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Muscle Physiology
Bowman Test
71
Physiology
11th Grade
11/17/2008

Additional Physiology Flashcards

 


 

Cards

Term
Characteristics of Muscle
Definition

Excitability- responds to stimuli (nervous impulses)

Contactability- able to shorten in length (so bones can move

Extensibility- stretches when pulled

Elasticity- tents to return to original shape and length after contraction or estension

Term
Functions of Muscle
Definition

Motion

 

Maintenance of posture

 

heat production

Term
Types of Muscle
Definition

Skeletal- attached to bones and moves skeleton; also called striated muscle becasue of its appearance under the microscope; voluntary muscle

Smooth- involuntary muscle; muscle of the viscera; in blood vessels, intestine, and other hollow structures and organs in the body

Cardiac- muscle of the heart; involuntary

 

Term
[image]
Definition

Smooth Muscle

Location- walls of hollow organs,blood vessels, eyes, glands, and skin

Shape- spindle shaped; broadest point in middle

Nucleus- single, centrally located

Special Features- gap junctions join some visceral smooth musle cells together (gap junctions allow the cell to communicate)

Striations- no

Control- Involuntary

Capable of spontanous contraction- yes (some)

Function- food movement through the digestive tract, emptying of the urinary bladder, regulation of blood vessel diameter, change in pupil size, contraction of many gland ducts, movement of hair, and many more

Term
[image]
Definition

Skeletal Muscle

Location- attached to bones

Cell Shape- very long and cylindrical

Nucleus- multiple, peripherally located

Special Features- nada

Striations- yahh

Controll- coluntary and involuntary (motor controlls)

Capable of Spontaneous Contraction- no

Function- Body movement

Term
[image]
Definition

Cardiac Muscle

Location- heart

Cell Shape- cylindrical and branched

Nucleus- single centrally located

Special Features- intercalated disks join cells to each other; fibers very short compared to skeletal

Striations- yes

Control- involuntary (no controll of heart beat)

Capable of spontaneous contraction- Yes

Function- pumps blood; contractions provide the major force for propelling blood through blood vessels

Term
Facioscapullohumeral Muscular Dystrophy
Definition

it is an inherited and progressice condition. the muscles of the face and shoulder girdle are primarily involved

 

Term
Muscular Atrophy
Definition
this results from the decrease in size of individual muscle fibers and a progressive loss of myofiberals
Term
Duchene Muscular Dystrophy
Definition
is almost exclusively affects males, and by early adolescence, the individual is weelchair bound
Term
Fibrosis
Definition
the scarring is associated with severe trauma to skeletal muscle and with heart attacks in cardiac muscle
Term

Duchene Muscular Atrophy

Definition
This condition is inherited as a sex-linked recessive gene. eventually, the muscles shorten casue immobility of the joints and scoliosis
Term
Disuse Atrophy
Definition
It occurs form lack of use and is typically seen in bedridden individuals, thoes with limbs in cast, or thoes who are inactive for a variety of reasons
Term
Deneruation Atrophy
Definition
when motor neurons innercation skeletal muscles are severed it results in flaccid paralysis
Term
Cramps
Definition
these are painful spastic muscle contractions that usually result form an irritation within a muscle
Term
Fibromayalgia
Definition
the pain occurs in muscles or where muscles join their tendons, but no the joints. The pain is chronic and widespread and it has no cure
Term

Fibrositis

 

 

Muscular Dystrophy

Definition

it is not progressice and does not lead to tissure destruction. It resaults in stiffness, pain, soreness due to inflammation of the fibrous

 

 

 

one group of disease that distroys muscle tissue

Term
The most immediate usable form of energy for muscle contraction is:
Definition
atp
Term
If muscle is not supplied with enough oxygen during the process of cellular respiration, latic acid will form. This will result in the conditions know as:
Definition
Oxygen Dept
Term
a special muscle protein that has the capacity to store a modest amount of oxygen in reserve and to assist in the transfer of oxygen from the blood to the body cell is:
Definition
myoglobin
Term
What are the main sources of energy for muscle contraction?
Definition

aeoriciv resperisation, anaeobic resperation, cellular resperation, creatine phosphate, glycogen

 

Term
ATP and creatine phosphate present in the cell provide enough energy to sustain contractions for what length of time?
Definition
10-15 sec
Term

Anaerobic respiration is less efficient than the other processes. However, it can produce ATP rapidly for a short period of time. During wuch sctivity as sprinting, anerociv respiration and the breakdown of creatine phosphate can provide enough ATP to support intense muscle contractionfor up to how long?

