Kinesiology Notes and Vocab-Unit 3

660-840

• depends on grouping/decoupling or person

How many muscles are in the human body?

Three Types of Muscles: Smooth

Involuntary, fatigue-resistant, and non-striated muscle with slow and uniform contractions.

Three Types of Muscles: Cardiac

Involuntary, fatigue-resistant, and striated muscle with characteristics of both smooth and skeletal muscle.

Three Types of Muscles: Skeletal

Voluntary, fatigued, and striated muscle that is attached to bone.

1. Movement (gross/fine)

2. Posture (keeping/maintaining)

3. Heat (Muscles contract to generate heat)

4. Protection

What are the 4 functions of skeletal muscle?

1. Extensibility (extend/stretch)

2. Excitability (Ability to respond to stimuli)

3. Elasticity (return to original form)

4. Contractility (contractions for movement)

What are the 4 properties of skeletal muscle?

Epimysium

Fibrous tissues that surround the entire muscle

• Protects muscles from friction against other muscles and bones

Perimysium

A connective tissue sheath that surrounds a bundle of fibers (fascicle)

Endomysium

Network of connective tissue that surrounds individual muscle fibers

• Contains vessels and nerves that supply the muscle fibers

Fascicle

Bundle of skeletal muscles enveloped by perimysium

Muscle Fiber

Multi-nucleated cells that contract to move bones

Blood Vessel

Help muscles contact and get oxygen and nutrients

(Artenes, artorioels, and capillaries)

Sarcomere

The basic contractile unit of muscle fiber

Myofibril

Bundles of protein filaments that contain the contractile elements of the cardiomyocyte

Actin (protein)

A protein that forms with myosin, the contractile filaments of muscle cells

Myosins (protein)

A motor protein responsible for muscle contraction

1. Muscle

2. Fascicle

3. Muscle Fibers

4. Myofibril

5. Sacromere

6. Myofilament (actin and myosin)

Organized Skeletal Muscle Structure (Big to Small)

Sliding Filament Theory

The act of actin(thin) filaments sliding over the myosin(thick) filaments to shorten the muscle, ultimately creating movement/contraction.

• Rowing simulation explains act

Cross Bridge Formation (Rowing Simulation)

The signal reaches the motor nerve, the heads of the myosin filaments temporarily attach themselves to actin filaments.

Central Nervous System (Motor)

Composed of the brain and spinal cord—the motor/response to stimuli

Peripheral Nervous System (Sensory)

Composed of various nerves, carry signals to the CNS.

Sensory Function (PNS)

Collects information from the senses throughout the body and send the information to the brain.

Motor Function (CNS)

Conducts the signals from the CNS to activate muscle contractions in response to stimuli.

Motor Unit

A group of fibers activated via the same nerve that extends from the spinal cord to the muscle fibers.

• All muscle fibers inside of motor units are the same fiber (FT/ST)

Requires few muscle fibers and has a large number of motor units.

Fine Motor Movements

Requires lots of muscle fiber but few motor units.

Gross Motor Movements

NO, a typical individual only uses 60% of fiber.

• Athletes ~85%

Is it possible to use 100% of our muscle fibers simultaneously?

Intramuscular Coordination

The interaction between the nervous System and muscle; excitability

YES, there are trainable (diameter, coordination) and non-trainable factors (number/structure of fibers)

Are muscle fibers trainable?

High endurance capacity (fatigue tolerant) and slow contraction speed.

• Aerobic energy and less lactic acid

Slow Twitch Fibers

Fast contractions with low endurance (fatigued).

• More lactic acid and uses anaerobic energy

Fast Twitch Fibers

Agonist (prime mover)

The muscle or group of muscles producing a desired effect—contracting muscle

Antagonist

Muscle or group of muscles opposing the action of the prime mover

Synergist

Muscles surrounding the joint being moved and supporting it in the action.

Fixators

Steady joints closer to the body axis so that the desired action can occur

• Stabilizes joint to achieve intended movement

1. Carbohydrates

2. Fats

3. Protein

What are the 3 complex nutrients?

ATP (Adenosine Triphosphate)

The energy of the body

ADP (Adenosine Diphosphate)

Plays a crucial role in energy transfers within the cell

• Releases energy

Kilocalorie

The amount of heat energy needed to raise 1,000 grams of water by 1 degree Celsius (heat energy)

• measures how much energy food provides to the body

1. Anaerobic Alactic system (Immediate alactic/high energy phosphate system)

2. Anaerobic Lacitic System (Short-term lactic/glycolytic system)

3. Aerobic System (Long-term/oxygen system)

What are the three energy systems?

• Large amount of energy in short amount of time but rapid recovery

• Fueled by ATP and CP (creatine + phosphate)—CP breaks down, leaving extra phosphate for ADP

• The limitations are that it doesn’t last long and requires CP.

Anaerobic Alactic System (Anaerobic alactic system, ATP-CP System)

1. Calcium

2. Magnesium

3. Sodium

4. Potassium

What are the four important electrolytes that are important for muscle function?

• Short-term, produces lactic acid

• Fueled by carbohydrates—gets broken down into glycogen (liver/muscle) and blood glucose

Anaerobic Lactic System (Glygolytic system/anaerobic system)

Lactic Acid

Makes your muscles burn when you expert yourself.

Glycogen breaks down, creates pyruvic acid and ATP, pyrivic acid is converted to lactic.

Why/How do we release lactic acid?

Anaerobic Threshold

The point during exercise when you start to feel the burn in your muscles

1. Decreasing intensity/stopping workout

2. Increase the effectiveness of the aerobic system

How can lactic acid be decreased?

• Requires oxygen, sufficient mitochondria, and no limiting enzymes on the rate of energy in Krebs cycle

• The limitations are that it requires oxygen and fuel (food) and rate of ATP utilization must be slow

Aerobic System (long-term/oxygen system)

a. Krebs cycle

b. Cori Cycle

What are the two ways lactic is removed from the body?

Krebs Cycle

A metabolic process through which pyruvic acid, glucose, fat, and protein are metabolized

Cori Cycle

Removes lactic acid from muscle and allows for continuation of exercise.

• Lactic acid is converted back to usable glucose (liver/muscle)

Static and Dynamic.

How is muscle action divided?

Static/Isometric Action

Contraction in which there is no visible change in muscle length—standstill

Dynamic Action

Involves movement and the external load/force is smaller than the internal force generated by the athlete

• Divided into isotonic, isokinetic, plyometric

Isotonic

An exercise where you hold one position and muscles stay still and do not move.

Isotonic: Concentric

Shortens and contracts under tension (Flexion)

Isotonic: Eccentric

Lengthens and contracts under tension (extension)

Isokinetic

A contraction of the same speed over the entire range of motion

• swimming, Rowing stationary bike, PT

Ploymetric

A fast eccentric muscle action followed by an explosive concentric action

• Box jump, burpees, lunge

Golgi Tendon Organ Reflex

Protects muscles from too much stretch/overstretching

1. Joint angle

2. muscle cross-sectional area

3. Speed of movement

4. Muscle fiber type

5. Age

6. Biological Sex

What are the 6 factors affecting muscle action?

• Women have more ST fibers (type 1) than men—endurance

• Men have more FT fibers (type 2) than women—strength/muscle size

Strength-to-weight ratio

Testosterone

Hormone responsible for muscle growth.