Muscle Physiology Lecture

Flashcards covering the Muscle Physiology lecture notes

What percentage of body heat is produced by muscles?

85%

What are the functions of the muscular system?

Body movement, posture, stabilize joints, mineral storage, and producing heat

Name the 4 characteristics of muscle tissue:

Excitability, Conductivity, Contractility, Extensibility, Elasticity

Is cardiac muscle voluntary or involuntary?

Involuntary

Is skeletal muscle voluntary or involuntary?

Voluntary

Is smooth muscle striated or non-striated?

Non-striated

Name the three things that serve each muscle:

A nerve, an artery, and veins

What are the connective tissue sheaths for muscle fibers?

Endomysium, perimysium, epimysium

What is the definition of a fascicle?

A discrete bundle of muscle cells, segregated from the rest of the muscle by a connective tissue sheath.

What is the function of the neuromuscular junction?

Site where motor neuron interfaces (synapses) onto individual skeletal muscle fibers/cells

What creates the striated appearance within skeletal muscle?

Alternating bands of myofilaments

What two units make up myofibrils?

Thick and thin filaments

What is the function of the sarcoplasmic reticulum?

Interconnecting tubules surrounding EACH myofibril, store calcium and release it when muscle is stimulated to contract

What is the function of T-tubules?

Conducts electrical impulses from nerves (action potentials) deeper into cell interior and Ensures every myofibril in the muscle fiber contracts simultaneously

What causes the H-zone to disappear during muscle contraction?

The actin and myosin filaments overlap

What occurs during the sliding model of muscle contraction?

Myosin heads attach to binding sites on actin, creating cross bridges that pulls actin towards the center of the sarcomere

Name 4 functional groups of muscles:

Prime mover/agonist, antagonist, synergists, fixators

What are some of the ways skeletal muscles may be named?

Direction of fibers, Relative size of muscle, Location of muscle, Number of origins, Location of origin & insertion, Shape of muscle, Action of muscle

What causes Duchenne's muscular dystrophy?

Lack of dystrophin, which maintains sarcolemma

Name 3 Intramuscular injection sites:

Deltoid, Vastus lateralis, Dorsogluteal

What part of the sarcomere shortens when a muscle contracts?

Sarcomere

What part of the sarcomere does NOT shorten when the muscle contracts?

A band

Which part of the sarcomere is the functional contractile unit?

Sarcomere

Does the M line shorten when the muscle contracts?

No

H zone

Lighter region in the middle of the A band; contains thick filaments only