Definition
3 mins
Term
Although aerobic respiration is a very efficient process, it is a slow process. What type of exercise depends primarily on this process?
Definition
sistained exersises-- running and swimming cartio exercises
Term

The tension generated by elastic elements is called ------- and tension generated by contractile elements is --------.

Definition

passive tension

 

active tension

Term
The process of increasing the number of active motor units is called -------.
Definition
multiple motor unit summation
Term

Recruitment is ----- a factor responsibel for producing jerky movements rather than a series of smooth movements.

 

Definition
not
Term

At the optimum sarcomere length, the number of mysosin crossbridges making contact with thin filaments brings about a ------------ force of attraction.

Definition
Maximul
Term
----- fibers are common in sprinters where large amounts of myoglobin, many mitochondria, and many blood capillaries are advantages for high velocity activity of short duration.
Definition
Fast twitch
Term
An ------- occurs when the muscle  does not or cannot shorten, but the tension on the muslce greatly increases.
Definition
Isometric contraction
Term
If the skeletal muscle fiber is stretched ---- percent of its optimal length, myosin crossbridges can bind to thin filaments and contraction occurs.
Definition
75%
Term
Red muscle fibers have a ----- myoglobin content and more motochondria and more capillarioes that white muscle fibers.
Definition
Term

Contraction can be sustained for long periods of time by allowing -------- to be active while others are inactive.

Definition
alternate motor units
Term
--- motor units are emplyed where maintaining constant precision is important and position or posture is not.
Definition
Fine
Term
[image]
Definition

a- Lag phase

b- Contraction phase

c- Relaxation Phase

d- stimulus applied

e- tension

f- time in miliseconds

g- Muscle twitch

Term

Easy Definations for:

 

Lag Phase

Concentration Phase

Relaxation Phase

Definition

Lag phase- thime period between application of stim. to the motor neuron and the beginning of the contraction (waiting for the sodium channels to open up)

Contraction Phase- time during which contraction occurs

Relaxation phase; time during which relaxation occures ( sacormere recoils and goes back to resting lengith

 

REQUIRES UP TO ONE SECOND TO OCCUR

Term
Lag Phase
Definition

1. Wave of depolerization (action potential)

 

2. permeability of presynaptic terminal is increased

 

3. calcuim ions diffuse into presynaptic termainal- acetylcohline is released by exosytosis into synaptic cleft

 

4. Acetylcholine diffuses across the synaptic cleft and bings to acetylecholine receptor molecules

 

5. post synaptic membrane becomes more permeable to sodium ions

 

6. Acetylcholine is turned into acetic acid and choline, limiting the length of time acetylcholine is bound to the rececptor cite; so one presynaptuc action potential produces one postsynaptic action potential in the musle fibers

 

7. action potential produced is sent into the t tubles

 

8. electrial changes occur in the t tuble and makes the membrane of the sarcoplasmic reticulum very permible to ca+ ions

 

9. calcium Ions diffuse fromthe sarcoplasmic reticulum into the sarcoplasm

 

10. Ions bind to troponin; the troponin-tropomyosin complex changes its position and exposes the active site on the actin myofliaments

 

Term
Contraction Phase
Definition

1. cross bridges between actin and myosine molecules form, move, realese over and over causeing sarocmere to shorten

 

2. energy from head of myosine molecule

 

3. ATP binds to myosine head and then is broken down by ADP

 

4. cross bridge is released and moces bak to resting position ready to form another cross bridge

 

5. some energy is released as heat

Term
Relaxation Phase
Definition

1. calicum ions are actively transported into the saroplasmic reticulum

2. troponin-tropomysine cover the active sites

3. muscle fibers relengthen passively

Term

Muscle Fiber Type I

(Slow-Twitch Fibers)

