Chaper 6 Flashcards
Describe similarities and differences in the
structure and function of the three types of
muscle tissue, and indicate where they are
found in the body
Cardiac muscle - branching chains, wallsof the heart
Skeletal - long cyndrical, voluntary moving, attached to bones
Smooth - single cells, walls of organs
describe the connective tissue membranes of a skeletal muscle (3)
Endomysium - covers each muscle fibre cell
Perimysium - covers each fascicle (groups of muscle cells)
Epimysium - wraps entire muscle
- Describe the 4 functions of skeletal muscles
- movement
- Heat
- Posture
- Joints
- Describe the microscopic anatomy of a
skeletal muscle cell
Muscle fibre cell > myofibril > sarcomere (between z lines) > thin and thick filaments (dark striations/stripes)
Explain how nerve cells work with muscle cells to produce skeletal muscle contraction,
and apply this knowledge
Signal from nerves > goes to neuromuscular junction (axon terminal) > release acetylcholine in gap > electrical impulse in the sarcolemma membrane releases calcium from the endoplasmic reticulum > calcium bind with troponin pushing tropomyosin out the way on the thin actin > thick myosin can now bind with actin (cross bridging) > filaments slide
Describe the events of the sliding filament
theory of muscle cell contraction and apply
this knowledge
Sliding filament theory - Calcium lands on the thin actin (on traponin) then the covering tropomyosin moves over and allows an area for the myosin heads to attach to and pull the actin filaments towards the H line
Sarcomere must shorten for muscle to contract, but the thick myosin and thin actin don’t change shape, just overlap and slide toward the centre (H or M line). Myosin head gets ATP (AH+P) and can now bind to the thin actin (called cross bridging). It will get more ATP to separate from thin actin.
Regulation committee:
Tropomyosin: does not let myosin bind
Traponin: also blocks myosin
Calcium (released by neurons): allows the myosin heads to bind by moving tropomyosin out of the way
What 3 things can muscles do to get more ATP during exercise?
- Aerobic pathway – oxygen burns glucose and other substances
ATP (32 – 36 units)
o Hours of energy and no muscle soreness
o Produces heat
o You can also burn fatty acid and amino acids but its primary concern is glucose
o As long as your inhaling enough oxygen you can keep going - Anerobic pathway
burns glucose only
o Only 2 units of ATP because their isn’t much oxygen in cytosol
Can cause lactic acid buildup and sore muscles and muscle fatigue
o 40 seconds of energy - phosphorylatin - uses cretin(1 unit only) 15 seconds of energy
- Describe the concepts of oxygen deficit
and muscle fatigue
- Anerobic pathway
o Glucose enters the muscle fibers
o Only 2 units of ATP because their isn’t enough oxygen in cytosol
o Because of all the lactic acid buildup in your muscles that’s why they feel sore after you workout
o 40 seconds of energy
o When you have so much lactic acid you become paralyzed (muscle fatigue)
definition of muscle fatigue - when the muscle is unable to contract even when
stimulated by a motor neuron (like a temporary paralysis)
* during prolonged muscle activity, a person cannot take in enough oxygen to
supply the muscles with the oxygen needed by the muscles
Describe the types of muscle contractions (2)
Isotonic muscle contraction – muscles are shortening and contracting back and forth (running, walking)
Isometric muscle contraction – holding something still, tension increases, no movement occurs and muscle does not shorten.
(holding a weight, holding a plank, etc.)
- Describe the effects of aerobic and resistance exercise on skeletal muscles
Aerobic exercise, or endurance exercise, such as participating in an aerobics class, jogging, hiking, or biking, results in stronger, more flexible muscles with greater resistance to fatigue. These changes come about, because the blood supply to the muscles increases, and the
individual muscle fibers form more mitochondria and store more oxygen. Aerobic exercise helps us reach a steady rate of ATP production and improves
the efficiency of aerobic respiration. Aerobic exercise does not cause the muscles to
increase much in size, even though the exercise may
go on for hours.
Identify and describe the different types of
body movements. (7)
Flexion - brings bones closer together
Making angle smaller.
Moving anything forward in front of body
The only exception is when the knee is bent and foot is behind you that’s flexion
Extension –moves bones farther apart
Straightening or standing straight
Making angle bigger
Moving anything behind the body
hyperextension - more that 180 degrees apart (ex. tipping your head backwards).
Moving anything backward
Rotation - rotating around a longitudinal axis (shaking head no)
Abduction - away from the body
Adduction - toward the body (adding a body part by bringing it closer to your trunk)
Circumduction - combination flexion, extension, abduction, and adduction (such as arms doing big circles)
- Define origin, insertion, prime mover,
antagonist, synergist, and fixator as they
relate to muscles
Origin - bone that doesn’t move (fixed)
Insertion - bone moves closer to origin (mobile)
Prime Mover - Main muscle moving (biceps brachii in a curl).
Synergists - Muscle assisting the prime mover (brachialis in a curl)
Antagonists - opposite muscle (triceps in a curl).
Fixators - hold a bone still
- List seven criteria used in naming muscles
Size
Shape
Action
Number of origins
Direction
Location of muscle
Location of origin and intersection
- Name, locate, and describe the functions of selected major muscles of the human body (11)
Trapezius - traps
Deltoid - shoulder
Pectoralis major - pecs
Bicep - upper arm
Triceps brachii - back of arm
Brachio radialis - on radius
Latissimus dorsi - back
Elector spinae - spine
Rectus Abdominis - abs
Gluteus medius - above bum
Gluteus maximus - bum
15.What happens to the muscular system during the aging process.
-our connective tissue increases
-muscle tissue decreases
-muscles more sinewy
- body weight declines
- muscle strength decreases by about 50% by age 80
- Describe the homeostatic relationship between the muscular system and other body systems
physical exercise helps the other systems
