Muscular system Flashcards
Myology
Study of muscles
Myoglobin
Found in muscle cells, it functions as an oxygen-storage unit, providing oxygen to the working muscles
Antagonists
Muscle that opposes the action of a prime mover
Connected tissue
Binds together bone, muscle and joints such as cartilage, ligaments, and tendons
Myofascia
Connected tissue that secures muscle fibres and large muscles together (cobwebs)
-contains nerves, blood and lymph vessels, filling space between muscles
-insulates muscle fibres from one another’s electrical activity (impulses)
3 Layers of Myofascia
- Epimysium
-Covered by 1st connected fascia layer
-Surrounds entire muscle - Perimysium
-Covered by 2nd connected fascia layer
-Surrounds fasciculi (bundles of muscle fibres) eg: Ponytail - Endomysium
-Covered by 3rd connected fascia layer
-surrounds individual muscle fibre eg: strand of hair
Fasciculi/ Fasicicle
Bundles of muscle
Myofascial Massage
Rolling of skin/muscle using foam roller to breakdown adhesions between muscle to improve blood and lymph circulation and nerve function
Tendons
Attach muscle to bone and continuations of fascia layers
Aponeurosis
sheet like tendon that connects large muscle structures
Synovial Tendon Sheaths
Encircle tendons that need additional lubrication (shoulder / knee)
Bursae
Synovial padding, like a pillow protecting boney areas (kneecap, elbow, hip, shoulder)
6 Functions of Muscle Tissue
- Body movement
- Stabilize posture
- Regulate organ volume
- Move substances within the body
- Generates heat
- Protects organs
Functions of Muscle Tissue (4)
- Electrical excitability
Ability to respond to stimuli - Contractility
Ability of muscle to develop tension and produce force
—Isometric contraction: tension without movement (jaw)
—Isotonic contraction: develops tension when shortening/lengthening (arm curl) - Extensibility
Ability for muscle to be extended without damage to tissue - Elasticity
The ability for muscle to return to original shape after contraction or stretch
Isometric contraction
Tension of muscle without movement (jaw)
Isotonic contraction
Muscle that develops tension when shortening/lengthening (arm curl)
3 types of muscle tissue
- Cardiac muscle (striated) involuntary muscle tissue forms wall of heart
- Smooth, visceral muscle tissue in the internal organs that is involuntary
- Striated/ Skeletal
Muscle tissue Attaches to skeletal that is voluntary
Myocardium
Cardiac muscle tissue that forms the wall of heart
Perimysium
Connected muscle tissue that surrounds fascicles from one another and binds muscle fibre together
eg: Ponytail
Epimysium/ Epimisium
Layer of myofascia that surrounds entire muscle
Endomysium
Each muscle fibre is encased in a connected sheath called endomysium and is made up of thousands of smaller fibrils called myofibrils
Layer of myofascia that surrounds individual muscle fibre
eg: strand of hair
Muscle Belly
Entire muscle as a whole (biceps)
Fascicles
Each fascicle bundle contains thousands of muscle fibres (eg: ponytail)
Muscle Fibre/ Muscle Cell
Long, thin fibre (eg: single strand of hair)
Myofibril
Smaller than muscle fibre, hundreds inside muscle fibre (eg: chain)
Sarcomere
is the basic contractile unit of muscle fiber with each composed of two main protein filaments—actin and myosin—which are the active structures responsible for muscular contraction.
Smallest contractile unit of a myofibril, sacromere is linked together like a chain to make one myofibril (1cm=4500 sacromere of myofibril)
Myofilaments
2 protein filaments found within sarcomere (actin & myosin)
Actin & Myosin
2 small myofilaments inside the sarcomere responsible for muscle contraction
Muscle Tissue Components (6 large to small)
Largest to smallest:
1. Muscle belly
2. Fascicle
3. Muscle fibre
4. Myofibril
5. Sarcomere
6. Myosin & Actin
Z Line
Where 2 Sarcomere attach within a muscle
Actin Myofilament (sarcomere 1)
Thinner Sarcomere that slides past myosin / gets pulled by myosin
Myosin Myofilament (sarcomere 2)
Linked together like box cars on a train, represents myofibril, that is thick and anchored in sarcomere, and pulls Z Lines together
Myocytes
Muscle fibres/ muscle cells that are bundled together and organized into separate bundles
Adenosine triphosphate (ATP)
Body fuel made from food nutrients such as carbs, fats, protein
ATP-CP (Creatine Phosphate)
Explosive/ high intensity /0-30 sec
Anaerobic Glycolytic
30secs-4 minutes/ glucose can extend higher intensity / fatigue indicates build up of lactic acid
Aerobic glycolytic
Activity lasting 4-30 mins / burns oxygen & glucose
Beta oxidation
process where fatty acid molecules are broken down to produce energy. More specifically, beta oxidation consists in breaking down long fatty acids that have been converted to acyl-CoA chains into progressively smaller fatty acyl-CoA chains.
Mitochondria
Mitochondria job is to process oxygen and convert substances from food into energy, they produce 90% of energy bodies need to function.
Insertion
Insertion of a muscle is usually the distal attachment and moves with the bone during contraction
Nerve stimulus
Controls muscle
EPOC
Muscle fatigue / Excessive post exercise oxygen consumption/ can’t produce ATP / after burn from intense exercise
Hypertrophy
An increase in size of muscle fibre
Sarcoplasmic Hypertrophy
Muscle appears bigger because greater amount of fluid and glycogen stored inside (can last 1-3 days)
Transient Hypertrophy
Quick increase in muscle size “muscle pump” (lasts 1-3 hours)
Myofibrillar Hypertrophy
Muscle is bigger because it has more Myofibrils
Muscular Atrophy
Shrinking of muscles
What is the sliding filament theory
Process used for muscles to contract /when actin myofilaments slide past myosin myofilaments during muscle contraction
Difference between Hypertrophy and Hyperplasia
Hypertrophy refers to an increase in the SIZE of muscle fibers, whereas hyperplasia refers to splitting of the muscle fibre for an increase in the NUMBER
