Kine 433 Test 1

Front 1

Slow Twitch Fibers (Type 1)

Back 1

*High Oxidative Capacity
* High mitochondrial density because slow twitch fibers use alot of energy constantly.
*Have high capillary density b/c they have a high amount of blood flow
*High myoglobin levels: high oxygen storage and transfer.

Front 2

Slow twitch fibers have low glycolytic capacity

Back 2

They also have a relatively slow contractile speed because:
1. myosin ATPase activity is low
2. Little SR (slow Calcium release and uptake)
*Also les than 300 fibers per motor neuron

Front 3

Fast twitch (type 2a)

Back 3

*They have a high oxidative capacity and are fatigue resistant.
*High glycolytic capacity
*Theres high glycolytic enzymes, thus high lactic acid production
*Fast contractice speed of type 2a fibers
This is due to high myosin ATPase activity. and high density of SR.
*relatively large motor units

Front 4

Fast twitch (type 2x)

Back 4

*Low oxidative capacity & low fatigue
*High glycolytic capacity & high lactate production when active
*fast contractile speed
*relatively large motor units, greater than 300 muscle fibers per motor neuron
*very hard to activate

Front 5

Theres a higher isometric force in type 2 then type 1 due to more muscle fibers per motor neuron and larger size of the fibers.

Back 5

Cross-innervation of slow and fast muscles shows us that the alpha motoneuron

Front 6

Genes determine which motor neurons innervate individual muscle fibers and generally MU's are made up of homogenous fiber composition. They also determine how fast the ATPase is.

Back 6

Fibers in a motor unit are recruited when an alpha motorneuron carries an action potential from the CNS.

Front 7

Principle of orderly recruitment states that motor units are activated in a fixed order

Back 7

The size principle states that the order of recruitment is directly related to the motor neuron size

Front 8

Cerebrum:

Back 8

Site of intellect; primary motor and sensory area

Front 9

Diencephalon:

Back 9

Location of the hypothalamus, which is essential to homeostasis.

Front 10

Cerebellum:

Back 10

Important for coordinating movement.

Front 11

Brain Stem:

Back 11

Connects the brain to spinal cord; coordinates skeletal muscle Fx and maintains muscle tone.

It also contains regulators for respiratory and cardiovascular systems.

Front 12

Nervous System is divided into two distinct subsystems: The Central Nervous System and the Peripheral.

Back 12

The peripheral is further divided into the Sensory and Motor Divisions. Motor division is efferent, takes info from PNS to the tissues. Sensory division is afferent, takes info from body and relays to PNS.

Front 13

Motor Division is further divided into Autonomic and Somatic: Somatic controls skeletal muscles and the Autonomic is fuether divided into ParaSympa and Sympa

Back 13

There are 12 pairs of cranial nerves and 31 pairs of spinal nerves.

The autonomic system controls involuntary internal functions.

Front 14

Sympathetic:
*fight or flight; norepinephrine is neurotransmitter; also stimulates release of catecholamines (norep and Epi) from adrenal medulla.

Back 14

Sympathetic NS reacts to the motor response by increasing HR, BP, strength of heart contraction, blood supply to heart and active muscles, rate of gas exchange, mental alertness

Front 15

Parasympathetic NS reacts to the motor response by:
*slowing down HR, constricts coronary vessels, constricts tissues in lungs.

Back 15

Parasympathetic is known as the Internal "Housekeeping".
*controls digestion, urination, gland secretion and energy conservation. It uses ACh mostly

Front 16

Types of Sensory Receptors:
Mechano: pressure, touch, stretch, vibration...
Thermo: Temperature changes
Nocio: Painful stimuli
Photo: respond to light to allow vision
Chemo: chemical stimuli from foods, odors, blood concentrations
Proprio: body mvmt and positio

Back 16

Muscle Spindles sense muscle length and how much it changes during contraction.

Golgi Tendon Organs: detect the tension of a muscle on its tendon, thus provides info on strength of muscle contraction.

Front 17

Muscle Spindles: A group of4-20 small muscle fibers called INTRAFUSAL fibers with Sens/Mtr nerve endings, connected in parallel with regular muscle fibers, aka EXTRAFUSAL.

Back 17

The middle of the muscle spindle stretches but doesn't contract because it contains little to no actin/myosin.

Front 18

When extrafusal muscle fibers attached to the spindle are stretched, sensory neurons on the spindle transmit information to the CNS about the muscles length

Back 18

Gamma motorneurons activate intrafusal fibers, making the spindle sensitive to small degrees of stretch.

Front 19

GTO's are encapsulated sensory organs that muscle tendon fibers pass thru.

Back 19

They sense small changes in muscle tension and can inhibit contracting (agonist) muscles and excite the antagonist muscles to prevent injury

Front 20

Different Integration Centers are utilized by the nervous system for different neural inputs.
*Spinal Cord - Simple motor reflexes such as pulling your hand away after touching a stovetop
*Lower Brain stem - more complex subconscious mtr reactions such as posture control

Back 20

*Cerebellum - subcon control of movement such as what would be needed to coordinate multiple movements at once.
*Thalamus - Conscious distinction among sensations, such as feeling hot or cold.
* Cerebral cortex - cons. awareness of a senstation and the location within body where it originates.

