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AP Exam 3 - Muscles
AP Exam 3 - Muscles
55
Anatomy
Undergraduate 3
11/03/2016

Additional Anatomy Flashcards

 


 

Cards

Term
Function of muscle tissue
Definition
  1. Producing body movement
  2. Stabalizing body positions
  3. Moving substances within the body
  4. Generating heat
  5. Regulating organ volume
Term
Characterisitics of skeletal muscle
Definition
  • Most move bones
  • Strated
  • Voluntary control
  • Each muscle is an organ
Term
Characteristics of cardiac muscle
Definition
  • Located in the heart
  • Striated
  • Voluntary control
Term
Characteristics of cardiac muscle
Definition
  • Located in the heart
  • Striated
  • Voluntary control
Term
Characteristics of smooth muscle
Definition
  • Located in walls of hollow internal structures
  • Nonstriated
  • Involuntary control
Term
Endomysium
Definition

Component surrounding individual fibers/sarcomeres

Made up of reticular fibers

Term
Permysium
Definition

Components surround fascicles

Made up of dense irregular connective tissue

Term
Epimysium
Definition

Surround entire muscle

Made up of densce irregular connective tissue

Term
What are fascicles
Definition
Groups of 10 to 100 or more muscle fibers bundles together
Term
What is fascia?
Definition
Dense sheet or broad band of irregular connective tissue surrounding organs
Term
What is a tendon?
Definition
Connects muscle to bone
Term
What is aponeurosis?
Definition
Flat, broad, sheet like tendon. (NOT IN BUNDLES)
Term
What is significant about somatic motor innervation?
Definition
Those neurons stimulate skeletal muscle contractions
Term
Nerve supply from brain or spinal cord
Definition
Muscles of the extremities recieve innervation from the spinal cord, while facial expression muscles receive innercation from the brain
Term
Nerve supply from neuromuscular junction
Definition
Action potentials travel from either the brain or the spinal cord to the muscle via neuromuscular junction
Term
Function of arteries
Definition
Supply muscle with oxygen and nutrients
Term
Function of veins
Definition
Drain muscle of carbon dioxide and wastes
Term
Function of capillaries
Definition
Gas (O2,CO2) and nutrient/waste exchange occurs at capillaries
Term
Muscle fiber formation
Definition

Myoblasts form muscle fibers.

 

Multinucleated with poor regerneation (Born with fixed number of muscle fibers in body, only grow through enlargement of existing fibers.)

Term
What is the SARCOLEMMA
Definition
Muscle fiber's plasma membrane
Term
What is SARCOPLASM
Definition

Muscle fiber cytoplasm

-Contains Glycogen and Myoglobin

Term
Transverse Tubules
Definition
  • Invaginators on sarcolemma
  • Form tunnel from surface to fiber center
  • Filled with extracellular fluid
  • Help spread electrical current through cell
Term
Myofibrils
Definition
Contractile structures give striated appearance
Term
Sarcoplasmic reticulum
Definition
  • Fluid filled sacs surrounding myofibrils
  • Store calcium
  • Terminal cisterns
Term
A Band
Definition
Entire length of THICK filament (Myosin)
Term
H Zone
Definition
Center of A band. Only thick filaments.
Term
Sarcomere
Definition
Functional unit of myofibril
Term
Zone of overlap
Definition
Thick and thin fibers overlap
Term
M Line
Definition
Center of sarcomere
Term
I Band
Definition
Only THIN filaments (Actin)
Term
Myosin
Definition
  • Thick filaments
  • Contractile protein
  • Approximately 300 molecules of myosin form thick filaments
  • Tail points toward M LINE
Term
Actin
Definition
  • Thin Filaments
  • Contractile protein
Term
Actin
Definition
  • Thin Filaments
  • Contractile protein
Term
Tropomyosin
Definition

Keeps actin from binding to myosin in a relaxed muscle

REGULATORY protein

Term
Troponin
Definition

Hold tropomyosin in place

REGULATORY Protein

Term
Titin
Definition
  • Anchor thick filaments to Z dick and M line
  • Keeps thick and thin filaments arranged
  • Elastic and extensible
  • Structural protein
Term
Sliding filament mechanism
Definition

Thin filaments move toward M line

Meet at center of sarcomere

Z disc come close together

Thick and thin filaments overlap

Sarcomere shortens

 

Term
Synaptic Vesicles
Definition
  • Membrance enclosed sacs on synaptic end bulbs of motor neuron
  • Store Acetylcholine molecules
Term
NEUROTRANSMITTER of synapse component of Neuromusclar Junction
Definition
Acetylcholine (ACh)
Term
Motor end plate
Definition
  • Region of sarcolemma adjacent to synaptic end bulb
  • Houses ACh receptors
Term

Muscle contraction cycle

BEFORE CYCLE

Step 1

Definition

BEFORE CYCLE

Nerve sends a motor action potential thourh a motor neuron (either from the brain or spinal cord) to neuromuscular junction

Action potential arrices at synaptic end bulbs stimulating the release of ACh via exoytosis from the synaptic vesicles into the synaptic cleft.

ACh bings to ACh receptors on the motor end plate, triggering muscle action potential.

Term

Muscle Contraction Cycle

BEFORE CYCLE

Step 2

Definition
Muscle action potential travels through the sarcolemma and t-tubules
Term

Muscle Contraction Cycle

BEFORE CYCLE

Step 3

Definition
Sarcoplasmic Reticulum releases calcium
Term

Muscle contraction cycle

BEFORE CYCLE

Step 4

Definition
Calcium binds to troponin
Term

Muscle contraction cycle

BEFORE CYCLE

Step 5

Definition
Troponin-tropomyosin complex moes away from myosin binding site on actin
Term
Muscle Contraction Cycle
Definition
  1. ATP Hydrolysis
  2. Myosin heads attaches to actin
  3. Power stroke
  4. Myosin detached from actin
Term

Muscle Contraction Cycle

Step 1

Definition

ATP Hydrolysis

Energize myosin head to attach to actin

Term

Muscle Contraction Cycle

Step 2

Definition

Myosin head attaches to actin

at myosin binding site forming cross bridges

Term

Muscle Contraction Cycle

STEP 3

Definition

Power stroke

Myosin head rotates, releasing ADP and P.

Move thin filament along thick filament toward M line.

Term

Muscle Contraction Cycle

STEP 4

Definition

Myosin detached from actin

ATP bound to myosin head again

Myosin head detached from actin

Term
Needed to happen for contraction cycle to continue
Definition
ATP available and calcium level in sarcoplasm is high
Term
Muscle fatigue associated with
Definition

REDUCTIONS in

Calcium

Creatine Phosphate

Oxygen

Glycogen and other nutrients

ACh

 

BUILDUP of

Lactic Acid and ADP

Term
Slow oxidative fibers
Definition

Slow twitch

Small diameter fibers

Large amounts of myoglobin and capillaries

Slow due to Slow rate of ATPase in myosin heads

Term
Fast oxidative glycolytic fibers
Definition

Intermediate diameter fibers

Large amounts of myoglobin, capillaries

Generate ATP through aerobic or anaerobic cellular respiration

FAST becasue ATPase hydrolyzes ATP in myosin FASTER than SO

Term
Fast glycolytic fibers
Definition

Fast twitch

Largest diameter

Low myoglobin content, few capilaries

ATP throuh glycolysis

Hydrolyze ATP rapidly

STRONG, RAPID muscle contractions, fatique quickly

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