Muscular System

Question 1

What is myology?

Answer 1

the study of muscle

Question 2

What are the functions of the muscular system?

Answer 2

Movement
Posture maintenance
heat protection
only 40% of the energy released is muscle activity is useful at work
the remaining 60% is given off as heat

Question 3

What are the characteristics of muscle?

Answer 3

Excitability- ability to receive and respond to stimuli- contract
Contractility- the ability to shorten forcibly
Extensibility- the ability to be stretched or extended
Elasticity- ability to recoil and resume the original resting

Question 4

What are the types of muscle?

Answer 4

Smooth muscle
Skeletal muscle
Cardiac muscle

Question 5

What are the characteristics of smooth muscle?

Answer 5

Spindle shaped cells
cells contain a single nucleus
No striations
Contain actin (thin) and myosin (thick) filaments
Have less developed endoplasmic reticulum
Involuntary

Question 6

What are the types of Smooth muscle?

Answer 6

Multiunit smooth muscles
Visceral smooth muscles

Question 7

What are the characteristics of multiunit smooth muscle?

Answer 7

Less organized
Functions as individual muscle units
Found in the wall of blood vessel (increase or decrease blood pressure)

Question 8

What are the characteristics of Visceral smooth muscle?

Answer 8

More organized
Show rhythmicity and peristaltic movements (waves of motion)
mostly found in the wall of the GI tract, uterus, urinary bladder

Question 9

What are the characteristics of skeletal muscle?

Answer 9

cells are elongated like fibers-called muscle fibers
multinucleated cells
Striated
Voluntary
attached to the bone- associated with posture and movement

Question 10

Which muscle tissue has spindle shaped cells?

Answer 10

Smooth Muscle

Question 11

What are the characteristics of cardiac muscles?

Answer 11

cells are elongated and branched
cells are single or multiple nuclei (mostly single)
have intercalated discs
cells are striated
involuntary
muscle fibers contract as a unit
contract for longer time period due to Endoplasmic Ret. having extra calcium
self exciting and rhythmic
EX) Heart muscle

Question 12

Histology: Each muscle cell is a ?

Answer 12

Myofiber (when elongated)

Question 13

What is Plasmalemma called in the muscular system?

Answer 13

Sarcolomma

Question 14

What is cytoplasm called in the muscular system?

Answer 14

Sarcoplasm

Question 15

What is Endoplasmic reticulum called?

Answer 15

sarcoplasmic reticulum

Question 16

Each myofiber consists of several cylindrical structures called?

Answer 16

Myofibrils

Question 17

Each myofibril consists of?

Answer 17

thick and thin myofilaments

Question 18

Thick myofilaments are?

Answer 18

myosin (protein) filament

Question 19

Thin myofilaments are?

Answer 19

actin (protein) filament

Question 20

Overlapping of thick and thin filaments form?

Answer 20

A- band (anisotropic band) Also known as dark band

Question 21

Each myofibril is divided into compartments called?

Answer 21

sarcomeres

Question 22

Thin myofilaments form?

Answer 22

I-Band (isotropic band) also called light band

Question 23

Sarcomeres are separated from one another by?

Answer 23

Z-line

Question 24

Part of the A-Band that contains think myofilaments ONLY is the?

Answer 24

H-zone

Question 25

Line in the middle of the H-zone is the?

Answer 25

M- line (where the myosin filaments are thick)

Question 26

The myosin filaments are connected to one another by?

Answer 26

titin (connectin) proteins

Question 27

What proteins are associated with actin filaments are?

Answer 27

tropomyosin and troponin

Question 28

with in the cell, sarcoplasmic reticulum gets enlarged to form

Answer 28

cisterna