muscles

Question 1

what are the 3 types of muscles

Answer 1

1. ) smooth muscle
2. ) cardiac muscle
3. ) skeletal muscle

Question 2

skeletal muscle

Answer 2

attached bones via tendons
striated (light and dark protein bands)
voluntary control

Question 3

cardiac muscle

Answer 3

wall of the heart
striated-
involuntary control

Question 4

smooth muscle

Answer 4

wall of blood vessels and internal organs.
non striated
involuntary control

Question 5

functions of the muscle

Answer 5

1. ) motion (of muscle/body part, substances within the body)
2. ) stabilizes posture- sitting, standing
3. ) thermogenesis- shivering

Question 6

charateristics of muscle tx

Answer 6

1. ) excitability- respond to stimuli by producing electrical signals
2. ) contractibility - can shorten or thicken to produce force
3. ) extensibility- can stretch
4. ) elasticity- can recoil

Question 7

fascia

Answer 7

a sheet(s) of connective tissue that surround(s) the muscle 
protect, support and separate the muscle
tendons are extensions of the fascia which attach muscle to bone

Question 8

general blood and nervous supply

Answer 8

Capillaries
are linked to each individual muscle fiber
Motor neurons
linked to each muscle fiber

Question 9

general structure of muscle

Answer 9

muscle– fascicle— muscle fiber(muscle cell)— myofibrils– filaments

Question 10

a motor unit

Answer 10

a motor neuron plus all the muscle fibers it stimulate
Stimulation -> simultaneous contraction of all the muscle fibers of the motor unit
a single motor neuron will stimulate approx. 150 fibers through branches (average)
(For fine precision movements
e.g. larynx,
a motor unit may have only 2-3 fibers
powerful gross movements
e.g. biceps,
there may be as many as 2000 fibers)

Question 11

pathways of ATP

Answer 11

ATP regeneration (creatine
phosphate, for short burst )
glycogen lactic acid, 30-40 sec-400)
aerobic respiration, cellular respiration in mitochondria.

Question 12

Myoglobin

Answer 12

O2 source for muscle tx

O2 binding protein- oxygen inside muscle fibers, it gets released when required.

Question 13

muscle fatigue

Answer 13

inability of muscle to maintain it’s contraction due to lack of ATP. may result from:
insufficiency of oxygen,
glycogen depletion or
lactic acid build-up

Question 14

oxygen debt

Answer 14

increased Vm after exercising to payback depleted O2 levels.
recovery O2 consump.
1) liver converts lactic acid to glycogen stores
2) creatine phosphate and ATP stores resynthesized
3) replace oxygen stores in myoglobin

Question 15

the all-or-none principle of muscle contraction

Answer 15

When muscle fibers receive a stimulus to contract, they contract fully.
(i.e. a muscle fiber never partially contracts).
*Whole muscles can have various degrees of contraction
Why - only some fibers contract.

Question 16

isotonic contraction

Answer 16

tension remains a constant

you are making the muscle work by moving your joint

Question 17

isometric contraction

Answer 17

length of muscle constant

tension of the muscle increases during the contraction but no movement is produced

Question 18

muscle tone

Answer 18

sustained partial muscle contractions muscle
“firms” the muscle without producing movement
maintain posture

Question 19

origin

Answer 19

point of attachment on stationary bone

Question 20

insertion

Answer 20

point of attachment on moveable bone