Definition
  • loaded with mitochondria
  • depend on cellular resperation for atp production
  • fatty acids the major energy source
  • resistant to fatigue
  • rich in myoglobin and hence red in color (dark meat in turkey)
  • activated by small-diameter, thus slow-conducting motor neurons
  • dominate in muscles used in acivites requiring endurance
Term

Muscle Fiber Type II

( Fast-Twitch Fibers )

Definition
  • few mitochondria
  • rich in glycongen
  • depend on creatine phosphate and glyocolysis for atp production
  • fatique easily with prodcuion of lactic acid
  • low in myoglobin hence whitish in color (white meat in turkey)
  • activated by large diameter, thus, fast-conduction motor neurons
  • dominant in muscles used for rapid movement
Term
Synaptic Cleft
Definition
the space between the presynaptic terminal and the postsynaptic terminal where the acetylcholine pass through and connects to the recptor molecules
Term
Synaptic Vessicals
Definition
a neutrotransmitter substance that carries the acetylcholine to the synaptic cleft
Term
Motor Neuron
Definition
where the acetyolcholine leaves the presynaptic terminal and enters the synaptic cleft
Term
Acetylocholine
Definition
what moves through the synapes
Term
Acetycholinesterase
Definition
the protein that pulls acetylcholine out of the receptor site so the sodium channels automaticly shut
Term
Sarcolemma
Definition
The outside most part of the sarcomere
Term
Presynaptic Terminal
Definition

where there is a flow of depolarization and ca+ ions enter through the calicum channels and move along sacs of acetoylcholine to the synaptic cleft

Term
[image]
Definition
  1. there is a wave of depolarization
  2. ca+ channels open and and ca+ enters the presynaptic terminal
  3. ca= moves  along the sacs of acetylcholine to the opening
  4. acetylcholine spills into the synaptic cleft and connects to the receptor molecules, Opening the sodium, Na+ molecules pour out into the postsynaptic terminal
Term
[image]
Definition
  1. a protein called acetylcholinesterase pulls the acetylocholine away form the receptor molecule, closing the Na channel
  2. it seperates the acetic acid from the choline
  3. the acetic acid is a waste product that is difused through the blood stream
  4. the choline is a very valueable substance and is recyled through a carrier protein that pumps the choline back into the motor neuron when acetic acid is waiting to combine with it
Term
[image]
Definition

A: Epimysiom- the CT which binds the entire muscle

B: Perimysium- the CT which binds the muscle

C: Fascicle- A bundle of muscle fibers

D- Muscle Fiber- a single muscle cell

E: muscle

F: Dndomysium- the CT that covers the muscle fiber

Term
[image]
Definition

A- Cut edge of sarcolemma: cell membrane of muscle fiber

B- Saroplasmic Reticulum: a network of interlocking tubles which run lengthwise; has periodic inlarged portions called sisterns which are filled with calicum

C- T Tubule: just underneth cell membrane, ring length tuble, sits on top of S.R.

D- Myofibril : a very small subcomponent of a muscle fiber (tiny tiny)

F- Sarcoplasmic Reticulum and T Tubles forming triad

Term
[image]
Definition

Sarcomere

 

*highly orginized into arrangement*

Term
[image]
Definition

1st Step: Resting State or Polorized State

  • lots of sodium outside
  • lots of K+ inside- K+ present in relative abundance, (-) anions present in overwelming abundance
Term
[image]
Definition

Action Potential 2: Depolarization

  • occurs apon stimulation from neurons
  • permeability of cell membrane chanes to do the stim. and it becomes perm. to Na+ and it diffuses into the cell and changes the charge
  • as it spreads over the entire surface of the cell membrane in a continual wave it is know was action potential
Term
[image]
Definition

Action Potential 3: Post Stimulation

  • permability of cell membrane changes again and the membrane become permable to K+ only
  • K+ diffuses throughout the cell and changes along the cell membrane are restored to the original state
  • except now K is outside and Na is inside
  • once i is repolarized all channels close and K is stuck outside and Na inside
Term
[image]
Definition

Action Potential 4: Activation of Active Transport Mechanism

  • a special carrier mechanish
  • energy is used to push Na and K back to their regular postions
  • this demenstates active transport
  • also know was ionic restoration
Term
[image]
Definition

