Key Terms Chapter 10 Flashcards
The scientific study of muscles is ______
Myology
Three types of muscular tissue include:
Skeletal muscle tissue, cardiac muscle tissue, and smooth muscle tissue
Built-in rhythm that initiates contractions involuntarily
Autorhythmicity
AS muscular tissue contracts, it produces heat, a process known as ________.
Thermogenesis
Four key functions of muscular tissue:
Producing body movements, stabilizing body positions, storing and moving substances within the body, and generating heat.
Four special properties of muscular tissue:
Electrical excitability, contractility, extensibility, and elasticity.
Another name of a muscle cell is _____
Muscle fiber due to their elongated shape
The _______ separates muscle from skin and is composed of areolar connective tissue and adipose tissue.
Subcutaneous layer or hypodermic
A dense sheet or broad band of irregular connective tissue that lines the body wall and limbs and supports and surrounds muscles and other organs of the body
Fascia
The outer layer of dense irregular connective tissue that encircles the entire muscle
Epimysium
A layer of dense irregular connective tissue that surrounds a group of 10 or more muscle fibers separating them into fascicles.
Perimysium
Made up of mostly reticular fibers, this penetrates the interior of each fascicle and separates individual muscle fibers from one another.
Endomysium
The plasma membrane of a muscle cell
Sarcolemma
The cytoplasm of a muscle fiber
sarcoplasm
This protein, found only in muscle, binds oxygen molecules that diffuse into muscle fibers from interstitial fluid and releases it when needed by the mitochondria for ATP production.
Myoglobin
Tiny, striated threadlike structures found in the sarcoplasm of muscle fibers. The contractile organelles of skeletal muscle.
Myofibrils
A fluid-filled system of membraneous sacs that encircles each myofibril.
Sarcoplasmic Reticulum (SR)
The replacement of muscle fibers by fibrous scar tissue.
Fibrosis
Tiny invaginations of the sarcolemma of each muscle fiber that are filled with interstitial fluid.
Transverse tubules
Dilated end sacs of the SR that butt against the T tubule from both sides.
Terminal cisterns
A transverse tubule and the two terminal cisterns form a _____.
Triad
Smaller protein structures within myofibrils are ______.
Myofilaments
The two types of myofilaments or contractile proteins are ______ and ______.
Actin (thin filament) and Myosin (thick filament)
Basic functional unit of myofibrils.
Sarcomeres
These plate-shaped regions of dense protein material separate one sarcomere from the next
Z discs
A sarcomere extends from ____ to ____.
Z disc to Z disc
The darker middle part of the sarcomere which extends the entire length of the thick filaments is the ____.
A band
The lighter, less dense area that contains the rest of the thin filaments and no thick filaments is the ______. A Z disc passes through the center of each I band
I band
A narrow _______ in the center of each A band contains thick but no thin filaments
H zone
Supporting proteins that hold the thick filaments together at the H zone form the ____.
M line (m for middle of the sarcomere)
Site covered by tropomyosin where myosin head can attach to actin
Myosin binding site
Two regulatory proteins of thin filaments:
Tropomyosin and troponin
Tropomyosin proteins that cover the myosin binding sites on actin (in relaxed muscles) are held in place by _______ molecules.
Troponin
