Chapter # 10 Muscular System Notes Bio201In

Front 1

name the four functions of the muscular system

Back 1

Movement
Posture
Protection
Heat Production

Front 2

Name the four major functional characteristics of muscle tissue:

Back 2

Contractility
Excitability
Extensibility
Elasticity

Front 3

One of the four major functional characteristics of muscle that allow the muscle tissue to contract forcefully

Back 3

Contractility

Front 4

One of the four major functional characteristics of muscle tissue that allows muscle tissue to respond to a stimulus

Back 4

Excitability

Front 5

One of the four major functional characteristics of muscle tissue that allow muscles to be stretched

Back 5

Extensibility

Front 6

One of four major functional characteristics that allow muscles to recoil to their resting length after being stretched

Back 6

Elasticity

Front 7

Skeletal muscle cells are also called muscle _______

Back 7

Fibers

Front 8

These cells are multinucleated, meaning they have many nuculi

Back 8

Skeletal muscle cells

Front 9

These cells are enlongated and cylindrical

Back 9

Skeletal muscle cells

Front 10

These cells are visibily striated, meaning they appear striped (2)

Back 10

Skeletal muscle cells
Cardiac muscle cells

Front 11

These muscle cells are under voluntary control

Back 11

Skeletal muscle cells

Front 12

These muscle cells can extend the entire length of a muscle

Back 12

Skeletal muscle cells

Front 13

Are the muscle cells of the heart

Back 13

Cardiac muscle cells

Front 14

These cells are branching cells that connect to each other at intercalated disks

Back 14

Cardiac muscle cells

Front 15

These muscle cells are under involuntary control (2)

Back 15

Cardiac muscle cells
Smooth muscle cells

Front 16

Muscle cells that are found in the walls of internal organs

Back 16

Smooth muscle cells

Front 17

These muscle cells are spindle chaped with a single nucleus

Back 17

Smooth muscle cells

Front 18

These muscle cells are not striated

Back 18

Smooth muscle cells

Front 19

These muscle cells are 1000X shorter than skeletal muscle fibers

Back 19

Smooth muscle cells

Front 20

In these muscle cells actin and myosin myofilaments are present but not organized into sarcomeres

Back 20

Smooth muscle cells

Front 21

Are another name for muscle cells

Back 21

Muscle fibers

Front 22

Are comprised of a group of muscle fibers

Back 22

Fasciculi

Front 23

Is compried of a group of fasciculi

Back 23

Whole muscle

Front 24

Surrounds each structural level of a muscle

Back 24

Connective tissue

Front 25

_______ binds the cells together giving strength and support to the entire muscle

Back 25

Connective tissue

Front 26

Connective tissues surrounding the muscle fibers

Back 26

Endomysium

Front 27

This connective tissue surrounds, separates, and electrically insulates muscle cells

Back 27

Endomysium

Front 28

Connective tissue sheath that surround the fascicles

Back 28

Perimysium

Front 29

Connective tissue sheath around the whole muscle

Back 29

Epimysium

Front 30

A second connective tissue layer surrounds the whole muscle, superficial to the epimysium

Back 30

Fascia

Front 31

The many _____ of the muscle fibers lie just inside the plasma membrane

Back 31

Nuclei

Front 32

The name of the plasma membrane of muscle fibers

Back 32

Sarcolemma

Front 33

Is the smooth endoplasmic reticulum of the muscle fiber. It forms a tubular network around each myofibril

Back 33

Sarcoplasmic reticulum

Front 34

An enlargement of the sarcoplasmic reticulum on either side of a transverse tubule

Back 34

Terminal cisterna

Front 35

________ is stored in the terminal cisternae

Back 35

Calcium ions

Front 36

Is a transverse tubule and two adjacent terminal cisterna

Back 36

Triad

Front 37

Are tubes that extend at right angles from the sarcolemma into the interior of the cell

Back 37

T Tubules

Front 38

______ impulses can travel along these tubules to the interior

Back 38

Electrical

Front 39

There are many mitochondria in muscle fibers that generate _______ which is stored in the energy surrency molecule ATP

Back 39

Energy

Front 40

Are the contractile structures that extend from one end of the muscle fiber to the other. They fill up most of the cell's cytoplasm

Back 40

Myofibrils

Front 41

Myofibrils are composed of two types of ______

Back 41

myofilaments

Front 42

The ______ are the contractile proteins

Back 42

Myofilaments

Front 43

A thin myofilament

Back 43

Actin

Front 44

A thick myofilament

Back 44

Myosin

Front 45

The myofilaments are arranged in such a manner to form visible alternating light and dark ____

Back 45

bands

Front 46

Myofilaments are organized into repeating functional units called _____

Back 46

Sacromeres

Front 47

Dark band formed by the thick myofilaments

Back 47

A band

Front 48

Light band between A bands. Contains only thin filaments

Back 48

I band

Front 49

The line where the actin myofilaments are held in place

Back 49

Z line

Front 50

The Z line is found within the _ band

Back 50

I

Front 51

Region between ends of actin myofilaments. Contains only myosin

Back 51

H zone

Front 52

The _ line is in the middle of the H zone

Back 52

M

Front 53

Each myosin molecule is shaped like a _______

Back 53

golf club

Front 54

The rod portion of myosin lies _______ to the myofilament

Back 54

Parallel

Front 55

In a thick myofilament, the double ____ portion extend laterally from the rods

Back 55

Head

Front 56

The head of the myosin can bind to an ____ subunit forming a crossbridge

Back 56

Actin

Front 57

____ myofilament is comprised of actin, tropomyosin and troponin

Back 57

Thin

Front 58

The strands of subunits form a double helix

Back 58

Actin

Front 59

Each subsuit in actin has a binding site for

Back 59

Myosin

Front 60

Elongated protein that wraps around the actin

Back 60

Tropomyosin

Front 61

______ covers the binding site on teh actin subunits

Back 61

Tropomyosin

Front 62

______ prevents the myosin head from attaching

Back 62

Tropomyosin

Front 63

Binds to actin, tropomyosin and calcium

Back 63

Troponin

Front 64

When _____ binds to troponin, tropomyosin moves uncovering the binding sites on the actin subunits making it possible for myosin to bind to the actin

Back 64

Ca++

Front 65

Composed of many elongated myosin molecules clumped together

Back 65

Thick myofilament

Front 66

How the mechanism works- In response to a nerve stimulus Ca++ is released from the terminal cisternae

Back 66

1. Ca++ binds to the binding site on troponin
2. Tropomyosin moves uncovering the binding site on the actin
3. Myosin binds to actin forming a crossbridge
4. The myosin head moves in a power stroke which causes the thin myofilament to slide past the thick myofilament
5. ATP binds to the myosin head causing the yosin to disconnect from the actin
6. The hydrolysis of ATP activates the myosin head and repositions it
7. Ca++ is actively transported back into the sacroplasmic reticulum

Front 67

When all crossbridges are neither bound or disconnected at the same time

Back 67

Multiple crossbridge cycles