HA&P: Chapter 9

Skeletal and smooth muscle cells are elongated and can be called what?

Muscle fibers

What two prefixes means “muscle?”

Myo ; Mys

What prefix means “flesh?”

Sarco

What is packaged into the skeletal muscles, organs that attach to and cover the skeleton?

Skeletal muscle tissue

Skeletal muscle fibers are the longest muscle cells and have obvious stripes that can be called what and are a repeating series of dark and light band?

Striations

What occurs only in the heart, where it constitutes the bulk of the heart walls and are striated?

Cardiac muscle tissue

What is found in the walls of hollow visceral organs, its role is to force fluids and other substances through internal body channels, forms valves to regulate the passage of substances through internal body openings, consists of elongated cells, and it contractions are slow and sustained?

Smooth muscle tissue

What characteristic of muscle tissue also means responsiveness, is the ability of a cell to receive and respond to a stimulus by changing its membrane potential?

Excitability

What characteristic of the muscle tissue is the ability to shorten forcibly when adequately stimulated and it sets muscle apart from all other tissue types?

Contractility

What characteristic of muscle tissue is the ability to extend or stretch?

Extensibility

What characteristic of muscle tissue is the ability of a muscle cell to recoil and resume its resting length after stretching?

Elasticity

What are the four muscle functions for the body?

1. Produce movement

2. Maintain posture and body position

3. Stabilize joints

4. Generate heat

This kind of muscle fibers predominate, but blood vessels, nerve fibers, and substantial amounts of connective tissue are also present?

Skeletal muscle

What connective tissue sheath is an “overcoat” of dense irregular connective tissue that surrounds the whole muscle and sometimes it blends with the deep fascia that lies between neighboring muscles or the superficial fascia deep to the skin?

Epimysium

Within each skeletal muscle, the muscle fibers are grouped into what that resembles bundles of sticks?

Fascicles

Surrounding each fascicle is a layer of dense irregular connective tissue called what?

Perimysium

What connective tissue sheath is a wispy sheath of connective tissue that surrounds each individual muscle fiber and it consists of fine areolar connective tissue?

Endomysium

What is of the epimysium of the muscle is fused to the periosteum of a bone or perichondrium of a cartilage?

Direct (fleshy) attachments

a. This of the muscle’s connective tissue wrappings extend beyond the muscle either as a ropelike tendon or as a sheetlike b. ______?

a. Indirect attachments

b. Aponeurosis

Each skeletal muscle fiber is a long cylindrical cell with multiple oval nuclei just beneath its _______ (plasma membrane)?

Sarcolemma

a. This is the cytoplasm of a muscle cell, and it contains large amounts of b.________ (granules of stored glycogen that provide glucose during muscle cell activity for ATP production and c.________, a red pigment that stores oxygen?

a. Sarcoplasm

b. Glycosomes

c. Myoglobin

A single muscle fiber contains hundreds to thousands of rodlike ________ that run parallel to its length and are densely packed in the fiber that mitochondria and other organelles appear to be squeezed between them and are made up of a chain of sarcomeres linked end to end?

Myofibrils

In an intact muscle fiber, the dark a.______ and light b._____ are nearly perfectly aligned, giving the cell its striated appearance?

a. A bands

b. I bands

Each dark A band has a lighter region in its midsection called what?

H zone

Each H zone is bisected vertically by a dark line called what that is formed by molecules of the protein myomesin?

M line

Each light I band also has a midline interruption, a darker area called what?

Z disc (Z line)

The region of a myofibril between two successive Z discs is what that is the smallest contractile unit of a muscle fiber and contains an A band flanked by half an I band at each end?

Sarcomere

What are the muscle equivalents of the actin-containing microfilaments and myosin motor proteins?

Myofilaments

What type of contractile myofilament in a sarcomere contains myosin (red) that extends the entire length of the A band and connected in the middle of the sarcomere at the M line?

Thick filaments

What other type of contractile myofilaments in a sarcomere contains actin (blue) that extends across the I band and pathway into the A band and the Z disc anchors this?

Thin filaments

Each myosin molecule consists of six polypeptide chains of what where a. it twist together to form myosin’s rodlike talk and each ends in a globular head is attached to the tail & b. that are the “business end” of myosin, and during contraction, they link the thick and thin filaments together, forming cross bridges?

a. Two heavy chains

b. Four light chains

The thin filaments are composed chiefly of the protein of what that had kidney-shaped polypeptide subunits called globular actin (G actin) that has a myosin-binding site to which the myosin heads attach during contraction?

Actin

G actin subunits polymerize into long actins filaments called what?

Filamentous (F Actin)

Polypeptide strands of ______ , a rod-shape protein, spiral about the actin core and help stiffen and stabilize it and its molecules are arranged end to end along the actin filaments?

Tropomyosin