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

Motion

Maintenance of posture

heat production

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

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

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

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

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

Duchene Muscular Atrophy

Fibrositis

Muscular Dystrophy

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

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

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?

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

passive tension

active tension

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

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

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

a- Lag phase

b- Contraction phase

c- Relaxation Phase

d- stimulus applied

e- tension

f- time in miliseconds

g- Muscle twitch

Easy Definations for:

Lag Phase

Concentration Phase

Relaxation Phase

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

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

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

1. calicum ions are actively transported into the saroplasmic reticulum

2. troponin-tropomysine cover the active sites

3. muscle fibers relengthen passively

Muscle Fiber Type I

(Slow-Twitch Fibers)

• 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

Muscle Fiber Type II

( Fast-Twitch Fibers )

• 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

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

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

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

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

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

Sarcomere

*highly orginized into arrangement*

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

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

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

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

Action Potential 5: COMPLETE

• back to orginal state
• now prepared to respond to another stimulation

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

• 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

• 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

• 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

Myoglobin

• 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

• 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)

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

A- myosin

b- crossectional perspective to both

c- Actin

*very orginized

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

1. Action potential
2. Neuromuscular junction
3. Actin and Myosine Contraction

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

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