Lab 20 - Skeletal Muscle Structure and Function

Layer of connective tissue that surrounds an individual muscle fiber.

Endomysium

Layer of connective tissue that surrounds a skeletal muscle.

Epimysium

(T/F) The role of a particular muscle is always the same.

False

Connective tissue located between adjacent muscles.

Fascia

A small bundle of muscle fibers.

Fascicle

Protein found within thick filament.

Myosin

Layer of connective tissue that separates a muscle into small bundles called fascicles.

Perimysium

Plasma membrane of a muscle fiber.

Sarcolemma

Unit of alternating light and dark striations between Z lines.

Sarcomere

Cytoplasm of a muscle fiber.

Sarcoplasm

Cellular organelle in muscle fiber corresponding to the endoplasmic reticulum.

Sarcoplasmic Reticulum

Cordlike part that attaches a muscle to a bone.

Tendon

Membranous channel extending inward from muscle fiber membrane.

Transverse (T) Tubule

(T/F) A synergist muscle contraction assists the prime mover.

True

(T/F) The plasma membrane of a muscle fiber (cell) is called the sarcolemma.

True

When the biceps brachii acts as the prime mover, the ________ muscle assists as a synergist.

brachialis

The outermost layer of connective tissue of a muscle is the A) fascicle B) endomysium C) epimysium D) perimysium

epimysium

The ________ of a muscle is usually attached to a moveable location.

insertion

The neuron and the collection of muscle fibers it innervates is called the A) neural impulse B) muscle fiber C) motor neuron D) motor unit

motor unit

The thick myofibril filament of a sarcomere is composed of which protein? A) myosin B) actin C) titin D) sarcolemma

myosin

The ________ of a muscle is usually attached to a fixed location.

origin

A muscle responsible for most of a movement is called a ___________.

prime mover

The muscle primarily responsible for a movement is the A) synergist B) prime mover (agonist) C) antagonist D) origin

prime mover (agonist)

Antagonists are muscles that resist the actions of _________ and cause movement in the opposite direction.

prime movers

The functional contractile unit of a muscle fiber (cell) is a A) sarcoplasm B) sarcolemma C) sarcomere D) sarcoplasmic reticulum

sarcomere

Assisting muscles are called _________.

synergists

When the forearm is extended at the elbow joint, the ________ muscle acts as the prime mover.

triceps brachii