Skeletal and Muscular System

Question 1

Main functions of skeleton?

Answer 1

support, protection and movement

Question 2

Main types of skeleton?

Answer 2

• hydrostatic skeletons
• exoskeletons
• endoskeletons

Question 3

hydrostatic skeleton?

Answer 3

• consist of fluid held under pressure in a closed body compartment
• flatworms, cnidarians, nematodes and annelids
• to change the shape of fluid-filled compartments

Question 4

exoskeleton?

Answer 4

• hard encasement
• deposited on the surface of animal
• found in molluscs and arthropods

Question 5

endoskeleton?

Answer 5

-hard supporting elements
-bones
-found in sponges, echinoderms and chordates
mammalian skeleton is built more than 200 bones

Question 6

Function of muscles and tendons?

Answer 6

help to support large land vertebrates

Question 7

skeletal muscles are attached to the skeleton in?

Answer 7

antagonistic pairs

Question 8

skeletal muscle consists of?

Answer 8

bundle of long fibers

Question 9

muscle fiber?

Answer 9

bundle of smaller myofibrils arranged longitudinally

Question 10

myofibrils are composed of?

Answer 10

1. thin filaments (2 strands of actin and 1 strand of regulatory protein)
2. thick filaments (staggered arrays of myosin molecules)

Question 11

skeletal muscle is also known as and why?

Answer 11

• striated muscle

- the regular arrangement of the myofilaments creates a pattern of light and dark bands

Question 12

in vertebrate skeletal muscle, each repeating unit is called?

Answer 12

• sarcomere
• bordered by Z lines
• thick filaments attached at the M lines centered in the sarcomere
• area contain myofilaments
• I band, A band and H zone
• muscle at rest
• partially overlap (thick and thin filaments)

Question 13

sliding-filament model of muscle contraction?

Answer 13

• the filaments slide past each other longitudinally

- producing more overlap between thin and thick filaments

Question 14

result of sliding?

Answer 14

• I band and H zone shrink
  a. relaxed muscle fiber
• I bands and H zone wide
  b. contracting muscle fiber
• thick and thin slide past each other, reducing the width of the I bands and H zone and shortening sarcomere
  c. fully contracted muscle fiber.
• sarcomere is shorter still
• thin filament overlap, eliminating H zone
• I bands disappear as the end of thick filament contract the Z lines

Question 15

skeletal muscle fiber contracts?

Answer 15

when stimulated by a motor neuron

Question 16

infoldings of the plasma membrane called?

Answer 16

transverse tubules

Question 17

action potential along the T tubules?

Answer 17

causes the sarcoplasmic reticulum to release Ca2+

Question 18

Why the Ca2+ binds to the troponin-tropomyosin complex on the thick filament?

Answer 18

exposing the myosin-binding sites and allowing the cross-bridge cycle to proceed

Question 19

how many muscles are in the human body?

Answer 19

600 / 640

Question 20

how many bones are in a adult human body?

Answer 20

206

Question 21

Which system is responsible for creating red blood cells?

Answer 21

skeletal

Question 22

A socket type of joint is one that can move to multiple directions. Which one below is a socket type of joint?

Answer 22

shoulder

Question 23

A hinge type of joint is one that moves back and forth only. Which one below is an example of hinge type of joint?

Answer 23

elbow

Question 24

What is the difference between ligament and tendon?

Answer 24

• ligament connects bone to bone

- tendon connects muscle to bone

Question 25

What are the 3 types of muscles?

Answer 25

Cardiac, skeletal, smooth

Question 26

in vertebrate skeletal muscle, near the edge of sarcomere?

Answer 26

only THIN filaments

Question 27

in vertebrate skeletal muscle, zone in the center contain

Answer 27

only THICK filaments