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BIO 201
Chapter 10
65
Anatomy
Undergraduate 2
06/10/2013

Additional Anatomy Flashcards

 


 

Cards

Term
Excitable
Definition

have the ability to respond to a stimulus

 

Term
Contractible
Definition
they can shorten in length
Term
Extensible
Definition
they can extend or stretch
Term
Elastic
Definition
they can return to their original shape
Term
Muscle functions
Definition
  • movement of the body
  • maintain posture
  • store substances
  • move substances
  • heat production
Term
Contractility refers to the ability of a muscle to?
Definition
shorten in length
Term
Elasticity refers to the ability of muscle to
Definition
return to its normal shape after being contacted or stretched
Term

Location, function, appearance, and control of 

SKELETAL MUSCLE

Definition
  1. Skeleton
  2. Movement, heat, posture
  3. Striated, mulei-nucleated (eccentric), fibers parallel 
  4. voluntary
Term

Location, function, appearance, and control of 

CARDIAC MUSCLE

Definition
  1. Heart
  2. Pump blood contiuously
  3. Striated, one central mucleus
  4. incoluntary
Term

Location, function, appearance, and control of 

Visceral (smooth muscle)

Definition
  1. G.I. tract, uterus,eye, blood vessels
  2. Peristalsis, blood pressure, pupil size, erects hairs
  3. No Striations, one central nucleus
  4. involuntary
Term

Organization of Muscle Tissue

(smallest to biggest)

Definition
myofibril -> endomysium ->muscle fiber (cell) -> perimysium -> fascicle -> epimysium -> muscle
Term
Aponeurosis
Definition

a thick fascia that connects two muscle bellies

ex. frontal belly of the occipitolfrontalis muscle

Term
learn the names of the internal structures of the muscle fiber (beable to draw and lable these):
Definition
  • sarcolemma
  • sarcoplasm
  • myofibril
  • t-tubles
  • sarcoplasmis reticulum
  • trian (w/ terminal cisterns)
  • sarcomere
Term
Sarco
Definition
flesh
Term
Myo-
Definition
muscle
Term
Sarcolemma
Definition
cell membrane
Term
T-tubules
Definition
invaginations (fold ins) of the sarcolemma
Term
Sarcoplasm
Definition
cytoplasm
Term
Sarcoplasmic reticulum
Definition
fluid-filled system of membranous sac
Term
Terminal cistern
Definition
dilated end sacs of the sarcoplasmic reticulum
Term
Triad
Definition
1 transverse tubule with 2 terminal cisterns
Term
T-tubules:
Definition
are invaginations (fold ins) of the sarcolemma
Term
Triad composed of?
Definition
2 terminal cisterna and 1 t-tubule
Term
muscle fascicle is covered in?
Definition
Epimysuim
Term
muscle cell membrane is called?
Definition
Sarcomembrane
Term

Thick filaments 

(myosin)

Definition
myosin proteins look like golf clubs bound together
Term

Thin filaments 

(actin)

Definition
Actin proteins are strung together like a bead of pearls
Term

Parts of sarcomere:

  • A band
  • I band
  • Z disc
  • H zone
  • M line
  • Zone of overlap
Definition
A band – H zone + zone of overlap
•I band - only actin (troponin and tropomyosin)
•Z disc – through center of I band
•H zone - only myosin
•M line – middle of sacromere
•Zone of overlap- Myosin + Actin
Term
Contractile proteins
Definition

generate force during contraction

  • myosin
  • actin
Term
Regulatory Proteins
Definition

help switch the contration process on and off 

  • tropomyosin
  • troponin
Term
Structural proteins
Definition

keep the thick and thin filaments in proper alignment and link the myofibrils to the sarcolemma and extracellular matrix

  • titin
  • alpha actinin
  • myomesin
  • nebulin
  • Dystrophin
Term
Contraction of a Sarcomere
Definition
  1. Myosin heads hydrolyze ATP and become reoriented (ADP) and energized
  2. Mysoin heads bind to actin, forming crossbridges
  3. Myosin crossbridges rotate toward center of the sarcomere (power stroke) using ADP
  4. As myosin heads bind ATP, the crossbridges detach from actin
Term
Neuromuscular junction
Definition

a synapse or site of communication between a neuron and muscle is usually named a neuromuscular junction (NMJ)

  • Neuromuscular junction= axon terminal (synaptic end bulb) + motor end plate (sarcolemma under motor neuron)
Term

Presynaptic membrane

&

Postsynaptic membrane

Definition

Presynaptic- on the neuron

Postsynaptic- and the end

  • they are seperated by a space called the snaptic cleft
Term
Neuromuscular Junctions
Definition
Term
What does acetylcholine do?
Definition
moves a muscle! by activated a motor neuron (which is a electrical stimulus) then acetylchlorine is released which allows sodium channels to open causing a chemical stimulus across the synaptic cleft. Once it gets a across to the postsynaptic it become electrical again.
Term
Electrical event of a muscle action
Definition
  1. ACH is released from synaptic vesicle
  2. ACh binds to ACh receptor
  3. Muscle action potential is produced
  4. ACh is broken down

