubular system (TT)

A

Invaginations of sarcolemma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Triad

A

Terminal cisternae of 2 SR and TT in close proximity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Sarcomere

A

Unit of contraction of the myofibril

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Z line

A

Either ends of the sarcomere; thin filaments insertion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

M line

A

Origin of thick filaments, middle of sarcomere

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

A band

A

Overlap of thick and thin filaments

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

I band

A

Only thin filaments

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What does the myosin head bind to and what features allow this

A

Actin
2 alkali light chains help stabilise myosin head
Hinge region allows movement of myosin head

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What is the myosin tail formed of

A

2 intertwined heavy chains

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What allows ATPase activity on myosin

A

2 regulatory light chains

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Actin

A

Binding site for myosin

Thin filaments

40
Q

What does tropmyosin do

A

Block myosin receptors

41
Q

What does troponin do

A

Control tropomyosin position

42
Q

What happens to the sarcomere during contraction

A

All bands and H-zone gets smaller

43
Q

Excitation-contraction coupling

A

AP motor nerve end plate propagates along membrane and down TT
Opens Vg L-type Ca2+ channels on TT
Coupling between DHP receptor and Ca2+ release channels, releases the Ca2+ from the SR
Ca2+ released into myofibril activating troponin C and cross-bridge cycling

44
Q

Initiation of cross-bridge cycling

A

Tropomyosin blocks myosin binding site
When Ca2+ binds to the high affinity sites on troponin C a conformational change takes place in the troponin complex
Troponin I moves away from the actin filament
Troponin T pushes tropomyosin away from myosin binding site on actin
Myosin head binds to actin

45
Q

How does calcium modulate contraction

A

Through regulatory proteins rather than direct interaction w/ actin and myosin

46
Q

Types of troponin

A

C: binds Ca2+
I: anchors complex to actin
T: binds to tropomyosin

47
Q

Cross-bridge cycle in skeletal muscle

A 
Initially myosin head attached to actin filament after ‘power stroke’ from previous cycle – can remain in this state for indefinitely longer period, as occurs in rigor mortis 
Step 1 – ATP binding 
Step 2 – ATP hydrolysis 
Step 3 – cross-bridge formation 
Step 4 – release of Pi from myosin 
Step 5 - ADP release
48
Q

Terminating muscle contraction

A

Ca must be removed from cytoplasm
Na-Ca exchanger
Ca pump at plasma membrane
Ca reuptake into SR and binds to calsequestrin

49
Q

How can muscle force be determined

A

By no. individual muscle fibres stimulated at a given time

50
Q

What does amount of muscle force generated depend on

A 
No. active muscle fibres 
Cross-sectional area of muscle 
Initial resting length of muscle 
Rate at which muscle shortens 
Frequency of stimulation
51
Q

Isometric contraction

A

Muscle length fixed, stimulation of muscle will cause increase in tension but no shortening

52
Q

Analogy for isometric contraction

A

Similar to holding a weight in your hand w/ your arm outstretched, you will feel that the muscle is working w/out changing length

53
Q

Isotonic contraction

A

Muscle length not fixed

Stimulation of muscle will cause muscle shortening provided tension generated is stronger than opposing load

54
Q

Analogy for isotonic contraction

A

Similar to holding a weight in your hand and lifting and lowering your hand, bending at the elbow

55
Q

Passive tension

A

Tension measured before muscle contraction

56
Q

Length tension rship

A

At any fixed length if muscle is contracted an addn. active tension develops due to cross-bridge formation
Length-tension relationship is direct result of the anatomy of the thick and thin filaments overlapping within individual sarcomeres

57
Q

Force-length rship

A

As velocity increases, force decreases

At maximum power is generated at approx. 1/3 shortening velocity

58
Q

Summation in single muscle fibres

A

One AP will lead to single skeletal muscle twitch

As muscle twitch far exceeds duration of AP it is possible to generate a 2nd AP before 1st contraction has subsided

