EXAM III

Voluntary = conscious control

Involuntary = not under conscious control

Skeletal, Smooth, Cardiac

Voluntary

Used for: movement, posture/support, speech production, defecation/giving birth, breathing

1. Skeletal muscle cells are huge, each cell have 2. multiple nuclei = multinucleated.

3. Shaped liked cylinders.

4. Nuclei are proliferated located. Striated.

Involuntary

1. Located in walls of hallow organs. (ex: small intestine)

2. Spindle shaped cells

3. Prostaglandin: stimulates smooth muscle to contract.

4. Single nucleus

Branched

1. Located only in the heart. Wall of heart has very thin outer and inner layer, everything in between those two thin layers is Cardiac Muscle Tissue.

2. Extremely specialized

3. Intercalated disc which are special cell junctions that hold the cells together, and facilitate spreading of signal to cell-to-cell.

Heart would destroy itself if not for intercalated discs.

Avg. Human @ Rest pumps = 1.39 gpm

Avg. Human @ Exercise pumps = 5.35 gpm

Olympic @ exercise pumps = 10.3 gpm

point of attachment that moves the least

point of attachment that moves the most towards the origin.

1. Functionally the same, connect muscle to bone.

2. Made of Dense Irregular CT.

3. Differences at gross/macro level.

Aponeurosis = flat, sheet-like structure. ex: iliotibial tract. Gives stability.

Tendons = cord like structure

inflammation of iliotibial band, pain can range anywhere from iliac crest to knee lateral aspect, often caused by running downhill.

causes an action

prevents an action OR causes opposite action

The whole is greater than the sum of its parts. Muscles work together to do more than they could individually.

Most powerful muscle in an action.

1. Extensibility - they can be stretched

2. Elasticity - return to normal length after stretching.

3. Irritability - excitability/react

4. Contractility - contracting

frontal lobe: point of stimulation to send signals by neurons to stimulate muscle contractility

Neurons send signals for muscles to contract.

Muscles stimulated by motor nerves.

Functional units of Muscle = muscle cells/fibers

Functional units of Nerves = nerve cells/neurons

Signals = action potentials, similar to electricity, trillions of signals per movement.

A single neuron innervates a small group of muscle cells (fibers). This single neuron + the muscle cells it innervates constitute a motor unit. Recruit more motor units to meet resistance.

1. Epimysium (muscle) -> Perimysium (fascicle) -> Endomysium (fiber).

Surrounds, binds, holds together subunit

superficial layer of muscle tissue (outermost layer).

Muscle -> Fascicles -> Fibers/Cells -> Myofibrils -> Myofilaments

Muscle cells have 2 outer boundaries.

1. Sarcolemma = cell membrane

2. Endomysium

functional units of muscle

(sarcoplasm = endoplasmic reticulum)

sarcomeres shorten to constrict muscles.

1. Actin = thin

2. Myosin = thick

Overlap region between Actin and Myosin filaments stain the darkest, which cause an appearance of striations at low magnifications.

Actin only (thin only)

where actin meets myosin. (where thin meets thick)

myosin (THICK) only

Area of overlap actin + myosin (Thin+thick)

Myomesin, filaments are sliding and as they are sliding the z line is moving closer to myosin, as they are moving closer they need shock absorber which is Titin.

A band - stays the same

Z-line - moves closer together

I-band - gets smaller

M-line - doesn't change

H-zone - smaller, negative overlap

Sarcomeres contract, filaments shorten

bind actin, and pull in actin, = why filaments slide Bind, Swivel, Release

Components - Actin, tropomyosin, and troponin

Binding/active site - where myosin binds

Tropomyosin is blocking binding site.

Calcium bound troponin moves tropomyosin, to allow myosin head to bind to active site, forming a Crossbridge.

Powerstroke - head of myosin swivels

After the powerstroke, crossbridge breaks.

*Sarcomere is resting.

Tropomyosin is blocking binding site.

Myosin heads are holding on ADP + organic phosphate from previously used ATP.

1. Action potential in a motor neuron.

2. Release of acetylcholine at the myoneural junction.

3. The action potential spreads across the sarcolemma into the transverse tubules. (associated with sarcoplasm)

4. Sarcoplasm reticulum releases Ca+.

5. Ca+ binds troponin.

6. The Troponin/Tropomyosin complex moves to the side and exposes the binding site on actin.

7. Myosin head binds actin forming a "cross-bridge".

7.5. - myosin head releases ADP + inorganic Phosphate (The energy for the power-stroke came from the release of ADP + P_i)

8. Power-stroke occurs pulling actin in toward the H-zone.

9. The head must bind a new molecule of ATP to break the crossbridge.

10. Head splits the ATP and is ready to begin another cycle.

1. Power-stroke

2. Break-crossbridges

3. Action Potential

4. "Pump" Ca+ back into sarcoplasmic reticulum.

