GROUP 2

Question 1

an organ system, involved majorly in the movement of the body.

Answer 1

muscular system

Question 2

found in the heart, blood vessels, and digestive system.

Answer 2

muscle tissues

Question 3

Every muscle is a different organ made of (4)

Answer 3

blood vessels
skeletal muscle tissue
nerves
tendons

Question 4

Importance

Answer 4

fundamental for promoting physical health, preventing injuries, enhancing athletic performance, and facilitating rehabilitation.

Question 5

types of muscles

Answer 5

1. smooth (present only in the heart; spindle-shaped)
2. cardiac (within organs such as the intestines, the blood vessels and the stomach; cylindrical, branched)
3. skeletal (body parts that are connected to the bone; long, cylindrical)

Question 6

Individual muscle cells that makes up the skeletal muscles

Answer 6

muscle fiber

Question 7

Many oval nuclei can be seen just beneath the plasma membrane, which is called

Answer 7

sarcolemma

Question 8

The nuclei are pushed aside by long ribbonlike organelles which nearly fill the cytoplasm

Answer 8

myofibrils

Question 9

give the muscle cell as a whole its striped appearance.

Answer 9

light and dark bands

Question 10

The myofibrils are actually chains of tiny contractile units called ________, which are aligned end to end like boxcars in a train along the length of the myofibrils.

Answer 10

sarcomeres

Question 11

There are two types of threadlike protein _________ within each of our “boxcar” sarcomeres.

Answer 11

myofilaments

Question 12

also called myosin filaments, are made mostly of bundled molecules of the protein myosin, but they also contain ATPase enzymes, which split ATP to generate the power for muscle contraction.

Answer 12

thick filaments

Question 13

Notice that the midparts of the thick filaments are smooth, but their ends are studded with thick projections; these projections, or myosin beads, are called ___________ when they link the thick and thin filaments together during contraction.

Answer 13

cross bridges

Question 14

composed of the contractile protein called actin, plus some regulatory proteins that play a role in allowing (or preventing) myosin-bead

Answer 14

thin filaments

Question 15

• very important muscle fiber organelle
• a specialized smooth endoplasmic reticulum
• the interconnecting tubules and sacs of the SR surround each and every myofibril just as the sleeve of a loosely crocheted sweater surrounds your arm, and its major role is to store calcium and to release it on demand.

Answer 15

sarcoplasmic reticulum

Question 16

made up of hundreds of thousands of muscle cells (also called muscle fibres). These muscle cells act together to perform the functions of the specific muscle they are part of.

Answer 16

skeletal muscle

Question 17

macro structure

Answer 17

muscle
fascicles
muscle fibers

Question 18

micro structure

Answer 18

muscle fibers (bundle of myofibrils)

myofibrils

sarcomeres

myofilaments (actin, myosin)

Question 19

Parts of Muscle Fiber

Answer 19

1) Sarcolemma
2) Mitochondria
3) Transverse tubules
4) Terminal cisternae
5) Sarcoplasmic reticulum

Question 20

• Forms Short or Thinner Filaments
• Have smooth surface
• Have a lighter striations
• Slide into the H-zone during contraction
• Free at one end

Answer 20

actin

Question 21

• Forms Long or Thick Filaments
• Have rough surface
• Have a dark striations
• Do not slide during contraction
• Free at both ends

Answer 21

myosin

Question 22

3 structures of actin

Answer 22

g-actin
tropomyosin
troponin

Question 23

2 structures of myosin

Answer 23

head
rod

Question 24

FOUR MAJOR FUNCTIONS of the muscular system

Answer 24

contractility
excitability
extensibility
elasticity

Question 25

ability of muscle to shorten forcefully, when muscle contracts, it either causes the structures to which it is attached to move or increases pressure inside a hollow organ or vessel.

Answer 25

contractility

Question 26

capacity of muscle to respond to a stimulus.

Answer 26

excitability

Question 27

muscle can be stretched beyond its normal resting length and still be able to contract.

Answer 27

extensibility

Question 28

ability of muscle to recoil to its original resting length after it has been stretched.

Answer 28

elasticity

Question 29

In an unstimulated cell, the uneven distribution of charges is referred to as the

Answer 29

resting membrane

Question 30

Enables the determination of cell potential under non-standard conditions

Answer 30

nernst equation

Question 31

Movement of 3 Na ions out of the cell and 2 K ions move inside the cell.

