6.4 Flashcards
Skeletal muscle is AKA
Voluntary muscle because you have control over when to contract these muscles and bring about movement
Skeletal muscle is the muscle tissue attached to the
Bones of your body
Another name for skeletal muscle is striated muscle due to its
Striped appearance when you look at it under the microscope
The muscle fibre is surrounded by a plasma membrane called the
Sarcolemma
The cytoplasm in the muscle fibre is called the
Sarcoplasm
The sarcoplasm contains large numbers of
Mitochondria
The muscle fibre is not divided up into individual cells but is more like several cells fused together. This means that it has
Several nuclei along its length
The muscle fibres appear striped or striate because they are made up of bundles of many smaller
Myofibrils (also striped)
Each Myofibril is striped in the same way and they line up together to give a striped appearance
The Myofibrils are made up of many smaller protein filaments called
Myofilaments
(ANTAGONISTIC PAIRS) muscles can contract and
Relax
(ANTAGONISTIC PAIRS) they can exert a pulling force when they contract but they cannot push. Therefore to bring about movement an antagonistic pair of muscles is
Needed
(ANTAGONISTIC PAIRS) an example is biceps and triceps. When the biceps contracts and the triceps relaxes, the arm
Bends at the elbow
(ANTAGONISTIC PAIRS) to straighten the arm, the
Biceps relaxes and the triceps contracts
(ANTAGONISTIC PAIRS) muscles that bend a limb are called
Flexors
(ANTAGONISTIC PAIRS) muscle that straighten a limb are called
Extensors
(ANTAGONISTIC PAIRS) several different pairs of antagonistic muscles are involved in controlling
Posture in humans
(ANTAGONISTIC PAIRS) contraction of Soleus muscle pulls the heel up and extends the foot, whereas contraction of the tibialis anterior bends the ankle raising the foot.
To stand upright, both muscles need to contract a little so that they both exert a tension. This is called.
Isometric contraction
(ANTAGONISTIC PAIRS) to keep the leg straight at the knee, the rectus femoris and biceps femoris also need to show
Isometric contraction
(ANTAGONISTIC PAIRS) when the gluteus Maximus and rectus femoris both contract isometrically the trunk is kept
Upright
(ANTAGONISTIC PAIRS) only a small number of fibres contract at any time in each of these muscles and the fibres involved change constantly, ensuring that the muscle does not become
Fatigued
(SLOW-TWITCH/FAST-TWITCH MUSCLE FIBRES) aerobic exercise, the fibres most active are
Slow-twitch
(SLOW-TWITCH/FAST-TWITCH MUSCLE FIBRES) slow twitch five are used for endurance sports and look red in colour because they contain a lot of
Myoglobin
(SLOW-TWITCH/FAST-TWITCH MUSCLE FIBRES) myoglobin is a red pigment that stores
Oxygen
(SLOW-TWITCH/FAST-TWITCH MUSCLE FIBRES) fast twitch fibres are mainly used in intensive exercise that is carried out for a
Short period of time
Sprinting
(SLOW-TWITCH/FAST-TWITCH MUSCLE FIBRES) fast-twitch produce
Most of their ATP by
Anaerobic respiration
(SLOW-TWITCH/FAST-TWITCH MUSCLE FIBRES) fast twitch appear whiter in colour as they do not contain
Much myoglobin
(SLOW-TWITCH/FAST-TWITCH MUSCLE FIBRES) most of the muscles contain a mixture of slow and fast twitch muscle fibres but there are exceptions
Muscles in back involved in maintaining posture mainly contain:
Muscles that move eyes and the muscle in eyelids are made up of mainly:
Slow twitch
Fast Twitch
5 factors of Slow twitch fibres:
Contain large numbers of mitochondria
Produce ATP by aerobic respiration
Supplied by many capillaries
Much smaller diameter than fast-twitch
Contain a large amount of myoglobin
5 factors of Fast twitch fibres:
Contain few mitochondria
Produce ATP by anaerobic respiration
Supplied by fewer capillaries
Much larger diameter than slow-twitch fibres
Contain very little myoglobin