1. Phosphagen energy system - stored energy in cytoplasm. Neither aerobic or anaerobic, already made. 8-10 seconds of energy. Functions immediately.

a.) Stored ATP - ATP -> ADP + P_i + E

b.) Stored Creatine Phosphate (CP) - CP + ADP -> Creatine + ATP -> ADP + P_i + E

2. Glycogen / Lactate System - (Anaerobic system), 1.3-1.6 minutes of energy

a.) Glycolysis

b.) Fermentation

3. Complete Oxidation of Glucose (Aerobic): 2-4 Hours of energy

i.) Glycolysis - Glucosee - Pyruvate1, Pyruvate2

ii.) Transition Reaction: Pyruvate -> Acetyl CoA

iii.) Kreb's cycle

iv.) Electron transport system

v.) Oxidative Phosphorylation

Range in energy: Depends on amount of glycogen reserves and consumption during activity.

4. Oxidation of Lipids (Aerobic) - Lots of energy, burns fat

β = ((n/2 - 1) x 5) - 1) + (n/2 x 12), where n = # of C, fatty acid

Carbs = 4 kcal/g

Protein = 4kcal/g

Fats = 9kcal/g

1 cal = 1 dietary calorie = 1kcal = 1,000 calories

ex: 100 calories = (100*1,000) = 100,000 calories

Carbohydrates are main pathway in animals. Proteins and fats intersect carb pathway.

Acetyl CoA is a coupling enzyme, puts together 4-C and 2-C.

Type I

Aerobic

Highly Vascular

Inc. Mitochondria

Inc. Myoglobin

Split ATP Slowly

Resist fatigue

Very good @ burning fat

More intramuscular fat

More Lipoprotein Lipase

Smaller motor units

Endurance

Type II

Anaerobic

Less vascular

Less mitochondria

Less myoglobin

Split ATP quickly

Fatigue easily

Depends on carbs

Not much intramuscular fat

Larger motor units

Sprinting

1. Recruit all red motor units before recruitment of white motor units.

2. Distribution of red/white fibers is thought to be genetically determined, may be able to convert between the two.

3. Can improve red/white fibers.

1. Send pyruvate to aerobic pathway as long as you have oxygen, remaining pyruvate go to anaerobic pathway.

2. % of aerobic vs. anaerobic usage is a function of your heart rate, that is the % of your Max HR you are functioning at.

1. Classic Aerobic = 70-75%

2. High Aerobic = 75-80%

3. Lactate Threshold = 80-85%

Max HR = 220-age (males) or Max = HR = 225-age (females),

to find max HR, induce it.

95% Americans sedentary

HRR = Max HR - Resting HR

Training HR = [(Max - Rest) x %Intensity] + Rest

ex: Sally, age 32 wants to train in Lacatate-threshold zone. Max HR = 192, Rest HR = 61. Calc training zone.

Training HR = [(192-61) x %80)] + 61 = 166

Training HR = [(192-61) x %85)] + 61 = 172

166-172 bpm training zone HR.

1. Decrease resting HR

2. Decrease triglycerides

3. Decrease cholesterol

4. Decrease LDL

5. Slight increase in HDL

6. Little increase in myo size

7. Increase myo tone

8. Increase endurance

9. Increase intramuscular mitochondria

10. Increase intramuscular fat

11. Less dependent on carbs

1. Increase HDL

2. Increase intramuscular myofilaments

3. Increase in power and speed

4. Increase in Lactate-Threshold

5. Increase in VO2 Max

6. Increase in size

VO₂ Max = max volume of O₂ consumed and used per kg bodyweight/minute

the muscle fires (or activates with a force and tension) but there is no movement at a joint. In other words, the joint is static. Muscle length does not change.

An isotonic muscle contraction occurs when the force or tension in the muscle remains constant while the length of the muscle changes.

myoglobin, a protein found in the muscle cells of animals. It functions as an oxygen-storage unit, providing oxygen to the working muscles.

Troponin and Tropomyosin

The electron transport chain is located on the inner membrane of the mitochondria, as shown below. The electron transport chain contains a number of electron carriers. These carriers take the electrons from NADH and FADH2, pass them down the chain of complexes and electron carriers, and ultimately produce ATP.