 

Term
Problems with Neuromuscuar Junctions (NMJ)
Definition
  • Curare- binds to and blocks ACh receptors (competes w/ but doesnt stimulate the ACh receptors
  • Myasthenia gravis- antibodies bing and block ACh receptors, making there be no stimulus causing paralysis
  • Botulism- inhibits ACh release (botox, relaxes muscles)
  • tetanus- produces a toxin that blocks an inhibitory neurotransmitter (police locked up)
  • Organophosphates- inhibits acetylcholinesterase (muscle spasms)
Term
Excitation-Contraction Coupling Process
Definition
  • thought process through the brain
  • AP arrives at the neuromuscular junction
  • regeneration of an AP on the muscle membrane
  • release of Ca2+ from the sarcoplasmic reticulum
  • sliding of thick on thin filaments in sarcomeres
  • generation of muscle tension
Term

Excitation-Contraction Coupling

At rest

Definition
  • calcium in SR (terminal cisternae
  • troponin-tropomyosin prevents myosin from binding to site on actin
  • concentration of ATP in high in relaxed muscle
Term

Excitation-Contraction Coupling

Action Potential (AP)

Definition

ACh binds to its receptor on the motor end plate

  • AP will travel along the sarclemma down into T tubules
  • production of AP in muscle leads to contraction
Term
Sliding Filament Mechanism
Definition
  • the action potential running through the T tubules causes the sarcoplasmic reticulum's terminal cisterae to release calcium into the sarcoplasm
  • the calcium will then bind to troponin
  • tropomyosin changes shape so myosin binding sites on actin are uncovered
  • Myosin then can bind to actin
  • the calcium will also activate ATPase ability of myosin
  • the ATPase activity of myosin activates its power stroke movement (pulls actin inward (H zones and I bands narrow and may disappear; A band does not change its length). At the end of power stroke, a new ATP binds to ATP binding site on the myosin cross bridge, resulting in detachment of myosin from actin. Attach, pull, detach=steps in contraction. if lack ATP- rigor mortis.)
  • A relax following contraction (ACh is inactivted by acetycholinesterase (from sarcolemma surface) calcium is actively transported back into SR (ATP attaches to myosin cross bridge and it releases from actin). Troponin-tropomyosin comvers myosin cross bridges.)
Term
ATP and Muscle Function
Definition

ATP is required for

  • power stroke- movement of myosin cross bridges pull actin inward in a sarcomere
  • at end of power stroke, ATP binds to ATP binding site, resulting in detachment of myosin from actin (ATP needed to release cross bridges)
  • pumping Ca2+ back into terminal cisternae of the SR

******know the steps********

Term

Sources of Muscle Energy

 

Definition

Stored ATP- 3 secs

3 types of production

  • Creatine phosphate ATP- 12 secs (combined with ATP-15 secs)
  • Aerobis ATP production- oxygen
  • Anaerobic ATP production- Glucose, 30-40 secs
Term
ATP and Muscle Function
Definition
  • even as ATP and CP are being used, ATP is generated by aerobic respiration and anaerobic respiration
  • in active contractin muscles, glucose is primary fuel supply
  • anaerobic pathway: glucose-> lactic acid+2 ATP
  • resting and slowly contractin muscles obtain bulk of ATP via aerobic respiration of fatty acids
  • Aerobic pathway: glucose+O2->CO2+H2O+36ATP
  • Aerobic produces 20X more ATP but take 2.5 times longer
Term

Sources of Muscle Energy:

ATP from anaerobic glycolysis

Definition

muscle glycogne

to

From blood->Glucose               

to

                           2 Pyruvic acid && 2 ATP (Glycolysis)

to

              2 Lactic acid -> into blood

 

duration of energy provided is 30-40 sec

Term

Sources of Muscle Energy:

ATP from creatine phoschate

Definition

ATP\/      Creatine       \/ATP\

                                  (Energy

                                   of muscle

                                     contraction)

ADP/\Reatin Phosphate/\ADP/

  relaxed             contracting

muscle                 muscle

Duration of energy provided is 15 secs

Term

Sources of Muscle Energy:

ATP from aerobic cellular respiration

Definition
  • Fatty acids liberated from adipose cels
  • Amino acids from protein breakdown
  • Pryuvic acid from glycolysis
  • Oxygen from hemoglobin in blood or from myoglobin in muscle fibers

TO

Cellular respiration in mitochondria

 

Term
Skeletal Muscle Metabolism
Definition

Oxygen Debt or labored breathing is the amount of O2 repayment required after exercise in skeletal muscle to:

