Chapter 15 muscle system

Select all of the functions of skeletal muscle: support maintenance of constant body temperature movement blood cell production hormone secretion

-support -maintenance of constant body temperature -movement

The muscular system is made up of all the muscles, ligaments, and tendons. all the muscles plus the nerves attached to them. all the muscles. all the voluntarily-controlled muscles.

All the muscles

What test is used to help determine if an individual has muscular dystrophy? EKC EEG EMG ECG

EMG

In a skeletal muscle fiber, the sarcolemma forms -------- tubules that penetrate into the cell and contact the sarcoplasmic reticulum.

T

Select all of the following that are components of a muscle fiber. axon terminal T tubule sarcoplasm sarcolemma myelin sheath

T tubule sarcoplasm sarcolemma

What is the definition of a motor unit? a nerve fiber with all of the muscle fibers it innervates all of the nerves that supply a particular muscle a motor neuron plus a neuromuscular junction a single contraction of a group of muscle fibers

a nerve fiber with all of the muscle fibers it innervates

The major protein that is found in the thin filaments in myofibrils of muscle fibers, is------called .

actin

There are two types of myofilaments. Thin filaments primarily consist of two intertwining strands of a protein called------.

actin

What is the major protein in the myofilament that is composed of two intertwined strands? tropomyosin actin troponin myosin

actin

What gives skeletal muscle its striated appearance? alignment of Z-bands arrangement of muscle fibers dark bands of mitochondra-rich tissue arrangement of myofilaments

arrangement of myofilaments

Select all the components of a neuromuscular junction. axon terminal cell body sarcolemma ATP receptors synaptic cleft

axon terminal sarcolemma synaptic cleft

What is the principle purpose of the muscular system? create movement control movement defend the body frame the body

create movement

Identify the mutated protein that leads to muscular dystrophy. dystrophin myosin tryptophan actin

dystrophin

The sarcoplasmic reticulum of a muscle fiber is the nucleus. plasma membrane. cytoplasm. endoplasmic reticulum.

endoplasmic reticulum.

As it relates to muscle contraction, the phenomenon known as recruitment is when a muscle sustains a maximal contraction. more motor units are activated as the intensity of nervous stimulation increase. a muscle is stimulated by infrequent electrical impulses resulting in a single contraction. motor units are simultaneously activated.

more motor units are activated as the intensity of nervous stimulation increase.

A nerve fiber with all of the muscle fibers it innervates is called------unit.

motor

The long, cylindrical, contractile portions of a muscle fiber, which are composed of even smaller myofilaments, are------called .

myofibrils

Within each muscle fiber are hundreds or thousands of cylindrical structures that runs the entire length of the muscle fiber. These are called T-tubules. sarcomeres. myofibrils. myofilaments.

myofibrils.

The striated appearance of skeletal muscle is due to the arrangement of nuclei myofilaments T tubules cells

myofilaments

Arrange these components that make up muscle tissue with the smallest component at the top, and the largest component at the bottom.

myofilaments myofibrils muscle fibers

nside a skeletal muscle cell, a set of small cylinders called _______ are assembled into larger cylinders called _______.

myofilaments; myofibrils

The main protein that is found in the thick filaments in the myofibrils is called------.

myosin

What protein makes up a thick myofilament? actin troponin tropomyosin myosin

myosin

The region where the end of an axon from a neuron comes into close contact with a muscle fiber is called a -------junction.

neuromuscular

The sarcolemma of a muscle fiber is the rough endoplasmic reticulum. plasma membrane. smooth endoplasmic reticulum. cytoplasm.

plasma membrane

When one motor unit begins to fatigue more motor units assist to provide more force. This is known as--------

recruitment

The plasma membrane of a muscle fiber is called the _________. sarcoplasm sarcoplasmic reticulum sarcolemma

sarcolemma

The three types of muscle tissue are cardiac, skeletal, and-------.

smooth

Select the three types of human muscle tissue. digestive smooth rough skeletal cardiac

smooth skeletal cardiac

A single contraction of a motor unit is called a muscle _______. twitch cramp depolarization tic

twitch