Two common cofactors that are derived from the B vitamins, niacin and riboflavin, are nicotinamide adenine dinucleotide (NAD) and flavin adenine dinucleotide (FAD), respectively.

1. AP in a motor neuron (nerve)2. When signal (AP) reaches the end of the nerve it goes in to the synapse and Ach isreleased @ myoneural (neuromuscular) junction; and the signal is transferred from end of motor neuron to the myo3. AP spreads across sarcolemma into transverse (t) tubules4. SR releases Ca++5. Ca++ binds troponin6. Troponin/tropomyosin complex shifts (changes shape) and exposes binding site on actin for myosin head7. Myosin head, holding an ADP and Pi from a previously split ATP, binds actin8 Myosin head releases ADP and Pi and Epo turns into Eko9 Filaments slide (cross bridge is in place)power stroke10 Myosin head binds a new moleculr of ATP (it is still bound to actin)11 Cross bridge breaks12 Process continues as long as AP's continue13 When AP's stop, Ca++ is pumped back into the SR14 Troponin and tropomyosin shift and block binding site on actin*As speed increases more motor neurons are recruited

Movement, support, ventilation, heat production, protection

Specific nerve

motor unit

1. Skeletal myo: voluntary, apperance of striation, multinucleated, very large

2. Smooth myo: involuntary, in walls of hallow organs

3. Cardiac myo: only in heart, appears striated, highly branched, has specialized cell to cell junctions called intercalated discs.

Conduct the electrical signal between cardiac myo cells and holds cells together.

myo working together to accomplish a particular action (a muscle that assists the prime mover)

Both. Agonist - both invert foot; Antagonist - tibialis anterior flexes and tibialis posterior extends.

Sarcomere

1) Action potential

2) Power stroke & release

3) Pump Ca2+ back into the sarcoplasmic reticulum

a. phosphogen energy system 8-10 secondsb. glycogen lactate 2-4 minutesc. complete oxidation of glucose 2-4 hours

1. Inability to continued repeated contractions for running at aerobic pace. (how long can you maintain an aerobic pace or how many times can you lift bar?)

2. Inability to to maintain a sustained contraction. (how long can you main an intense anaerobic pace and how long can you hold the bar?)

1. Depleted stored ATP

2. Depleted stored glycogen

3. Lactic acid production -> Lowers intramuscular pH

4. Na+ and K+ are out of balance -> action potentials are inhibited

1. CNS consists of brain and spinal cord

2. Processes information

3. Reflexes are processed in spinal cord

4. Spinal cord conducts info up and down throughout cord.

1. PNS conducts signals

2. Cranial nerves (12 pairs)

3. Spinals Nerves (31) in intervertebral foramen

Somatic- voluntary

Autonomic - automatic, ex: pupil constriction, heart rate, urine production, sweating

Sympathetic-exercise

Parasympathetic-rest

1. Conduct signals, action potentials (electricity)

1. short processes

2. Dendrites conduct signals TOWARDS cell body

Cell bodies integrate incoming info, majority rules.

1. long processes

2. axons conduct AWAY from cell body

Cell bodies integrate incoming info, majority rules

1. support nervous system

Sensory neurons conduct info TOWARDS CNS (Afferent)

Motor neurons conduct info AWAY CNS (efferent)

ciliated cells line the ventricles of the brain and move cerebral spinal fluid

form blood-brain barrier

phagocytes, devour foreign material in brain, dead cells, injured cells

cell web cover

provide physical support. stabilizing.

insulate nerve cell processes, primarily axons. This insulation is called myelin sheath. Insulation is discontinuous. Insulation increases action potential by a factor of 10x.

ex: 10 meter/sec without sheath vs. 100 m/s with sheath

MS disorder attacks myosheath

bundle of neurons or group of nerve cell process in PNS

ex: Sensory Nerves, Motor Nerves, or Mixed Nerves

1. Spinal Cord Tracts

i.) Ascending Tracts (sensory)

ii.) Descending Tracts (motor)

2. Brain Tracts - CPA

i.) Commissural Tracts - connect left/right hemispheres

ii.) Projection Tracts - connect cerebrum w/inferior parts of brain and primitive parts.

iii.) Association Tracts - connect different lobes of the brain

Motor Activity = Frontal Lobe

Sensory Activity = Parietal Lobe

Vision = Occipital Lobe

Hearing = Temporal Lobe