MGRADES
IB SEHS Topic 4 UPDATED ACTUAL
Exam Questions and CORRECT Answers
Myofibril - CORRECT ANSWER - One of the slender threads of a muscle fiber,
composed of numerous myofilaments
Myofilament - CORRECT ANSWER - Myofibrils are made up of even smaller threadlike
structures
Actin Filament and Myosin Filament - CORRECT ANSWER - Two protein sites
responsible for movement
Sarcomere - CORRECT ANSWER - Is the basic unit of a muscle and is the part of the
muscle that contracts
H Zone - CORRECT ANSWER - The region of the sarcomere that contains only thick
myofilaments
I Band - CORRECT ANSWER - From the end of the Myosin to the Z Line
A Band - CORRECT ANSWER - The band of the sarcomere that extends the full length of
the thick filament
Z Line - CORRECT ANSWER - Separates one sarcomere from the next and is where actin
filaments attach
Tropomyosin - CORRECT ANSWER - An actin-binding protein which regulates muscle
contraction. Active sites of actin are blocked by this
, MGRADES
Troponin - CORRECT ANSWER - The protein that acts as a calcium receptor in skeletal
muscle
Sarcoplasmic Reticulum - CORRECT ANSWER - Organelle of the muscle fiber that
stores calcium. (Ca+)
Calcium Ions - CORRECT ANSWER - Serves as the actual "trigger" for muscle
contraction by removing the inhibition of the troponin molecules
ATP (Adenosine Triphosphate) - CORRECT ANSWER - The main energy source that
cells use for most of their work
Movement types - CORRECT ANSWER - Flexion, Extension, Adduction, Abduction,
Rotation, Circumduction, Plantar, Dorsi, Supination, Pronation, Inversion, Eversion, Depression,
Elevation
Muscle contraction - CORRECT ANSWER - Shortening/lengthening of sarcomere. Z
Lines move closer, I Band, H Zone decrease
Straited (striped) Muscle - CORRECT ANSWER - Another name for skeletal muscle
Motor Unit - CORRECT ANSWER - A motor neuron and all the muscle cells it stimulates
Neurotransmitters - CORRECT ANSWER - Chemical messengers that cross the synaptic
gaps between neurons. Acetylcholine
Nueron - CORRECT ANSWER - Nerve cell that carries messages throughout the body as
electrical signals
Fast twitch muscle fibres - CORRECT ANSWER - Rapid contraction speed but tire easily
IB SEHS Topic 4 UPDATED ACTUAL
Exam Questions and CORRECT Answers
Myofibril - CORRECT ANSWER - One of the slender threads of a muscle fiber,
composed of numerous myofilaments
Myofilament - CORRECT ANSWER - Myofibrils are made up of even smaller threadlike
structures
Actin Filament and Myosin Filament - CORRECT ANSWER - Two protein sites
responsible for movement
Sarcomere - CORRECT ANSWER - Is the basic unit of a muscle and is the part of the
muscle that contracts
H Zone - CORRECT ANSWER - The region of the sarcomere that contains only thick
myofilaments
I Band - CORRECT ANSWER - From the end of the Myosin to the Z Line
A Band - CORRECT ANSWER - The band of the sarcomere that extends the full length of
the thick filament
Z Line - CORRECT ANSWER - Separates one sarcomere from the next and is where actin
filaments attach
Tropomyosin - CORRECT ANSWER - An actin-binding protein which regulates muscle
contraction. Active sites of actin are blocked by this
, MGRADES
Troponin - CORRECT ANSWER - The protein that acts as a calcium receptor in skeletal
muscle
Sarcoplasmic Reticulum - CORRECT ANSWER - Organelle of the muscle fiber that
stores calcium. (Ca+)
Calcium Ions - CORRECT ANSWER - Serves as the actual "trigger" for muscle
contraction by removing the inhibition of the troponin molecules
ATP (Adenosine Triphosphate) - CORRECT ANSWER - The main energy source that
cells use for most of their work
Movement types - CORRECT ANSWER - Flexion, Extension, Adduction, Abduction,
Rotation, Circumduction, Plantar, Dorsi, Supination, Pronation, Inversion, Eversion, Depression,
Elevation
Muscle contraction - CORRECT ANSWER - Shortening/lengthening of sarcomere. Z
Lines move closer, I Band, H Zone decrease
Straited (striped) Muscle - CORRECT ANSWER - Another name for skeletal muscle
Motor Unit - CORRECT ANSWER - A motor neuron and all the muscle cells it stimulates
Neurotransmitters - CORRECT ANSWER - Chemical messengers that cross the synaptic
gaps between neurons. Acetylcholine
Nueron - CORRECT ANSWER - Nerve cell that carries messages throughout the body as
electrical signals
Fast twitch muscle fibres - CORRECT ANSWER - Rapid contraction speed but tire easily