59
Q

Tetanus state

A

Twitches – AP generated faster than muscles can react

60
Q

Types of muscle fibres

A

Red
White
Intermediate

61
Q

Red muscle fibres

A

Slow twitch and fast twitch, requires oxygen and glycogen

62
Q

White muscle fibres

A

Fast twitch, glycogen is main energy store, gets fatigued quickly

63
Q

Fast twitch (2b) muscle fibres

A

Fatiguable
White
Glycolytic metabolism
High levels of glycogen

64
Q

Slow twitch muscle fibres

A

Resistant to fatigue
Red (myoglobin)
Oxidative metabolism
Low levels of glycogen

65
Q

What determines strength of skeletal muscle

A

Size

66
Q

What is the cross sectional area of muscle fibres proportional to

A

The strength that can be generated

67
Q

What are long muscle fibres good for

A

Rapid movement

68
Q

What are shirt muscle fibres good for

A

Large forces

69
Q

Fast twitch (2a) muscle fibres

A

Red
Either endurance or rapid force
Quickly fatigue

70
Q

Concentric isotonic contraction

A

Length of muscle changes in direction of contraction

71
Q

Eccentric isotonic contraction

A

Length of muscle changes opposite to direction of contraction

72
Q

Effects of endurance exercise training

A

Increased mitochondrial function –> increased O2
Hypoxia inducible factors (HIFs) involved in gene control of red muscle cell production and regulation of glycolytic enzymes
Increased [Hb]

73
Q

Individual variation in proportion of diff fibre types

A

Training does not significantly change proportions of fibre types
Athletes find the sport that fits their abilities

74
Q

Respiratory substrates in intense short-term exercise - 10-15s

A

Creatine phosphate

75
Q

Respiratory substrates in intense short-term exercise -up to 2 mins

A

Glycogen to glucose-6-phiosphate

76
Q

Respiration inintense short-term exercise - several min

A

Lactic acid build up
Oxygen debt
About 2L of oxygen required to replenish ATP and creatine phosphate

77
Q

Respiration in longer, less intense exercise

A

Glycogen from circulation
Glucose from plasma
Hepatic glucose production increases

78
Q

What happens when hepatic glucose increases

A

Short term glycogenesis

Longer term gluconeogenesis – muscle proteolysis, glucagon and insulin, fatty acid release

79
Q

VO2 max

A

Oxygen usage under maximal aerobic activity

80
Q

EPOC

A

Excess post exercise oxygen consumption

81
Q

Fast component of recovery phase

A

Resting levels of ATP and CP restored

82
Q

Slow component of recovery phase

A

Lactic acid converted to glucose in liver

Lactic acid converted to pyruvic acid

83
Q

How is the increased oxygen demand met during exercise

A

Increase in ventilation rate

Increase in tidal volume

84
Q

Tidal volume

A

Volume of air displaced during respiration

85
Q

Changes in blood gases during exercise

A

Arterial O2 and venous CO2 do not change significantly during exercise
Respiratory system can provide adequate aeration

86
Q

Oxygen consumption during exercise

A

Oxygen consumption increases
Similar rate for first few seconds reaches steady state where lactate acid accumulation is minimal
Other factors like fuel availability limit exercise
VO2max when steady state oxygen consumption doesn’t increase w/ work intensity

87
Q

Changes in alveolar diffusion during exercise

A

Oxygen and carbon dioxide diffusion capacity increases w/ exercise
Related to increase in perfusion more than ventilation

88
Q

Redistibutrion of blood flow during exercise

A

As exercise continues, blood flow to the muscles increase substantially

89
Q

Cardiac changes in exercise

A

Increased cardiac output by increased stroke volume and increased heart rate

90
Q

Stroke volume

A

How much blood pumped out with each cycle

91
Q

Control of cardiac output

A

Increase in activity of sympathetic nerves –> increases stroke volume, ventricular myocardium

decrease ion parasympathetic nerves –> increases hr, SA node

These both increase cardiac output

92
Q

Control of stroke volume

A

Decreased venous return –> increases end-diastolic volume
Increased sympathetic activity/ epinephrine –> increases contractibility of ventricle
Arterial pressure also decrease

These increase stake volume

93
Q

What does change in central venous pressure change

A

Diastolic filling pressure, more blood available to fill heart

94
Q

What does total peripheral resistance change

A

Ability to expel blood into arterial system

95
Q

Starlings Law

A

The fuller the heart is, the harder it will contract increasing the stroke volume (ventricular performance)

96
Q

Benefits of exercise and reducing cardiovascular disease risk

A

Reduced blood pressure
Increased circulating HDL and reduced Triglycerides
Changes in arterial wall homeostasis reducing atherosclerotic disease
Improved aortic valve function and reduction in calcification
Increased ventricular chamber wall thickness
Increased red cells (to a point)
Changes in cardiac vasculature to increase oxygen availability

97
Q

Exercise and depression

A

Moderate clinical effect in a decline in depression
Long term follow up on mood found in favor of exercise
No more effective than psychological or pharmacological treatments
Important for those who do not want pharmacological treatment

MBBS - Year 1 (93 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions