Muscular System Quiz- Honors Anatomy and Physiology

Muscles

Organs made up of specialized cells using chemical energy to pull on structures to which they attach

What are the 3 muscle types?

skeletal, smooth, and cardiac

What are the functions of muscle?

movement, posture, stabilize joints, and generate heart

Skeletal muscle is…

on organ composed of skeletal muscle tissue, nervous tissue, blood, and connective tissues

What is fascia?

Layers of dense connective tissue, separate individual skeletal muscles and old it in place

What is Aponeuroses?

Broad sheets of connective tissue, may attach to bone or other muscles

What are the three layers of connective tissue surrounding muscles?

Epimysium, perimysium, and endomysium

What is epimysium?

Outermost layer surrounding the entire muscle

What is perimysium?

Separates and surrounds individual fascicles (muscle fiber bundles)

What is endomysium?

Surrounds individual muscle fibers

Muscle fiber is…

single cell that contracts (shortens0 in response to stimulation and them relaxes at the end of stimulation

Cytoplasm is…

(sarcoplasm) contain many small nuclei

Sarcoplasm also contains many parallel…

myofibrils

Myosin is…

thick protein filaments

Actin is…

thin protein filaments

Organization of these filaments forms…

striations

Striations form repeating units called…

sarcomeres

I bands are…

lights bands- thin (actin)

A bands are…

dark bands- thick (myosin

I bands attach to…

Z lines

Sarcoplasmic reticulum…

Networks of channels surrounding each myofibril (stores calcium ions)

Transverse tubules (T tubules)…

Extent inward from the fiber’s membrane (extension of sarcolemma aka cell membrane)

Neurons works to help…

control muscle action

Motor neurons…

control effectors

Synapse is the…

connection (gap) between neuron and muscle fiber

Neurons communicate with other cells by releasing chemical called…

neurotransmitters

Synapse between motor neuron and muscle fiber is called a…

neuromuscular junction

Motor end plate

folded region to allow communication

Neurons stores neurotransmitters in

Synaptic vesicles

Neurotransmitters travel the gap (________) to stimulate contraction

synaptic cleftMyo

Myosin binds to actin and exerts…

pulling force

What is the resulting movement in actin and myosin filaments?

they slide past each other and shorten the muscle fiber

Myosin is made of many

cross-bridges

Actin as _______ for where myosin ________

binding sites; cross-bridges attach

Sarcomeres shorten from cross-bridges pulling on what?

actin filaments

Sliding filament model is…

the process by how sarcomeres shorten from actin-myosin interactions

What is ATPase?

an enzyme which breaks down ATP, an energy molecule

Where is acetylcholine (Ach) stored?

Vesicles in motor neuron axons

What are the 2 events that cause muscles to relax?

1. ACh gets broken down

2. Once ACh is broken down, calcium (Ca) ions are transported back into the sarcoplasmic reticulum (SR). This causes actin-myosin links to break and muscle fibers to relax.

creatine phosphate is…

much more abundant than ATP in muscle fibers but also can’t directly supply energy

Oxygen is carried by red blood cells by a molecule of what?

hemoglobin

What is made by muscle fibers to accept oxygen?

Myoglobin (red-brown color to muscles)

Strenuous activity doesn’t take long for muscles to produce energy without oxygen and creates what?

lactic acid

Where does lactic acid et broken down which also requires ATP?

the liver

Amount of oxygen liver cells need to break down lactic acid plus the amount muscle cells need to restore ATP

oxygen debt

Lose ability to contract

Fatigue

when muscles exercise for a long period of time, they can become…

fatigued

What do skeletal muscles do after death?

Contract and are rigid

What prevents muscles from relaxing?

an increase in Calcium (Ca) ions and a decrease in ATP

A major generator of heat in the body

Muscle tissue

transports heat from muscles to other tissues or to skin surface to regulate body temp

blood

less than half the energy released during cellular respiration is used to make…

ATP