Locomotion is the voluntary movements resulting in a elements like microfilaments also help for this. E.g. change
in location. All locomotion are movements but all Macrophages & leucocytes.
movements are not locomotion. Both are interlinked. E.g. • Ciliary movement: By cilia. E.g. ciliary movements in
• In Paramoecium, cilia help in the movement of food trachea (to remove dust particles and foreign substances),
through cytopharynx and in locomotion. and oviducts (for the passage of ova).
• Hydra use tentacles to capture prey and for locomotion. • Muscular movement: By muscles. E.g. movement of limbs.
• Limbs help to change body postures and for locomotion. Flagellar movement helps in the swimming of spermatozoa,
Types of movement in human being maintenance of water current in the canal system of sponges
• Amoeboid movement: By pseudopodia formed by and in locomotion of Protozoans like Euglena.
streaming of protoplasm as in Amoeba. Cytoskeletal
HUMAN MUSCULAR SYSTEM
- It includes muscles which are mesodermal in origin.
- Muscles constitute 40-50% of the body weight.
- Muscles have excitability, contractility, extensibility &
elasticity.
- Based on location, muscles are 3 types:
Skeletal (striated) Visceral (Non- Cardiac
muscles striated) muscles muscles
Attached to skeleton In visceral organs In heart wall
Striations present Absent Present
Voluntary Involuntary Involuntary
Rich blood supply Poor blood supply Rich blood supply
Fatigue muscle Non-fatigue Non-fatigue
Multinucleate Uninucleate Uninucleate
More mitochondria Less mitochondria More mitochondria
STRUCTURE OF STRIATED MUSCLE
- Skeletal muscle is made of muscle bundles (fascicles) held
together by collagenous connective tissue layer (fascia).
Structure of contractile proteins
- An actin filament is made of 2 filamentous (F) actins
which form double helix.
- F-actin is a polymer of monomeric Globular (G) actins.
- Actin contains 2 other proteins (tropomyosin & troponin).
- Two filaments of tropomyosin run along the grooves of
the F-actin double helix.
- Each fascicle contains many muscle fibres (muscle cells).
- Muscle fibres are lined by plasma membrane - Troponin has 3 subunits. It is seen at regular intervals on
(sarcolemma) enclosing the sarcoplasm. tropomyosin. In the resting state, a subunit of troponin
- Each muscle fibre contains myofilaments (myofibrils). masks the binding sites for myosin on the actin filaments.
- Each myofibril has alternate dark (Anisotropic or A- - Each myosin filament is a polymer of many monomeric
proteins called Meromyosins.
band) and light striations (Isotropic or I-band). This is
due to the presence of 2 fibrous contractile proteins- thin
Actin filament and thick Myosin filament.
- I-bands contain actin. A-bands contain actin and myosin.
They are arranged parallel to each other.
- A-band bears a lighter middle region (H band) formed of - A meromyosin has 2 parts:
only myosin. A thin dark line (M-line) runs through the o Heavy meromyosin or HMM or cross arm (globular
centre of H-zone. head + short arm): It projects outwards.
- I-band is bisected by a dense dark band called Z-line. o Light meromyosin or LMM (tail).
Region between two Z-lines is called sarcomere. They are - The globular head is an active ATPase enzyme and has
the functional units of muscle contraction. binding sites for ATP and active sites for actin.
1
in location. All locomotion are movements but all Macrophages & leucocytes.
movements are not locomotion. Both are interlinked. E.g. • Ciliary movement: By cilia. E.g. ciliary movements in
• In Paramoecium, cilia help in the movement of food trachea (to remove dust particles and foreign substances),
through cytopharynx and in locomotion. and oviducts (for the passage of ova).
• Hydra use tentacles to capture prey and for locomotion. • Muscular movement: By muscles. E.g. movement of limbs.
• Limbs help to change body postures and for locomotion. Flagellar movement helps in the swimming of spermatozoa,
Types of movement in human being maintenance of water current in the canal system of sponges
• Amoeboid movement: By pseudopodia formed by and in locomotion of Protozoans like Euglena.
streaming of protoplasm as in Amoeba. Cytoskeletal
HUMAN MUSCULAR SYSTEM
- It includes muscles which are mesodermal in origin.
- Muscles constitute 40-50% of the body weight.
- Muscles have excitability, contractility, extensibility &
elasticity.
- Based on location, muscles are 3 types:
Skeletal (striated) Visceral (Non- Cardiac
muscles striated) muscles muscles
Attached to skeleton In visceral organs In heart wall
Striations present Absent Present
Voluntary Involuntary Involuntary
Rich blood supply Poor blood supply Rich blood supply
Fatigue muscle Non-fatigue Non-fatigue
Multinucleate Uninucleate Uninucleate
More mitochondria Less mitochondria More mitochondria
STRUCTURE OF STRIATED MUSCLE
- Skeletal muscle is made of muscle bundles (fascicles) held
together by collagenous connective tissue layer (fascia).
Structure of contractile proteins
- An actin filament is made of 2 filamentous (F) actins
which form double helix.
- F-actin is a polymer of monomeric Globular (G) actins.
- Actin contains 2 other proteins (tropomyosin & troponin).
- Two filaments of tropomyosin run along the grooves of
the F-actin double helix.
- Each fascicle contains many muscle fibres (muscle cells).
- Muscle fibres are lined by plasma membrane - Troponin has 3 subunits. It is seen at regular intervals on
(sarcolemma) enclosing the sarcoplasm. tropomyosin. In the resting state, a subunit of troponin
- Each muscle fibre contains myofilaments (myofibrils). masks the binding sites for myosin on the actin filaments.
- Each myofibril has alternate dark (Anisotropic or A- - Each myosin filament is a polymer of many monomeric
proteins called Meromyosins.
band) and light striations (Isotropic or I-band). This is
due to the presence of 2 fibrous contractile proteins- thin
Actin filament and thick Myosin filament.
- I-bands contain actin. A-bands contain actin and myosin.
They are arranged parallel to each other.
- A-band bears a lighter middle region (H band) formed of - A meromyosin has 2 parts:
only myosin. A thin dark line (M-line) runs through the o Heavy meromyosin or HMM or cross arm (globular
centre of H-zone. head + short arm): It projects outwards.
- I-band is bisected by a dense dark band called Z-line. o Light meromyosin or LMM (tail).
Region between two Z-lines is called sarcomere. They are - The globular head is an active ATPase enzyme and has
the functional units of muscle contraction. binding sites for ATP and active sites for actin.
1