Answer 31

sodium potassium pump

Question 32

Muscle cells and nerve cells are excitable cells

Question 33

Integral membrane proteins that contain a pore which allows the regulated flow of selected ions across the plasma membrane

Answer 33

gated-ion channels

Question 34

the initial increase of the membrane potential to the value of the threshold potential

Answer 34

hypopolarization

Question 35

the value of the membrane potential which, if reached, leads to the all-or-nothing initiation of an action potential

Answer 35

threshold

Question 36

The movement of Na is called the local current, which causes the inside of the cell membrane to become positively charged.

Answer 36

depolarization The depolarization result is called the local potential

Question 37

the peak of the action potential where the membrane potential is positive

Answer 37

overshoot

Question 38

The subsequent return to resting potential, repolarization, is mediated by the opening of potassium ion channels

Answer 38

Repolarization

Question 39

The process of depolarization and repolarization is what is referred to as the

Answer 39

action potential

Question 40

action potential propagate towards the synaptic terminal which stimulates the release of a neurotransmitters Cause calcium channels to open up, which is essential for

Answer 40

muscle contraction

Question 41

the end of the motor neuron that divides into a cluster of synaptic end bulbs

Answer 41

axon terminal

Question 42

neural part of NMJ

Answer 42

Synaptic End Bulbs

Question 43

suspended in the cytosol within each synaptic end bulb are hundreds of membrane-enclosed sacs.

Answer 43

Synaptic Vesicles

Question 44

the neurotransmitter released at the NMJ

Answer 44

Acetylcholine (ACh)

Question 45

the muscular part of the NMJ. The region of the sarcolemma opposite the synaptic end bulbs. The region of the sarcolemma opposite the synaptic end bulbs.

Answer 45

Motor End Plate

Question 46

integral transmembrane proteins to which ACh specifically binds.

Answer 46

Acetyl Choline Receptors

Question 47

deep grooves in the motor end plate that provide a large surface area for ACh.

Answer 47

Junctional Folds

Question 48

NEUROMUSCULAR JUNCTIONS

Answer 48

SKELETAL MUSCLE

Question 49

NEUROCARDIAC JUNCTIONS

Answer 49

CARDIAC MUSCLE

Question 50

NEUROEFFECTOR JUNCTIONS

Answer 50

SMOOTH MUSCLE

Question 51

The neuromuscular junction is composed of three parts:

Answer 51

Presynaptic motor nerve terminal Synaptic cleft or junctional cleft Postsynaptic muscle fiber

Question 52

- Terminal end branches to one to two hundred nerve terminals - Each ending of these terminal lies close to the membrane of the muscle

Answer 52

Presynaptic motor nerve terminal

Question 53

- thick ends of the nerve terminals that contains special proteins, voltage-gated calcium channels, and potassium channels. - contains a variety of cell organelles including mitochondria and endoplasmic reticulum. - Many mitochondria mean there is enough energy for acetylcholine synthesis.

Answer 53

Active Zone

Question 54

The space between the nerve terminal and the plasma membrane of muscle The neurotransmitter acetylcholine (ACh) released from vesicles in the active zone of the motor nerve terminal must cross this gap to cause an effect in the muscle

Answer 54

Synaptic cleft or junctional cleft

Question 55

The synaptic cleft contains quantities of an enzyme called helps to break down acetylcholine into acetic acid and choline much more quickly – it is a catalyst. Function: end a nerve impulse once it has reached the target muscle. The release of acetylcholine requires calcium ions.

Answer 55

acetylcholinesterase (AChE).

Question 56

positioned on the receiving end of the synaptic cleft The power that is caused by changes in membrane voltage by the acceptance of ACh in the motor endplate receptors can depolarize a muscle fiber and cause it to contract. ACh receptors are ligand-gated ion channels. Between +50 and +75 millivolts are required. This power surge is called the end plate potential (EPP). Only higher-volume release from large numbers of vesicles can produce the voltage changes that forward a nerve impulse. When enough is released to produce at least +50 mV, muscle contraction can occur.

Answer 56

Postsynaptic muscle fiber

Question 57

ccurs because myosin heads attach to and “walk” along the thin filaments at both ends of a sarcomere, progressively pulling the thin filaments toward the M line

Answer 57

Muscle contraction

Question 58

A muscle rests if the motor neuron stops releasing signals