Muscular System Flashcards
1
Q
What are the functions of the muscular system?
A
- movement
- maintenance of posture
- respiration ( diaphragm)
- heat production
- communication ( verbally talking, writing, throughout the body )
- construction of organs and vessels ( blood vessels, smooth muscles etc )
- contraction of heart
2
Q
What are the general properties of muscle?
A
- contractility: ability of muscle to shorten with force
- excitability: capacity of muscle to respond to a stimulus ( from our nerves )
- extendability: muscle can be stretched to its normal resting length and beyond to a limited degree
- elasticity: ability of muscle to recoil to original resting length after stretched
3
Q
What are the types of muscle tissue??
A
- skeletal : attached to bone, responsible for facial expressions, posture, other types of body movement
- voluntary
- smooth : most muscles, walls of hallow organ, blood vessels, eyes glands and skin
- propel urine, mix good in digestive tract, regulating blood flow
- controlled, involuntary by endocrine and autonomic nervous system
- Cardiac : heart: major source of movement of blood
- autorhythmic
- controlled involuntary by endocrine and autonomic nervous system
4
Q
Explain the skeletal muscle structure
A
- composed of muscle cells , connective tissue, blood vessels and nerves
- tend to be smaller diameter in small muscles and larger in large muscles
- develop from myoblasts
- striated appearance due to light and dark banding
5
Q
Explain muscle twitch
A
- muscle contraction in response to a stimulus that causes action potential in one or more muscle fibers
6
Q
Phases of muscle twitch
A
- lag or latent
- contraction
- relaxation
7
Q
Explain muscle fatigue
A
- decreased ability to work and reduced efficiency of performance
8
Q
What are the types of muscle fatigues
A
- psychological: depends on emotional state of individual
- muscular: results from ATP depletion
- synaptic: occurs in NMJ due to lack of acetylcholine
9
Q
What are the 3 sources that comes from ATP
A
-Creatine phosphate: during resting conditions stored energy to synthesize ATP
- anaerobic respiration
- occurs in a sense of oxygen and results in breakdown of glucose to yield ATP and lactic acid
- aerobic respiration
- requires oxygen and breaks down glucose to produce ATP, CO2 and water
- more efficient than anaerobic
10
Q
What is oxygen debt?
A
- oxygen taken in by the body, above that required for resting metabolism after exercise
11
Q
What is hypertrophy?
A
Increase in muscle size
12
Q
What is atrophy?
A
Decrease in muscle size
13
Q
Cardiac muscle
A
- only found in heart
- striated
- each cell usually only has one nucleus
- autorhythmic cells
14
Q
What are the effects of aging on skeletal Muscle
A
- reduced muscle mass
- increased time for muscle to contract in response to nervous stimuli
- reduced stamina
- increased recovery time
- loss of muscle fibers
- decreased density of capillaries in muscles
15
Q
Physiology of the skeletal muscle fibers
A
- nervous system controls muscle contractions through action potentials
- resting membrane potentials
* inside cell more negative accumulation of large protein molecules
* more K on inside than outside. K leaks out but not completely because negative proteins hold some back
* outside cell more positive and more Na on outside than inside- Na / K pump maintains this situation
