Module 4: Support & Movement Flashcards
which muscles type is involved in the function of the digestive tract and blood vessels?
smooth muscle
how does cardiac muscle differ from the other types of muscle?
it contains branched cells
true or false?
myofibrils are the alternating light-dark units that produce the banded appearance of muscle fibres.
false - sarcomeres are the alternating light-dark units that produce the banded appearance of myofibrils, which are the strands that make up each muscle fibre.
which type of muscles have one nucleus per muscle cell
cardiac muscle, smooth muscle
what is the intercalated disk, and which muscle has it?
cardiac muscle fibres interconnect at intercalated disk allowing the electrical signal to pass from one muscle cell to another. -> it helps synchronise heart muscle contraction.
why could it be useful for muscle fibres (cells) to have multiple nuclei?
nuclei enable the cell to make proteins, repair, proteins, and grow proteins.
nuclei direct protein synthesis, growth, and repair along the length of the cell.
which molecules form the thick filaments of sarcomeres?
myosin
which of the following interactions is the molecular basis of muscle contraction?
A) troponin and tropomyosin
B) myosin and thin filaments
C) myosin and thick filaments
D) sarcomeres and T tubules
B
Thin filaments (actin) attach at the ____ line and Thick filaments (myosin) anchor at the ____ line in the centre of the sarcomere.
fill the blank.
Z, M
explain the step of the power stroke of muscle contraction.
power stroke- attach and pull producing force
The phosphate ion is released, and the myosin head moves back to its original position.
three types of microstructure of muscle
1) perimysium 2) epimysium 3) endomysium
muscle cells are stimulated by neurotransmitters released from the synaptic terminal of ______
motor neuron axons
which function associated with muscle would be most directly affected by low levels of calcium
1) ATP hydrolysis
2) muscle contraction
3) the initiation of an action potential
4) muscle fatigue
5) the muscle fibre resting membrane potential
muscle contraction
skeletal fibres may be classified as either oxidative or glycolytic.
what muscles would be called glycolytic?
the ones most easily fatigued
myofibrils are composed of
sarcomere
muscle cells are each innervated by ______, direct from the spinal cord.
fill the blank
motor neuron
force is altered depending on
size (number of muscle fibres), contractile properties (speed, fatigability)
which muscle is better at controlling movement over joints that have a large range of motion between long muscles and shorter-wider muscles?
long muscles
which muscle is better at generating larger forces over a smaller range of joint motion?
shorter-wider muscles
why the physiological cross-sectional area (PCSA) of a muscle is considered one of the greatest predictors of force-generating capacity?
The force a muscle can generate is directly related to its PCSA. As the cross-sectional area increases, there is a larger number of muscle fibres available for contraction.
what are the two important factors that contribute to the calculation of a muscle PCSA?
PCSA = muscle volume/fibre length
when passive force is generated and which factors contribute to it?
- passive force is generated when the muscle is stretched.
- Titin and tendon.
The knee joint has a relatively large range of motion. Is it likely that the muscles that produce force in knee motion are long or short?
long.
Because large PCSA produces more force.
muscle fibres, myofibrils, fascicle
list the top concepts first.
muscle fibres > fascicle > myofibrils
> means ‘consist of’
when active force is generated and which factors contribute to it?
- active force is generated when the muscle is contracted.
- actin and myosin
what is the contractile component (CC)?
actin and myosin coss bridge
what is the series elastic component (SEC)?
titin and tendon
what is the parallel elastic component (PEC)?
epimysium, endomysium, and perimysium
Force is influenced by the fibre type of active motor units. explain it
Type 1- slow oxidative motor units, slow twitch, low force, fatigue resistant
Type 2A - fast oxidative motor units, quicker twitch duration, higher force, less fatigue resistant than Type 1
Type 3B - fast glycotic, fast twitch, more force, fatigues quickly
Force is influenced by the fibre type of active motor units. explain it
Type 1- slow oxidative motor units, slow twitch, low force, fatigue resistant
Type 2A - fast oxidative motor units, quicker twitch duration, higher force, less fatigue resistant than Type 1
Type 3B - fast glycolytic, fast twitch, more force, fatigues quickly
there are two types of skeletal muscle fibres: oxidative and glycolytic
which type of skeletal muscle has more myoglobin?
oxidative one. Because O2 binds to myoglobin more than haemoglobin - efficient transfer of O2 from blood to muscle
What is Henneman’s size principle?
motor units are categorized based on the size and strength of their motor neuron.
small motor units are recruited first -> intermediate -> large
what are isometric, concentric, and eccentric?
isometric - same length
concentric - shortening
eccentric - lengthening
true or false
an eccentrically contracting muscle can produce more force at the same length than a concentrically contracting muscle.
true
skull
protects ____
supports____
allows movement ____
protects the brain
supports soft tissues of the head
allows movement of the jaw during chewing
Rib cage including the sternum
protects ____
supports ____
allows movement ____
protects the heart and lungs
supports shoulder girdle and
allows movement respiration
Vertebral column
protects ____
supports ____
allows movement ____
protects the spinal cord
supports the rib cage
allows movement of the trunk
the function of the shoulder girdle, upper limb, hand
supports and allows movement of the arm and hand
the function of the pelvic girdle
supports and protects the abdominal contents and upper body, support attachment of lower limb, allows movement inlocomotion
the function of lower limb including the foot
support entire weight of the body, allow movement in locomotion
which muscle type is involved in the function of the digestive tract and blood vessels?
smooth muscle
list types of bone structure
long, short, flat, irregular
why is the ‘long’ which is the type of bone structure important?
it is important for leverage and movement.
ex) femur, phalanges (finger)
why is the ‘short’ which is the type of bone structure important?
it is important for fine movements.
ex) carpals, sesamoid bones
why is the ‘flat’ which is the type of bone structure important?
it is important for protection and hematopoiesis occur in flat bones.
ex) sternum, sacapula, ribs
why is the ‘irregular’ which is the type of bone structure important?
it is important for protection, support, movement and hematopoiesis.
bone consists of two things, which are _____
collagen (protein) - 40%
calcium and salts - 60%
types of bone cells
osteoclasts, osteoblasts, osteocytes, and osteogenic cell
what is osteoclasts
it is a very large cell and has many nuclei.
osteoclasts are responsible for bone RESORPTION and BREAK DOWN of bone tissue.
what is osteoblasts
it is responsible for CREATING bone matrix and BUILDING bone
what is osteocytes
it is responsible for MAINTAINING bone matrix.
what is osteogenic cells
it is a stem cell and develops into an osteoblast and osteocyte.
how myo electric action potentials are initiated?
by acetylcholine by the motor neuron and it binds to proteins on muscle cell membrane
how myo electric action potentials are initiated
by acetylcholine released by the motor neuron. it binds to proteins on the muscle cell membrane.
where myo electric action potential is propagated?
T tubules
role of sarcoplasmic reticulum
it releases Ca 2+.
action potential triggers Ca 2+ release from SR
what is axial skeleton
relating to the head and trunk region of the body
what is appendicular skeleton
relating to limbs