Action Potential 5: COMPLETE

  • back to orginal state
  • now prepared to respond to another stimulation
Term
Fueling Muscle Contraction
Definition

ATP= immediate source of energy

Three sources of high energy phosphate to keep the ATP pool filled:

 

1) creatine phosphate

 

2) Glycogen

 

3) Cellular Respiration- inthe mitochondria of the fibers

Term
Creatine Phosphate
Definition
  • attached by a high energy bond like in ATP
  • derives its high energy phosphate from ATp and can donate it back to ADP to form ATP
  • 10 times more of it then ATP
Term
Glycogen
Definition
  • skeletal muscle fibers contain about 1% glycogen
  • keeps muscle functioning if it fails to recieve a sufficient oxygen amount to meet its ATP needs by resperation
  • source very limited
Term
Cellular Respiration
Definition
  • required to meet ATP needs of a muscle engaged in prolonged activity
  • also required afterwards to enable the body to resynthesizw glycogen formthe lactic acid produced earlier
  • works to repay the bodys oxygen dept
Term

Myoglobin

Definition
  • protein found in muscle fibers
  • muscle rich in myoglobin is called red muscle
  • slow twitch muscle fibers
  • combines with oxygen to form oxymyoglobin
  • stores oxygen
  • found abundently in cardic muscle
Term
Energy Supply for Muscle Contraction
Definition
  • ATP is not found abundently in the cells it must be rapidly produced
  • Creatine phosphate converts ADP back to ATP
  • using creatine phosphate as a sufficient source of energy is called alactic anaerobic: it allows bursts of speed or power
  • no oxygen is required (anaerobic)
Term
[image]
Definition
  1. I-Band: an are to the side in which only actin is found
  2. A- Band: is equal to the length of the protein called myosin; contains a slight amound of overlaping actin tothe right and left; also called the thick band
  3. H- Zone: gap between the pooisite strands of actin
  4. M- Line: the midpoint of sacromere
  5. Z-Line: a zigzag line of actin that marks the boarders of the sarcomere
  6. Actin- one of the major muscle proteins that form the sarcomere
  7. Myofilaments- equall actin and myosin
  8. Myosin- the other major muslce protein that forms the sacromore
Term
[image]
Definition

A- myosin

 

b- crossectional perspective to both

 

c- Actin

 

*very orginized

Term
[image]
Definition

A- Troponin

B-Acitn

C- tropornyosin

D- Myosin

  1. Ca+ binds to troponin which tightens the tropomysin exposing the active sites now myosin has the potential to bind to the actin
  2. as soon as inhibitation is broken Atpase perks up and cause ATP to diffuse into ADP and a little burst of energy is released and the myosin can know form with the actin
  3. myosine flexes, springs back over and over pulling on the actin
  4. H-zone gets reduced
  5. any shortining on the h zone= muscle contraction

Going back to normal

  1. as sarcomere is shortening, repolorization of the sarcolemma occurs
  2. actives CA+ pumps and yanks the myosin away
  3. no ca+ pumpes= tropomysine uncoils and relaxes- active sites are covered
  4. myosine settles down, sarcomere not making attemp
  5. elastic recoil= sarcomere will relenghen
  6. active sodium pumps puts sodium out and potasuim in
  7. back to normal
Term
Steps of Muscular Contraction
Definition
  1. Action potential
  2. Neuromuscular junction
  3. Actin and Myosine Contraction
Term
[image]
Definition

1- subthreshold stimulus is not stong enough to casue a action potential and casues no contraction

2- threshold stimulus- a stimulus where one motor neuron resonds

3-5- Submaximul Stimulus- activates additional motor neurons

6- Maximul Stimulus- all motor neurons are activated

7-9- Supramaximul Stimulus- a greater stimulus above mas has no additional effect

Term
[image]
Definition

1- Insuring rest and recovery

2- incomplete recovery

3- incomplete recovery

4- even less amount of recovery

5- no recovery sistaned state on contraction- doesnt occur under normal conditions

Term
[image]
Definition
an increase in strength of the first few conditions in a rested muscle occurs in response to several stimuli of constant strengh
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