  • replenish ATP stores
  • replenish creatine phosphate and myoglobin stores
  • convert lactic acid back into glycogen

Ina state of homeostasis- muscle uses O2 & nutrients to be balanced by the production of manageable levels of waste like: CO2, Heat, & Lactic Acid

Term
Cardiac Muscle Metabolism
Definition
  • cardiac muscle contracts 10-15 times longer than skeletal muscle
  • cardiac uses a lot of O2 whcih is generated by ATP through aerobic respiration
Term
Smooth Muscle Metabolism
Definition
  • deep inside organs, involuntary (digestion)
  • has low capacity for generating ATP and does it through anaerobic respiration (glycolysis)
Term
The Motor Unit
Definition

All or none principle of muscle contraction

  • when an individual muscle fiber is stimulated and action potential is prolongated along its sarcolemma
  • all muscle fibers must contract at the same time
  • does not apply to the entire muscle, only to motor units

Motor neuron plus all the muscle cells it innervates

  • High precision= fewer muscle fibers per neuon & Laryngeal and extraocular muscles
  • Low precision= many muscle fibers per neuron & Thigh muscle
Term

Skeletal Muscle Fiber Types:

Appearance

(red muscle fibers)

Definition

Red muscle fibers (dark meat)- have a high myoglobin content, more mitochondria, more energy stores, and a greater blood supply

 

Term

Skeletal Muscle Fiber Types:

Appearance

(white muscle fibers)

Definition
White muscle fibers (white meat)- have less myoglobin, mitochondria, and blood supply
Term

Skeletal Muscle Fiber Types:

Slow oxidative

Definition
  • Slow oxidative (SO) fibers- appear dark red (same reason), least powerful, fatigue resistant.
  • used for endurance distance runners: slow contraction, aerobic respiration, more capillaries, small diameter
Term

Skeletal Muscle Fiber Types:

Fast oxidative-glycolytic

Definition
  • Fast oxidative-glycolytic (FOG) fibers are intermediate size, dark red (more myoglobin and capillaries), moderately to fatigue.
  • used for walking: fast contraction, anaerobic and aerobic respiration, more mitochondria, high glycogen
Term

Skeletal Muscle Fiber Types:

Fast glycolytic

Definition

Large, white (low myoglobin content and fewer capillaries) & powerful

  • intese anaerobic activity of short duration
  • rapid contraction
  • anaerobic respitaion/glucose
  • high glycoge
  • large diameter
Term
Skeletal Muscle Fiber Types
Definition

Mot skeletal muscle is mixed, aout 1/2 is slow oxidative

  • within a unit all the fibers are the same

Endurance activities trasform fast twitch (produce more mitochondria and increase myoglobin

 

Term
Tension in a Muscle
Definition

Latent period- AP sweeps over the sarcolemma and Ca2+ ions are released from the sarcoplasmic reticulum

contracting- during next phasethe fiber is active

relaxation- the Ca2+ ions are reseqestered into the SR and myosin inding sites are covered by tropomyosin

Refractory period- temprart loss of excitability

twitch- a stimulus that results in contraction of a sigle muscle fiber is measured over a very brief millisecond time frame

wave summation- stimuli arriving a t different times cause larger contractions

recruitment- allows a muscle to accomplish increasing gradations of contractile strength

 

Term
Muscle Contraction
Definition

Istonic Contractions= movement

  • Concentric isotonic- muscle is contracted and shortened
  • Eccentric isotonic- muscle is contracted and long

Isometric contraction=no movements

  • muscle force and resistance are equal
  • supporting objects in a fixed position and posture

Term

Imbalances of Homeostasis:

exercis-induced muscle damage

Definition
  • After intense exercise electrom micrographs reveal muscle damage including torn sarcolemmas and dirupted Z-discs
  • blood levels of proteins normally confined only oto muscle (myoglobin & creatine kinase) increase as they are released from damaged muscle
Term

Imbalances of Homeostasis:

Spasm and Cramp

Definition

Spasm- sudden involuntary contraction of a single mucsle (usually painless)

Cramp- involuntary and painful muscle contraction. cause by inadequate blood flow to muscle, overuse, abnormal blood electrolyte levels

Term

Imbalances of Homeostasis:

Disease States and Disorders

Definition

Fibrosis (myofibrosis)- replacment of muscle fibers by excessive amounts of C.T. (fibrous)

Myosclerosis- hardening of muscle becuase of calcification

**both occur b/c of trauma and various metabolic disorders

Term

Imbalances of Homeostasis:

Aging

Definition
  • decrease in physical activity, you undergo a slow, progressive loss of skeletonal muscle mass that is replaced largely by fibrous C.T. tissue and adipose tissue
  • muscle strength at 85 is about half compared to 25
  • of the 3 fiber types the slow oxidative fibers appears to increase.
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