LAB PRACTICAL #2: Muscle Tissue

______ is the area in a relaxed muscle fiber where the thick and thin myofilaments overlap; forms a dark dense band

A band

the _____ is in the middle of the A band, where only thick filaments are present

H zone

______ is composed of only thin myofilaments; it forms a light-colored less dense band

I band

the _____ is the attachment site for the thick filaments. This line is in the center of the A band and formed by molecules of the protein myomesin.

M line

________ are narrow plate-shaped regions that separate neighboring sarcomeres

Z discs

____ is a globular protein that polymerizes (joins together many small molecules) to form thin filaments.

actin

the __ is a long, slender projection of a nerve cell, or neuron, that typically conducts electrical impulses away from the neuron's cell bod

axon

in a nueromuscular junction, the bulbs at the end of the motor axon is the ______.

axon terminals

the _____ tissue is branching, striated and contains uni nucleate cells.

cardiac muscle

skeletal muscle that is cut transversely is called the _____ and has grouped fascicles.

cross section

______ surrounds (covers) each single muscle fiber(cell)

endomysium (C)

the ______ in skeletal muscle (cross section) surrounds each muscle fiber.

endomysium (C)

the ____ is skeletal muscle (cross section) wraps around the whole muscle.

epimysium

the ____ in skeletal muscle (cross section) is the entire width within a cell; it is a bundle of muscle fibers

fascicle

in a nueromuscular junction, the muscle ____ run alongside.

fiber

the _______ are rod-shaped organelles that can be considered the power generators of the cell.

mitochondrion (5)

in a nueromuscular junction, the _____ is the dark band that runs along the muscle fibers.

motor axon

Compared to skeletal muscle, smooth ______ are small. They are spindle shaped and have no striations. Instead, they have bundles of thin and thick filaments.

muscle cells

skeletal _____ are the large bands between nuclei and striations.

muscle fiber

the _______ in skeletal muscle (cross section) is also known as the muscle cell.

muscle fiber

cardiac ______ are elongated, branches, and striated

muscles

_______ protects and electrically insulates fibers and increases the transmission speed of nerve impulses.

myelin sheath (10)

a ______ is a basic rod-like unit of a muscle cell.

myofibril

____ is a protein that looks like a golf club which composes thick myofilaments; contains heads

myosin

the ________ is the chemical synapse formed by the contact between a motor neuron and a muscle fiber.

neuromuscular junction

____ of skeletal muscle are long, cylindrical cells between striations.

nuclei

cardiac muscle _____ are located in the center of each fiber.

nucleus

A single and centrally placed _____ is located in each smooth muscle cell.

nucleus (2)

the ____ is at the center of a muscle cell and forms the basis for its activity and growth.

nucleus (E)

the ____ in skeletal muscle (cross section) surrounds bundles of muscle fibers and between fascicles (large and narrow "tubes")

perimysium (D)

the ______ (within the endomysium) is a cell membrane that surrounds each muscle cell.

sarcolemma (1)

stacked units of myofilaments, the functional units of muscle responsible for contraction are _______

sarcomere

the ________ surrounds each myofibril and is physically separated from the sarcolemma. These tubules or tubes sometimes branch forming a network that is reticular in appearance.

sarcoplasmic reticulum

____ muscle long, cylindrical, multi-nucleate cells with obvious striations.

skeletal

_______ muscle is made up of cells that contain a single central nucleus. No striated appearance.

smooth

the ______ is the fluid filled space that separates presynaptic and postsynaptic membranes.

synaptic cleft (8)

the _____ is the tiny membrane bound sacs that contain neurotransmitters.

synaptic vesicles (A)

the _______ are a series of elongated tubes that run through the sarcoplasm

t tubule (2)

the large perpendicular cross channels that wraps around the SR is the _____

terminal cisternae

a ____ is 2 paired terminal cisterns along with a T tubule that runs in between them.

triad

associated with thin myofilaments, proteins that cover the myosin-binding sites in a relaxed muscle fiber are ______

tropomyosin and troponin