Front 21

The closer to the brain, or the higher in the brain that the sensory impulse stops, the more complex the motor reaction is.
*a mtr reflex is preprogrammed and happens without cons thought

Back 21

Neurons originating in the primary motor cortex control voluntary muscle movement. Also called cerebro-spinal motorneurons, pyramidal, or upper motorneurons.

Front 22

Clusters of nerve cells in the basal ganglia initiate sustained and repetitive movements such as runnig, walking, maintaining posture, and muscle tone

Back 22

The cerebellum compares the actual movement with the intended movement. It is nicknamed the "Comparator."

Front 23

Engrams are 'learned motor patterns' that are stored in the cortex

Back 23

Resistance training can lead to:
*alterations of neural control of the trained muscle.
*and increased muscle size

Front 24

Muscular Endurance can be increased by(2):

Back 24

*through gains in muscular strength.
*through changes in local muscular metabolic and circulatory capacity

Front 25

Neural Adaptations that take effect with gains in muscle strength:

Back 25

*There will be synchronization & recruitment of additional mtr units
*decreased neural inhibition(ex: decreased GTO effects)
*a decrease in co-activation of antagonist muscles during stress
*increased rate coding
*fiber hypertrophy yes, hyperplasia? probably not.

Front 26

for muscle size increases while training: more than 3 sets of 6RM to 12RM loads with short rests

Back 26

for muscular endurance (20RM used)

Front 27

Muscle Hypertrophy can either be transient(short term) or chronic(long term)

Back 27

transient is the pumping up of muscle due to squeezing of fluid from the blood plasma into interstitial spaces of muscle due to high muscle pressures.

Front 28

Chronic muscle hypertrophy happens due to changes in muscle fiber number(fiber hyperplasia) or muscle fiber size(fiber hypertrophy)

Back 28

With muscle fiber hypertrophy the # of myofibrils and actin/myosin filaments increase so theres more cross-bridges which allows for a greater amt of strength to be utilized.

Front 29

Muscle fibers MAY experience Hyperplasia(split in two) during intense weight training. Each half would ten increase in size. Hasn't been demonstrated clearly in humans.

Back 29

For double muscled animals: within the embryo, the myotome(composed of myoblasts) which the myoblasts form myotubes, which go on to form myofibers.

Front 30

myostatin either signals for cells to stop dividing or signals for satellite cells to remain quiescent. In dbl muscled animals, myostatin isnt activated so you get constant reproduction of muscle cells, so u get dbl muscled animals.

Back 30

intersting..

Front 31

Ways to study muscular inactivity:

Back 31

In Humans: Casting/bed rest
In Animals: hindlimb suspension, casting, denervation

Front 32

Acute Muscle Soreness - usually goes away right after exercise due to diffusion of waste from muscle

Back 32

due to accumulation of EDEMA(water) or waste products in muscles such as lactic acid, pyruvate, CO2.

Front 33

DOMS - primarily from eccentric contractions.
*assoc with dmg or injury to muscle fibers.

Back 33

Can be due to edema, inflammation..felt 12 to 48 hours.

Front 34

Satellite Cells - Adult stem cells available to maintain a relatively constant nucleus to muscle mass ratio

Back 34

If muscle injury is bad enough, S cell fuses in with myofiber and you see the nucleus of S cell being added to myofiber nuclei.

Front 35

S cells get to site thanks to chemotaxia.

Back 35

This could be a different type of hyperplasia too, this theory says that the satellite cells once done proliferating turn into new fibers. Just a theory. But more accepted.

Front 36

Sequence of events leading to DOMS

Back 36

* Structural damage to muscle fibers
*impaired calcium homeostsis resulting in necrosis(cell death)
*inflammation occurs as macrophages invade the damaged tissue
*accumulation of irritants stimulate nociceptors(dull aching pain) within muscle

Front 37

Muscle injury causes a reduction in force-generating capacity of muscles due to:

Back 37

1. physical disruption of the muscle.
2. failure in the excit/contrac coupling process.
3. loss of contractile protein
*muscle glycogen synthesis is impaired

Front 38

Muscle glycoggen synthesis is impaired because it costs the cell energy to build glycogen, which your body has to focus first on repairing muscle tissue.

Back 38

To Reduce DOMS affect:
1. reduce eccentric workouts during early training
2. gradual increase in training
3. begin with high intensity eccentric workout so you can just get it over with and then hit it hard they recover.

Front 39

Exercise induced muscle cramps

Back 39

May be due to fluid/electrolyte imbalances and/or sustained alpha motor neuron activity from increased muscle spindle activity and/or GTO activity

Front 40

electrolyte imbalance that increases muscle contraction: Calcium excess in cell would cause contraction, thus a cramp.

Back 40

decrease in sSTR after injury mostly due to E-C Coupling failure.